/* ==============================================
   收好车 — 官网样式
   Design: Precision Engineering / Industrial Refined
   ============================================== */

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

:root {
  /* Palette */
  --bg-deep:    #0b0b0c;
  --bg-surface: #141416;
  --bg-card:    #1a1a1d;
  --bg-elevated:#202024;
  --border:     rgba(255,255,255,0.06);
  --border-hover: rgba(255,255,255,0.12);
  --text-primary:   #e8e4e0;
  --text-secondary: #9a9793;
  --text-muted:     #5c5956;
  --accent:      #c8964a;
  --accent-dim:  #a67c3a;
  --accent-glow: rgba(200,150,74,0.15);

  /* Typography */
  --font-display: "PingFang SC", "Noto Serif SC", "STSong", "Songti SC", "SimSun", serif;
  --font-body:    "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "STHeiti", sans-serif;
  --font-mono:    "SF Mono", "Cascadia Code", "Consolas", monospace;

  /* Spacing */
  --max-width: 1040px;
  --section-gap: 120px;
}

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

body {
  background: var(--bg-deep);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  overflow-x: hidden;
}

/* Selection */
::selection {
  background: var(--accent);
  color: var(--bg-deep);
}

/* --- Typography --- */
a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.25s ease;
}

a:hover {
  color: var(--accent-dim);
}

/* --- Header --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  background: rgba(11,11,12,0.72);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 32px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-primary);
  transition: opacity 0.25s ease;
}

.logo:hover {
  opacity: 0.8;
}

.logo-icon {
  display: flex;
  color: var(--accent);
}

.logo-text {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.06em;
}

.nav {
  display: flex;
  gap: 32px;
}

.nav-link {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  letter-spacing: 0.03em;
  position: relative;
  padding: 4px 0;
  transition: color 0.25s ease;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--accent);
  transition: width 0.3s ease;
}

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

.nav-link:hover::after {
  width: 100%;
}

/* --- Hero --- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 120px 32px 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% 40%, rgba(200,150,74,0.06) 0%, transparent 70%),
    radial-gradient(ellipse 60% 50% at 80% 80%, rgba(200,150,74,0.04) 0%, transparent 70%),
    radial-gradient(ellipse 50% 40% at 20% 20%, rgba(200,150,74,0.03) 0%, transparent 70%);
  pointer-events: none;
}

.hero-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.015) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.015) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 60% 50% at 50% 40%, black 0%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 60% 50% at 50% 40%, black 0%, transparent 70%);
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 640px;
}

.hero-eyebrow {
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 24px;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(56px, 10vw, 96px);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: 0.04em;
  color: var(--text-primary);
  margin-bottom: 20px;
}

.hero-desc {
  font-size: 18px;
  color: var(--text-secondary);
  letter-spacing: 0.06em;
  margin-bottom: 48px;
}

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

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 48px;
  padding: 0 32px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.05em;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.3s ease;
  border: 1px solid transparent;
  font-family: var(--font-body);
}

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

.btn-primary:hover {
  background: var(--accent-dim);
  border-color: var(--accent-dim);
  color: var(--bg-deep);
  box-shadow: 0 0 32px var(--accent-glow);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-primary);
  border-color: rgba(255,255,255,0.2);
}

.btn-ghost:hover {
  border-color: rgba(255,255,255,0.4);
  background: rgba(255,255,255,0.04);
  color: var(--text-primary);
}

/* --- Sections --- */
.section {
  padding: var(--section-gap) 32px;
}

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(28px, 5vw, 40px);
  font-weight: 800;
  letter-spacing: 0.05em;
  color: var(--text-primary);
  margin-bottom: 56px;
  position: relative;
}

.section-title::before {
  content: '';
  position: absolute;
  top: -16px;
  left: 0;
  width: 40px;
  height: 2px;
  background: var(--accent);
}

/* --- About --- */
.about {
  background: var(--bg-surface);
}

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

.about-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 40px 32px;
  transition: border-color 0.35s ease, transform 0.35s ease, box-shadow 0.35s ease;
}

.about-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: 0 20px 48px rgba(0,0,0,0.4);
}

.about-card-icon {
  color: var(--accent);
  margin-bottom: 20px;
}

.about-card h3 {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.about-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
}

/* --- Features --- */
.features {
  position: relative;
}

.features::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 1px;
  height: 100%;
  background: var(--border);
  pointer-events: none;
  display: none;
}

.features-list {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: 40px;
  padding: 36px 0;
  border-bottom: 1px solid var(--border);
  transition: border-color 0.35s ease;
}

.feature-item:first-child {
  border-top: 1px solid var(--border);
}

.feature-item:hover {
  border-color: var(--border-hover);
}

.feature-num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.1em;
  flex-shrink: 0;
  padding-top: 3px;
  opacity: 0.7;
}

.feature-body h3 {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.04em;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.feature-body p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
  max-width: 560px;
}

/* --- Contact --- */
.contact {
  background: var(--bg-surface);
}

.contact-content {
  max-width: 640px;
}

.contact-text {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 40px;
}

.contact-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.contact-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.contact-label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
}

.contact-value {
  font-size: 14px;
  color: var(--text-primary);
  word-break: break-all;
}

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--border);
  padding: 48px 32px 32px;
  background: var(--bg-deep);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 40px;
}

.footer-logo {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--text-primary);
}

.footer-tagline {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 8px;
}

.footer-info {
  text-align: right;
}

.footer-icp {
  margin-bottom: 8px;
}

.footer-icp a {
  font-size: 13px;
  color: var(--text-muted);
  transition: color 0.25s ease;
}

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

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

/* --- Reveal Animations --- */
/* Default: visible (works without JS). JS adds .reveal-hidden to enable animation. */
.reveal {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.reveal-hidden {
  opacity: 0;
  transform: translateY(24px);
}

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

/* Stagger delays */
.about-card.reveal-hidden:nth-child(1),
.about-card.reveal-hidden:nth-child(2),
.about-card.reveal-hidden:nth-child(3) { transition-delay: 0s; }

.feature-item.reveal-hidden:nth-child(1),
.feature-item.reveal-hidden:nth-child(2),
.feature-item.reveal-hidden:nth-child(3),
.feature-item.reveal-hidden:nth-child(4) { transition-delay: 0s; }

/* Hero and section titles always visible */
.hero .reveal,
.section-title.reveal {
  opacity: 1;
  transform: translateY(0);
  transition: none;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  :root {
    --section-gap: 72px;
  }

  .header-inner {
    padding: 0 20px;
  }

  .nav {
    gap: 20px;
  }

  .nav-link {
    font-size: 13px;
  }

  .hero {
    padding: 100px 20px 60px;
    min-height: 90vh;
  }

  .hero-title {
    font-size: clamp(40px, 12vw, 64px);
  }

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

  .features-list {
    gap: 0;
  }

  .feature-item {
    flex-direction: column;
    gap: 12px;
    padding: 28px 0;
  }

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

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

  .footer-info {
    text-align: center;
  }

  .section {
    padding-left: 20px;
    padding-right: 20px;
  }
}

@media (max-width: 480px) {
  .nav-link {
    font-size: 12px;
  }

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

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