/* ===== Reset & Base ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #4361ee;
  --primary-dark: #3451de;
  --primary-light: #eef1ff;
  --text: #1a1a2e;
  --text-secondary: #64748b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 4px 24px rgba(67, 97, 238, 0.08);
  --shadow-lg: 0 12px 48px rgba(67, 97, 238, 0.12);
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

a {
  color: var(--primary);
  text-decoration: none;
}

/* ===== Navigation ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-brand {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
}

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

.nav-links a {
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--primary);
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  padding: 4px 4px 4px 10px;
  border-radius: 999px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  transition: all 0.2s ease;
}

.lang-switch:hover {
  border-color: var(--primary);
  box-shadow: 0 2px 8px rgba(67, 97, 238, 0.12);
}

.lang-switch-icon {
  font-size: 14px;
  line-height: 1;
  margin-right: 4px;
  opacity: 0.7;
}

.lang-option {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 30px;
  height: 26px;
  padding: 0 10px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  transition: all 0.2s ease;
  user-select: none;
}

.lang-option:hover {
  color: var(--primary);
}

.lang-option.active {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 2px 6px rgba(67, 97, 238, 0.3);
  pointer-events: none;
}

.lang-option.active:hover {
  color: #fff;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  padding: 12px 28px;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  transition: all 0.2s;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 4px 16px rgba(67, 97, 238, 0.3);
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(67, 97, 238, 0.4);
}

.btn-secondary {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  border-color: var(--primary);
  color: var(--primary);
}

/* ===== Hero ===== */
.hero {
  padding: 140px 0 80px;
  background: linear-gradient(180deg, var(--primary-light) 0%, var(--bg) 100%);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.hero-title {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

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

.hero-desc {
  margin-top: 20px;
  font-size: 18px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.hero-actions {
  margin-top: 32px;
  display: flex;
  gap: 16px;
}

.hero-note {
  margin-top: 16px;
  font-size: 13px;
  color: var(--text-secondary);
}

/* ===== Mockup ===== */
.mockup-popup {
  background: #fff;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: 16px;
  width: 340px;
  margin-left: auto;
  border: 1px solid var(--border);
}

.mockup-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.mockup-title {
  font-size: 16px;
  font-weight: 700;
}

.mockup-icon {
  font-size: 16px;
  opacity: 0.6;
}

.mockup-item {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding: 12px;
  border-radius: 10px;
  background: var(--bg-alt);
  margin-bottom: 8px;
}

.mockup-item-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 6px;
  white-space: nowrap;
}

.mockup-item-badge.bilibili {
  background: #fb7299;
  color: #fff;
}

.mockup-item-badge.youtube {
  background: #ff0000;
  color: #fff;
}

.mockup-item-badge.iqiyi {
  background: #00be06;
  color: #fff;
}

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

.mockup-item-title {
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 6px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.mockup-item-progress {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  color: var(--text-secondary);
}

.progress-bar {
  flex: 1;
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--primary);
  border-radius: 2px;
}

.mockup-btn {
  margin-top: 12px;
  text-align: center;
  padding: 10px;
  background: var(--bg-alt);
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--primary);
}

/* ===== Sections ===== */
.section-title {
  text-align: center;
  font-size: 36px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.section-desc {
  text-align: center;
  color: var(--text-secondary);
  font-size: 16px;
  margin-top: 8px;
  margin-bottom: 48px;
}

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

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

.feature-card {
  padding: 32px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  transition: all 0.2s;
}

.feature-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.feature-icon {
  font-size: 32px;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===== Platforms ===== */
.platforms {
  padding: 100px 0;
  background: var(--bg-alt);
}

.platforms-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 20px;
}

.platform-card {
  text-align: center;
  padding: 32px 16px;
  border-radius: var(--radius-lg);
  background: #fff;
  border: 1px solid var(--border);
  transition: all 0.2s;
}

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

.platform-card.custom {
  border-style: dashed;
  border-color: var(--primary);
  background: var(--primary-light);
}

.platform-logo {
  font-size: 36px;
  margin-bottom: 12px;
}

.platform-name {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 4px;
}

.platform-domain {
  font-size: 12px;
  color: var(--text-secondary);
}

/* ===== How it works ===== */
.how-it-works {
  padding: 100px 0;
}

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.step {
  text-align: center;
  position: relative;
}

.step-num {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-size: 20px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.step h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 8px;
}

.step p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===== Privacy ===== */
.privacy {
  padding: 100px 0;
  background: var(--bg-alt);
}

.privacy-card {
  max-width: 640px;
  margin: 0 auto;
  text-align: center;
}

.privacy-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.privacy-card h2 {
  font-size: 32px;
  font-weight: 800;
}

.privacy-desc {
  color: var(--text-secondary);
  font-size: 16px;
  margin-top: 8px;
  margin-bottom: 32px;
}

.privacy-points {
  text-align: left;
  display: inline-flex;
  flex-direction: column;
  gap: 12px;
}

.privacy-point {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 15px;
}

.privacy-point .check {
  color: #10b981;
  font-weight: 700;
  font-size: 18px;
}

/* ===== CTA ===== */
.cta {
  padding: 100px 0;
}

.cta-inner {
  text-align: center;
}

.cta-inner h2 {
  font-size: 36px;
  font-weight: 800;
}

.cta-inner p {
  color: var(--text-secondary);
  font-size: 16px;
  margin-top: 8px;
}

.cta-actions {
  margin-top: 32px;
  display: flex;
  justify-content: center;
  gap: 16px;
}

/* ===== Footer ===== */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--border);
}

.footer-inner {
  text-align: center;
  font-size: 14px;
  color: var(--text-secondary);
}

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

.footer-links a {
  color: var(--text-secondary);
}

.footer-links a:hover {
  color: var(--primary);
}

.footer-links span {
  margin: 0 8px;
  opacity: 0.4;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

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

  .hero-visual {
    display: flex;
    justify-content: center;
  }

  .mockup-popup {
    margin-left: 0;
  }

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

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

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

@media (max-width: 640px) {
  .hero-title {
    font-size: 32px;
  }

  .hero-desc {
    font-size: 16px;
  }

  .hero-actions {
    flex-direction: column;
    align-items: center;
  }

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

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

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

  .section-title {
    font-size: 28px;
  }

  .nav-links {
    gap: 16px;
  }

  .nav-links a {
    font-size: 13px;
  }

  .cta-actions {
    flex-direction: column;
    align-items: center;
  }
}