/* ==========================================================================
   方案 A · 深色科技感（Dark Tech）
   气质：深空底色 + 渐变光晕 + 网格纹理，面向 AI / 大模型 / 技术服务
   用法：首页 /index.html 及全部内页
   ========================================================================== */

:root {
  --bg: #060912;
  --bg-soft: #0b1020;
  --bg-elev: #101830;
  --surface: rgba(255, 255, 255, .035);
  --border: rgba(255, 255, 255, .10);
  --header-bg: rgba(6, 9, 18, .78);
  --header-bg-solid: #0b1020;
  --shadow: rgba(0, 0, 0, .6);

  --text: #e9eefb;
  --text-strong: #ffffff;
  --text-dim: #96a3bd;

  --brand-1: #4f7cff;
  --brand-2: #22d3ee;
  --accent:   #a855f7;
  --brand-soft: rgba(79, 124, 255, .12);
  --brand-line: rgba(79, 124, 255, .38);
  --focus: #7dd3fc;
}

/* 背景氛围：极光光晕 + 细网格，仅装饰层，不影响文字可读性 */
body::before {
  content: ""; position: fixed; inset: 0; z-index: -2; pointer-events: none;
  background:
    radial-gradient(900px 520px at 12% -8%,  rgba(79, 124, 255, .28), transparent 62%),
    radial-gradient(760px 480px at 92% 4%,   rgba(168, 85, 247, .22), transparent 60%),
    radial-gradient(900px 600px at 50% 108%, rgba(34, 211, 238, .16), transparent 60%);
}
body::after {
  content: ""; position: fixed; inset: 0; z-index: -1; pointer-events: none; opacity: .5;
  background-image:
    linear-gradient(rgba(255, 255, 255, .028) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .028) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 78%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 30%, transparent 78%);
}

.site-header { box-shadow: 0 1px 0 rgba(255, 255, 255, .04); }
.brand__mark { filter: drop-shadow(0 0 12px rgba(79, 124, 255, .5)); }
.btn--primary { background: linear-gradient(120deg, var(--brand-1), var(--accent) 90%); }
.card { backdrop-filter: blur(6px); -webkit-backdrop-filter: blur(6px); }
.card:hover { transform: translateY(-4px); }

/* 首屏：居中超宽标题 + 光标高光 */
.hero { position: relative; padding: clamp(72px, 11vw, 148px) 0 clamp(56px, 8vw, 104px); text-align: center; }
.hero h1 { max-width: 20ch; margin-inline: auto; }
.hero .lead { margin-inline: auto; }
.hero__actions { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; margin-top: 32px; }
.hero__note { margin-top: 20px; color: var(--text-dim); font-size: var(--step--1); }

/* 首屏右侧数据面板：方案 A 的标志性元素 */
.hero-split { display: grid; gap: clamp(28px, 4vw, 56px); align-items: center; }
@media (min-width: 960px) { .hero-split { grid-template-columns: 1.15fr .85fr; } .hero-split .hero { text-align: left; padding: 0; } .hero-split .hero h1, .hero-split .hero .lead { margin-inline: 0; } .hero-split .hero__actions { justify-content: flex-start; } }

.panel {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-l);
  padding: 22px; backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 40px 80px -50px var(--shadow);
}
.panel__head { display: flex; align-items: center; gap: 8px; padding-bottom: 14px; border-bottom: 1px solid var(--border); margin-bottom: 16px; }
.panel__dots { display: flex; gap: 6px; }
.panel__dots i { width: 10px; height: 10px; border-radius: 50%; background: var(--border); display: block; }
.panel__title { font-size: var(--step--1); color: var(--text-dim); font-family: var(--font-mono); }
.metric-row { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; padding: 11px 0; border-bottom: 1px dashed var(--border); }
.metric-row:last-child { border-bottom: 0; }
.metric-row dt { color: var(--text-dim); font-size: var(--step--1); }
.metric-row dd { margin: 0; font-weight: 700; font-family: var(--font-mono); }
.metric-row dd small { color: var(--text-dim); font-weight: 500; margin-left: 6px; }

/* 数据条 */
.bars { display: grid; gap: 12px; }
.bar__top { display: flex; justify-content: space-between; font-size: var(--step--1); color: var(--text-dim); margin-bottom: 6px; }
.bar__track { height: 7px; border-radius: 999px; background: var(--surface); overflow: hidden; border: 1px solid var(--border); }
.bar__fill { height: 100%; border-radius: 999px; background: linear-gradient(90deg, var(--brand-1), var(--brand-2)); }
.bar__fill--accent { background: linear-gradient(90deg, var(--accent), var(--brand-2)); }

/* 标语条 */
.marquee-strip { border-block: 1px solid var(--border); background: var(--surface); padding: 14px 0; overflow: hidden; }
.marquee-strip__inner { display: flex; flex-wrap: wrap; gap: 12px 34px; justify-content: center; color: var(--text-dim); font-size: var(--step--1); font-family: var(--font-mono); }

/* 能力卡：悬停发光描边 */
.card--glow:hover { box-shadow: 0 0 0 1px var(--brand-line), 0 30px 60px -30px var(--brand-1); }

@media (prefers-reduced-motion: no-preference) {
  .hero h1 { animation: a-rise .7s var(--ease) both; }
  .hero .lead { animation: a-rise .7s .08s var(--ease) both; }
  .hero__actions { animation: a-rise .7s .16s var(--ease) both; }
  @keyframes a-rise { from { opacity: 0; transform: translateY(22px); } to { opacity: 1; transform: none; } }
}