/* ==========================================================================
   筑研毕设 · 土木工程毕业设计指导网站
   设计令牌 / 布局 / 组件 / 响应式
   ========================================================================== */

/* --------------------------- 1. 设计令牌 --------------------------- */
:root {
  /* 主色：蓝图深蓝体系 */
  --navy-900: #0a1f36;
  --navy-800: #0e2a47;
  --navy-700: #143a5e;
  --blue-600: #1b5fa8;
  --blue-500: #2a7ac9;
  --blue-100: #e4effa;
  --blue-050: #f2f7fd;

  /* 强调色：工程橙 */
  --amber-600: #e06a1e;
  --amber-500: #ff8a3d;
  --amber-100: #fff1e4;

  /* 中性色 */
  --ink: #1b2733;
  --ink-soft: #3d4c5c;
  --muted: #64748b;
  --line: #dde7f1;
  --line-soft: #eaf1f8;
  --bg: #ffffff;
  --bg-alt: #f5f8fc;

  /* 功能色 */
  --ok: #12805c;
  --err: #d64545;

  /* 尺寸与效果 */
  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 22px;
  --shadow-sm: 0 1px 2px rgba(14, 42, 71, .06), 0 2px 8px rgba(14, 42, 71, .05);
  --shadow: 0 6px 24px rgba(14, 42, 71, .08), 0 2px 6px rgba(14, 42, 71, .05);
  --shadow-lg: 0 18px 48px rgba(14, 42, 71, .13);
  --wrap: 1180px;
  --header-h: 72px;

  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", system-ui, -apple-system, "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

/* --------------------------- 2. 基础重置 --------------------------- */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h) + 12px); }

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5 { margin: 0; line-height: 1.28; font-weight: 700; letter-spacing: -.01em; }
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }
button { font: inherit; cursor: pointer; }

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

:focus-visible {
  outline: 3px solid rgba(42, 122, 201, .45);
  outline-offset: 2px;
  border-radius: 4px;
}

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }
.wrap-narrow { max-width: 860px; }

/* 滚动进度条 */
.scroll-progress {
  position: fixed; inset: 0 auto auto 0;
  height: 3px; width: 0;
  background: linear-gradient(90deg, var(--blue-600), var(--amber-500));
  z-index: 200;
  transition: width .1s linear;
}

/* --------------------------- 3. 按钮 --------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border: 1.5px solid transparent;
  border-radius: 999px;
  font-size: 15.5px;
  font-weight: 600;
  line-height: 1.2;
  white-space: nowrap;
  transition: transform .18s ease, box-shadow .22s ease, background .22s ease, color .22s ease, border-color .22s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }

.btn-primary {
  background: var(--amber-500);
  color: #fff;
  box-shadow: 0 8px 20px rgba(224, 106, 30, .3);
}
.btn-primary:hover { background: var(--amber-600); box-shadow: 0 12px 26px rgba(224, 106, 30, .36); }

.btn-ghost {
  background: transparent;
  color: var(--navy-800);
  border-color: var(--line);
}
.btn-ghost:hover { border-color: var(--blue-500); color: var(--blue-600); background: var(--blue-050); }

.btn.full { width: 100%; }

/* --------------------------- 4. 页头导航 --------------------------- */
.site-header {
  position: fixed; top: 0; left: 0; right: 0;
  height: var(--header-h);
  z-index: 100;
  background: rgba(255, 255, 255, .78);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s ease, box-shadow .25s ease, background .25s ease;
}
.site-header.is-stuck {
  border-bottom-color: var(--line-soft);
  box-shadow: 0 4px 20px rgba(14, 42, 71, .06);
  background: rgba(255, 255, 255, .93);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 100%; gap: 20px; }

.brand { display: inline-flex; align-items: center; gap: 11px; }
.brand-mark { flex: none; filter: drop-shadow(0 3px 8px rgba(14, 42, 71, .18)); }
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-text strong { font-size: 18px; font-weight: 800; color: var(--navy-800); letter-spacing: .02em; }
.brand-text em { font-size: 11.5px; font-style: normal; color: var(--muted); letter-spacing: .04em; }

.nav { display: flex; align-items: center; gap: 4px; }
.nav a {
  position: relative;
  padding: 8px 13px;
  font-size: 15px;
  font-weight: 500;
  color: var(--ink-soft);
  border-radius: 999px;
  transition: color .2s ease, background .2s ease;
}
.nav a:hover { color: var(--blue-600); background: var(--blue-050); }
.nav a.nav-cta {
  margin-left: 10px;
  background: var(--navy-800);
  color: #fff;
  font-weight: 600;
  padding: 10px 20px;
}
.nav a.nav-cta:hover { background: var(--blue-600); color: #fff; }

.nav-toggle {
  display: none;
  flex-direction: column; justify-content: center; gap: 5px;
  width: 42px; height: 42px;
  border: 1px solid var(--line);
  border-radius: 11px;
  background: #fff;
}
.nav-toggle span {
  display: block; height: 2px; width: 19px; margin: 0 auto;
  background: var(--navy-800); border-radius: 2px;
  transition: transform .25s ease, opacity .2s ease;
}
.nav-toggle.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.is-open span:nth-child(2) { opacity: 0; }
.nav-toggle.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* --------------------------- 5. Hero --------------------------- */
.hero {
  position: relative;
  padding: calc(var(--header-h) + 66px) 0 0;
  overflow: hidden;
  background:
    radial-gradient(1100px 520px at 88% -8%, var(--blue-100) 0%, transparent 62%),
    radial-gradient(760px 420px at 4% 6%, var(--amber-100) 0%, transparent 58%),
    linear-gradient(180deg, #fbfdff 0%, #ffffff 78%);
}
.hero-grid-bg {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(27, 95, 168, .055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(27, 95, 168, .055) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: radial-gradient(1000px 620px at 50% 10%, #000 8%, transparent 78%);
  -webkit-mask-image: radial-gradient(1000px 620px at 50% 10%, #000 8%, transparent 78%);
  pointer-events: none;
}
.hero-inner {
  position: relative;
  display: grid;
  grid-template-columns: 1.06fr .94fr;
  align-items: center;
  gap: 56px;
  padding-bottom: 72px;
}

.eyebrow {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 7px 16px 7px 12px;
  margin-bottom: 22px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--navy-700);
  box-shadow: var(--shadow-sm);
}
.eyebrow .dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--ok);
  box-shadow: 0 0 0 4px rgba(18, 128, 92, .16);
  animation: pulse 2.4s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 4px rgba(18, 128, 92, .16); }
  50% { box-shadow: 0 0 0 7px rgba(18, 128, 92, .05); }
}

.hero h1 {
  font-size: clamp(30px, 4.35vw, 54px);
  font-weight: 800;
  letter-spacing: -.022em;
  color: var(--navy-900);
  margin-bottom: 20px;
}
.hero h1 .hl {
  position: relative;
  z-index: 0; /* 建立层叠上下文，使高亮色块不会沉到 section 背景之下 */
  color: var(--blue-600);
  white-space: nowrap;
}
.hero h1 .hl::after {
  content: "";
  position: absolute; left: 0; right: 0; bottom: .06em;
  height: .3em;
  background: linear-gradient(90deg, rgba(255, 138, 61, .3), rgba(255, 138, 61, .12));
  border-radius: 3px;
  z-index: -1;
}

.hero .lead { max-width: 34em; font-size: 16.5px; color: var(--ink-soft); }

.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin: 32px 0 38px; }

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  padding-top: 26px;
  border-top: 1px dashed var(--line);
}
.hero-stats dt { font-size: 26px; font-weight: 800; color: var(--navy-800); letter-spacing: -.02em; }
.hero-stats dd { margin: 2px 0 0; font-size: 13px; color: var(--muted); }

.hero-art { display: flex; justify-content: center; }
.blueprint { width: 100%; max-width: 520px; filter: drop-shadow(0 26px 48px rgba(14, 42, 71, .16)); }
.float-a, .float-b { animation: float 6.5s ease-in-out infinite; }
.float-b { animation-delay: -3.2s; }
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-11px); }
}
@media (prefers-reduced-motion: reduce) {
  .float-a, .float-b, .eyebrow .dot { animation: none; }
  html { scroll-behavior: auto; }
}

/* 滚动标语带 */
.marquee-band {
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  background: var(--bg-alt);
  overflow: hidden;
  padding: 15px 0;
  mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
  -webkit-mask-image: linear-gradient(90deg, transparent, #000 12%, #000 88%, transparent);
}
.marquee-track {
  display: flex; gap: 44px; width: max-content;
  animation: slide 34s linear infinite;
}
.marquee-track span {
  position: relative;
  font-size: 13.5px;
  font-weight: 600;
  letter-spacing: .06em;
  color: var(--blue-600);
  padding-left: 20px;
  white-space: nowrap;
}
.marquee-track span::before {
  content: "";
  position: absolute; left: 0; top: 50%;
  width: 6px; height: 6px; margin-top: -3px;
  background: var(--amber-500); border-radius: 1px; transform: rotate(45deg);
}
@keyframes slide {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

/* --------------------------- 6. 通用区块 --------------------------- */
.section { padding: 96px 0; }
.section-alt { background: var(--bg-alt); }
.section-dark {
  background:
    radial-gradient(900px 460px at 88% 0%, rgba(42, 122, 201, .3) 0%, transparent 60%),
    linear-gradient(160deg, var(--navy-900) 0%, var(--navy-700) 100%);
  color: #e8f1fa;
}

.sec-head { max-width: 44em; margin-bottom: 54px; }
.sec-head h2 { font-size: clamp(24px, 2.75vw, 36px); color: var(--navy-900); margin-bottom: 14px; }
.sec-sub { font-size: 16px; color: var(--muted); }
.sec-tag {
  display: inline-block;
  margin-bottom: 14px;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: .16em;
  color: var(--amber-600);
  text-transform: uppercase;
}
.sec-tag::before {
  content: "";
  display: inline-block;
  width: 22px; height: 2px;
  margin-right: 9px; vertical-align: middle;
  background: var(--amber-500);
}
.sec-head-light h2 { color: #fff; }
.sec-head-light .sec-sub { color: #a8c4dd; }

/* --------------------------- 7. 服务卡片 --------------------------- */
.card-grid { display: grid; gap: 22px; }
.cols-3 { grid-template-columns: repeat(3, 1fr); }

.svc-card {
  position: relative;
  padding: 30px 28px 28px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: transform .28s cubic-bezier(.22, .8, .3, 1), box-shadow .28s ease, border-color .28s ease;
  overflow: hidden;
}
.svc-card::before {
  content: "";
  position: absolute; inset: 0 0 auto 0;
  height: 3px;
  background: linear-gradient(90deg, var(--blue-600), var(--amber-500));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .38s cubic-bezier(.22, .8, .3, 1);
}
.svc-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); border-color: #cfe0f0; }
.svc-card:hover::before { transform: scaleX(1); }

.svc-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 50px; height: 50px;
  margin-bottom: 18px;
  border-radius: 14px;
  background: linear-gradient(145deg, var(--blue-100), #fff);
  border: 1px solid #d5e5f6;
  color: var(--blue-600);
}
.svc-card h3 { font-size: 19px; color: var(--navy-900); margin-bottom: 10px; }
.svc-card > p { font-size: 14.6px; color: var(--muted); }

.svc-list { margin-top: 18px; padding-top: 16px; border-top: 1px dashed var(--line); display: grid; gap: 7px; }
.svc-list li {
  font-size: 13.8px;
  color: var(--ink-soft);
  padding-left: 18px;
  position: relative;
}
.svc-list li::before {
  content: "";
  position: absolute; left: 2px; top: .62em;
  width: 5px; height: 5px;
  background: var(--amber-500);
  border-radius: 1px; transform: rotate(45deg);
}

/* --------------------------- 8. 交付内容 --------------------------- */
.deliver-grid { display: grid; grid-template-columns: 1.5fr 1fr; gap: 30px; align-items: start; }

.check-list { display: grid; gap: 14px; }
.check-list li {
  display: flex; gap: 16px;
  padding: 20px 22px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color .22s ease, box-shadow .22s ease, transform .22s ease;
}
.check-list li:hover { border-color: #cfe0f0; box-shadow: var(--shadow); transform: translateX(4px); }
.check-list h4 { font-size: 16.5px; color: var(--navy-900); margin-bottom: 4px; }
.check-list p { font-size: 14.3px; color: var(--muted); }

.tick {
  flex: none;
  position: relative;
  width: 26px; height: 26px;
  margin-top: 3px;
  border-radius: 50%;
  background: var(--blue-100);
}
.tick::after {
  content: "";
  position: absolute; left: 9px; top: 6px;
  width: 5px; height: 10px;
  border: solid var(--blue-600);
  border-width: 0 2.4px 2.4px 0;
  transform: rotate(42deg);
}

.side-card {
  padding: 28px 26px;
  background: linear-gradient(170deg, #fff, var(--blue-050));
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}
.side-card h4 { font-size: 14.5px; color: var(--navy-800); margin-bottom: 12px; letter-spacing: .02em; }
.side-card hr { margin: 22px 0; border: none; border-top: 1px dashed var(--line); }
.side-note { font-size: 14px; color: var(--muted); }
.chip-row { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  padding: 5px 11px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--blue-600);
  background: #fff;
  border: 1px solid #d5e5f6;
  border-radius: 7px;
}

/* --------------------------- 9. 时间线 --------------------------- */
.timeline {
  position: relative;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px 26px;
}
.timeline::before {
  content: "";
  position: absolute; top: 26px; left: 4%; right: 4%;
  height: 1px;
  background: repeating-linear-gradient(90deg, var(--line) 0 8px, transparent 8px 16px);
}
.timeline li {
  position: relative;
  padding: 0 4px;
}
.timeline li::before {
  content: "";
  position: absolute; top: 20px; left: 0;
  width: 13px; height: 13px;
  background: #fff;
  border: 3px solid var(--blue-600);
  border-radius: 50%;
  box-shadow: 0 0 0 5px rgba(42, 122, 201, .1);
  z-index: 1;
}
.tl-idx {
  display: block;
  padding-left: 34px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--amber-600);
  margin-bottom: 14px;
  height: 26px;
}
.timeline h4 { padding-left: 34px; font-size: 17.5px; color: var(--navy-900); margin-bottom: 8px; }
.timeline p { padding-left: 34px; font-size: 14.4px; color: var(--muted); }

/* --------------------------- 10. 优势 --------------------------- */
.why-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: rgba(255, 255, 255, .12);
  border: 1px solid rgba(255, 255, 255, .12);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.why-card {
  padding: 32px 28px;
  background: rgba(10, 31, 54, .55);
  transition: background .25s ease;
}
.why-card:hover { background: rgba(27, 95, 168, .38); }
.why-card h4 { font-size: 17.5px; color: #fff; margin-bottom: 10px; }
.why-card h4::before {
  content: "";
  display: inline-block;
  width: 7px; height: 7px;
  margin-right: 10px; vertical-align: middle;
  background: var(--amber-500);
  border-radius: 1px; transform: rotate(45deg);
}
.why-card p { font-size: 14.4px; color: #a8c4dd; }

.why-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 22px;
  margin-top: 46px;
  padding-top: 40px;
  border-top: 1px solid rgba(255, 255, 255, .14);
  text-align: center;
}
.why-stats .num { font-size: 34px; font-weight: 800; color: var(--amber-500); letter-spacing: -.02em; }
.why-stats p { margin-top: 4px; font-size: 13.5px; color: #a8c4dd; }

/* --------------------------- 11. 案例 --------------------------- */
.filter-bar { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 30px; }
.filter-btn {
  padding: 9px 20px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 14.5px;
  font-weight: 500;
  color: var(--ink-soft);
  transition: all .2s ease;
}
.filter-btn:hover { border-color: var(--blue-500); color: var(--blue-600); }
.filter-btn.is-active {
  background: var(--navy-800);
  border-color: var(--navy-800);
  color: #fff;
  font-weight: 600;
}

.case-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.case-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform .28s cubic-bezier(.22, .8, .3, 1), box-shadow .28s ease;
}
.case-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.case-card.is-hidden { display: none; }

.case-thumb { position: relative; aspect-ratio: 16 / 9; display: grid; place-items: center; }
.case-thumb svg { width: 100%; height: 100%; }
.grad-1 { background: linear-gradient(140deg, #143a5e, #2a7ac9); }
.grad-2 { background: linear-gradient(140deg, #0f3b52, #1f8a8a); }
.grad-3 { background: linear-gradient(140deg, #3a2a5e, #6a56c4); }
.grad-4 { background: linear-gradient(140deg, #4a3312, #c98a2a); }
.grad-5 { background: linear-gradient(140deg, #123f2f, #1f9c74); }
.grad-6 { background: linear-gradient(140deg, #5e1f33, #c0517a); }

.case-badge {
  position: absolute; top: 12px; left: 12px;
  padding: 4px 12px;
  font-size: 12px; font-weight: 600;
  color: var(--navy-800);
  background: rgba(255, 255, 255, .92);
  border-radius: 999px;
  backdrop-filter: blur(4px);
}
.case-body { padding: 20px 22px 22px; }
.case-body h4 { font-size: 16.5px; color: var(--navy-900); margin-bottom: 8px; }
.case-body > p { font-size: 13.8px; color: var(--muted); }
.case-meta {
  margin-top: 12px; padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 13px !important;
  font-family: var(--font-mono);
  color: var(--blue-600) !important;
}

/* --------------------------- 12. 评价 --------------------------- */
.voice-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.voice-card {
  display: flex; flex-direction: column;
  margin: 0;
  padding: 30px 28px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: transform .28s ease, box-shadow .28s ease;
}
.voice-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); }
.stars { color: var(--amber-500); font-size: 15px; letter-spacing: 3px; margin-bottom: 16px; }
.voice-card blockquote {
  margin: 0 0 22px;
  font-size: 15.2px;
  line-height: 1.8;
  color: var(--ink-soft);
}
.voice-card figcaption { display: flex; align-items: center; gap: 12px; margin-top: auto; }
.avatar {
  display: grid; place-items: center;
  width: 42px; height: 42px;
  flex: none;
  border-radius: 50%;
  background: linear-gradient(145deg, var(--navy-700), var(--blue-500));
  color: #fff; font-weight: 700; font-size: 16px;
}
.voice-card figcaption div { display: flex; flex-direction: column; line-height: 1.3; }
.voice-card figcaption strong { font-size: 14.5px; color: var(--navy-900); }
.voice-card figcaption em { font-style: normal; font-size: 12.5px; color: var(--muted); }

/* --------------------------- 13. 价格 --------------------------- */
.price-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; align-items: start; }
.price-card {
  position: relative;
  padding: 34px 30px 30px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: transform .28s ease, box-shadow .28s ease;
}
.price-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); }
.price-card.is-featured {
  border-color: var(--blue-500);
  box-shadow: 0 20px 50px rgba(27, 95, 168, .18);
  background: linear-gradient(180deg, #fff, var(--blue-050));
}
.ribbon {
  position: absolute; top: -13px; left: 50%;
  transform: translateX(-50%);
  padding: 5px 18px;
  font-size: 12.5px; font-weight: 700;
  color: #fff;
  background: linear-gradient(90deg, var(--amber-500), var(--amber-600));
  border-radius: 999px;
  box-shadow: 0 6px 16px rgba(224, 106, 30, .32);
  white-space: nowrap;
}
.price-card h4 { font-size: 18px; color: var(--navy-900); margin-bottom: 12px; }
.price { display: flex; align-items: baseline; gap: 3px; margin-bottom: 8px; }
.price .cur { font-size: 19px; font-weight: 700; color: var(--navy-800); }
.price strong { font-size: 42px; font-weight: 800; color: var(--navy-900); letter-spacing: -.03em; line-height: 1; }
.price .from { font-size: 14px; color: var(--muted); margin-left: 3px; }
.price-desc { font-size: 14px; color: var(--muted); }

.price-list { margin: 24px 0 26px; padding-top: 22px; border-top: 1px dashed var(--line); display: grid; gap: 11px; }
.price-list li {
  position: relative;
  padding-left: 26px;
  font-size: 14.4px;
  color: var(--ink-soft);
}
.price-list li::before {
  content: "";
  position: absolute; left: 2px; top: 6px;
  width: 13px; height: 7px;
  border: solid var(--ok);
  border-width: 0 0 2px 2px;
  transform: rotate(-45deg);
}

/* --------------------------- 14. FAQ --------------------------- */
.faq { display: grid; gap: 12px; }
.faq-item {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color .22s ease, box-shadow .22s ease;
}
.faq-item[open] { border-color: #cfe0f0; box-shadow: var(--shadow); }
.faq-item summary {
  position: relative;
  padding: 20px 56px 20px 24px;
  font-size: 16.2px;
  font-weight: 600;
  color: var(--navy-900);
  cursor: pointer;
  list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "";
  position: absolute; right: 24px; top: 50%;
  width: 9px; height: 9px;
  margin-top: -6px;
  border: solid var(--blue-600);
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
  transition: transform .25s ease;
}
.faq-item[open] summary::after { transform: rotate(225deg); margin-top: -2px; }
.faq-body { padding: 0 24px 22px; }
.faq-body p { font-size: 14.8px; color: var(--muted); }

/* --------------------------- 15. 咨询表单 --------------------------- */
.contact-card {
  display: grid;
  grid-template-columns: 1fr 1.05fr;
  gap: 0;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}
.contact-info {
  padding: 44px 40px;
  background:
    radial-gradient(520px 300px at 100% 0%, rgba(42, 122, 201, .35) 0%, transparent 65%),
    linear-gradient(165deg, var(--navy-900), var(--navy-700));
  color: #dce9f6;
}
.contact-info h2 { font-size: clamp(22px, 2.3vw, 30px); color: #fff; margin-bottom: 14px; }
.contact-info .sec-tag { color: var(--amber-500); }
.contact-sub { font-size: 14.8px; color: #a8c4dd; }

.contact-list { margin-top: 32px; display: grid; gap: 18px; }
.contact-list li { display: flex; align-items: center; gap: 14px; }
.ci-icon {
  display: grid; place-items: center;
  width: 40px; height: 40px; flex: none;
  border-radius: 11px;
  background: rgba(255, 255, 255, .1);
  border: 1px solid rgba(255, 255, 255, .16);
  color: var(--amber-500);
}
.contact-list div { display: flex; flex-direction: column; line-height: 1.35; }
.contact-list strong { font-size: 13px; color: #8fb8e0; font-weight: 600; }
.contact-list em { font-style: normal; font-size: 14.6px; color: #fff; }

.contact-form { padding: 40px 38px; display: grid; gap: 18px; align-content: start; }
.field { display: grid; gap: 7px; }
.field label { font-size: 14px; font-weight: 600; color: var(--navy-800); }
.req { color: var(--amber-600); }
.field input, .field select, .field textarea {
  width: 100%;
  padding: 12px 15px;
  font-family: inherit;
  font-size: 15px;
  color: var(--ink);
  background: var(--bg-alt);
  border: 1.5px solid var(--line);
  border-radius: var(--radius-sm);
  transition: border-color .2s ease, background .2s ease, box-shadow .2s ease;
}
.field textarea { resize: vertical; min-height: 118px; line-height: 1.7; }
.field input::placeholder, .field textarea::placeholder { color: #9aabbd; }
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none;
  background: #fff;
  border-color: var(--blue-500);
  box-shadow: 0 0 0 4px rgba(42, 122, 201, .12);
}
.field.has-error input, .field.has-error select, .field.has-error textarea { border-color: var(--err); background: #fff6f6; }
.err { min-height: 0; font-size: 12.8px; color: var(--err); }

.form-foot { font-size: 12.6px; color: var(--muted); text-align: center; }
.form-ok {
  padding: 13px 16px;
  font-size: 14px;
  font-weight: 600;
  color: var(--ok);
  background: #eaf7f2;
  border: 1px solid #bfe6d8;
  border-radius: var(--radius-sm);
  text-align: center;
}

/* --------------------------- 16. 页脚 --------------------------- */
.site-footer { background: var(--navy-900); color: #a8c4dd; padding: 68px 0 26px; }
.footer-inner {
  display: grid;
  grid-template-columns: 1.7fr 1fr 1fr;
  gap: 44px;
  padding-bottom: 44px;
  border-bottom: 1px solid rgba(255, 255, 255, .1);
}
.footer-brand .brand { margin-bottom: 18px; }
.brand-light .brand-text strong { color: #fff; }
.brand-light .brand-text em { color: #8fb8e0; }
.footer-brand p { font-size: 14.2px; max-width: 34em; }
.footer-links, .footer-contact { display: flex; flex-direction: column; gap: 10px; }
.footer-links h5, .footer-contact h5 {
  font-size: 14px; color: #fff; margin-bottom: 6px; letter-spacing: .04em;
}
.footer-links a { font-size: 14.2px; transition: color .2s ease, padding-left .2s ease; }
.footer-links a:hover { color: var(--amber-500); padding-left: 4px; }
.footer-contact p { font-size: 14.2px; }

.footer-bottom {
  display: flex; flex-wrap: wrap; gap: 8px 28px;
  justify-content: space-between;
  padding-top: 24px;
  font-size: 12.8px;
  color: #7e9cba;
}
.disclaimer { max-width: 46em; }

/* 回到顶部 */
.to-top {
  position: fixed; right: 26px; bottom: 26px;
  display: grid; place-items: center;
  width: 46px; height: 46px;
  background: var(--navy-800);
  color: #fff;
  border-radius: 50%;
  box-shadow: var(--shadow-lg);
  opacity: 0; visibility: hidden;
  transform: translateY(14px);
  transition: all .28s ease;
  z-index: 90;
}
.to-top.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { background: var(--amber-500); }

/* --------------------------- 17. 入场动画 --------------------------- */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity .7s cubic-bezier(.22, .8, .3, 1), transform .7s cubic-bezier(.22, .8, .3, 1);
  will-change: opacity, transform;
}
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  .marquee-track { animation: none; }
}

/* --------------------------- 18. 响应式 --------------------------- */
@media (max-width: 1080px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; padding-bottom: 56px; }
  .hero-art { order: -1; max-width: 440px; margin: 0 auto; }
  .hero .lead { max-width: none; }
  .cols-3, .case-grid, .voice-grid, .price-grid { grid-template-columns: repeat(2, 1fr); }
  .timeline { grid-template-columns: repeat(2, 1fr); }
  .timeline::before { display: none; }
  .deliver-grid { grid-template-columns: 1fr; }
  .contact-card { grid-template-columns: 1fr; }
  .why-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 860px) {
  .nav {
    position: fixed;
    top: var(--header-h); left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 14px 20px 22px;
    background: #fff;
    border-bottom: 1px solid var(--line);
    box-shadow: 0 18px 34px rgba(14, 42, 71, .12);
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: all .24s ease;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
  }
  .nav.is-open { transform: none; opacity: 1; visibility: visible; }
  .nav a { padding: 13px 14px; border-radius: var(--radius-sm); font-size: 16px; }
  .nav a.nav-cta { margin: 12px 0 0; text-align: center; justify-content: center; }
  .nav-toggle { display: flex; }

  .section { padding: 72px 0; }
  .sec-head { margin-bottom: 38px; }
  .hero { padding-top: calc(var(--header-h) + 44px); }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 20px 12px; }
  .why-stats { grid-template-columns: repeat(2, 1fr); gap: 26px; }
}

@media (max-width: 620px) {
  body { font-size: 15.5px; }
  .wrap { padding: 0 18px; }
  .cols-3, .case-grid, .voice-grid, .price-grid, .timeline, .why-grid { grid-template-columns: 1fr; }
  .timeline li::before { top: 22px; }
  .hero-actions { gap: 12px; }
  .hero-actions .btn { flex: 1 1 100%; }
  .contact-info, .contact-form { padding: 30px 22px; }
  .price-card { padding: 30px 24px 26px; }
  .why-card { padding: 26px 22px; }
  .footer-inner { grid-template-columns: 1fr; gap: 32px; }
  .to-top { right: 16px; bottom: 16px; }
  .case-body { padding: 18px; }
}

/* --------------------------- 19. 打印 --------------------------- */
@media print {
  .site-header, .to-top, .scroll-progress, .hero-art, .marquee-band, .contact-form { display: none; }
  .reveal { opacity: 1; transform: none; }
  body { color: #000; }
}