:root {
  --bg: #0b0e14;
  --bg-2: #0f131c;
  --card: #141925;
  --card-hover: #1a2130;
  --line: #232b3b;
  --ink: #e8ebf2;
  --ink-2: #8b93a7;
  --accent: #7aa2ff;
  --accent-2: #ffb454;
  --accent-3: #5ad0a5;
  --danger: #ff6b7a;
  --accent-soft: rgba(122, 162, 255, .12);
  --radius: 14px;
  --glow: 0 0 40px rgba(122, 162, 255, .08);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  background:
    radial-gradient(1000px 500px at 70% -10%, rgba(122,162,255,.07), transparent 60%),
    radial-gradient(800px 400px at 10% 20%, rgba(255,180,84,.04), transparent 60%),
    var(--bg);
  color: var(--ink);
  line-height: 1.8;
}
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* Hero */
.hero { padding: 110px 0 64px; text-align: center; }
.hero .tag {
  display: inline-block; font-size: 12.5px; letter-spacing: 3px;
  color: var(--accent); background: var(--accent-soft);
  border: 1px solid rgba(122,162,255,.25);
  padding: 6px 16px; border-radius: 999px; margin-bottom: 24px;
}
.hero h1 {
  font-size: 44px; font-weight: 700; letter-spacing: 2px;
  background: linear-gradient(120deg, #fff 30%, var(--accent) 75%, var(--accent-2));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.hero .thesis {
  color: var(--ink-2); margin-top: 20px; font-size: 17px;
  max-width: 660px; margin-left: auto; margin-right: auto;
}
.hero .thesis em { color: var(--ink); font-style: normal; border-bottom: 1px solid var(--accent); }
.stats { display: flex; justify-content: center; gap: 72px; margin-top: 52px; flex-wrap: wrap; }
.stats .num { font-size: 34px; font-weight: 700; color: var(--accent); font-variant-numeric: tabular-nums; }
.stats .lab { font-size: 13px; color: var(--ink-2); margin-top: 2px; }

/* Sections */
section { padding: 48px 0; }
.sec-head { margin-bottom: 28px; }
.sec-head .no { font-size: 12.5px; color: var(--accent); font-weight: 600; letter-spacing: 3px; }
.sec-head h2 { font-size: 27px; font-weight: 700; margin-top: 6px; }
.sec-head p { color: var(--ink-2); font-size: 14.5px; margin-top: 8px; max-width: 760px; }
.sec-head p b { color: var(--ink); font-weight: 600; }

/* Cards */
.grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
@media (max-width: 900px) { .grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .grid { grid-template-columns: 1fr; } }
.card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 24px 22px; transition: .25s;
}
.card:hover { transform: translateY(-4px); background: var(--card-hover); box-shadow: var(--glow); border-color: rgba(122,162,255,.3); }
.card .ico { font-size: 22px; margin-bottom: 12px; }
.card h3 { font-size: 16px; font-weight: 600; }
.card p { font-size: 13px; color: var(--ink-2); margin-top: 8px; }

/* Insight callouts */
.insight {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 16px;
}
@media (max-width: 900px) { .insight { grid-template-columns: 1fr; } }
.insight .item {
  background: linear-gradient(160deg, rgba(122,162,255,.06), rgba(122,162,255,0) 60%), var(--card);
  border: 1px solid var(--line); border-radius: var(--radius); padding: 22px;
}
.insight .item .q { font-size: 15px; font-weight: 600; color: var(--ink); }
.insight .item .q::before { content: '◆ '; color: var(--accent-2); font-size: 11px; vertical-align: 2px; }
.insight .item p { font-size: 13.5px; color: var(--ink-2); margin-top: 8px; }
.insight .item p b { color: var(--accent-3); font-weight: 600; }

/* Chart blocks */
.chart-card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px; margin-bottom: 26px;
}
.chart-card:hover { border-color: rgba(122,162,255,.22); }
.chart-card .head { display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap; margin-bottom: 6px; }
.chart-card .head h3 { font-size: 17px; font-weight: 600; }
.chart-card .pill { font-size: 11.5px; color: var(--accent); background: var(--accent-soft); border: 1px solid rgba(122,162,255,.2); border-radius: 999px; padding: 2px 11px; }
.chart-card .desc { font-size: 13.5px; color: var(--ink-2); margin-bottom: 6px; }
.chart-card .takeaway { font-size: 13px; color: var(--accent-2); padding-top: 10px; border-top: 1px dashed var(--line); }
.chart-card .takeaway::before { content: '💡 洞察：'; color: var(--ink-2); }
.chart { width: 100%; height: 380px; }
.chart.tall { height: 430px; }
code.k {
  font-family: Consolas, Monaco, monospace; font-size: 12.5px;
  background: rgba(122,162,255,.1); color: var(--accent);
  padding: 2px 8px; border-radius: 6px; border: 1px solid rgba(122,162,255,.15);
}

/* API table */
.api { width: 100%; border-collapse: collapse; font-size: 13.5px; background: var(--card); border-radius: var(--radius); overflow: hidden; border: 1px solid var(--line); }
.api th { text-align: left; background: var(--bg-2); padding: 13px 18px; font-weight: 600; color: var(--ink-2); border-bottom: 1px solid var(--line); }
.api td { padding: 13px 18px; border-bottom: 1px solid var(--line); vertical-align: top; color: #c6ccda; }
.api tr:last-child td { border-bottom: none; }
.api tr:hover td { background: rgba(122,162,255,.04); }
.api td:first-child { font-family: Consolas, Monaco, monospace; color: var(--accent); white-space: nowrap; }

/* Summary */
.summary {
  background: linear-gradient(160deg, rgba(122,162,255,.1), rgba(255,180,84,.05) 70%), var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius); padding: 40px 36px;
}
.summary h2 { font-size: 23px; margin-bottom: 14px; }
.summary .line { width: 44px; height: 3px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); border-radius: 2px; margin-bottom: 18px; }
.summary p { color: var(--ink-2); font-size: 15px; max-width: 780px; }
.summary p b { color: var(--ink); }
.summary .chips { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 26px; }
.summary .chip { font-size: 12.5px; border: 1px solid var(--line); background: var(--bg-2); border-radius: 999px; padding: 6px 16px; color: #aab2c4; }

footer { text-align: center; color: #565e70; font-size: 12.5px; padding: 44px 0 36px; }