:root {
  --bg-primary: #0F172A;
  --bg-secondary: #1E293B;
  --bg-card: #1E293B;
  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --accent: #F59E0B;
  --accent-hover: #D97706;
  --border: #334155;
  --radius: 12px;
  --max-width: 1200px;
}

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

html {
  scroll-behavior: smooth;
}

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

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

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

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

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1.1rem;
}

.nav-brand em, .footer-brand em {
  font-style: normal;
  color: var(--accent);
  font-weight: 600;
}

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

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

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s;
}

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

.nav-cta {
  background: var(--accent);
  color: var(--bg-primary) !important;
  padding: 8px 20px;
  border-radius: 8px;
  font-weight: 600;
  transition: background 0.2s !important;
}

.nav-cta:hover {
  background: var(--accent-hover);
}

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

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

/* Hero */
.hero {
  padding: 160px 0 100px;
  background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-brand {
  font-size: 1rem;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

.hero h1 {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
}

.highlight {
  color: var(--accent);
}

.hero-sub {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.hero-tagline {
  font-size: 1rem;
  color: var(--text-secondary);
  font-style: italic;
  opacity: 0.8;
  margin-bottom: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 10px;
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s, transform 0.1s;
}

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

.btn-primary {
  background: var(--accent);
  color: var(--bg-primary);
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-lg {
  padding: 18px 40px;
  font-size: 1.1rem;
}

.hero-note {
  margin-top: 16px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.phone-mockup {
  width: 280px;
  margin: 0 auto;
  background: var(--bg-card);
  border-radius: 36px;
  border: 3px solid var(--border);
  padding: 16px;
  box-shadow: 0 40px 80px rgba(0, 0, 0, 0.4);
}

.phone-screen {
  aspect-ratio: 9 / 19;
  border-radius: 24px;
  overflow: hidden;
}

.phone-screen-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top center;
  display: block;
}

/* Social Proof */
.proof {
  padding: 48px 0;
  border-bottom: 1px solid var(--border);
}

.proof-inner {
  display: flex;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
}

.proof-item {
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.proof-item strong {
  font-size: 1.8rem;
  font-weight: 800;
  color: var(--accent);
}

.proof-item span {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Sections */
section {
  padding: 100px 0;
}

.section-title {
  text-align: center;
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 56px;
}

/* Features */
.features {
  background: var(--bg-primary);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
  transition: transform 0.2s, border-color 0.2s;
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
}

.feature-icon {
  width: 48px;
  height: 48px;
  color: var(--accent);
  margin-bottom: 20px;
}

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

.feature-card h3 {
  font-size: 1.15rem;
  margin-bottom: 12px;
}

.feature-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* 品牌故事板块 */
.story .section-title { color: var(--accent); }
.story-intro { text-align: center; color: var(--text-secondary); max-width: 640px; margin: 0 auto 40px; font-size: 1.05rem; }
.story-closing { text-align: center; color: var(--text-primary); max-width: 680px; margin: 40px auto 0; font-size: 1.1rem; font-weight: 600; }

/* Screenshots */
.screenshots {
  background: var(--bg-secondary);
}

.screenshots-sub {
  text-align: center;
  color: var(--text-secondary);
  margin-top: -32px;
  margin-bottom: 48px;
  font-size: 1rem;
}

/* Gallery (长图横向滚动) */

.gallery-scroll {
  display: flex;
  gap: 32px;
  overflow-x: auto;
  padding-bottom: 16px;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

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

.gallery-scroll::-webkit-scrollbar-track {
  background: transparent;
}

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

.gallery-item {
  flex: 1 1 0;
  min-width: 0;
  scroll-snap-align: start;
  text-align: center;
}

.gallery-frame {
  height: 680px;
  border-radius: 20px;
  border: 3px solid var(--border);
  overflow-y: auto;
  overflow-x: hidden;
  margin-bottom: 12px;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.3);
  scrollbar-width: none;
}

.gallery-frame::-webkit-scrollbar {
  display: none;
}

.gallery-frame img {
  width: 100%;
  display: block;
}

.gallery-item span {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Use Cases */
.use-cases {
  background: var(--bg-primary);
}

.use-cases-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.use-case-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 32px;
}

.use-case-badge {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.use-case-badge.saver {
  background: rgba(16, 185, 129, 0.15);
  color: #34D399;
}

.use-case-badge.debtor {
  background: rgba(245, 158, 11, 0.15);
  color: #FBBF24;
}

.use-case-card h3 {
  font-size: 1.3rem;
  margin-bottom: 12px;
}

.use-case-card > p {
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.7;
}

.use-case-card ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.use-case-card li {
  font-size: 0.9rem;
  color: var(--text-secondary);
  padding-left: 20px;
  position: relative;
}

.use-case-card li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

/* Download */
.download {
  background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
  text-align: center;
}

.download-inner h2 {
  font-size: 2.2rem;
  margin-bottom: 12px;
}

.download-inner > p {
  color: var(--text-secondary);
  margin-bottom: 32px;
  font-size: 1.1rem;
}

.download-note {
  margin-top: 16px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
}

.footer-logo {
  width: 28px;
  height: 28px;
  border-radius: 6px;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s;
}

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

.footer-copy {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* Mobile CTA */
.mobile-cta {
  display: none;
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 99;
  background: var(--accent);
  color: var(--bg-primary);
  padding: 14px 32px;
  border-radius: 28px;
  font-weight: 700;
  font-size: 0.95rem;
  text-decoration: none;
  box-shadow: 0 8px 32px rgba(245, 158, 11, 0.35);
}

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

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

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

@media (max-width: 768px) {
  .mobile-cta {
    display: block;
  }
  .nav-toggle {
    display: flex;
  }
  .nav-links {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg-primary);
    flex-direction: column;
    padding: 24px;
    gap: 20px;
    border-bottom: 1px solid var(--border);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.3s, opacity 0.3s;
  }
  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }
  .hero h1 {
    font-size: 2.4rem;
  }
  .hero-visual {
    order: -1;
  }
  .phone-mockup {
    width: 220px;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .screenshots-scroll {
    grid-template-columns: repeat(2, 1fr);
  }
  .use-cases-grid {
    grid-template-columns: 1fr;
  }
  .section-title {
    font-size: 1.6rem;
  }
}

@media (max-width: 768px) {
  .gallery-item {
    flex: 0 0 260px;
  }
}

@media (max-width: 480px) {
  .gallery-item {
    flex: 0 0 240px;
  }
  .gallery-frame {
    height: 540px;
  }
  .hero {
    padding: 120px 0 60px;
  }
  section {
    padding: 60px 0;
  }
}