/* ============================================
   闪念 (FlashMind) — 官网样式
   ============================================ */

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

:root {
  --primary: #4F46E5;
  --primary-light: #6366F1;
  --primary-dark: #3730A3;
  --accent: #818CF8;
  --bg: #FFFFFF;
  --bg-secondary: #F8FAFC;
  --bg-dark: #0F172A;
  --text: #1E293B;
  --text-secondary: #64748B;
  --text-light: #94A3B8;
  --border: #E2E8F0;
  --shadow-sm: 0 1px 2px rgba(0,0,0,.05);
  --shadow: 0 4px 6px -1px rgba(0,0,0,.07), 0 2px 4px -2px rgba(0,0,0,.05);
  --shadow-lg: 0 20px 40px -12px rgba(79,70,229,.15);
  --radius: 12px;
  --radius-lg: 20px;
  --max-width: 1200px;
  --transition: .3s cubic-bezier(.4,0,.2,1);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "Helvetica Neue", "PingFang SC", "Noto Sans CJK SC", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  overflow-x: hidden;
}

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

a:hover {
  color: var(--primary-light);
}

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Navigation ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255,255,255,.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(0,0,0,.06);
  transition: box-shadow var(--transition);
}

.navbar.scrolled {
  box-shadow: var(--shadow);
}

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

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

.nav-brand img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition);
}

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

.nav-cta {
  display: inline-flex;
  align-items: center;
  padding: 8px 20px;
  background: var(--primary);
  color: #fff !important;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
  transition: all var(--transition);
}

.nav-cta:hover {
  background: var(--primary-light);
  color: #fff !important;
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  margin: 5px 0;
  border-radius: 2px;
  transition: all var(--transition);
}

/* ---------- Hero Section ---------- */
.hero {
  padding: 140px 0 100px;
  text-align: center;
  background: linear-gradient(180deg, #F0F0FF 0%, var(--bg) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle at 50% 50%, rgba(79,70,229,.04) 0%, transparent 50%);
  animation: pulse 8s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.05); opacity: .7; }
}

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

.hero-icon {
  width: 100px;
  height: 100px;
  border-radius: 22px;
  margin: 0 auto 32px;
  box-shadow: var(--shadow-lg);
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

.hero h1 {
  font-size: 56px;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 16px;
  background: linear-gradient(135deg, var(--text) 0%, var(--primary-dark) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero .subtitle {
  font-size: 22px;
  color: var(--text-secondary);
  margin-bottom: 40px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.5;
}

.hero-buttons {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 60px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 999px;
  font-size: 16px;
  font-weight: 600;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 4px 14px rgba(79,70,229,.3);
}

.btn-primary:hover {
  background: var(--primary-light);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(79,70,229,.35);
}

.btn-secondary {
  background: var(--bg);
  color: var(--text);
  border: 1.5px solid var(--border);
}

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

.hero-screenshot {
  max-width: 900px;
  margin: 0 auto;
  position: relative;
}

.hero-screenshot img {
  border-radius: var(--radius-lg);
  box-shadow: 0 30px 60px rgba(0,0,0,.12);
}

/* ---------- Features Section ---------- */
.features {
  padding: 120px 0;
  background: var(--bg-secondary);
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-header h2 {
  font-size: 40px;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin-bottom: 16px;
}

.section-header p {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

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

.feature-card {
  background: var(--bg);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  border: 1px solid var(--border);
  transition: all var(--transition);
}

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

.feature-icon {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #EEF2FF, #E0E7FF);
}

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

.feature-card p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ---------- Screenshots Section ---------- */
.screenshots {
  padding: 120px 0;
}

.screenshots-scroll {
  display: flex;
  gap: 20px;
  overflow-x: auto;
  padding: 20px 24px 40px;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}

.screenshots-scroll::-webkit-scrollbar {
  height: 6px;
}

.screenshots-scroll::-webkit-scrollbar-track {
  background: var(--bg-secondary);
  border-radius: 3px;
}

.screenshots-scroll::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

.screenshot-item {
  flex: 0 0 auto;
  width: 260px;
  scroll-snap-align: center;
}

.screenshot-item img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  transition: transform var(--transition);
}

.screenshot-item:hover img {
  transform: scale(1.03);
}

/* ---------- AI Section ---------- */
.ai-section {
  padding: 120px 0;
  background: var(--bg-dark);
  color: #fff;
}

.ai-section .section-header h2 {
  color: #fff;
}

.ai-section .section-header p {
  color: var(--text-light);
}

.ai-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  max-width: 800px;
  margin: 0 auto;
}

.ai-card {
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.1);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
  transition: all var(--transition);
}

.ai-card:hover {
  background: rgba(255,255,255,.1);
  border-color: rgba(255,255,255,.2);
  transform: translateY(-2px);
}

.ai-card .ai-logo {
  font-size: 28px;
  margin-bottom: 8px;
}

.ai-card h4 {
  font-size: 16px;
  font-weight: 600;
  color: #fff;
}

.ai-card p {
  font-size: 13px;
  color: var(--text-light);
  margin-top: 4px;
}

/* ---------- CTA Section ---------- */
.cta-section {
  padding: 120px 0;
  text-align: center;
  background: linear-gradient(180deg, var(--bg) 0%, #F0F0FF 100%);
}

.cta-section h2 {
  font-size: 40px;
  font-weight: 800;
  margin-bottom: 16px;
}

.cta-section p {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 40px;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

/* ---------- Footer ---------- */
.footer {
  background: var(--bg-dark);
  color: var(--text-light);
  padding: 48px 0 32px;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.footer-brand img {
  width: 32px;
  height: 32px;
  border-radius: 7px;
}

.footer-brand span {
  font-size: 18px;
  font-weight: 700;
  color: #fff;
}

.footer-desc {
  font-size: 14px;
  color: var(--text-light);
  max-width: 300px;
  line-height: 1.6;
}

.footer-links {
  display: flex;
  gap: 60px;
}

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

.footer-links-col ul {
  list-style: none;
}

.footer-links-col li {
  margin-bottom: 10px;
}

.footer-links-col a {
  font-size: 14px;
  color: var(--text-light);
  transition: color var(--transition);
}

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

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.08);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-copyright {
  font-size: 13px;
  color: var(--text-light);
}

.footer-beian {
  font-size: 13px;
  color: var(--text-light);
}

.footer-beian a {
  color: var(--text-light);
  transition: color var(--transition);
}

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

.footer-beian img {
  display: inline-block;
  vertical-align: middle;
  margin-right: 4px;
}

/* ---------- Legal Pages (Terms & Privacy) ---------- */
.legal-hero {
  padding: 120px 0 60px;
  background: var(--bg-secondary);
  text-align: center;
}

.legal-hero h1 {
  font-size: 40px;
  font-weight: 800;
  margin-bottom: 8px;
}

.legal-hero .update-date {
  font-size: 15px;
  color: var(--text-secondary);
}

.legal-content {
  padding: 60px 0 100px;
  max-width: 800px;
  margin: 0 auto;
}

.legal-content h2 {
  font-size: 22px;
  font-weight: 700;
  margin-top: 40px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.legal-content h3 {
  font-size: 18px;
  font-weight: 600;
  margin-top: 28px;
  margin-bottom: 12px;
}

.legal-content p {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
}

.legal-content ul,
.legal-content ol {
  padding-left: 24px;
  margin-bottom: 16px;
}

.legal-content li {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 8px;
}

.legal-content .contact-info {
  background: var(--bg-secondary);
  border-radius: var(--radius);
  padding: 20px 24px;
  margin-top: 32px;
}

.legal-content .contact-info p {
  margin-bottom: 8px;
}

/* ---------- Animations ---------- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity .6s ease, transform .6s ease;
}

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

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: rgba(255,255,255,.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 24px;
    gap: 20px;
    border-bottom: 1px solid var(--border);
  }

  .nav-links.open {
    display: flex;
  }

  .nav-toggle {
    display: block;
  }

  .hero {
    padding: 120px 0 60px;
  }

  .hero h1 {
    font-size: 36px;
  }

  .hero .subtitle {
    font-size: 18px;
  }

  .hero-icon {
    width: 80px;
    height: 80px;
    border-radius: 18px;
  }

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

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

  .section-header h2,
  .cta-section h2 {
    font-size: 30px;
  }

  .footer-content {
    flex-direction: column;
  }

  .footer-links {
    gap: 40px;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .screenshot-item {
    width: 220px;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 30px;
  }

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

  .btn {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }
}