/* ==========================================================================
   大理蔚蓝科技 · 官网模板  base.css
   设计令牌 / 重置 / 排版 / 工具类
   ========================================================================== */

:root {
  /* 品牌色 */
  --c-primary: #0b3c8c;
  --c-primary-2: #1a56db;
  --c-primary-3: #e8effb;
  --c-cyan: #00a9c4;
  --c-pink: #ff6b81;
  --c-green: #22a45d;
  --c-orange: #f59e0b;
  --c-purple: #8b5cf6;
  --c-rose: #e11d48;

  /* 中性色 */
  --c-ink: #0f172a;
  --c-text: #475569;
  --c-muted: #64748b;
  --c-sub: #94a3b8;
  --c-line: #e2e8f0;
  --c-line-2: #cbd5e1;
  --c-bg: #f5f7fa;
  --c-bg-2: #eef2f7;
  --c-white: #ffffff;

  /* 渐变 */
  --grad-main: linear-gradient(135deg, #0b3c8c 0%, #1a56db 100%);
  --grad-soft: linear-gradient(180deg, #f5f7fa 0%, #ffffff 100%);
  --grad-dark: linear-gradient(135deg, #082a63 0%, #0f172a 100%);

  /* 圆角 */
  --r-sm: 8px;
  --r: 12px;
  --r-lg: 16px;
  --r-pill: 999px;

  /* 阴影 */
  --sh-1: 0 2px 8px rgba(15, 23, 42, .06);
  --sh-2: 0 8px 24px rgba(15, 23, 42, .08);
  --sh-3: 0 12px 28px rgba(11, 60, 140, .14);
  --sh-blue: 0 8px 20px rgba(26, 86, 219, .28);

  /* 尺寸 */
  --container: 1280px;
  --header-h: 72px;
  --gap: 24px;

  /* 动效 */
  --ease: cubic-bezier(.4, 0, .2, 1);
  --t: .28s var(--ease);
}

/* ---------- 重置 ---------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "HarmonyOS Sans SC", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-text);
  background: var(--c-white);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

body.is-locked { overflow: hidden; }

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  color: var(--c-ink);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -.01em;
}

h1 { font-size: clamp(30px, 4.2vw, 52px); }
h2 { font-size: clamp(24px, 3vw, 38px); }
h3 { font-size: clamp(19px, 1.6vw, 24px); }
h4 { font-size: 18px; }
h5 { font-size: 16px; }

p { margin: 0 0 14px; }
p:last-child { margin-bottom: 0; }

a { color: var(--c-primary-2); text-decoration: none; transition: color var(--t); }
a:hover { color: var(--c-primary); }

img, svg, video { max-width: 100%; display: block; }
ul, ol { margin: 0; padding: 0; list-style: none; }
button { font: inherit; color: inherit; border: 0; background: none; cursor: pointer; }
input, select, textarea { font: inherit; color: inherit; }
table { border-collapse: collapse; width: 100%; }
hr { border: 0; border-top: 1px solid var(--c-line); margin: 32px 0; }

::selection { background: var(--c-primary); color: #fff; }

:focus-visible {
  outline: 2px solid var(--c-primary-2);
  outline-offset: 2px;
  border-radius: 4px;
}

/* ---------- 容器与栅格 ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}
.container--narrow { max-width: 960px; }
.container--wide { max-width: 1440px; }

.grid { display: grid; gap: var(--gap); }
.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }
.grid--5 { grid-template-columns: repeat(5, 1fr); }
.grid--6 { grid-template-columns: repeat(6, 1fr); }
.grid--23 { grid-template-columns: 2fr 3fr; }
.grid--32 { grid-template-columns: 3fr 2fr; }
.grid--sidebar { grid-template-columns: 260px 1fr; }

.flex { display: flex; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-wrap { display: flex; flex-wrap: wrap; gap: 12px; }
.flex-1 { flex: 1; }
.col { display: flex; flex-direction: column; }

/* ---------- 区块 ---------- */
.section { padding: 96px 0; position: relative; }
.section--sm { padding: 64px 0; }
.section--lg { padding: 120px 0; }
.section--bg { background: var(--c-bg); }
.section--grad { background: var(--grad-soft); }
.section--dark { background: var(--grad-dark); color: #cbd5e1; }
.section--dark h1, .section--dark h2, .section--dark h3, .section--dark h4 { color: #fff; }

.section__head { max-width: 760px; margin: 0 auto 56px; text-align: center; }
.section__head--left { margin-left: 0; text-align: left; }
.section__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--c-primary-2);
  background: var(--c-primary-3);
  padding: 6px 14px;
  border-radius: var(--r-pill);
  margin-bottom: 18px;
}
.section__head--left .section__eyebrow { margin-left: 0; }
.section__title { margin-bottom: 16px; }
.section__desc { font-size: 17px; color: var(--c-muted); }

.divider { height: 1px; background: var(--c-line); border: 0; margin: 0; }

/* ---------- 文字工具 ---------- */
.t-ink { color: var(--c-ink); }
.t-muted { color: var(--c-muted); }
.t-sub { color: var(--c-sub); }
.t-primary { color: var(--c-primary-2); }
.t-pink { color: var(--c-pink); }
.t-green { color: var(--c-green); }
.t-white { color: #fff; }
.t-sm { font-size: 14px; }
.t-xs { font-size: 13px; }
.t-lg { font-size: 18px; }
.t-center { text-align: center; }
.t-right { text-align: right; }
.t-bold { font-weight: 600; }
.t-nowrap { white-space: nowrap; }
.grad-text {
  background: var(--grad-main);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ---------- 间距工具 ---------- */
.mt-0 { margin-top: 0; } .mt-1 { margin-top: 8px; } .mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; } .mt-4 { margin-top: 32px; } .mt-5 { margin-top: 48px; }
.mb-1 { margin-bottom: 8px; } .mb-2 { margin-bottom: 16px; } .mb-3 { margin-bottom: 24px; }
.mb-4 { margin-bottom: 32px; } .mb-5 { margin-bottom: 48px; }

/* ---------- 占位图 ---------- */
.ph {
  position: relative;
  margin: 0;
  background: var(--c-bg-2);
  border: 1px dashed var(--c-line-2);
  border-radius: var(--r);
  overflow: hidden;
}
.ph > img { width: 100%; height: 100%; object-fit: cover; }
.ph::after {
  content: attr(data-label);
  position: absolute;
  left: 0; right: 0; bottom: 10px;
  text-align: center;
  font-size: 12px;
  color: var(--c-sub);
  letter-spacing: .04em;
  pointer-events: none;
}
.ph--16x9 { aspect-ratio: 16 / 9; }
.ph--4x3 { aspect-ratio: 4 / 3; }
.ph--3x2 { aspect-ratio: 3 / 2; }
.ph--1x1 { aspect-ratio: 1 / 1; }
.ph--3x4 { aspect-ratio: 3 / 4; }
.ph--9x16 { aspect-ratio: 9 / 16; }
.ph--21x9 { aspect-ratio: 21 / 9; }
.ph--plain::after { display: none; }
/* 占位图换成真实图片后：去掉虚线框与占位说明 */
.ph--img { border: 0; background: #fff; box-shadow: var(--sh-2); }
.ph--img::after { display: none; }

/* ---------- 动效 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}
.reveal.is-in { opacity: 1; transform: none; }
.reveal-d1 { transition-delay: .08s; }
.reveal-d2 { transition-delay: .16s; }
.reveal-d3 { transition-delay: .24s; }
.reveal-d4 { transition-delay: .32s; }

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

/* ---------- 响应式排版 ---------- */
@media (max-width: 1279px) {
  :root { --container: 1140px; }
  .grid--5 { grid-template-columns: repeat(3, 1fr); }
  .grid--6 { grid-template-columns: repeat(4, 1fr); }
}
@media (max-width: 1023px) {
  :root { --container: 900px; }
  .section { padding: 72px 0; }
  .section--lg { padding: 88px 0; }
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
  .grid--5 { grid-template-columns: repeat(2, 1fr); }
  .grid--6 { grid-template-columns: repeat(3, 1fr); }
  .grid--23, .grid--32 { grid-template-columns: 1fr; }
  .grid--sidebar { grid-template-columns: 1fr; }
  .section__head { margin-bottom: 40px; }
}
@media (max-width: 767px) {
  :root { --container: 100%; --gap: 16px; }
  .container { padding: 0 16px; }
  .section { padding: 56px 0; }
  .section--lg { padding: 64px 0; }
  .grid, .grid--2, .grid--3, .grid--4, .grid--5, .grid--6 { grid-template-columns: 1fr; }
  .grid--keep2 { grid-template-columns: repeat(2, 1fr); }
  .section__desc { font-size: 15px; }
}