/* CPA Master - Premium Styles */
/* Theme System + Glass Morphism + Premium Animations */

/* ===== CSS Variables & Theme System ===== */
:root {
  /* Primary palette */
  --c-primary: #6366F1;
  --c-primary-light: #818CF8;
  --c-primary-dark: #4F46E5;
  --c-primary-50: #EEF2FF;
  --c-primary-100: #E0E7FF;

  /* Accent */
  --c-accent: #10B981;
  --c-accent-light: #34D399;
  --c-accent-dark: #059669;

  /* Semantic */
  --c-success: #10B981;
  --c-warning: #F59E0B;
  --c-danger: #F43F5E;
  --c-info: #3B82F6;

  /* Neutral - Light Theme */
  --c-bg: #F8FAFC;
  --c-bg-secondary: #F1F5F9;
  --c-bg-card: #FFFFFF;
  --c-bg-card-hover: #F8FAFC;
  --c-bg-nav: rgba(255, 255, 255, 0.85);
  --c-text: #1E293B;
  --c-text-secondary: #475569;
  --c-text-muted: #94A3B8;
  --c-border: #E2E8F0;
  --c-border-light: #F1F5F9;
  --c-shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
  --c-shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.1);
  --c-shadow-glow: 0 0 30px rgba(99, 102, 241, 0.15);

  /* Glass */
  --c-glass-bg: rgba(255, 255, 255, 0.7);
  --c-glass-border: rgba(255, 255, 255, 0.3);
  --c-glass-blur: 20px;

  /* Radius */
  --r-sm: 8px;
  --r-md: 12px;
  --r-lg: 16px;
  --r-xl: 24px;
  --r-2xl: 32px;

  /* Font */
  --f-sans: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  --f-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Question font size (adjustable via settings) */
  --question-font-size: 17px;

  /* Transition */
  --t-base: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --t-smooth: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  --t-magnetic: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Dark theme */
[data-theme="dark"] {
  --c-bg: #0F172A;
  --c-bg-secondary: #1E293B;
  --c-bg-card: #1E293B;
  --c-bg-card-hover: #334155;
  --c-bg-nav: rgba(15, 23, 42, 0.85);
  --c-text: #F1F5F9;
  --c-text-secondary: #CBD5E1;
  --c-text-muted: #64748B;
  --c-border: #334155;
  --c-border-light: #1E293B;
  --c-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --c-shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
  --c-shadow-glow: 0 0 30px rgba(99, 102, 241, 0.25);
  --c-glass-bg: rgba(30, 41, 59, 0.7);
  --c-glass-border: rgba(51, 65, 85, 0.3);
  --c-primary-50: rgba(99, 102, 241, 0.1);
  --c-primary-100: rgba(99, 102, 241, 0.15);
  /* ===== Conversion Color System ===== */
  --c-free: #27ae60;
  --c-free-light: #2ecc71;
  --c-free-dark: #1e8449;
  --c-free-bg: #eafaf1;
  --c-free-border: #abebc6;

  --c-lowprice: #e67e22;
  --c-lowprice-light: #f39c12;
  --c-lowprice-dark: #d35400;
  --c-lowprice-bg: #fef5e7;
  --c-lowprice-border: #f8c471;

  --c-vip-gray: #95a5a6;
  --c-vip-gray-light: #bdc3c7;
  --c-vip-gray-bg: #f4f6f7;
  --c-vip-gray-border: #d5dbdb;
}

/* ===== Conversion Component Styles ===== */

/* Free zone section */
.free-zone {
  background: linear-gradient(135deg, #eafaf1 0%, #d5f5e3 100%);
  border-radius: var(--r-xl);
  padding: 32px 24px;
  margin-bottom: 24px;
  border: 2px solid var(--c-free-border);
  position: relative;
  overflow: hidden;
}
[data-theme="dark"] .free-zone {
  background: linear-gradient(135deg, rgba(39,174,96,0.12) 0%, rgba(39,174,96,0.06) 100%);
  border-color: rgba(39,174,96,0.3);
}
.free-zone-title {
  font-size: 22px;
  font-weight: 800;
  color: var(--c-free-dark);
  margin-bottom: 4px;
}
[data-theme="dark"] .free-zone-title { color: var(--c-free-light); }
.free-zone-subtitle {
  font-size: 14px;
  color: var(--c-free);
  margin-bottom: 20px;
}
.free-benefit-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 10px;
  margin-bottom: 20px;
}
.free-benefit-item {
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(255,255,255,0.7);
  border-radius: var(--r-md);
  padding: 12px 16px;
  font-size: 14px;
  font-weight: 500;
}
[data-theme="dark"] .free-benefit-item { background: rgba(255,255,255,0.06); }
.free-benefit-item .check {
  width: 22px; height: 22px; border-radius: 50%;
  background: var(--c-free); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 13px; flex-shrink: 0;
}
.free-benefit-item .cross {
  background: var(--c-vip-gray); font-size: 13px;
}
.free-benefit-item.restricted { opacity: 0.6; }

/* Free banner */
.free-banner {
  background: linear-gradient(90deg, #27ae60 0%, #2ecc71 100%);
  border-radius: var(--r-lg);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  color: #fff;
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 20px;
  box-shadow: 0 4px 20px rgba(39,174,96,0.25);
}

/* Free subject card badge */
.free-badge-corner {
  position: absolute;
  top: -8px; right: -8px;
  background: var(--c-free);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 20px;
  box-shadow: 0 2px 10px rgba(39,174,96,0.4);
  z-index: 2;
}

/* Subject card free enhancement */
.subject-card-free {
  transform: scale(1.05);
  border: 3px solid var(--c-free) !important;
  box-shadow: 0 8px 30px rgba(39,174,96,0.15);
}
.subject-card-free:hover {
  transform: scale(1.08) translateY(-4px);
  box-shadow: 0 12px 40px rgba(39,174,96,0.25);
}

/* Free CTA button */
.btn-free {
  background: var(--c-free);
  color: #fff;
  border: none;
}
.btn-free:hover {
  background: var(--c-free-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(39,174,96,0.3);
}

/* Low-price button */
.btn-lowprice {
  background: var(--c-lowprice);
  color: #fff;
  border: none;
}
.btn-lowprice:hover {
  background: var(--c-lowprice-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(230,126,34,0.3);
}

/* Pricing tier cards */
.pricing-comparison {
  display: grid;
  grid-template-columns: 1fr 1.2fr 1fr;
  gap: 16px;
  margin-bottom: 24px;
}
@media (max-width: 768px) {
  .pricing-comparison { grid-template-columns: 1fr; }
}
.pricing-tier {
  border-radius: var(--r-xl);
  padding: 28px 20px;
  text-align: center;
  position: relative;
  transition: var(--t-smooth);
  background: var(--c-bg-card);
  border: 2px solid var(--c-border);
}
.pricing-tier:hover { transform: translateY(-4px); }
.pricing-tier-free {
  border-color: var(--c-free-border);
  background: var(--c-free-bg);
}
[data-theme="dark"] .pricing-tier-free {
  background: rgba(39,174,96,0.06);
  border-color: rgba(39,174,96,0.2);
}
.pricing-tier-low {
  border-color: var(--c-lowprice);
  background: var(--c-lowprice-bg);
  transform: scale(1.05);
  box-shadow: 0 10px 40px rgba(230,126,34,0.15);
}
[data-theme="dark"] .pricing-tier-low {
  background: rgba(230,126,34,0.08);
  border-color: rgba(230,126,34,0.4);
}
.pricing-tier-vip {
  border-color: var(--c-vip-gray-border);
  background: var(--c-vip-gray-bg);
  opacity: 0.85;
}
[data-theme="dark"] .pricing-tier-vip {
  background: rgba(149,165,166,0.06);
  border-color: rgba(149,165,166,0.2);
}
.pricing-tier-label {
  font-size: 14px;
  font-weight: 600;
  color: var(--c-text-muted);
  margin-bottom: 8px;
}
.pricing-tier-name {
  font-size: 20px;
  font-weight: 800;
  margin-bottom: 12px;
}
.pricing-tier-price {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 4px;
}
.pricing-tier-price .unit {
  font-size: 14px;
  font-weight: 500;
  color: var(--c-text-muted);
}
.pricing-tier-price .original {
  font-size: 14px;
  color: var(--c-text-muted);
  text-decoration: line-through;
  margin-left: 6px;
}
.pricing-tier-features {
  text-align: left;
  margin: 16px 0;
  font-size: 13px;
  line-height: 1.8;
}
.pricing-tier-features li {
  list-style: none;
  padding-left: 20px;
  position: relative;
}
.pricing-tier-features li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--c-free);
  font-weight: 700;
}
.pricing-tier-features li.disabled {
  color: var(--c-text-muted);
  opacity: 0.5;
}
.pricing-tier-features li.disabled::before {
  content: '✗';
  color: var(--c-vip-gray);
}

/* ===== Pricing Feature Compare (feat-row) ===== */
.pricing-features-compare { padding: 0; }
.feat-row { display: flex; align-items: center; gap: 8px; padding: 6px 0; font-size: 14px; }
.feat-icon { display: inline-block; width: 20px; height: 20px; border-radius: 50%; text-align: center; font-size: 12px; }
.feat-yes { background: var(--c-accent); color: #fff; }
.feat-yes::before { content: '✓'; }
.feat-no { background: var(--c-border); color: var(--c-text-muted); }
.feat-no::before { content: '✗'; }
.feat-row.disabled { color: var(--c-text-muted); }

.pricing-badge-hot {
  position: absolute;
  top: -12px; left: 50%;
  transform: translateX(-50%);
  background: var(--c-lowprice);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: 20px;
  white-space: nowrap;
  box-shadow: 0 2px 10px rgba(230,126,34,0.4);
}

/* Countdown banner */
.countdown-banner {
  background: linear-gradient(90deg, #e74c3c 0%, #e67e22 100%);
  border-radius: var(--r-lg);
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  color: #fff;
  margin-bottom: 20px;
  box-shadow: 0 4px 20px rgba(231,76,60,0.2);
  flex-wrap: wrap;
}
.countdown-banner .label {
  font-size: 15px;
  font-weight: 600;
}
.countdown-timer {
  display: flex;
  gap: 6px;
  align-items: center;
}
.countdown-unit {
  background: rgba(255,255,255,0.2);
  border-radius: 8px;
  padding: 4px 10px;
  font-size: 18px;
  font-weight: 800;
  min-width: 40px;
  text-align: center;
}
.countdown-sep {
  font-size: 18px;
  font-weight: 800;
  opacity: 0.7;
}

/* Materials download card */
.materials-card {
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  border-radius: var(--r-xl);
  padding: 28px;
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 24px;
  transition: var(--t-smooth);
}
.materials-card:hover {
  border-color: var(--c-free);
  box-shadow: 0 4px 20px rgba(39,174,96,0.1);
}
.materials-icon {
  width: 56px; height: 56px;
  background: var(--c-free-bg);
  border-radius: var(--r-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  flex-shrink: 0;
}
[data-theme="dark"] .materials-icon { background: rgba(39,174,96,0.1); }

/* Testimonials */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}
.testimonial-card {
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  border-radius: var(--r-lg);
  padding: 20px;
  transition: var(--t-smooth);
}
.testimonial-card:hover {
  border-color: var(--c-primary);
  box-shadow: var(--c-shadow);
}
.testimonial-text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-secondary);
  margin-bottom: 12px;
}
.testimonial-author {
  display: flex;
  align-items: center;
  gap: 10px;
}
.testimonial-avatar {
  width: 36px; height: 36px;
  border-radius: 50%;
  background: var(--c-primary-50);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 700;
  color: var(--c-primary);
}
.testimonial-name {
  font-size: 14px;
  font-weight: 600;
}
.testimonial-tag {
  font-size: 12px;
  color: var(--c-text-muted);
}

/* FAQ accordion */
.faq-item {
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  border-radius: var(--r-md);
  margin-bottom: 8px;
  overflow: hidden;
  transition: var(--t-base);
}
.faq-item:hover { border-color: var(--c-primary-light); }
.faq-question {
  padding: 16px 20px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--t-base);
}
.faq-question:hover { background: var(--c-bg-secondary); }
.faq-question .arrow {
  transition: transform 0.3s ease;
  font-size: 12px;
  color: var(--c-text-muted);
}
.faq-item.open .faq-question .arrow {
  transform: rotate(180deg);
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  padding: 0 20px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-secondary);
}
.faq-item.open .faq-answer {
  max-height: 300px;
  padding: 0 20px 16px;
}

/* Bottom CTA section */
.bottom-cta {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 24px;
}
@media (max-width: 768px) {
  .bottom-cta { grid-template-columns: 1fr; }
}
.bottom-cta-card {
  border-radius: var(--r-xl);
  padding: 32px 24px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.bottom-cta-free {
  background: linear-gradient(135deg, #27ae60 0%, #2ecc71 100%);
  color: #fff;
}
.bottom-cta-low {
  background: linear-gradient(135deg, #e67e22 0%, #f39c12 100%);
  color: #fff;
}

/* Trust badges */
.trust-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin-bottom: 20px;
}
.trust-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--c-bg-secondary);
  border-radius: 20px;
  padding: 6px 14px;
  font-size: 13px;
  color: var(--c-text-secondary);
}
.trust-badge .dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: var(--c-free);
}

/* Simplified register modal */
.register-simple .form-group { margin-bottom: 12px; }
.code-input-row {
  display: flex;
  gap: 8px;
}
.code-input-row .form-input { flex: 1; }
.btn-send-code {
  white-space: nowrap;
  min-width: 110px;
}

/* ===== Base Styles ===== */
* { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--f-sans);
  background: var(--c-bg);
  color: var(--c-text);
  line-height: 1.6;
  min-height: 100vh;
  transition: background var(--t-smooth), color var(--t-smooth);
}

/* ===== Typography Scale ===== */
.text-xs { font-size: 12px; line-height: 1.5; }
.text-sm { font-size: 14px; line-height: 1.6; }
.text-base { font-size: 16px; line-height: 1.6; }
.text-lg { font-size: 18px; line-height: 1.7; }
.text-xl { font-size: 22px; line-height: 1.4; }
.text-2xl { font-size: 28px; line-height: 1.3; }
.text-3xl { font-size: 36px; line-height: 1.2; }
.text-4xl { font-size: 48px; line-height: 1.1; }

.font-medium { font-weight: 500; }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }
.font-extrabold { font-weight: 800; }

/* ===== Navigation ===== */
.app-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--c-bg-nav);
  backdrop-filter: blur(var(--c-glass-blur)) saturate(180%);
  border-bottom: 1px solid var(--c-border);
  transition: background var(--t-smooth), border-color var(--t-smooth);
}

.nav-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--c-primary);
  cursor: pointer;
  transition: transform var(--t-magnetic);
}

.nav-logo:hover { transform: scale(1.02); }

.nav-logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  border-radius: var(--r-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 18px;
  font-weight: 800;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-link {
  padding: 8px 16px;
  font-size: 14px;
  font-weight: 500;
  color: var(--c-text-secondary);
  border-radius: var(--r-md);
  cursor: pointer;
  transition: all var(--t-smooth);
  position: relative;
}

.nav-link:hover {
  color: var(--c-primary);
  background: var(--c-primary-50);
}

.nav-link.active {
  color: var(--c-primary);
  background: var(--c-primary-50);
  font-weight: 600;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* ===== Theme Toggle ===== */
.theme-toggle {
  width: 40px;
  height: 40px;
  border-radius: var(--r-md);
  border: 1px solid var(--c-border);
  background: var(--c-bg-card);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--t-smooth);
  font-size: 18px;
  color: var(--c-text-secondary);
}

.theme-toggle:hover {
  background: var(--c-primary-50);
  color: var(--c-primary);
  transform: scale(1.05);
}

/* ===== Search Trigger ===== */
.search-trigger {
  cursor: pointer;
  font-size: 18px;
  padding: 4px 8px;
  border-radius: 8px;
  transition: background 0.2s;
}
.search-trigger:hover {
  background: var(--c-bg-secondary);
}

/* ===== Buttons ===== */
.btn {
  padding: 10px 20px;
  border-radius: var(--r-md);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--t-magnetic);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
}

.btn:active { transform: scale(0.97); }

.btn-primary {
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-dark));
  color: white;
  box-shadow: 0 2px 12px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
  box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
  transform: translateY(-2px);
}

.btn-accent {
  background: linear-gradient(135deg, var(--c-accent), var(--c-accent-dark));
  color: white;
  box-shadow: 0 2px 12px rgba(16, 185, 129, 0.3);
}

.btn-accent:hover {
  box-shadow: 0 4px 20px rgba(16, 185, 129, 0.4);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  color: var(--c-primary);
  border: 2px solid var(--c-primary);
}

.btn-outline:hover {
  background: var(--c-primary-50);
  transform: translateY(-1px);
}

.btn-ghost {
  background: var(--c-bg-secondary);
  color: var(--c-text-secondary);
}

.btn-ghost:hover {
  background: var(--c-bg-card-hover);
  color: var(--c-text);
}

.btn-sm { padding: 6px 14px; font-size: 13px; }
.btn-lg { padding: 14px 28px; font-size: 16px; }
.btn-xl { padding: 18px 36px; font-size: 18px; }

.btn-danger {
  background: linear-gradient(135deg, var(--c-danger), #E11D48);
  color: white;
}

/* ===== Cards ===== */
.card {
  background: var(--c-bg-card);
  border-radius: var(--r-lg);
  border: 1px solid var(--c-border);
  padding: 24px;
  transition: all var(--t-magnetic);
}

.card:hover {
  box-shadow: var(--c-shadow);
  transform: translateY(-2px);
}

.card-sm { padding: 16px; border-radius: var(--r-md); }
.card-lg { padding: 32px; border-radius: var(--r-xl); }

.card-glass {
  background: var(--c-glass-bg);
  backdrop-filter: blur(var(--c-glass-blur)) saturate(180%);
  border: 1px solid var(--c-glass-border);
  border-radius: var(--r-xl);
  padding: 24px;
  transition: all var(--t-magnetic);
}

.card-glass:hover {
  transform: translateY(-3px);
  box-shadow: var(--c-shadow-glow);
}

/* ===== Badges ===== */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 600;
  border-radius: 20px;
  white-space: nowrap;
}

.badge-primary { background: var(--c-primary-50); color: var(--c-primary); }
.badge-accent { background: rgba(16,185,129,0.1); color: var(--c-accent); }
.badge-warning { background: rgba(245,158,11,0.1); color: var(--c-warning); }
.badge-danger { background: rgba(244,63,94,0.1); color: var(--c-danger); }

/* ===== Progress ===== */
.progress-bar {
  height: 8px;
  background: var(--c-bg-secondary);
  border-radius: 4px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--c-primary), var(--c-accent));
  border-radius: 4px;
  transition: width 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ===== Stats ===== */
.stat-number {
  font-size: 32px;
  font-weight: 800;
  color: var(--c-text);
  line-height: 1;
}

.stat-label {
  font-size: 13px;
  color: var(--c-text-muted);
  margin-top: 4px;
}

/* ===== Layout Helpers ===== */
.container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }
.page { padding-top: 80px; min-height: 100vh; }
.page-header { margin-bottom: 32px; }
.page-title { font-size: 32px; font-weight: 700; color: var(--c-text); }
.page-subtitle { font-size: 16px; color: var(--c-text-muted); margin-top: 8px; }

.grid { display: grid; gap: 16px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-6 { grid-template-columns: repeat(6, 1fr); }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.gap-2 { gap: 8px; }
.gap-3 { gap: 12px; }
.gap-4 { gap: 16px; }
.gap-6 { gap: 24px; }
.gap-8 { gap: 32px; }

.w-full { width: 100%; }
.h-full { height: 100%; }
.overflow-hidden { overflow: hidden; }
.relative { position: relative; }

/* ===== Hero Section ===== */
.hero {
  padding: 80px 0 60px;
  position: relative;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, var(--c-primary-50) 0%, transparent 50%, rgba(16,185,129,0.05) 100%);
  z-index: 0;
}

[data-theme="dark"] .hero-bg {
  background: linear-gradient(135deg, rgba(99,102,241,0.15) 0%, transparent 50%, rgba(16,185,129,0.08) 100%);
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
}

.hero-title {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 16px;
}

.gradient-text {
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 18px;
  color: var(--c-text-secondary);
  max-width: 600px;
  margin: 0 auto 32px;
}

/* ===== Subject Cards ===== */
.subject-card {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.subject-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--r-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  flex-shrink: 0;
}

.subject-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--c-text);
}

.subject-meta {
  font-size: 13px;
  color: var(--c-text-muted);
  display: flex;
  gap: 12px;
  margin-top: 4px;
}

.subject-badge-free {
  position: absolute;
  top: 12px;
  right: 12px;
}

.subject-badge {
  position: absolute;
  top: 12px;
  right: 12px;
}

/* ===== 卡通风格 SVG 图标容器 ===== */
.subject-icon-wrap {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  position: relative;
  box-shadow:
    0 4px 12px rgba(0, 0, 0, 0.08),
    inset 0 1px 0 rgba(255, 255, 255, 0.6);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.3s ease;
}

.subject-card:hover .subject-icon-wrap {
  transform: translateY(-2px) scale(1.05) rotate(-3deg);
  box-shadow:
    0 8px 20px rgba(0, 0, 0, 0.12),
    inset 0 1px 0 rgba(255, 255, 255, 0.6);
}

.subject-icon-svg {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.subject-icon-svg svg {
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 2px 3px rgba(0, 0, 0, 0.1));
}

.subject-info {
  flex: 1;
  min-width: 0;
}

.subject-meta .dot {
  opacity: 0.4;
}

/* ===== 练习模式卡片（卡通图标） ===== */
.mode-card {
  padding: 22px 16px 18px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
}

.mode-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--c-primary), var(--c-accent));
  opacity: 0;
  transition: opacity 0.3s ease;
}

.mode-card:hover::before {
  opacity: 1;
}

.mode-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 28px rgba(99, 102, 241, 0.18);
  border-color: var(--c-primary);
}

.mode-icon-wrap {
  width: 64px;
  height: 64px;
  margin: 0 auto 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.1));
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.mode-card:hover .mode-icon-wrap {
  transform: scale(1.1) rotate(-5deg);
}

.mode-icon-wrap svg {
  width: 100%;
  height: 100%;
}

.mode-icon-sm {
  width: 48px;
  height: 48px;
}

.mode-desc {
  color: var(--c-text-muted);
  margin-top: 4px;
  font-size: 12px;
}

/* ===== 题库 Tab 小图标 ===== */
.tab-icon-sm {
  display: inline-flex;
  width: 20px;
  height: 20px;
  vertical-align: middle;
  margin-right: 4px;
}

.tab-icon-sm svg {
  width: 100%;
  height: 100%;
}

/* ===== 考试选择科目卡片 ===== */
.exam-subject-card {
  padding: 12px 14px;
  transition: all 0.3s ease;
}

.exam-subject-card:hover {
  transform: translateX(4px);
  border-color: var(--c-primary);
  background: var(--c-primary-50);
}

/* ===== Practice Workbench ===== */
.practice-layout {
  display: grid;
  grid-template-columns: 200px 1fr 240px;
  gap: 16px;
  min-height: calc(100vh - 80px);
  padding: 16px 0;
}

.question-nav-panel {
  background: var(--c-bg-card);
  border-radius: var(--r-lg);
  border: 1px solid var(--c-border);
  padding: 16px;
  overflow-y: auto;
  height: calc(100vh - 100px);
  position: sticky;
  top: 80px;
}

.nav-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 6px;
}

.nav-cell {
  width: 100%;
  aspect-ratio: 1;
  border-radius: var(--r-sm);
  border: 1px solid var(--c-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 500;
  color: var(--c-text-muted);
  cursor: pointer;
  transition: all var(--t-smooth);
}

.nav-cell:hover { border-color: var(--c-primary); color: var(--c-primary); }

.nav-cell.current {
  background: var(--c-primary);
  color: white;
  border-color: var(--c-primary);
}

.nav-cell.answered {
  background: var(--c-primary-50);
  color: var(--c-primary);
  border-color: var(--c-primary-light);
}

.nav-cell.correct {
  background: rgba(16,185,129,0.15);
  color: var(--c-accent);
  border-color: var(--c-accent);
}

.nav-cell.wrong {
  background: rgba(244,63,94,0.15);
  color: var(--c-danger);
  border-color: var(--c-danger);
}

.nav-cell.flagged {
  border-color: var(--c-warning);
  color: var(--c-warning);
}

.question-panel {
  background: var(--c-bg-card);
  border-radius: var(--r-lg);
  border: 1px solid var(--c-border);
  padding: 32px;
  min-height: calc(100vh - 100px);
}

.question-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.question-type-label {
  font-size: 13px;
  font-weight: 600;
}

.question-difficulty {
  display: flex;
  gap: 3px;
}

.diff-star {
  width: 14px;
  height: 14px;
  border-radius: 2px;
  background: var(--c-bg-secondary);
  transition: background var(--t-smooth);
}

.diff-star.filled { background: var(--c-warning); }

.question-content {
  font-size: var(--question-font-size, 17px);
  line-height: 1.8;
  color: var(--c-text);
  margin-bottom: 28px;
  font-weight: 500;
}

.options-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 24px;
}

.option-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 16px 20px;
  border-radius: var(--r-md);
  border: 2px solid var(--c-border);
  cursor: pointer;
  transition: all var(--t-smooth);
  font-size: 15px;
  line-height: 1.6;
}

.option-item:hover:not(.locked) {
  border-color: var(--c-primary-light);
  background: var(--c-primary-50);
}

.option-item.selected {
  border-color: var(--c-primary);
  background: var(--c-primary-50);
  font-weight: 500;
}

.option-item.selected.correct {
  border-color: var(--c-accent);
  background: rgba(16,185,129,0.1);
  color: var(--c-accent);
}

.option-item.selected.wrong {
  border-color: var(--c-danger);
  background: rgba(244,63,94,0.1);
  color: var(--c-danger);
}

.option-item.correct-answer {
  border-color: var(--c-accent);
  background: rgba(16,185,129,0.1);
}

.option-item.locked { cursor: default; }

.option-letter {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
  flex-shrink: 0;
  background: var(--c-bg-secondary);
  color: var(--c-text-secondary);
  transition: all var(--t-smooth);
}

.option-item.selected .option-letter {
  background: var(--c-primary);
  color: white;
}

.option-item.selected.correct .option-letter {
  background: var(--c-accent);
  color: white;
}

.option-item.selected.wrong .option-letter {
  background: var(--c-danger);
  color: white;
}

.option-item.correct-answer .option-letter {
  background: var(--c-accent);
  color: white;
}

.option-text { flex: 1; }

.question-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 24px;
  flex-wrap: wrap;
}

/* Analysis section */
.analysis-section {
  margin-top: 32px;
  padding: 24px;
  background: var(--c-primary-50);
  border-radius: var(--r-lg);
  border-left: 4px solid var(--c-primary);
  display: none;
}

.analysis-section.visible { display: block; }

.analysis-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--c-primary);
  margin-bottom: 12px;
}

.analysis-text {
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-text);
}

/* ===== Extended Analysis: Mistakes & Related Points ===== */
.analysis-subtitle {
  font-size: 16px;
  font-weight: 700;
  color: var(--c-primary);
  margin: 20px 0 12px;
  padding-top: 16px;
  border-top: 1px solid var(--c-border);
}

.mistakes-section { margin-top: 4px; }

.mistakes-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.mistakes-list li {
  position: relative;
  padding: 10px 16px 10px 32px;
  margin-bottom: 8px;
  background: rgba(245, 158, 11, 0.08);
  border-radius: var(--r-md);
  border-left: 3px solid var(--c-warning);
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text);
  transition: all var(--t-smooth);
}

.mistakes-list li:hover {
  background: rgba(245, 158, 11, 0.14);
  transform: translateX(4px);
}

.mistakes-list li::before {
  content: '!';
  position: absolute;
  left: 10px;
  top: 10px;
  width: 18px;
  height: 18px;
  background: var(--c-warning);
  color: #fff;
  border-radius: 50%;
  font-size: 12px;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.related-section { margin-top: 4px; }

.related-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.related-item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  padding: 12px 16px;
  background: rgba(99, 102, 241, 0.06);
  border-radius: var(--r-md);
  border-left: 3px solid var(--c-primary);
  transition: all var(--t-smooth);
}

.related-item:hover {
  background: rgba(99, 102, 241, 0.12);
  transform: translateX(4px);
}

.related-point {
  font-weight: 700;
  font-size: 14px;
  color: var(--c-primary);
}

.related-chapter {
  font-size: 12px;
  font-weight: 600;
  color: var(--c-text-muted);
  background: var(--c-bg-secondary);
  padding: 2px 10px;
  border-radius: var(--r-sm);
}

.related-desc {
  font-size: 13px;
  color: var(--c-text-muted);
  flex-basis: 100%;
  line-height: 1.6;
}

/* ===== Chapter Source Badge ===== */
.badge-chapter-source {
  background: rgba(139, 92, 246, 0.1);
  color: #8B5CF6;
  max-width: 320px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  cursor: default;
}

/* ===== SubQuestions (Analysis Type) ===== */
.subquestions-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.subquestion-item {
  background: var(--c-bg-secondary);
  border-radius: var(--r-md);
  margin-bottom: 12px;
  overflow: hidden;
  border: 1px solid var(--c-border);
  transition: all var(--t-smooth);
}

.subquestion-item.revealed {
  border-color: var(--c-primary);
  box-shadow: 0 2px 12px rgba(99, 102, 241, 0.08);
}

.subquestion-header {
  display: flex;
  gap: 12px;
  padding: 16px 20px;
  align-items: flex-start;
}

.subquestion-number {
  font-weight: 800;
  font-size: 15px;
  color: var(--c-primary);
  flex-shrink: 0;
  background: var(--c-primary-50);
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--r-sm);
}

.subquestion-content {
  font-size: 15px;
  font-weight: 500;
  line-height: 1.7;
  color: var(--c-text);
  flex: 1;
}

.subquestion-answer {
  padding: 0 20px 16px 60px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-text);
  border-top: 1px solid var(--c-border);
  padding-top: 14px;
  margin: 0 0 0 0;
  background: rgba(16, 185, 129, 0.04);
  animation: fadeSlideIn 0.3s ease;
}

@keyframes fadeSlideIn {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Side panel */
.side-panel {
  background: var(--c-bg-card);
  border-radius: var(--r-lg);
  border: 1px solid var(--c-border);
  padding: 16px;
  height: calc(100vh - 100px);
  position: sticky;
  top: 80px;
  overflow-y: auto;
}

.side-section {
  margin-bottom: 20px;
}

.side-section-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--c-text-muted);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.progress-ring-container {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 8px;
}

.progress-ring {
  width: 120px;
  height: 120px;
}

.timer-display {
  font-size: 24px;
  font-weight: 700;
  text-align: center;
  color: var(--c-text);
  font-family: var(--f-mono);
}

.side-btn {
  width: 100%;
  padding: 10px;
  border-radius: var(--r-md);
  border: 1px solid var(--c-border);
  background: var(--c-bg-secondary);
  color: var(--c-text-secondary);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--t-smooth);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.side-btn:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
  background: var(--c-primary-50);
}

.side-btn.active {
  border-color: var(--c-warning);
  color: var(--c-warning);
  background: rgba(245,158,11,0.1);
}

.side-btn.ai-btn {
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-dark));
  color: white;
  border: none;
}

.side-btn.ai-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(99,102,241,0.3);
}

/* ===== AI Chat ===== */
.ai-panel {
  margin-top: 16px;
  background: var(--c-bg-card);
  border-radius: var(--r-lg);
  border: 1px solid var(--c-border);
  overflow: hidden;
}

.ai-messages {
  padding: 16px;
  max-height: 400px;
  overflow-y: auto;
}

.ai-msg {
  margin-bottom: 12px;
  display: flex;
  gap: 10px;
}

.ai-msg-avatar {
  width: 32px;
  height: 32px;
  border-radius: var(--r-sm);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
}

.ai-msg-avatar.bot {
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  color: white;
}

.ai-msg-avatar.user {
  background: var(--c-bg-secondary);
  color: var(--c-text-secondary);
}

.ai-msg-content {
  flex: 1;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text);
  padding: 10px 14px;
  border-radius: var(--r-md);
  background: var(--c-bg-secondary);
}

.ai-msg.bot .ai-msg-content {
  background: var(--c-primary-50);
}

.ai-input-area {
  display: flex;
  gap: 8px;
  padding: 12px;
  border-top: 1px solid var(--c-border);
}

.ai-input {
  flex: 1;
  padding: 10px 14px;
  border-radius: var(--r-md);
  border: 1px solid var(--c-border);
  background: var(--c-bg-secondary);
  color: var(--c-text);
  font-size: 14px;
  outline: none;
  transition: border-color var(--t-smooth);
}

.ai-input:focus { border-color: var(--c-primary); }

/* ===== Learning Report Charts ===== */
.chart-container {
  position: relative;
  width: 100%;
  height: 200px;
}

.radar-chart {
  width: 200px;
  height: 200px;
  margin: 0 auto;
}

.stat-card {
  padding: 20px;
  display: flex;
  flex-direction: column;
}

.stat-value {
  font-size: 28px;
  font-weight: 800;
  line-height: 1;
}

.stat-label {
  font-size: 13px;
  color: var(--c-text-muted);
  margin-top: 6px;
}

.stat-change {
  font-size: 12px;
  margin-top: 4px;
  display: flex;
  align-items: center;
  gap: 4px;
}

.stat-change.up { color: var(--c-accent); }
.stat-change.down { color: var(--c-danger); }

/* ===== Modal ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all var(--t-smooth);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal {
  background: var(--c-bg-card);
  border-radius: var(--r-xl);
  border: 1px solid var(--c-border);
  padding: 32px;
  max-width: 480px;
  width: 90%;
  max-height: 90vh;
  overflow-y: auto;
  transform: translateY(20px) scale(0.95);
  transition: transform var(--t-magnetic);
}

.modal-overlay.active .modal {
  transform: translateY(0) scale(1);
}

.modal-title {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 24px;
}

/* ===== Knowledge Point Framework Panel ===== */

/* Side panel mini tree trigger */
.kp-trigger-section {
  border-top: 1px solid var(--c-border);
  padding-top: 12px;
}
.kp-mini-tree {
  font-size: 12px;
  line-height: 1.8;
  color: var(--c-text-secondary);
  max-height: 120px;
  overflow-y: auto;
  margin-bottom: 8px;
}
.kp-mini-tree .kp-mini-item {
  padding: 2px 0;
  display: flex;
  align-items: center;
  gap: 6px;
}
.kp-mini-tree .kp-mini-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--c-border);
  flex-shrink: 0;
}
.kp-mini-tree .kp-mini-item.active .kp-mini-dot {
  background: var(--c-primary);
  box-shadow: 0 0 6px rgba(99,102,241,0.4);
}
.kp-mini-tree .kp-mini-item.active {
  color: var(--c-primary);
  font-weight: 600;
}
.kp-expand-btn {
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-dark));
  color: #fff;
  font-weight: 600;
  border: none;
  border-radius: var(--r-md);
  cursor: pointer;
  transition: all 0.3s;
  position: relative;
  overflow: hidden;
}
.kp-expand-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(99,102,241,0.3);
}
.kp-expand-btn::before {
  content: '';
  position: absolute;
  top: 0; left: -100%;
  width: 100%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: left 0.5s;
}
.kp-expand-btn:hover::before {
  left: 100%;
}

/* Knowledge Detail Panel (overlay on question area) */
.kp-detail-panel {
  position: absolute;
  top: 0;
  right: 0;
  width: 420px;
  height: 100%;
  background: var(--c-bg-card);
  border-left: 1px solid var(--c-border);
  border-radius: var(--r-xl) 0 0 var(--r-xl);
  box-shadow: -8px 0 30px rgba(0,0,0,0.1);
  z-index: 50;
  transform: translateX(100%);
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}
.kp-detail-panel.visible {
  transform: translateX(0);
}
.kp-detail-panel.hidden {
  transform: translateX(100%);
}

.kp-detail-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--c-border);
  background: linear-gradient(135deg, rgba(99,102,241,0.08), rgba(99,102,241,0.02));
  position: sticky;
  top: 0;
  z-index: 2;
}
.kp-detail-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--c-primary);
}
.kp-detail-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}
.kp-voice-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--c-border);
  background: var(--c-bg);
  color: var(--c-text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}
.kp-voice-btn:hover {
  background: var(--c-primary-50);
  border-color: var(--c-primary);
  color: var(--c-primary);
}
.kp-voice-btn.playing {
  background: var(--c-primary);
  border-color: var(--c-primary);
  color: #fff;
  animation: voice-pulse 1.5s infinite;
}
@keyframes voice-pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(99,102,241,0.4); }
  50% { box-shadow: 0 0 0 8px rgba(99,102,241,0); }
}
/* ★★★ KEY FIX: 知识点面板关闭按钮 — 手机端加大触摸区域 ★★★ */
.kp-close-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: none;
  background: var(--c-bg-secondary);
  color: var(--c-text-secondary);
  cursor: pointer;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  /* 确保手机端有足够点击区域 */
  min-width: 44px;
  min-height: 44px;
  position: relative;
  z-index: 10;
}
.kp-close-btn:hover {
  background: var(--c-danger);
  color: #fff;
}
.kp-close-btn:active {
  transform: scale(0.9);
  background: var(--c-danger);
  color: #fff;
}

/* 知识点面板浮动展开按钮 */
.kp-floating-trigger {
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-600));
  color: #fff;
  border: none;
  border-radius: 999px 0 0 999px;
  padding: 12px 14px 12px 16px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  box-shadow: -4px 0 16px rgba(99, 102, 241, 0.25);
  z-index: 50;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  font-size: 12px;
  font-weight: 600;
  min-width: 48px;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}
.kp-floating-trigger:hover {
  padding-right: 22px;
  box-shadow: -6px 0 24px rgba(99, 102, 241, 0.35);
}
.kp-floating-trigger.hidden {
  display: none !important;
}

.kp-detail-body {
  padding: 20px;
  flex: 1;
  overflow-y: auto;
}

/* Knowledge Tree */
.kp-tree-section {
  margin-bottom: 24px;
}
.kp-tree-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--c-text);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.kp-tree-title::before {
  content: '';
  width: 3px;
  height: 14px;
  background: var(--c-primary);
  border-radius: 2px;
}
.kp-tree {
  font-size: 13px;
}
.kp-tree-node {
  margin-bottom: 4px;
}
.kp-tree-parent {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  background: var(--c-bg-secondary);
  border-radius: var(--r-md);
  font-weight: 600;
  color: var(--c-text);
  cursor: pointer;
  transition: all 0.2s;
}
.kp-tree-parent:hover {
  background: var(--c-primary-50);
}
.kp-tree-parent.active {
  background: rgba(99,102,241,0.12);
  color: var(--c-primary);
  border: 1px solid rgba(99,102,241,0.2);
}
.kp-tree-parent-icon {
  font-size: 10px;
  transition: transform 0.2s;
}
.kp-tree-parent-icon.expanded {
  transform: rotate(90deg);
}
.kp-tree-children {
  padding-left: 20px;
  border-left: 2px solid var(--c-border);
  margin-left: 12px;
  margin-top: 4px;
}
.kp-tree-children.collapsed {
  display: none;
}
.kp-tree-child {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  border-radius: var(--r-sm);
  color: var(--c-text-secondary);
  cursor: pointer;
  transition: all 0.2s;
  font-size: 13px;
}
.kp-tree-child:hover {
  background: var(--c-bg-secondary);
  color: var(--c-text);
}
.kp-tree-child.active {
  background: rgba(99,102,241,0.08);
  color: var(--c-primary);
  font-weight: 600;
}
.kp-tree-child-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-border);
  flex-shrink: 0;
  transition: all 0.2s;
}
.kp-tree-child.active .kp-tree-child-dot {
  background: var(--c-primary);
  box-shadow: 0 0 4px rgba(99,102,241,0.4);
}

/* Knowledge Explain Section */
.kp-explain-section {
  margin-bottom: 24px;
  padding: 20px;
  background: linear-gradient(135deg, rgba(99,102,241,0.05), rgba(16,185,129,0.05));
  border-radius: var(--r-xl);
  border: 1px solid rgba(99,102,241,0.1);
}
.kp-explain-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--c-primary);
  margin-bottom: 16px;
}
.kp-explain-content {
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-text);
}
.kp-explain-content p {
  margin-bottom: 12px;
}
.kp-explain-diagram {
  background: var(--c-bg-card);
  border-radius: var(--r-lg);
  border: 1px solid var(--c-border);
  padding: 16px;
  margin: 16px 0;
  text-align: center;
}
.kp-explain-diagram-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--c-text-secondary);
  margin-bottom: 12px;
}
.kp-explain-diagram svg {
  max-width: 100%;
  height: auto;
}
.kp-highlight {
  background: rgba(99,102,241,0.12);
  padding: 2px 6px;
  border-radius: 4px;
  font-weight: 600;
  color: var(--c-primary);
}
.kp-key-point {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  padding: 10px 12px;
  background: rgba(16,185,129,0.08);
  border-radius: var(--r-md);
  margin-bottom: 8px;
  font-size: 13px;
}
.kp-key-point-icon {
  color: var(--c-accent);
  flex-shrink: 0;
  font-weight: 700;
}
.kp-warning-point {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  padding: 10px 12px;
  background: rgba(239,68,68,0.08);
  border-radius: var(--r-md);
  margin-bottom: 8px;
  font-size: 13px;
}
.kp-warning-point-icon {
  color: var(--c-danger);
  flex-shrink: 0;
  font-weight: 700;
}
.kp-comparison-table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0;
  font-size: 13px;
}
.kp-comparison-table th {
  background: var(--c-bg-secondary);
  padding: 8px 12px;
  text-align: left;
  font-weight: 600;
  border-bottom: 2px solid var(--c-border);
}
.kp-comparison-table td {
  padding: 8px 12px;
  border-bottom: 1px solid var(--c-border-light);
}
.kp-flow-chart {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px;
  flex-wrap: wrap;
}
.kp-flow-step {
  padding: 8px 14px;
  background: var(--c-primary-50);
  border-radius: var(--r-md);
  font-size: 12px;
  font-weight: 600;
  color: var(--c-primary);
  text-align: center;
}
.kp-flow-arrow {
  color: var(--c-text-muted);
  font-size: 16px;
}

/* Related Knowledge Points */
.kp-related-section {
  margin-bottom: 16px;
}
.kp-related-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--c-text);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 6px;
}
.kp-related-title::before {
  content: '';
  width: 3px;
  height: 14px;
  background: var(--c-accent);
  border-radius: 2px;
}
.kp-related-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: var(--r-md);
  border: 1px solid var(--c-border);
  background: var(--c-bg);
  cursor: pointer;
  transition: all 0.2s;
  margin-bottom: 8px;
}
.kp-related-item:hover {
  border-color: var(--c-primary);
  background: var(--c-primary-50);
}
.kp-related-item-icon {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--c-bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  color: var(--c-primary);
}
.kp-related-item-name {
  font-weight: 600;
  font-size: 13px;
  color: var(--c-text);
}
.kp-related-item-desc {
  font-size: 12px;
  color: var(--c-text-muted);
}

/* Voice progress indicator */
.kp-voice-progress {
  height: 3px;
  background: var(--c-border);
  border-radius: 2px;
  margin: 8px 0 0;
  overflow: hidden;
}
.kp-voice-progress-bar {
  height: 100%;
  background: var(--c-primary);
  border-radius: 2px;
  width: 0%;
  transition: width 0.3s;
}

/* ★★★ KEY FIX: 全站所有 × 关闭按钮 — 手机端加大触摸区域 ★★★ */
.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 32px;
  height: 32px;
  border-radius: var(--r-sm);
  border: none;
  background: var(--c-bg-secondary);
  color: var(--c-text-muted);
  cursor: pointer;
  font-size: 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--t-smooth);
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  /* 手机端加大触控区域至44×44 */
  min-width: 44px;
  min-height: 44px;
  z-index: 10;
}

.modal-close:hover {
  background: var(--c-danger);
  color: white;
}
.modal-close:active {
  transform: scale(0.9);
  background: var(--c-danger);
  color: white;
}

.cs-close {
  background: none;
  border: none;
  color: #fff;
  font-size: 18px;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  min-width: 44px;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
}
.cs-close:hover { opacity: 1; }
.cs-close:active { opacity: 0.8; }

/* Mobile responsive for knowledge panel */
@media (max-width: 768px) {
  .kp-detail-panel {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    width: 100%;
    height: 100%;
    border-radius: 0;
    border-left: none;
    transform: translateY(100%);
    z-index: 200;
  }
  .kp-detail-panel.visible {
    transform: translateY(0);
  }
  .kp-detail-panel.hidden {
    transform: translateY(100%);
  }
  .kp-trigger-section {
    display: none;
  }
  .kp-floating-trigger {
    top: auto;
    bottom: 100px;
    right: 0;
    transform: translateY(0);
    border-radius: 999px 0 0 999px;
    padding: 10px 12px 10px 14px;
    min-width: 44px;
    min-height: 44px;
    font-size: 11px;
  }
  .kp-floating-trigger svg {
    width: 18px;
    height: 18px;
  }
  /* 手机端知识点面板×按钮确保可点击 */
  .kp-close-btn {
    min-width: 48px;
    min-height: 48px;
    font-size: 22px;
    position: relative;
    z-index: 210;
    background: rgba(239,68,68,0.1);
    border: 2px solid rgba(239,68,68,0.3);
  }
  .kp-voice-btn {
    min-width: 48px;
    min-height: 48px;
  }
  .kp-detail-header {
    padding: 20px 16px;
    position: sticky;
    top: 0;
    z-index: 210;
    background: var(--c-bg-card);
  }
  /* 手机端全站×按钮统一加大 */
  .modal-close {
    min-width: 48px;
    min-height: 48px;
    font-size: 22px;
    position: relative;
    z-index: 10;
  }
}


.form-group { margin-bottom: 16px; }

.form-label {
  font-size: 14px;
  font-weight: 600;
  color: var(--c-text);
  margin-bottom: 6px;
  display: block;
}

.form-input {
  width: 100%;
  padding: 12px 16px;
  border-radius: var(--r-md);
  border: 2px solid var(--c-border);
  background: var(--c-bg-secondary);
  color: var(--c-text);
  font-size: 15px;
  outline: none;
  transition: all var(--t-smooth);
}

.form-input:focus {
  border-color: var(--c-primary);
  background: var(--c-bg-card);
  box-shadow: 0 0 0 3px var(--c-primary-50);
}

/* ===== Tabs ===== */
.tabs {
  display: flex;
  gap: 4px;
  border-bottom: 2px solid var(--c-border);
  padding-bottom: 0;
  margin-bottom: 24px;
}

.tab {
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 500;
  color: var(--c-text-muted);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  transition: all var(--t-smooth);
}

.tab:hover { color: var(--c-text); }

.tab.active {
  color: var(--c-primary);
  border-bottom-color: var(--c-primary);
  font-weight: 600;
}

/* ===== Membership Cards ===== */
.plan-card {
  padding: 28px;
  border-radius: var(--r-xl);
  border: 2px solid var(--c-border);
  background: var(--c-bg-card);
  transition: all var(--t-magnetic);
  position: relative;
  overflow: hidden;
}

.plan-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--c-shadow-lg);
}

.plan-card.popular {
  border-color: var(--c-primary);
  box-shadow: var(--c-shadow-glow);
}

.plan-card.popular::before {
  content: '推荐';
  position: absolute;
  top: 0;
  right: 24px;
  background: linear-gradient(135deg, var(--c-primary), var(--c-accent));
  color: white;
  padding: 4px 16px 12px;
  font-size: 12px;
  font-weight: 700;
  border-radius: 0 0 8px 8px;
}

.plan-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--c-text);
}

.plan-price {
  font-size: 36px;
  font-weight: 800;
  color: var(--c-primary);
  margin-top: 8px;
}

.plan-price-unit {
  font-size: 14px;
  font-weight: 500;
  color: var(--c-text-muted);
}

.plan-savings {
  font-size: 13px;
  color: var(--c-accent);
  margin-top: 4px;
}

.plan-features {
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.plan-feature {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--c-text-secondary);
}

.plan-feature-icon {
  color: var(--c-accent);
  font-size: 16px;
}

/* ===== Mistake Book ===== */
.mistake-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 20px;
  border-radius: var(--r-md);
  border: 1px solid var(--c-border);
  background: var(--c-bg-card);
  cursor: pointer;
  transition: all var(--t-smooth);
}

.mistake-item:hover {
  background: var(--c-bg-card-hover);
  transform: translateX(4px);
}

.mistake-item.mistake-mastered {
  opacity: 0.45;
  border-style: dashed;
}

.mistake-item.mistake-mastered:hover {
  opacity: 0.65;
}

/* ===== Error Type Badge ===== */
.error-type-badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  font-size: 12px;
  font-weight: 600;
  border-radius: 4px;
  white-space: nowrap;
  line-height: 1.5;
}

/* ===== Streak / Gamification ===== */
.streak-counter {
  display: flex;
  align-items: center;
  gap: 4px;
}

.streak-day {
  width: 32px;
  height: 32px;
  border-radius: var(--r-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  font-weight: 600;
}

.streak-day.done {
  background: var(--c-accent);
  color: white;
}

.streak-day.today {
  background: var(--c-primary);
  color: white;
  box-shadow: 0 0 8px rgba(99,102,241,0.4);
}

.streak-day.future {
  background: var(--c-bg-secondary);
  color: var(--c-text-muted);
}

/* ===== Animations ===== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideInRight {
  from { opacity: 0; transform: translateX(30px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

@keyframes countUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.animate-fadeInUp { animation: fadeInUp 0.6s var(--t-magnetic) both; }
.animate-fadeIn { animation: fadeIn 0.4s var(--t-smooth) both; }
.animate-slideIn { animation: slideInRight 0.5s var(--t-magnetic) both; }
.animate-pulse { animation: pulse 2s infinite; }

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }
.delay-5 { animation-delay: 0.5s; }

/* ===== Journal Entry Editor ===== */
.je-header { display:flex;align-items:center;justify-content:space-between;padding:12px;border-bottom:1px solid var(--c-border); }
.je-lines { display:flex;flex-direction:column;gap:4px;padding:8px; }
.je-line { display:flex;align-items:center;gap:8px;padding:8px;border-radius:8px;background:var(--c-bg-secondary); }
.je-line-side { font-weight:600;font-size:13px;width:30px;color:var(--c-text-muted); }
.je-line-account { flex:1; }
.je-line-amount { width:120px; }
.je-line select, .je-line input { padding:6px 8px;border:1px solid var(--c-border);border-radius:6px;font-size:13px;background:var(--c-bg-card);color:var(--c-text); }
.je-line select { min-width:140px; }
.je-line .btn-remove { font-size:12px;padding:4px 8px; }
.je-total { padding:12px;border-top:1px solid var(--c-border);text-align:right;font-weight:600; }

/* ===== Difficulty Distribution Bar ===== */
.diff-bar { display:flex;height:6px;border-radius:3px;overflow:hidden;margin-top:6px; }
.diff-bar-segment { height:100%;transition:width 0.3s; }
.diff-bar-segment.basic { background:#10B981; }
.diff-bar-segment.highfreq { background:#F59E0B; }
.diff-bar-segment.sprint { background:#F43F5E; }
.diff-bar-labels { display:flex;gap:8px;margin-top:4px;font-size:11px;color:var(--c-text-muted); }
.chapter-tags { display:flex;gap:6px;margin-top:6px;flex-wrap:wrap; }

/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--c-border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--c-text-muted); }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .practice-layout {
    grid-template-columns: 1fr;
  }
  .question-nav-panel, .side-panel {
    position: static;
    height: auto;
  }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-6 { grid-template-columns: repeat(3, 1fr); }
  .hero-title { font-size: 36px; }
  .nav-links .nav-link { padding: 6px 10px; }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .mobile-menu-btn { display: flex !important; }
  .hero-title { font-size: 28px; }
  .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
  .grid-6 { grid-template-columns: repeat(2, 1fr); }
  .practice-layout { grid-template-columns: 1fr; gap: 12px; }
  .question-panel { padding: 20px; }
  .stat-value { font-size: 24px; }
  .plan-card { padding: 20px; }
}

/* Mobile menu button (hidden on desktop) */
.mobile-menu-btn {
  display: none !important;
  width: 40px;
  height: 40px;
  border-radius: var(--r-md);
  border: 1px solid var(--c-border);
  background: var(--c-bg-card);
  cursor: pointer;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  color: var(--c-text);
}

/* Mobile nav */
.mobile-nav {
  position: fixed;
  top: 64px;
  left: 0;
  right: 0;
  background: var(--c-bg-nav);
  backdrop-filter: blur(var(--c-glass-blur));
  border-bottom: 1px solid var(--c-border);
  padding: 16px 24px;
  z-index: 99;
  display: none;
  flex-direction: column;
  gap: 8px;
}

.mobile-nav.active { display: flex; }

.mobile-nav .nav-link {
  padding: 12px 16px;
  font-size: 16px;
}

/* ===== Toast ===== */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  padding: 14px 24px;
  border-radius: var(--r-md);
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  box-shadow: var(--c-shadow-lg);
  font-size: 14px;
  font-weight: 500;
  color: var(--c-text);
  z-index: 300;
  transform: translateY(100px);
  opacity: 0;
  transition: all var(--t-magnetic);
  display: flex;
  align-items: center;
  gap: 10px;
}

.toast.active {
  transform: translateY(0);
  opacity: 1;
}

.toast.success { border-color: var(--c-accent); }
.toast.error { border-color: var(--c-danger); }

/* ===== Utility ===== */
.hidden { display: none !important; }
.text-center { text-align: center; }
.text-right { text-align: right; }
.mb-2 { margin-bottom: 8px; }
.mb-3 { margin-bottom: 12px; }
.mb-4 { margin-bottom: 16px; }
.mb-6 { margin-bottom: 24px; }
.mb-8 { margin-bottom: 32px; }
.mt-2 { margin-top: 8px; }
.mt-4 { margin-top: 16px; }
.mt-6 { margin-top: 24px; }
.p-4 { padding: 16px; }
.p-6 { padding: 24px; }
.p-8 { padding: 32px; }
.rounded { border-radius: var(--r-md); }
.rounded-lg { border-radius: var(--r-lg); }
.rounded-xl { border-radius: var(--r-xl); }
.border { border: 1px solid var(--c-border); }
.shadow { box-shadow: var(--c-shadow); }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* ===== Search ===== */
.search-box {
  position: relative;
  width: 100%;
}

.search-input {
  width: 100%;
  padding: 10px 16px 10px 40px;
  border-radius: var(--r-md);
  border: 2px solid var(--c-border);
  background: var(--c-bg-secondary);
  color: var(--c-text);
  font-size: 14px;
  outline: none;
  transition: all var(--t-smooth);
}

.search-input:focus {
  border-color: var(--c-primary);
  background: var(--c-bg-card);
}

.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--c-text-muted);
  font-size: 16px;
}

/* ===== Notification dot ===== */
.notif-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-danger);
  position: absolute;
  top: -2px;
  right: -2px;
}

/* ===== Loading skeleton ===== */
.skeleton {
  background: linear-gradient(90deg, var(--c-bg-secondary) 25%, var(--c-bg-card) 50%, var(--c-bg-secondary) 75%);
  background-size: 200% 100%;
  animation: skeleton 1.5s infinite;
  border-radius: var(--r-md);
}

@keyframes skeleton {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ===== Page Transitions ===== */
.page-transition-enter {
  animation: pageSlideIn 0.4s cubic-bezier(0.16, 1, 0.3, 1) both;
}

@keyframes pageSlideIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ===== AI Typing Indicator ===== */
.ai-typing-indicator {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 14px;
  background: var(--c-primary-50);
  border-radius: var(--r-md);
  font-size: 14px;
  color: var(--c-text-muted);
}

.ai-typing-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-primary);
  animation: typingBounce 1.4s infinite;
}

.ai-typing-dot:nth-child(2) { animation-delay: 0.2s; }
.ai-typing-dot:nth-child(3) { animation-delay: 0.4s; }

@keyframes typingBounce {
  0%, 80%, 100% { transform: scale(0.6); opacity: 0.4; }
  40% { transform: scale(1); opacity: 1; }
}

/* ===== Hero Animated Background ===== */
.hero-particles {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
}

.hero-particle {
  position: absolute;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--c-primary);
  opacity: 0.3;
  animation: floatParticle 8s infinite ease-in-out;
}

@keyframes floatParticle {
  0%, 100% { transform: translateY(0) translateX(0); opacity: 0.3; }
  25% { transform: translateY(-30px) translateX(20px); opacity: 0.6; }
  50% { transform: translateY(-10px) translateX(-15px); opacity: 0.4; }
  75% { transform: translateY(-40px) translateX(10px); opacity: 0.5; }
}

/* ===== Stat Count Up Animation ===== */
@keyframes countUpAnim {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.stat-number.animated {
  animation: countUpAnim 0.6s cubic-bezier(0.16, 1, 0.3, 1) both;
}

/* ===== Theme Toggle Indicator ===== */
.theme-toggle-indicator {
  position: absolute;
  bottom: -16px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 9px;
  color: var(--c-text-muted);
  white-space: nowrap;
  pointer-events: none;
}

/* ===== Exam Styles ===== */
.exam-header-bar {
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-dark));
  color: white;
  padding: 16px 24px;
  border-radius: var(--r-xl);
  margin-bottom: 16px;
  box-shadow: 0 4px 20px rgba(99, 102, 241, 0.3);
}

.exam-header-bar * { color: white !important; }

.exam-timer-container {
  text-align: center;
}

.exam-timer {
  font-size: 28px;
  font-weight: 800;
  font-family: var(--f-mono);
  color: white;
  line-height: 1;
}

.exam-timer.warning {
  color: #F59E0B;
  animation: timerPulse 1s infinite;
}

.exam-timer.critical {
  color: #F43F5E;
  animation: timerPulse 0.5s infinite;
}

@keyframes timerPulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.exam-result-card {
  padding: 32px;
  border-radius: var(--r-xl);
  background: var(--c-bg-card);
  border: 1px solid var(--c-border);
  text-align: center;
}

.exam-result-score-big {
  font-size: 72px;
  font-weight: 800;
  line-height: 1;
  margin-bottom: 8px;
}

.exam-result-score-big.pass { color: var(--c-accent); }
.exam-result-score-big.fail { color: var(--c-danger); }

.exam-detail-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px;
  border-bottom: 1px solid var(--c-border-light);
  transition: background var(--t-smooth);
}

.exam-detail-item:hover {
  background: var(--c-bg-secondary);
}

.exam-detail-item:last-child {
  border-bottom: none;
}

/* ===== Ripple Effect for Buttons ===== */
.btn-ripple {
  position: relative;
  overflow: hidden;
}

.btn-ripple::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at var(--ripple-x, 50%) var(--ripple-y, 50%), rgba(255,255,255,0.3) 0%, transparent 60%);
  opacity: 0;
  transition: opacity 0.3s;
}

.btn-ripple:active::after {
  opacity: 1;
}

/* ===== Magnetic Hover Effect ===== */
.magnetic-hover {
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.3s ease;
}

.magnetic-hover:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 30px rgba(99, 102, 241, 0.2);
}

/* ===== Confetti Animation ===== */
@keyframes confettiDrop {
  0% { transform: translateY(-100vh) rotate(0deg); opacity: 1; }
  100% { transform: translateY(100vh) rotate(720deg); opacity: 0; }
}

.confetti-piece {
  position: fixed;
  width: 10px;
  height: 10px;
  z-index: 400;
  animation: confettiDrop 3s linear forwards;
}

/* ===== Exam Responsive ===== */
@media (max-width: 1024px) {
  .exam-header-bar { padding: 12px 16px; }
  .exam-timer { font-size: 20px; }
}

@media (max-width: 768px) {
  .exam-header-bar { padding: 10px 12px; }
  .exam-timer { font-size: 18px; }
  .grid-3 { grid-template-columns: 1fr; }
}

/* ===== Exam Answer Input (Analysis Questions) ===== */
.answer-input-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--c-border);
}
.answer-input-icon { font-size: 20px; }
.answer-input-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--c-primary);
}
.answer-input-hint {
  font-size: 12px;
  color: var(--c-text-muted);
}

.answer-textarea {
  width: 100%;
  min-height: 200px;
  padding: 16px;
  border-radius: var(--r-lg);
  border: 2px solid var(--c-border);
  background: var(--c-bg-secondary);
  color: var(--c-text);
  font-size: 15px;
  font-family: inherit;
  line-height: 1.8;
  resize: vertical;
  transition: border-color var(--t-smooth);
  box-sizing: border-box;
}
.answer-textarea:focus {
  outline: none;
  border-color: var(--c-primary);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.1);
}
.answer-textarea::placeholder {
  color: var(--c-text-muted);
  opacity: 0.7;
}

.answer-input-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--c-border);
}
.answer-char-count {
  font-size: 13px;
  color: var(--c-text-muted);
}

/* ===== Answer Review ===== */
.answer-review-block {
  margin-bottom: 16px;
  padding: 16px;
  border-radius: var(--r-lg);
  border: 1px solid var(--c-border);
}
.answer-review-block:not(.answer-review-model) {
  background: rgba(99,102,241,0.04);
  border-color: rgba(99,102,241,0.2);
}
.answer-review-model {
  background: rgba(16,185,129,0.04);
  border-color: rgba(16,185,129,0.2);
}
.answer-review-label {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--c-text-secondary);
}
.answer-review-model .answer-review-label {
  color: var(--c-accent);
}
.answer-review-content {
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-text);
  white-space: pre-wrap;
}

/* ===== Sub-questions ===== */
.subquestions-preview {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px dashed var(--c-border);
}
.sub-q-item {
  display: flex;
  gap: 8px;
  padding: 10px 14px;
  margin-bottom: 8px;
  background: var(--c-bg-secondary);
  border-radius: var(--r-md);
  font-size: 14px;
  line-height: 1.7;
}
.sub-q-num {
  font-weight: 700;
  color: var(--c-primary);
  flex-shrink: 0;
}
.sub-answer-item {
  padding: 8px 0;
  font-size: 14px;
  line-height: 1.7;
}

/* ===== Exam Result: Analysis Questions ===== */
.exam-detail-analysis {
  background: rgba(245,158,11,0.04) !important;
  border-left: 3px solid #F59E0B !important;
}
.exam-detail-user-answer {
  font-size: 12px;
  color: var(--c-primary);
  margin-top: 4px;
  padding: 6px 10px;
  background: rgba(99,102,241,0.08);
  border-radius: var(--r-sm);
}
.exam-detail-model {
  font-size: 12px;
  color: var(--c-accent);
  margin-top: 4px;
  padding: 6px 10px;
  background: rgba(16,185,129,0.08);
  border-radius: var(--r-sm);
}

/* ===== Setting Toggle Switch ===== */
.setting-toggle { cursor: pointer; }
.toggle-track { width: 48px; height: 24px; border-radius: 12px; background: var(--c-border); transition: background 0.3s; position: relative; }
.toggle-track.active { background: var(--c-primary); }
.toggle-thumb { width: 20px; height: 20px; border-radius: 10px; background: #fff; position: absolute; top: 2px; left: 2px; transition: left 0.3s; }
.toggle-track.active .toggle-thumb { left: 26px; }

/* ===== Privacy Authorization Modal ===== */
#privacyAuthModal .modal {
  border-radius: 20px;
  padding: 32px 24px;
}

/* ===== Floating Customer Service Widget ===== */
.cs-widget {
  position: fixed;
  right: 20px;
  bottom: 100px;
  z-index: 900;
}
.cs-trigger {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-dark));
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(99,102,241,0.35);
  transition: transform 0.3s, box-shadow 0.3s;
}
.cs-trigger:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 30px rgba(99,102,241,0.5);
}
.cs-icon {
  font-size: 13px;
  font-weight: 700;
}
.cs-window {
  position: absolute;
  bottom: 70px;
  right: 0;
  width: 340px;
  background: var(--c-bg-card);
  border-radius: 16px;
  box-shadow: var(--c-shadow-lg);
  overflow: hidden;
  border: 1px solid var(--c-border);
}
.cs-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px;
  background: linear-gradient(135deg, var(--c-primary), var(--c-primary-dark));
  color: #fff;
}
.cs-messages {
  padding: 16px;
  max-height: 280px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.cs-msg {
  max-width: 80%;
  padding: 10px 14px;
  border-radius: 12px;
  font-size: 14px;
  line-height: 1.5;
}
.cs-msg.bot {
  background: var(--c-bg-secondary);
  align-self: flex-start;
  border-bottom-left-radius: 4px;
}
.cs-msg.user {
  background: var(--c-primary);
  color: #fff;
  align-self: flex-end;
  border-bottom-right-radius: 4px;
}
.cs-input-area {
  display: flex;
  gap: 8px;
  padding: 12px;
  border-top: 1px solid var(--c-border);
}
.cs-input {
  flex: 1;
  padding: 10px 14px;
  border: 1px solid var(--c-border);
  border-radius: 8px;
  background: var(--c-bg);
  color: var(--c-text);
  font-size: 14px;
  outline: none;
}
.cs-input:focus { border-color: var(--c-primary); }
.cs-quick-links {
  display: flex;
  gap: 8px;
  padding: 0 12px 12px;
  flex-wrap: wrap;
}
.cs-quick-btn {
  padding: 6px 12px;
  border: 1px solid var(--c-border);
  border-radius: 20px;
  background: var(--c-bg);
  color: var(--c-text-secondary);
  font-size: 12px;
  cursor: pointer;
  transition: all 0.2s;
}
.cs-quick-btn:hover {
  background: var(--c-primary-50);
  border-color: var(--c-primary);
  color: var(--c-primary);
}

/* ===== Invite Card ===== */
.invite-card {
  background: linear-gradient(135deg, var(--c-lowprice) 0%, var(--c-lowprice-dark) 100%);
  border-radius: var(--r-xl);
  padding: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 24px;
  box-shadow: 0 8px 30px rgba(230,126,34,0.25);
  flex-wrap: wrap;
}
.invite-card-left { flex: 1; min-width: 200px; }
.invite-card-right {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}
.invite-code-box {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 2px;
}
.invite-code {
  font-size: 20px;
  font-weight: 800;
  color: #fff;
  letter-spacing: 2px;
}

/* ===== Compare Table ===== */
.compare-table-wrapper {
  overflow-x: auto;
  border-radius: var(--r-lg);
  border: 1px solid var(--c-border);
  background: var(--c-bg-card);
}
.compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}
.compare-table th {
  padding: 16px 12px;
  text-align: center;
  font-weight: 700;
  background: var(--c-bg-secondary);
  border-bottom: 2px solid var(--c-border);
  white-space: nowrap;
}
.compare-table th:first-child {
  text-align: left;
  color: var(--c-text);
}
.compare-table td {
  padding: 12px;
  text-align: center;
  border-bottom: 1px solid var(--c-border-light);
  color: var(--c-text-secondary);
}
.compare-table td:first-child {
  text-align: left;
  font-weight: 500;
  color: var(--c-text);
}
.compare-table tbody tr:hover {
  background: var(--c-bg-card-hover);
}
.compare-table .check {
  color: var(--c-free);
  font-size: 16px;
  font-weight: 700;
}
.compare-table .cross {
  color: var(--c-text-muted);
  font-size: 16px;
}

/* ===== Footer Public ===== */
.footer-public {
  text-align: center;
  padding: 24px 16px;
  margin-top: 16px;
  border-top: 1px solid var(--c-border);
}
.footer-public-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 4px;
  margin-bottom: 8px;
  font-size: 13px;
}
.footer-public-links a {
  color: var(--c-text-muted);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-public-links a:hover {
  color: var(--c-primary);
}
.footer-public-links .sep {
  color: var(--c-border);
}
.footer-public-notice {
  font-size: 12px;
  color: var(--c-text-muted);
  margin-top: 8px;
}

/* ===== Coupon Card ===== */
.coupon-card {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px;
  border-radius: var(--r-md);
  border: 1px dashed var(--c-border);
  background: var(--c-bg-card);
  transition: all 0.2s;
}
.coupon-card.active {
  border-color: var(--c-lowprice);
  background: var(--c-lowprice-bg);
}
.coupon-card.expired {
  opacity: 0.5;
}
.coupon-amount {
  font-size: 24px;
  font-weight: 800;
  color: var(--c-lowprice);
  flex-shrink: 0;
}
.coupon-info { flex: 1; }
.coupon-name { font-weight: 600; font-size: 14px; }
.coupon-desc { font-size: 12px; color: var(--c-text-muted); margin-top: 2px; }
.coupon-status {
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 20px;
  font-weight: 600;
}
.coupon-status.available {
  background: var(--c-free-bg);
  color: var(--c-free);
}
.coupon-status.used {
  background: var(--c-bg-secondary);
  color: var(--c-text-muted);
}

/* ===== Nav Search Box ===== */
.nav-search-box {
  flex: 1;
  max-width: 280px;
  margin: 0 16px;
}
.nav-search-input {
  width: 100%;
  padding: 8px 16px;
  border: 1px solid var(--c-border);
  border-radius: 20px;
  background: var(--c-bg-secondary);
  color: var(--c-text);
  font-size: 14px;
  outline: none;
  cursor: pointer;
  transition: all 0.2s;
}
.nav-search-input:hover {
  border-color: var(--c-primary);
  background: var(--c-bg-card);
}
.nav-search-input::placeholder {
  color: var(--c-text-muted);
}

/* ===== Mobile Optimization ===== */
@media (max-width: 768px) {
  .btn {
    min-height: 48px;
    font-size: 16px;
  }
  .btn-sm {
    min-height: 44px;
  }

  .pricing-comparison {
    flex-direction: column;
    gap: 16px;
  }
  .pricing-tier-low {
    order: -1;
    transform: none;
  }
  .pricing-tier-low:hover {
    transform: none;
  }

  body {
    font-size: 16px;
  }

  .nav-search-box {
    display: none;
  }

  .cs-window {
    width: calc(100vw - 24px);
    right: -8px;
  }

  .invite-card {
    flex-direction: column;
    text-align: center;
  }
  .invite-card-right {
    flex-direction: column;
  }
  .invite-code-box {
    align-items: center;
  }

  .compare-table-wrapper {
    font-size: 13px;
  }

  .free-zone {
    padding: 20px 16px;
  }
  .free-zone-title {
    font-size: 18px;
  }

  .footer-public-links {
    flex-direction: column;
    gap: 8px;
  }
  .footer-public-links .sep {
    display: none;
  }
}

@media (max-width: 480px) {
  .pricing-tier-low {
    transform: none;
  }
}

/* ===== Free Zone Enhancement ===== */
.free-zone {
  background: linear-gradient(135deg, #eafaf1 0%, #d5f5e3 50%, #eafaf1 100%);
  border-radius: var(--r-2xl);
  padding: 40px 32px;
  margin-bottom: 32px;
  border: 2px solid var(--c-free-border);
  position: relative;
  overflow: hidden;
}
.free-zone::before {
  content: '';
  position: absolute;
  top: -50px;
  right: -50px;
  width: 200px;
  height: 200px;
  background: radial-gradient(circle, rgba(39,174,96,0.08) 0%, transparent 70%);
  border-radius: 50%;
}
.free-zone-title {
  font-size: 26px;
  font-weight: 800;
  color: var(--c-free-dark);
  margin-bottom: 6px;
  position: relative;
  z-index: 1;
}
.free-zone-subtitle {
  font-size: 15px;
  color: var(--c-free);
  margin-bottom: 24px;
  position: relative;
  z-index: 1;
}

#freeChaptersList .card-sm {
  padding: 20px;
  border-radius: var(--r-lg);
  border: 1px solid var(--c-free-border);
  background: rgba(255,255,255,0.8);
  transition: all 0.3s;
}
#freeChaptersList .card-sm:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(39,174,96,0.15);
  background: rgba(255,255,255,0.95);
}