/* ===== 变量与重置 ===== */
:root {
  --color-primary: #4f46e5;
  --color-primary-dark: #3730a3;
  --color-primary-light: #818cf8;
  --color-accent: #f59e0b;
  --color-accent-light: #fbbf24;
  --color-bg: #f8fafc;
  --color-bg-dark: #0f172a;
  --color-surface: #ffffff;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-border: #e2e8f0;
  --color-success: #10b981;
  --color-danger: #ef4444;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --header-height: 72px;
  --transition: 0.25s ease;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  display: block;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn-sm {
  padding: 8px 16px;
  font-size: 14px;
}

.btn-lg {
  padding: 14px 28px;
  font-size: 16px;
}

.btn-block {
  width: 100%;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

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

.btn-outline:hover {
  background: var(--color-primary);
  color: #fff;
}

.btn-white {
  background: #fff;
  color: var(--color-primary);
  border-color: #fff;
}

.btn-white:hover {
  background: #f1f5f9;
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: #fff;
}

/* ===== 导航 ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition);
}

.header.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
}

.logo-img {
  display: block;
  height: 40px;
  width: auto;
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a:not(.btn) {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition);
}

.nav-links a:not(.btn):hover {
  color: var(--color-primary);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition);
}

/* ===== Hero ===== */
.hero {
  position: relative;
  padding: calc(var(--header-height) + 48px) 0 72px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 50% at 20% 0%, rgba(79, 70, 229, 0.12), transparent),
    radial-gradient(ellipse 60% 50% at 85% 30%, rgba(99, 102, 241, 0.1), transparent),
    linear-gradient(180deg, #eef2ff 0%, var(--color-bg) 100%);
  z-index: -1;
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: clamp(32px, 5vw, 64px);
  align-items: center;
}

.hero-copy {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 24px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: rgba(79, 70, 229, 0.08);
  color: var(--color-primary);
  font-size: 13px;
  font-weight: 600;
  border-radius: 100px;
  border: 1px solid rgba(79, 70, 229, 0.15);
}

.hero-badge::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.2);
}

.hero-badge-promo {
  background: linear-gradient(135deg, rgba(245, 158, 11, 0.15) 0%, rgba(249, 115, 22, 0.1) 100%);
  color: #b45309;
  border-color: rgba(245, 158, 11, 0.35);
}

.hero-badge-promo::before {
  background: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(245, 158, 11, 0.25);
}

.hero-title {
  font-size: clamp(32px, 4.2vw, 48px);
  font-weight: 800;
  line-height: 1.25;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
  color: var(--color-text);
}

.hero-title .gradient-text {
  display: block;
  margin-top: 8px;
  font-size: clamp(28px, 3.8vw, 42px);
}

.gradient-text {
  background: linear-gradient(135deg, var(--color-primary) 0%, #7c3aed 45%, var(--color-accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 17px;
  color: var(--color-text-muted);
  line-height: 1.75;
  margin-bottom: 32px;
  max-width: 480px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 28px;
}

.hero-panel {
  width: 100%;
  max-width: 480px;
  padding: 20px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.hero-stats {
  display: flex;
  gap: 12px;
  padding-bottom: 16px;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--color-border);
}

.stat-chip {
  flex: 1;
  min-width: 0;
  text-align: center;
}

.stat-chip strong {
  display: block;
  font-size: 22px;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1.2;
  margin-bottom: 4px;
}

.stat-chip strong span {
  font-size: 14px;
  font-weight: 600;
}

.stat-chip > span:last-child {
  font-size: 12px;
  color: var(--color-text-muted);
  line-height: 1.4;
}

.stat-original {
  display: block;
  font-size: 11px !important;
  color: #94a3b8 !important;
  text-decoration: line-through;
  margin-bottom: 2px;
}

.hero-features {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px 16px;
  list-style: none;
}

.hero-features li {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text);
  white-space: nowrap;
}

.feat-icon {
  font-size: 15px;
  line-height: 1;
}

/* App Mockup */
.hero-visual {
  position: relative;
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-visual-glow {
  position: absolute;
  width: 90%;
  height: 80%;
  background: radial-gradient(ellipse at center, rgba(79, 70, 229, 0.18) 0%, transparent 70%);
  filter: blur(40px);
  z-index: 0;
  pointer-events: none;
}

.app-mockup {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 520px;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  box-shadow:
    0 24px 48px -12px rgba(79, 70, 229, 0.18),
    0 12px 24px -8px rgba(15, 23, 42, 0.08);
  overflow: hidden;
  border: 1px solid rgba(79, 70, 229, 0.12);
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

.mockup-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 14px 18px;
  background: #f1f5f9;
  border-bottom: 1px solid var(--color-border);
}

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.dot.red { background: #ef4444; }
.dot.yellow { background: #f59e0b; }
.dot.green { background: #22c55e; }

.mockup-title {
  margin-left: 8px;
  font-size: 13px;
  color: var(--color-text-muted);
  font-weight: 500;
}

.mockup-body {
  display: flex;
  min-height: 280px;
}

.mockup-sidebar {
  width: 140px;
  padding: 16px 12px;
  background: #f8fafc;
  border-right: 1px solid var(--color-border);
}

.sidebar-item {
  padding: 10px 12px;
  font-size: 12px;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  margin-bottom: 4px;
}

.sidebar-item.active {
  background: rgba(79, 70, 229, 0.1);
  color: var(--color-primary);
  font-weight: 600;
}

.mockup-main {
  flex: 1;
  padding: 20px;
}

.mockup-card {
  background: linear-gradient(135deg, var(--color-primary) 0%, #6366f1 100%);
  color: #fff;
  padding: 20px;
  border-radius: var(--radius-md);
  margin-bottom: 16px;
}

.card-label {
  font-size: 12px;
  opacity: 0.8;
  margin-bottom: 6px;
}

.card-title {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 12px;
}

.progress-bar {
  height: 6px;
  background: rgba(255, 255, 255, 0.3);
  border-radius: 3px;
  margin-bottom: 8px;
}

.progress-fill {
  height: 100%;
  background: #fff;
  border-radius: 3px;
}

.card-meta {
  font-size: 12px;
  opacity: 0.85;
}

.mockup-cards-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.mini-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 12px 8px;
  background: #f8fafc;
  border-radius: var(--radius-sm);
  font-size: 11px;
  text-align: center;
  color: var(--color-text-muted);
}

.mini-icon {
  font-size: 18px;
}

/* ===== 通用区块 ===== */
.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-title {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
}

.section-desc {
  font-size: 18px;
  color: var(--color-text-muted);
  max-width: 640px;
  margin: 0 auto;
}

/* ===== 痛点 ===== */
.pain-points {
  padding: 80px 0;
  background: var(--color-surface);
}

.pain-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 40px;
}

.pain-card {
  text-align: center;
  padding: 28px 20px;
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: all var(--transition);
}

.pain-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-light);
}

.pain-icon {
  font-size: 36px;
  display: block;
  margin-bottom: 12px;
}

.pain-card p {
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.5;
}

.pain-solution {
  text-align: center;
  font-size: 20px;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 40px;
}

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

.value-prop {
  padding: 20px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition);
}

.value-prop:hover {
  border-color: rgba(79, 70, 229, 0.3);
  box-shadow: var(--shadow-sm);
}

.value-prop strong {
  display: block;
  font-size: 15px;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 6px;
}

.value-prop span {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* ===== 功能 ===== */
.features {
  padding: 100px 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  padding: 32px;
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: all var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.feature-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  border-radius: var(--radius-md);
  margin-bottom: 20px;
}

.feature-icon.teach { background: #eef2ff; }
.feature-icon.practice { background: #fef3c7; }
.feature-icon.diagnose { background: #d1fae5; }
.feature-icon.correct { background: #fce7f3; }
.feature-icon.supplement { background: #e0e7ff; }
.feature-icon.local { background: #f1f5f9; }

.feature-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

.feature-card p {
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}

.feature-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.feature-tags li {
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 500;
  background: var(--color-bg);
  color: var(--color-primary);
  border-radius: 100px;
}

/* ===== 学习闭环 ===== */
.loop {
  padding: 100px 0;
  background: var(--color-bg-dark);
  color: #fff;
}

.loop .section-title,
.loop .section-desc {
  color: #fff;
}

.loop .section-desc {
  color: #94a3b8;
}

.loop-flow {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 60px;
}

.loop-step {
  text-align: center;
  padding: 24px 20px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.1);
  min-width: 120px;
  transition: all var(--transition);
}

.loop-step:hover {
  background: rgba(79, 70, 229, 0.2);
  border-color: var(--color-primary-light);
  transform: translateY(-4px);
}

.loop-icon {
  font-size: 32px;
  margin-bottom: 8px;
}

.loop-step h4 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--color-accent-light);
}

.loop-step p {
  font-size: 13px;
  color: #94a3b8;
  line-height: 1.6;
}

.loop-arrow {
  font-size: 24px;
  color: var(--color-primary-light);
  font-weight: 300;
}

.audience-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.audience-card {
  padding: 28px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.audience-card h4 {
  font-size: 18px;
  margin-bottom: 12px;
}

.audience-card p {
  font-size: 15px;
  color: #94a3b8;
  line-height: 1.7;
}

/* ===== 卖点速览 ===== */
.sell-points {
  padding: 60px 0;
  background: linear-gradient(180deg, var(--color-bg) 0%, #eef2ff 100%);
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.sell-points-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
  margin-bottom: 24px;
}

.sell-point {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 8px;
  padding: 16px 12px;
  background: var(--color-surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}

.sell-icon {
  font-size: 24px;
}

.sell-point strong {
  display: block;
  font-size: 14px;
  font-weight: 700;
  color: var(--color-text);
}

.sell-point span {
  font-size: 12px;
  color: var(--color-text-muted);
  line-height: 1.4;
}

.sell-tagline {
  text-align: center;
  font-size: 16px;
  font-weight: 600;
  color: var(--color-primary);
}

/* ===== 定价 ===== */
.pricing {
  padding: 100px 0;
  background: var(--color-surface);
}

.pricing-notice {
  padding: 22px 28px;
  margin-bottom: 40px;
  background: linear-gradient(135deg, #fffbeb 0%, #fef3c7 100%);
  border: 1px solid #fcd34d;
  border-radius: var(--radius-lg);
}

.notice-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.notice-badge {
  flex-shrink: 0;
  padding: 5px 12px;
  background: linear-gradient(135deg, var(--color-accent) 0%, #f97316 100%);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  border-radius: 100px;
  white-space: nowrap;
}

.notice-header strong {
  font-size: 16px;
  font-weight: 700;
  color: #92400e;
}

.notice-points {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px 24px;
}

.notice-points li {
  font-size: 13px;
  color: #78350f;
  line-height: 1.6;
  padding-left: 14px;
  position: relative;
}

.notice-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--color-accent);
}

.notice-label {
  display: inline-block;
  min-width: 48px;
  margin-right: 4px;
  font-weight: 700;
  color: #92400e;
}

.version-guide {
  margin-bottom: 48px;
}

.version-guide h3 {
  font-size: 20px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 20px;
}

.guide-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 12px;
}

.guide-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 12px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  text-align: center;
}

.guide-item-featured {
  background: linear-gradient(180deg, #eef2ff 0%, var(--color-bg) 100%);
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.guide-scene {
  font-size: 12px;
  font-weight: 600;
  color: var(--color-text-muted);
  line-height: 1.4;
}

.guide-prices {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}

.guide-original {
  font-size: 13px;
  color: #94a3b8;
  text-decoration: line-through;
}

.guide-price {
  font-size: 22px;
  font-weight: 800;
  color: var(--color-primary);
}

.guide-desc {
  font-size: 11px;
  color: var(--color-text-muted);
  line-height: 1.4;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 60px;
}

.price-card {
  position: relative;
  padding: 32px;
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  border: 2px solid var(--color-border);
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
}

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

.price-card.featured {
  background: linear-gradient(180deg, #eef2ff 0%, var(--color-bg) 100%);
  border-color: var(--color-primary);
  box-shadow: var(--shadow-lg);
}

.price-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  padding: 6px 16px;
  background: linear-gradient(135deg, var(--color-accent) 0%, #f97316 100%);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  border-radius: 100px;
  white-space: nowrap;
}

.price-header {
  text-align: center;
  margin-bottom: 24px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--color-border);
}

.price-header h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

.price-amount {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  line-height: 1;
}

.price-row {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 10px;
}

.price-original {
  font-size: 18px;
  font-weight: 500;
  color: #94a3b8;
  text-decoration: line-through;
}

.price-current {
  font-size: 48px;
  font-weight: 800;
  color: var(--color-primary);
}

.price-tag {
  display: inline-block;
  padding: 3px 10px;
  font-size: 11px;
  font-weight: 700;
  color: #b45309;
  background: rgba(245, 158, 11, 0.15);
  border: 1px solid rgba(245, 158, 11, 0.35);
  border-radius: 100px;
  letter-spacing: 0.02em;
}

.currency {
  font-size: 24px;
  font-weight: 600;
  vertical-align: super;
}

.price-desc {
  font-size: 14px;
  color: var(--color-text-muted);
  margin-top: 8px;
}

.price-features {
  flex: 1;
  margin-bottom: 24px;
}

.price-features li {
  padding: 10px 0;
  font-size: 14px;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  gap: 8px;
}

.price-features li::before {
  font-size: 14px;
}

.price-features li.included::before {
  content: "✓";
  color: var(--color-success);
  font-weight: 700;
}

.price-features li.excluded {
  color: var(--color-text-muted);
  text-decoration: line-through;
  opacity: 0.6;
}

.price-features li.excluded::before {
  content: "✕";
  color: var(--color-danger);
}

/* 对比表 */
.compare-table-wrap {
  overflow-x: auto;
}

.compare-title {
  font-size: 24px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 24px;
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.compare-table th,
.compare-table td {
  padding: 16px 20px;
  text-align: center;
  border-bottom: 1px solid var(--color-border);
}

.compare-table th {
  background: var(--color-primary);
  color: #fff;
  font-weight: 600;
  font-size: 14px;
  line-height: 1.5;
}

.compare-table th s {
  opacity: 0.65;
  font-weight: 400;
  font-size: 12px;
}

.compare-table th:first-child {
  text-align: left;
}

.compare-table td:first-child {
  text-align: left;
  font-weight: 500;
}

.compare-table tbody tr:hover {
  background: rgba(79, 70, 229, 0.05);
}

.compare-table .yes {
  color: var(--color-success);
  font-weight: 600;
}

.compare-table .no {
  color: var(--color-danger);
}

.upgrade-guide {
  margin-top: 48px;
  padding: 32px;
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
}

.upgrade-guide h3 {
  font-size: 20px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 8px;
}

.upgrade-desc {
  text-align: center;
  font-size: 14px;
  color: var(--color-text-muted);
  margin-bottom: 24px;
}

.upgrade-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.upgrade-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 14px 18px;
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
}

.upgrade-item span {
  font-size: 14px;
  color: var(--color-text-muted);
}

.upgrade-item strong {
  font-size: 15px;
  font-weight: 700;
  color: var(--color-primary);
  white-space: nowrap;
}

/* ===== B2B ===== */
.b2b {
  padding: 100px 0;
  background: var(--color-bg);
}

.b2b-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
  margin-bottom: 60px;
}

.b2b-badge {
  display: inline-block;
  padding: 6px 14px;
  background: rgba(245, 158, 11, 0.15);
  color: #b45309;
  font-size: 13px;
  font-weight: 700;
  border-radius: 100px;
  margin-bottom: 16px;
}

.b2b-desc {
  font-size: 17px;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 28px;
}

.b2b-features li {
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}

.b2b-features strong {
  display: block;
  font-size: 16px;
  margin-bottom: 4px;
}

.b2b-features span {
  font-size: 14px;
  color: var(--color-text-muted);
}

.b2b-note {
  margin-top: 20px;
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.6;
}

.b2b-content .btn {
  margin-top: 20px;
}

.b2b-cards {
  display: grid;
  gap: 20px;
}

.b2b-pain-card,
.b2b-solution-card {
  padding: 28px;
  border-radius: var(--radius-lg);
}

.b2b-pain-card {
  background: #fef2f2;
  border: 1px solid #fecaca;
}

.b2b-solution-card {
  background: #ecfdf5;
  border: 1px solid #a7f3d0;
}

.b2b-pain-card h4,
.b2b-solution-card h4 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 16px;
}

.b2b-pain-card h4 { color: #dc2626; }
.b2b-solution-card h4 { color: #059669; }

.b2b-pain-card li,
.b2b-solution-card li {
  padding: 8px 0;
  font-size: 14px;
  color: var(--color-text-muted);
  padding-left: 20px;
  position: relative;
}

.b2b-pain-card li::before {
  content: "✕";
  position: absolute;
  left: 0;
  color: #dc2626;
  font-weight: 700;
}

.b2b-solution-card li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: #059669;
  font-weight: 700;
}

.b2b-flow h3 {
  font-size: 20px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 28px;
}

.flow-steps {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.flow-step {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 20px;
  background: var(--color-surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  font-size: 14px;
  font-weight: 500;
}

.flow-num {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  border-radius: 50%;
}

/* ===== FAQ ===== */
.faq {
  padding: 100px 0;
  background: var(--color-surface);
}

.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
}

.faq-item summary {
  padding: 24px 0;
  font-size: 17px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: color var(--transition);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  font-size: 24px;
  font-weight: 300;
  color: var(--color-primary);
  transition: transform var(--transition);
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-item summary:hover {
  color: var(--color-primary);
}

.faq-item p {
  padding: 0 0 24px;
  font-size: 15px;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ===== CTA ===== */
.cta {
  padding: 100px 0;
  background: var(--color-bg);
}

.cta-card {
  text-align: center;
  padding: 60px 40px;
  background: linear-gradient(135deg, var(--color-primary) 0%, #6366f1 50%, #818cf8 100%);
  border-radius: var(--radius-xl);
  color: #fff;
}

.cta-card h2 {
  font-size: clamp(28px, 4vw, 36px);
  font-weight: 800;
  margin-bottom: 16px;
}

.cta-card > p {
  font-size: 18px;
  opacity: 0.9;
  margin-bottom: 32px;
}

.cta-keywords {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 32px;
}

.cta-keywords span {
  font-size: 14px;
  opacity: 0.85;
}

.cta-promo-note {
  font-size: 15px;
  font-weight: 600;
  opacity: 0.95;
  margin-bottom: 24px;
}

.cta-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== Footer ===== */
.footer {
  background: var(--color-bg-dark);
  color: #94a3b8;
  padding-top: 60px;
}

.footer-content {
  display: grid;
  grid-template-columns: 1.5fr 2fr;
  gap: 60px;
  padding-bottom: 40px;
}

.footer-brand .logo {
  color: #fff;
  margin-bottom: 12px;
}

.footer-brand p {
  font-size: 14px;
  line-height: 1.6;
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.footer-col h4 {
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 16px;
}

.footer-col a {
  display: block;
  font-size: 14px;
  padding: 6px 0;
  transition: color var(--transition);
}

.footer-col a:hover {
  color: #fff;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding: 24px 0;
}

.footer-bottom p {
  font-size: 13px;
  text-align: center;
}

.footer-beian {
  margin-top: 8px;
}

.footer-beian a {
  color: #94a3b8;
  transition: color var(--transition);
}

.footer-beian a:hover {
  color: #fff;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .hero-copy {
    align-items: center;
    text-align: center;
  }

  .hero-desc {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-panel {
    max-width: 100%;
  }

  .hero-stats {
    flex-wrap: wrap;
  }

  .stat-chip {
    min-width: calc(33% - 8px);
  }

  .hero-visual {
    order: -1;
  }

  .features-grid,
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .pain-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .value-props {
    grid-template-columns: repeat(2, 1fr);
  }

  .sell-points-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .guide-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .upgrade-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .b2b-layout {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--color-surface);
    padding: 16px 24px 24px;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition);
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-links li {
    width: 100%;
  }

  .nav-links a {
    display: block;
    padding: 14px 0;
    border-bottom: 1px solid var(--color-border);
  }

  .nav-links a.btn {
    margin-top: 12px;
    text-align: center;
  }

  .features-grid,
  .pricing-grid,
  .audience-grid {
    grid-template-columns: 1fr;
  }

  .pain-grid {
    grid-template-columns: 1fr;
  }

  .value-props {
    grid-template-columns: 1fr;
  }

  .sell-points-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .guide-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .upgrade-grid {
    grid-template-columns: 1fr;
  }

  .notice-points {
    grid-template-columns: 1fr;
  }

  .loop-flow {
    flex-direction: column;
  }

  .loop-arrow {
    transform: rotate(90deg);
  }

  .footer-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .footer-links {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero-features {
    grid-template-columns: 1fr;
  }

  .mockup-cards-row {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .hero {
    padding: calc(var(--header-height) + 24px) 0 48px;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .hero-visual {
    order: -1;
  }

  .cta-card {
    padding: 40px 24px;
  }

  .footer-links {
    grid-template-columns: 1fr;
  }
}

/* ===== 滚动动画 ===== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}