/* ==========================================================================
   Oxfordbridge Base —— reset / 排版 / 通用工具类
   依赖 variables.css
   ========================================================================== */

/* ---- 字体加载（本地自托管，file:// 离线可用） ---- */
@font-face {
  font-family: 'Lora';
  src: url('../fonts/lora-400.woff2') format('woff2');
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'Lora';
  src: url('../fonts/lora-400i.woff2') format('woff2');
  font-weight: 400; font-style: italic; font-display: swap;
}
@font-face {
  font-family: 'Lora';
  src: url('../fonts/lora-600.woff2') format('woff2');
  font-weight: 600; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'Lora';
  src: url('../fonts/lora-700.woff2') format('woff2');
  font-weight: 700; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'Inter';
  src: url('../fonts/inter-400.woff2') format('woff2');
  font-weight: 400; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'Inter';
  src: url('../fonts/inter-500.woff2') format('woff2');
  font-weight: 500; font-style: normal; font-display: swap;
}
@font-face {
  font-family: 'Inter';
  src: url('../fonts/inter-700.woff2') format('woff2');
  font-weight: 700; font-style: normal; font-display: swap;
}

/* ---- Reset ---- */
*, *::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);
  font-size: var(--fs-body);
  line-height: 1.75;
  color: var(--c-text);
  background: var(--c-white);
  -webkit-font-smoothing: antialiased;
}

img, svg, video { display: block; max-width: 100%; }
img { height: auto; }

a { color: var(--c-blue-600); text-decoration: none; transition: color var(--dur) var(--ease); }
a:hover { color: var(--c-blue-800); }

ul, ol { list-style: none; }

button, input, select, textarea {
  font: inherit; color: inherit;
}

h1, h2, h3, h4, blockquote, figure { margin: 0; }

::selection { background: rgba(217, 119, 6, .22); }

:focus-visible { outline: 3px solid rgba(0, 119, 182, .55); outline-offset: 2px; border-radius: 4px; }

/* ---- 排版 ---- */
h1, h2, h3, h4, .serif {
  font-family: var(--font-serif);
  font-weight: 700;
  line-height: 1.28;
  color: var(--c-navy-900);
  letter-spacing: .01em;
}

h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); font-weight: 600; }

p { margin: 0; }
.lead { font-size: 1.08rem; color: var(--c-text-2); }

/* ---- 通用布局 ---- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--sp-5);
}
@media (min-width: 768px) {
  .container { padding-inline: var(--sp-7); }
}

section { position: relative; }

.section { padding-block: var(--sp-9); }
@media (min-width: 768px) { .section { padding-block: var(--sp-11); } }
@media (min-width: 1024px) { .section { padding-block: var(--sp-12); } }

.section--light { background: var(--c-bg-light); }
.section--navy  { background: var(--c-navy-900); }
.section--navy h2, .section--navy h3 { color: var(--c-white); }

/* ---- 区块头 ---- */
.section-head { max-width: 720px; margin: 0 auto var(--sp-8); text-align: center; }
.section-head .kicker {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--c-cta);
  margin-bottom: var(--sp-3);
}
.section-head .kicker::before,
.section-head .kicker::after {
  content: "";
  width: 22px; height: 2px;
  background: linear-gradient(90deg, transparent, var(--c-cta));
  border-radius: 2px;
}
.section-head .kicker::after { background: linear-gradient(90deg, var(--c-cta), transparent); }
.section-head p { margin-top: var(--sp-3); color: var(--c-text-2); }
.section--navy .section-head p { color: var(--c-text-inv-2); }

.section-head--left { margin-inline: 0; text-align: left; }
.section-head--left .kicker::before { display: none; }

/* ---- 页面 hero（内页通用） ---- */
.page-hero {
  position: relative;
  background:
    radial-gradient(1100px 500px at 85% -10%, rgba(0, 180, 216, .25), transparent 60%),
    radial-gradient(800px 420px at -10% 110%, rgba(13, 79, 94, .5), transparent 55%),
    linear-gradient(135deg, var(--c-navy-900) 0%, var(--c-navy-800) 55%, #04202a 100%);
  color: var(--c-text-inv);
  padding-block: var(--sp-9) var(--sp-10);
  overflow: hidden;
}
@media (min-width: 768px) { .page-hero { padding-block: var(--sp-10) var(--sp-11); } }

.page-hero .kicker {
  display: inline-block;
  font-size: var(--fs-xs);
  font-weight: 700;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-blue-400);
  margin-bottom: var(--sp-3);
}

.page-hero h1 {
  color: var(--c-white);
  font-size: var(--fs-h1);
  max-width: 15em;
}

.page-hero .lead {
  color: var(--c-text-inv-2);
  max-width: 44em;
  margin-top: var(--sp-4);
}

/* ---- 面包屑 ---- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-sm);
  color: var(--c-text-inv-2);
  margin-bottom: var(--sp-4);
}
.breadcrumb a { color: var(--c-blue-400); }
.breadcrumb a:hover { color: var(--c-white); }
.breadcrumb .sep { opacity: .5; }
.breadcrumb .current { color: var(--c-white); }

/* ---- 工具类 ---- */
.text-center { text-align: center; }
.text-cta { color: var(--c-cta); }
.mt-4 { margin-top: var(--sp-4); }
.mt-5 { margin-top: var(--sp-5); }
.mt-6 { margin-top: var(--sp-6); }
.mt-8 { margin-top: var(--sp-8); }
.mb-6 { margin-bottom: var(--sp-6); }
.mb-8 { margin-bottom: var(--sp-8); }
.grid { display: grid; gap: var(--sp-5); }

@media (min-width: 640px)  { .grid-2 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .grid-3 { grid-template-columns: repeat(3, 1fr); } }
@media (min-width: 640px)  { .grid-2\@sm { grid-template-columns: repeat(2, 1fr); } }

/* 屏幕阅读器专用 */
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* ---- 入场动画（IntersectionObserver 驱动） ---- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .7s var(--ease), transform .7s var(--ease);
}
.reveal.is-visible { opacity: 1; transform: none; }

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

/* ---- 数字统计 ---- */
.stat-num { font-variant-numeric: tabular-nums; }