@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600;700&display=swap');

:root {
  color-scheme: dark;
  --surface-0: #0a0b0d;
  --surface-1: #0e1013;
  --surface-2: #14171b;
  --surface-3: #1b1f24;
  --text-primary: #f3f4f6;
  --text-secondary: #9aa1ab;
  --text-muted: #676e78;
  --border: #22262c;
  --border-strong: #2e333a;
  --accent: #4f8fff;
  --accent-dim: #4f8fff26;
  --accent-2: #ff8a3d;
  --good: #2fd992;
  --good-dim: #2fd99220;
  --bad: #ff5c5c;
  --bad-dim: #ff5c5c20;
  --grid-line: #ffffff08;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SF Mono", Menlo, monospace;
}
:root[data-theme="light"] {
  color-scheme: light;
  --surface-0: #fafafa;
  --surface-1: #ffffff;
  --surface-2: #f5f5f4;
  --surface-3: #ececEa;
  --text-primary: #0b0c0e;
  --text-secondary: #52565d;
  --text-muted: #85898f;
  --border: #e6e5e2;
  --border-strong: #d7d6d2;
  --accent: #2a63d6;
  --accent-dim: #2a63d61a;
  --accent-2: #d9611f;
  --good: #0e9c66;
  --good-dim: #0e9c661a;
  --bad: #d63f3f;
  --bad-dim: #d63f3f1a;
  --grid-line: #00000006;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--surface-0);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.6;
  font-size: 15px;
}
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

/* subtle data-canvas grid texture behind the page */
.grid-bg {
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 40%, transparent 90%);
}

.nav {
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 32px; border-bottom: 1px solid var(--border);
  position: sticky; top: 0; background: color-mix(in srgb, var(--surface-0) 88%, transparent);
  backdrop-filter: blur(10px); z-index: 10;
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text-primary); }
.brand svg { display: block; }
.brand .word { font-weight: 800; font-size: 17px; letter-spacing: -0.01em; font-family: var(--font-body); }
.brand .word span { color: var(--accent); }
.nav .links { display: flex; align-items: center; gap: 30px; }
.nav .links a { color: var(--text-secondary); text-decoration: none; font-size: 14px; font-weight: 550; transition: color .15s; }
.nav .links a:hover, .nav .links a.active { color: var(--text-primary); }
.nav .links a.active { color: var(--accent); }
.nav-toggle {
  display: none; background: none; border: 1px solid var(--border-strong); border-radius: 8px;
  color: var(--text-primary); font-size: 18px; line-height: 1; padding: 6px 10px; cursor: pointer;
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 32px; }

.eyebrow {
  display: inline-flex; align-items: center; gap: 7px; padding: 5px 12px; border-radius: 100px;
  background: var(--surface-2); border: 1px solid var(--border); font-size: 12.5px; font-weight: 600;
  color: var(--text-secondary); font-family: var(--font-mono); letter-spacing: 0.02em; margin-bottom: 16px;
}
.eyebrow .dot { width: 6px; height: 6px; border-radius: 50%; background: var(--good); box-shadow: 0 0 8px var(--good); }

.hero { padding: 72px 0 36px; text-align: center; }
.hero h1 { font-size: 48px; font-weight: 800; letter-spacing: -0.03em; margin: 0 0 14px; line-height: 1.08; }
.hero h1 .accent-text { color: var(--accent); }
.hero p.sub { font-size: 18px; color: var(--text-secondary); max-width: 620px; margin: 0 auto 26px; }
.hero .cta { display: inline-flex; gap: 14px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 12px 22px; border-radius: 9px; font-weight: 650;
  font-size: 14.5px; text-decoration: none; border: 1px solid transparent; transition: all .15s; cursor: pointer;
}
.btn-primary { background: var(--accent); color: #fff !important; }
.btn-primary:hover { filter: brightness(1.1); }
.btn-secondary { background: var(--surface-2); color: var(--text-primary) !important; border-color: var(--border-strong); }
.btn-secondary:hover { background: var(--surface-3); }

.stat-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin: 28px 0 40px; background: var(--border); border: 1px solid var(--border); border-radius: 14px; overflow: hidden; }
.stat-tile { background: var(--surface-1); padding: 28px 20px; text-align: center; }
.stat-tile .value { font-family: var(--font-mono); font-size: 38px; font-weight: 700; letter-spacing: -0.02em; color: var(--accent); }
.stat-tile .label { font-size: 13.5px; color: var(--text-primary); font-weight: 600; margin-top: 6px; }
.stat-tile .n { font-size: 12px; color: var(--text-muted); margin-top: 3px; font-family: var(--font-mono); }

.chart-card {
  background: var(--surface-1); border: 1px solid var(--border); border-radius: 14px; padding: 28px; margin: 28px 0;
}
.chart-card .chart-head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 18px; }
.chart-card h3 { font-size: 15px; font-weight: 650; margin: 0; }
.chart-card .legend { display: flex; gap: 16px; font-size: 12px; color: var(--text-secondary); font-family: var(--font-mono); }
.chart-card .legend .item { display: flex; align-items: center; gap: 6px; }
.chart-card .legend .sw { width: 9px; height: 9px; border-radius: 2px; }

section { padding: 44px 0; border-top: 1px solid var(--border); }
section h2 { font-size: 27px; font-weight: 750; letter-spacing: -0.015em; margin: 0 0 10px; }
section p.lede { color: var(--text-secondary); font-size: 15.5px; max-width: 680px; margin: 0 0 28px; }

.philosophy-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.philosophy-card { background: var(--surface-1); border: 1px solid var(--border); border-radius: 12px; padding: 24px; position: relative; }
.philosophy-card .num { font-family: var(--font-mono); font-size: 12px; color: var(--accent); font-weight: 650; margin-bottom: 10px; }
.philosophy-card h3 { font-size: 16px; margin: 0 0 8px; font-weight: 650; }
.philosophy-card p { font-size: 14.5px; color: var(--text-secondary); margin: 0; }

table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
th, td { text-align: left; padding: 11px 13px; border-bottom: 1px solid var(--border); font-family: var(--font-mono); }
td:nth-child(3), th:nth-child(3) { font-family: var(--font-body); }
td:nth-child(6), th:nth-child(6) { font-family: var(--font-body); }
th { color: var(--text-muted); font-weight: 600; font-size: 11.5px; text-transform: uppercase; letter-spacing: 0.04em; cursor: pointer; user-select: none; background: var(--surface-2); }
th:hover { color: var(--accent); }
tr:hover td { background: var(--surface-2); }
.tag { display: inline-block; padding: 3px 9px; border-radius: 5px; font-size: 11.5px; font-weight: 700; font-family: var(--font-mono); letter-spacing: 0.02em; }
.tag-correct { background: var(--good-dim); color: var(--good); }
.tag-wrong { background: var(--bad-dim); color: var(--bad); }

.controls { display: flex; gap: 10px; margin-bottom: 20px; flex-wrap: wrap; align-items: center; }
.controls input {
  background: var(--surface-2); border: 1px solid var(--border-strong); border-radius: 7px;
  padding: 9px 13px; color: var(--text-primary); font-size: 13.5px; font-family: var(--font-body);
}
.controls .summary { margin-left: auto; font-size: 13px; color: var(--text-muted); font-family: var(--font-mono); }

/* Custom dropdown — native <select> popups can't be restyled cross-browser,
   so this wraps a (visually hidden but still functional, for existing
   .value/change-event JS) native select with a fully custom trigger+menu. */
.select-wrap { position: relative; display: inline-block; }
.select-wrap select { position: absolute; opacity: 0; pointer-events: none; width: 1px; height: 1px; }
.select-trigger {
  background: var(--surface-2); border: 1px solid var(--border-strong); border-radius: 7px;
  padding: 9px 30px 9px 13px; color: var(--text-primary); font-size: 13.5px; font-family: var(--font-body);
  cursor: pointer; position: relative; text-align: left; min-width: 140px; transition: border-color .15s;
}
.select-trigger:hover { border-color: var(--border); }
.select-wrap.open .select-trigger { border-color: var(--accent); }
.select-trigger::after {
  content: ''; position: absolute; right: 12px; top: 50%; transform: translateY(-50%);
  width: 10px; height: 6px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%239aa1ab'/%3E%3C/svg%3E");
  background-repeat: no-repeat; transition: transform .15s;
}
.select-wrap.open .select-trigger::after { transform: translateY(-50%) rotate(180deg); }
.select-menu {
  position: absolute; top: calc(100% + 6px); left: 0; min-width: 100%; z-index: 20;
  background: var(--surface-1); border: 1px solid var(--border-strong); border-radius: 10px;
  padding: 6px; box-shadow: 0 16px 36px rgba(0,0,0,0.45); display: none;
}
.select-wrap.open .select-menu { display: block; }
.select-option {
  padding: 8px 12px; border-radius: 6px; font-size: 13.5px; color: var(--text-secondary);
  cursor: pointer; white-space: nowrap; transition: background .1s;
}
.select-option:hover { background: var(--surface-2); color: var(--text-primary); }
.select-option.selected { color: var(--accent); font-weight: 600; }
.tabs { display: flex; gap: 8px; margin-bottom: 24px; }
.tab-btn {
  padding: 9px 18px; border-radius: 8px; border: 1px solid var(--border-strong); background: var(--surface-1);
  color: var(--text-secondary); font-weight: 600; font-size: 13.5px; cursor: pointer; font-family: var(--font-mono);
}
.tab-btn.active { background: var(--accent-dim); color: var(--accent); border-color: var(--accent); }

.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: 12px; background: var(--surface-1); }

footer { padding: 36px 0 48px; color: var(--text-muted); font-size: 12.5px; text-align: center; border-top: 1px solid var(--border); }
.disclaimer { max-width: 680px; margin: 0 auto; padding: 0 20px; }
.footer-links { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; margin: 0 0 14px; padding: 0 20px; }
.footer-links a { color: var(--text-muted); text-decoration: none; }
.footer-links a:hover { color: var(--text-secondary); }

.legal { padding: 48px 0 60px; max-width: 760px; margin: 0 auto; }
.legal h1 { font-size: 30px; font-weight: 800; letter-spacing: -0.02em; margin: 0 0 8px; }
.legal .updated { color: var(--text-muted); font-size: 13px; margin: 0 0 36px; font-family: var(--font-mono); }
.legal h2 { font-size: 18px; font-weight: 700; margin: 32px 0 12px; color: var(--text-primary); }
.legal p, .legal li { color: var(--text-secondary); font-size: 14.5px; line-height: 1.65; }
.legal ul { margin: 0 0 16px; padding-left: 20px; }
.legal p { margin: 0 0 16px; }
.legal a { color: var(--accent); }

@media (max-width: 720px) {
  .hero h1 { font-size: 32px; }
  .stat-row { grid-template-columns: 1fr; }
  .philosophy-grid { grid-template-columns: 1fr; }
  .container { padding: 0 20px; }
  .nav { padding: 14px 20px; }
  .nav-toggle { display: block; }
  .nav .links {
    display: none; flex-direction: column; align-items: stretch; gap: 4px;
    position: absolute; top: 100%; left: 0; right: 0;
    background: var(--surface-0); border-bottom: 1px solid var(--border);
    padding: 10px 20px 20px;
  }
  .nav.nav-open .links { display: flex; }
  .nav .links a { font-size: 15px; padding: 10px 4px; }
  .nav .links a.btn { margin-top: 6px; text-align: center; }
  .hero { padding: 56px 0 40px; }
  .hero-break { display: none; }
  .chart-card .chart-head { flex-direction: column; align-items: flex-start; gap: 12px; }
  .chart-card .chart-head .tabs { flex-wrap: wrap; }
}