/* ============================================================
   智行千里 · 车队管理系统官网 — 全站样式
   设计系统：科技蓝主色 / 白底简约 / 响应式
   ============================================================ */

/* ---------- 设计令牌 ---------- */
:root {
  /* 主色板 */
  --brand-900: #0b2545;
  --brand-800: #123a6b;
  --brand-700: #174e96;
  --brand-600: #1d5ec2;
  --brand-500: #2563eb;
  --brand-400: #3b82f6;
  --brand-300: #7da7f7;
  --brand-100: #dbeafe;
  --brand-50:  #eff6ff;

  --accent-500: #06b6d4;
  --accent-100: #cffafe;

  /* 中性色 */
  --ink-900: #0f172a;
  --ink-700: #334155;
  --ink-500: #64748b;
  --ink-400: #94a3b8;
  --ink-200: #e2e8f0;
  --ink-100: #f1f5f9;
  --ink-50:  #f8fafc;
  --white:   #ffffff;

  /* 功能色 */
  --success: #10b981;
  --warning: #f59e0b;
  --danger:  #ef4444;

  /* 字体 */
  --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue",
               "Source Han Sans SC", "Noto Sans SC", Arial, sans-serif;

  /* 间距 */
  --space-1: 4px;  --space-2: 8px;  --space-3: 12px; --space-4: 16px;
  --space-5: 24px; --space-6: 32px; --space-7: 48px; --space-8: 64px;
  --space-9: 96px;

  /* 圆角与阴影 */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, .08);
  --shadow-md: 0 6px 20px rgba(15, 23, 42, .10);
  --shadow-lg: 0 16px 48px rgba(11, 37, 69, .16);
  --shadow-brand: 0 10px 32px rgba(37, 99, 235, .28);

  /* 布局 */
  --container: 1200px;
  --nav-height: 72px;

  /* 动效 */
  --ease-out: cubic-bezier(.16, 1, .3, 1);
}

/* ---------- 基础重置 ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font-sans);
  color: var(--ink-700);
  background: var(--white);
  line-height: 1.7;
  font-size: 16px;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
input, select, textarea { font-family: inherit; font-size: 1rem; }

::selection { background: var(--brand-500); color: #fff; }

/* ---------- 工具类 ---------- */
.container {
  width: min(var(--container), 92%);
  margin-inline: auto;
}

.section { padding: var(--space-9) 0; }
.section-alt { background: var(--ink-50); }

.section-head { text-align: center; max-width: 720px; margin: 0 auto var(--space-7); }

.section-head .kicker {
  display: inline-flex; align-items: center; gap: 8px;
  color: var(--brand-500); font-weight: 600; font-size: .875rem;
  letter-spacing: .2em; text-transform: uppercase; margin-bottom: var(--space-3);
}
.section-head .kicker::before,
.section-head .kicker::after {
  content: ""; width: 24px; height: 2px; background: var(--brand-300);
  border-radius: 2px;
}

.section-head h2 {
  font-size: clamp(1.6rem, 3.2vw, 2.4rem);
  color: var(--ink-900);
  font-weight: 700;
  line-height: 1.3;
}

.section-head p { color: var(--ink-500); margin-top: var(--space-4); }

.text-gradient {
  background: linear-gradient(120deg, var(--brand-500), var(--accent-500));
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 32px; border-radius: 999px;
  font-size: .975rem; font-weight: 600; letter-spacing: .02em;
  transition: transform .25s var(--ease-out), box-shadow .25s, background .25s;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: linear-gradient(135deg, var(--brand-600), var(--brand-500));
  color: #fff; box-shadow: var(--shadow-brand);
}
.btn-primary:hover { box-shadow: 0 14px 40px rgba(37, 99, 235, .4); }

.btn-ghost {
  background: rgba(255,255,255,.12); color: #fff;
  border: 1.5px solid rgba(255,255,255,.55); backdrop-filter: blur(6px);
}
.btn-ghost:hover { background: rgba(255,255,255,.22); }

.btn-outline {
  background: #fff; color: var(--brand-600);
  border: 1.5px solid var(--brand-300);
}
.btn-outline:hover { border-color: var(--brand-500); box-shadow: var(--shadow-md); }

.btn .arrow { transition: transform .25s; }
.btn:hover .arrow { transform: translateX(4px); }

/* ---------- 固定导航 ---------- */
.site-nav {
  position: fixed; inset: 0 0 auto 0; z-index: 1000;
  height: var(--nav-height);
  display: flex; align-items: center;
  background: rgba(255, 255, 255, .88);
  backdrop-filter: blur(16px) saturate(1.4);
  -webkit-backdrop-filter: blur(16px) saturate(1.4);
  border-bottom: 1px solid transparent;
  transition: box-shadow .3s, border-color .3s, background .3s;
}
.site-nav.scrolled {
  border-bottom-color: var(--ink-200);
  box-shadow: 0 4px 24px rgba(11, 37, 69, .08);
}

.nav-inner {
  width: min(var(--container), 92%);
  margin-inline: auto;
  display: flex; align-items: center; justify-content: space-between; gap: var(--space-5);
}

.brand { display: flex; align-items: center; gap: 12px; }
.brand .logo {
  width: 42px; height: 42px; border-radius: 11px;
  background: linear-gradient(135deg, var(--brand-600), var(--accent-500));
  display: grid; place-items: center; color: #fff;
  box-shadow: var(--shadow-brand); flex-shrink: 0;
}
.brand .name { font-size: 1.22rem; font-weight: 800; color: var(--brand-900); letter-spacing: .04em; }
.brand .name small { display: block; font-size: .56rem; font-weight: 500; letter-spacing: .3em; color: var(--ink-400); text-transform: uppercase; }

.nav-links { display: flex; align-items: center; gap: var(--space-2); }
.nav-links a {
  position: relative; padding: 8px 18px; border-radius: 999px;
  font-size: .95rem; font-weight: 500; color: var(--ink-700);
  transition: color .25s, background .25s;
}
.nav-links a:hover { color: var(--brand-600); background: var(--brand-50); }
.nav-links a.active { color: var(--brand-600); font-weight: 700; }
.nav-links a.active::after {
  content: ""; position: absolute; left: 50%; bottom: -2px;
  transform: translateX(-50%);
  width: 22px; height: 3px; border-radius: 3px;
  background: linear-gradient(90deg, var(--brand-500), var(--accent-500));
}

.nav-cta { display: flex; align-items: center; gap: var(--space-3); }
.nav-cta .btn { padding: 10px 26px; font-size: .9rem; }
.nav-cta .hotline { display: flex; align-items: center; gap: 8px; font-size: .9rem; color: var(--ink-700); font-weight: 600; }
.nav-cta .hotline svg { color: var(--brand-500); }

.nav-toggle {
  display: none; flex-direction: column; justify-content: center; gap: 5px;
  width: 44px; height: 44px; border-radius: var(--radius-sm);
}
.nav-toggle span {
  display: block; width: 24px; height: 2.5px; margin-inline: auto;
  background: var(--brand-900); border-radius: 2px;
  transition: transform .3s, opacity .3s;
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

/* ---------- 页面顶部横幅（子页） ---------- */
.page-hero {
  position: relative;
  padding: calc(var(--nav-height) + var(--space-8)) 0 var(--space-8);
  background:
    radial-gradient(1000px 400px at 85% -10%, rgba(37, 99, 235, .35), transparent 60%),
    radial-gradient(700px 300px at 0% 110%, rgba(6, 182, 212, .22), transparent 60%),
    linear-gradient(160deg, var(--brand-900), var(--brand-700) 55%, var(--brand-600));
  color: #fff; overflow: hidden;
}
.page-hero::after {
  content: ""; position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(800px 400px at 50% 0%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(800px 400px at 50% 0%, #000 30%, transparent 75%);
  pointer-events: none;
}
.page-hero .inner { position: relative; z-index: 1; max-width: 780px; }
.page-hero h1 { font-size: clamp(1.9rem, 4vw, 2.8rem); font-weight: 800; line-height: 1.25; }
.page-hero p { margin-top: var(--space-4); color: rgba(255,255,255,.82); font-size: 1.05rem; max-width: 640px; }
.breadcrumb { margin-top: var(--space-5); font-size: .875rem; color: rgba(255,255,255,.65); }
.breadcrumb a:hover { color: #fff; text-decoration: underline; }

/* ---------- 卡片 ---------- */
.card {
  background: #fff; border-radius: var(--radius-lg);
  border: 1px solid var(--ink-100);
  box-shadow: var(--shadow-sm);
  transition: transform .35s var(--ease-out), box-shadow .35s, border-color .35s;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: var(--brand-100); }

.icon-badge {
  width: 58px; height: 58px; border-radius: 16px;
  display: grid; place-items: center; color: #fff;
  background: linear-gradient(135deg, var(--brand-600), var(--brand-400));
  box-shadow: 0 8px 20px rgba(37, 99, 235, .25);
  flex-shrink: 0;
}
.icon-badge.cyan   { background: linear-gradient(135deg, #0891b2, #22d3ee); box-shadow: 0 8px 20px rgba(6, 182, 212, .25); }
.icon-badge.green  { background: linear-gradient(135deg, #059669, #34d399); box-shadow: 0 8px 20px rgba(16, 185, 129, .25); }
.icon-badge.amber  { background: linear-gradient(135deg, #d97706, #fbbf24); box-shadow: 0 8px 20px rgba(245, 158, 11, .25); }
.icon-badge.violet { background: linear-gradient(135deg, #7c3aed, #a78bfa); box-shadow: 0 8px 20px rgba(124, 58, 237, .25); }
.icon-badge.rose   { background: linear-gradient(135deg, #e11d48, #fb7185); box-shadow: 0 8px 20px rgba(225, 29, 72, .25); }

/* ---------- 页脚 ---------- */
.site-footer {
  background: var(--brand-900);
  color: rgba(255,255,255,.72);
  padding: var(--space-8) 0 0;
  font-size: .9rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: var(--space-6);
  padding-bottom: var(--space-7);
}
.footer-brand .brand .name { color: #fff; }
.footer-brand .brand .name small { color: rgba(255,255,255,.4); }
.footer-brand p { margin-top: var(--space-4); line-height: 1.8; }
.footer-col h4 {
  color: #fff; font-size: 1rem; font-weight: 700; margin-bottom: var(--space-4);
  position: relative; padding-bottom: 10px;
}
.footer-col h4::after {
  content: ""; position: absolute; left: 0; bottom: 0;
  width: 28px; height: 2px; border-radius: 2px;
  background: linear-gradient(90deg, var(--brand-400), var(--accent-500));
}
.footer-col li { margin-bottom: 10px; }
.footer-col a { transition: color .2s, padding-left .2s; }
.footer-col a:hover { color: #fff; padding-left: 4px; }

.footer-contact li { display: flex; gap: 10px; align-items: flex-start; margin-bottom: 12px; }
.footer-contact svg { color: var(--brand-300); flex-shrink: 0; margin-top: 3px; }

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1);
  padding: var(--space-4) 0;
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: var(--space-3);
  font-size: .82rem; color: rgba(255,255,255,.45);
}
.footer-bottom .links { display: flex; gap: var(--space-4); flex-wrap: wrap; }
.footer-bottom a:hover { color: #fff; }

/* ---------- 回到顶部 ---------- */
.back-top {
  position: fixed; right: 28px; bottom: 28px; z-index: 900;
  width: 48px; height: 48px; border-radius: 50%;
  background: linear-gradient(135deg, var(--brand-600), var(--brand-500));
  color: #fff; display: grid; place-items: center;
  box-shadow: var(--shadow-brand);
  opacity: 0; visibility: hidden; transform: translateY(16px);
  transition: opacity .3s, visibility .3s, transform .3s;
}
.back-top.show { opacity: 1; visibility: visible; transform: translateY(0); }

/* ---------- 动画 ---------- */
@keyframes fade-up {
  from { opacity: 0; transform: translateY(28px); }
  to   { opacity: 1; transform: translateY(0); }
}
.reveal { opacity: 0; }
.reveal.visible { animation: fade-up .8s var(--ease-out) forwards; }
.reveal[data-delay="1"] { animation-delay: .1s; }
.reveal[data-delay="2"] { animation-delay: .2s; }
.reveal[data-delay="3"] { animation-delay: .3s; }
.reveal[data-delay="4"] { animation-delay: .4s; }
.reveal[data-delay="5"] { animation-delay: .5s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; animation: none !important; }
  *, *::before, *::after { transition-duration: .01ms !important; }
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1080px) {
  .nav-cta .hotline { display: none; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 860px) {
  :root { --nav-height: 64px; }

  .nav-toggle { display: flex; }

  .nav-links {
    position: fixed; top: var(--nav-height); left: 0; right: 0;
    flex-direction: column; align-items: stretch;
    background: #fff; padding: var(--space-3) 4%;
    box-shadow: 0 20px 40px rgba(11,37,69,.12);
    border-top: 1px solid var(--ink-100);
    transform: translateY(-12px); opacity: 0; visibility: hidden;
    transition: transform .3s var(--ease-out), opacity .3s, visibility .3s;
    max-height: calc(100vh - var(--nav-height));
    overflow-y: auto;
  }
  .nav-links.open { transform: translateY(0); opacity: 1; visibility: visible; }
  .nav-links a { padding: 13px 16px; border-radius: var(--radius-sm); }
  .nav-links a.active::after { display: none; }
  .nav-links a.active { background: var(--brand-50); }

  .nav-cta .btn { display: none; }

  .section { padding: var(--space-8) 0; }
}

@media (max-width: 560px) {
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; text-align: center; }
  .footer-bottom .links { justify-content: center; }
  .btn { padding: 12px 24px; font-size: .9rem; }
}