/* ==========================================================================
   GEO 作品集 — 设计系统（UI 参考 Vercel / 动效参考 Linear）
   ========================================================================== */

:root {
  color-scheme: light;
  --bg: #ffffff;
  --fg: #000000;
  --fg-soft: #333333;
  --muted: #666666;
  --muted-2: #999999;
  --border: #eaeaea;
  --border-strong: #d4d4d4;
  --surface: #fafafa;
  --surface-2: #f4f4f4;
  --accent: #000000;
  --accent-fg: #ffffff;
  --link: #0070f3;
  --pos: #0f8a4f;
  --nav: rgba(255, 255, 255, 0.82);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 10px 30px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 2px 4px rgba(0, 0, 0, 0.04), 0 24px 60px rgba(0, 0, 0, 0.10);
  --r-sm: 6px;
  --r: 10px;
  --r-lg: 14px;
  --pill: 999px;
  --max: 1200px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --dur: 0.5s;
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --bg: #000000;
    --fg: #ffffff;
    --fg-soft: #dddddd;
    --muted: #888888;
    --muted-2: #666666;
    --border: #333333;
    --border-strong: #4a4a4a;
    --surface: #0a0a0a;
    --surface-2: #131313;
    --accent: #ffffff;
    --accent-fg: #000000;
    --link: #3b82f6;
    --pos: #4ade80;
    --nav: rgba(0, 0, 0, 0.72);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.5);
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.6), 0 12px 34px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 2px 6px rgba(0, 0, 0, 0.6), 0 28px 70px rgba(0, 0, 0, 0.6);
  }
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #ffffff; --fg: #000000; --fg-soft: #333333; --muted: #666666; --muted-2: #999999;
  --border: #eaeaea; --border-strong: #d4d4d4; --surface: #fafafa; --surface-2: #f4f4f4;
  --accent: #000000; --accent-fg: #ffffff; --link: #0070f3; --pos: #0f8a4f;
  --nav: rgba(255, 255, 255, 0.82);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 10px 30px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 2px 4px rgba(0, 0, 0, 0.04), 0 24px 60px rgba(0, 0, 0, 0.10);
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #000000; --fg: #ffffff; --fg-soft: #dddddd; --muted: #888888; --muted-2: #666666;
  --border: #333333; --border-strong: #4a4a4a; --surface: #0a0a0a; --surface-2: #131313;
  --accent: #ffffff; --accent-fg: #000000; --link: #3b82f6; --pos: #4ade80;
  --nav: rgba(0, 0, 0, 0.72);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.5);
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.6), 0 12px 34px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 2px 6px rgba(0, 0, 0, 0.6), 0 28px 70px rgba(0, 0, 0, 0.6);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 76px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei UI",
    "PingFang SC", "Hiragino Sans GB", system-ui, sans-serif;
  font-size: 15px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body.is-loading { opacity: 0; }
body.is-ready { opacity: 1; transition: opacity 0.4s ease; }

button, a { -webkit-tap-highlight-color: transparent; }
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }

.mono,
.metric-table td,
.project-facts dt,
.eyebrow,
.result-grid strong,
.signal-grid strong {
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum";
}

/* ---------- scroll progress ---------- */
.scroll-progress {
  position: fixed;
  inset: 0 auto auto 0;
  z-index: 60;
  height: 2px;
  width: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: var(--fg);
  pointer-events: none;
}

/* ---------- header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  border-bottom: 1px solid var(--border);
  background: var(--nav);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
}

.nav-shell {
  display: grid;
  min-height: 64px;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  width: max-content;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.brand-mark {
  display: grid;
  width: 28px;
  height: 28px;
  place-items: center;
  border-radius: var(--r-sm);
  background: var(--accent);
  color: var(--accent-fg);
  font-size: 13px;
  font-weight: 800;
}

.brand i { padding-inline: 2px; color: var(--muted-2); font-style: normal; font-weight: 400; }

nav { display: flex; align-items: center; gap: 4px; white-space: nowrap; }

nav a {
  position: relative;
  padding: 6px 10px;
  border-radius: var(--r-sm);
  color: var(--muted);
  font-size: 13.5px;
  font-weight: 500;
  transition: color 0.18s ease, background-color 0.18s ease;
}

nav a::after {
  content: "";
  position: absolute;
  left: 10px;
  right: 10px;
  bottom: 1px;
  height: 1.5px;
  background: var(--fg);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 0.28s var(--ease);
}

nav a:hover { color: var(--fg); }
nav a.is-active { color: var(--fg); font-weight: 600; }
nav a.is-active::after { transform: scaleX(1); }

.theme-toggle {
  display: inline-flex;
  justify-self: end;
  align-items: center;
  gap: 6px;
  min-height: 34px;
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  background: var(--bg);
  color: var(--fg);
  padding: 6px 11px;
  font: inherit;
  font-size: 12.5px;
  font-weight: 500;
  cursor: pointer;
  transition: border-color 0.18s ease, background-color 0.18s ease, transform 0.12s ease;
}

.theme-toggle:hover { border-color: var(--border-strong); background: var(--surface); }
.theme-toggle:active { transform: translateY(1px); }

/* ---------- hero ---------- */
.hero {
  position: relative;
  display: grid;
  min-height: calc(100dvh - 64px);
  grid-template-columns: minmax(0, 1fr) minmax(420px, 1.05fr);
  align-content: center;
  gap: 26px 56px;
  padding-block: 88px 56px;
}

.hero::before {
  content: "";
  position: absolute;
  inset: -1px;
  z-index: 0;
  pointer-events: none;
  background: radial-gradient(
    520px circle at var(--mx, 50%) var(--my, 0%),
    color-mix(in srgb, var(--fg) 6%, transparent),
    transparent 70%
  );
  opacity: 0;
  transition: opacity 0.4s ease;
}

.hero:hover::before { opacity: 1; }
.hero > * { position: relative; z-index: 1; }

.hero-copy { align-self: center; max-width: 560px; }

.eyebrow {
  margin: 0 0 20px;
  color: var(--muted);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1, h2, h3, p { margin-top: 0; }

h1 {
  max-width: 12ch;
  margin-bottom: 22px;
  font-size: clamp(2.9rem, 6vw, 5.2rem);
  font-weight: 800;
  letter-spacing: -0.05em;
  line-height: 0.98;
}

.hero-summary {
  max-width: 34rem;
  margin-bottom: 18px;
  color: var(--fg-soft);
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  line-height: 1.7;
}

.hero-note {
  max-width: 40rem;
  margin: 0 0 28px;
  color: var(--muted);
  font-size: 0.95rem;
}

.hero-actions { display: flex; flex-wrap: wrap; gap: 10px; }

.button {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  justify-content: center;
  border: 1px solid transparent;
  border-radius: var(--r-sm);
  padding: 9px 16px;
  font-size: 14px;
  font-weight: 500;
  white-space: nowrap;
  transition: background-color 0.18s ease, border-color 0.18s ease, color 0.18s ease, transform 0.12s ease, box-shadow 0.18s ease;
}

.button:active { transform: translateY(1px); }

.button-primary { background: var(--accent); color: var(--accent-fg); }
.button-primary:hover { box-shadow: var(--shadow-sm); filter: brightness(1.08); }

.button-secondary { border-color: var(--border); background: var(--bg); color: var(--fg); }
.button-secondary:hover { border-color: var(--border-strong); background: var(--surface); }

.hero-visual { position: relative; align-self: center; margin: 0; }

.hero-visual a {
  position: relative;
  display: block;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: var(--surface);
  box-shadow: var(--shadow-lg);
  transition: transform 0.3s var(--ease), border-color 0.2s ease;
}

.hero-visual a:hover { transform: translateY(-3px); border-color: var(--border-strong); }
.hero-visual img { width: 100%; aspect-ratio: 1.16; object-fit: cover; object-position: top left; }
.hero-visual figcaption { margin-top: 12px; color: var(--muted-2); font-size: 12px; }

.project-facts {
  display: grid;
  grid-column: 1 / -1;
  grid-template-columns: 0.8fr 1.3fr 1fr;
  margin: 8px 0 0;
  border-top: 1px solid var(--border);
}

.project-facts > div { min-width: 0; padding: 20px 26px 0 0; }
.project-facts > div + div { border-left: 1px solid var(--border); padding-left: 26px; }
.project-facts dt { margin-bottom: 4px; color: var(--muted-2); font-size: 11.5px; letter-spacing: 0.04em; text-transform: uppercase; }
.project-facts dd { margin: 0; font-size: 14px; font-weight: 600; }

/* ---------- sections ---------- */
.shell { width: min(calc(100% - 44px), var(--max)); margin-inline: auto; }
.section { padding-block: 108px; }

.section-heading { max-width: 760px; margin-bottom: 44px; }
.section-heading h2 {
  max-width: 18ch;
  margin-bottom: 16px;
  font-size: clamp(1.8rem, 3.4vw, 2.7rem);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.1;
}
.section-heading p { max-width: 58ch; margin-bottom: 0; color: var(--muted); font-size: 15px; }
.compact-heading { margin-bottom: 40px; }

.signal-band { border-block: 1px solid var(--border); background: var(--surface); }
.signal-grid { display: grid; grid-template-columns: 0.8fr 1fr 0.9fr 1.6fr; align-items: center; }
.signal-grid > div, .signal-grid > p { min-height: 118px; margin: 0; padding: 24px 30px; }
.signal-grid > * + * { border-left: 1px solid var(--border); }
.signal-grid strong { display: block; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: clamp(1.5rem, 2.4vw, 2.1rem); font-weight: 700; letter-spacing: -0.03em; line-height: 1.2; }
.signal-grid span { color: var(--muted); font-size: 12.5px; }
.signal-grid p { display: grid; align-items: center; color: var(--muted); font-size: 14px; line-height: 1.7; }

/* ---------- problem flow ---------- */
.problem-flow { display: grid; grid-template-columns: 0.9fr 1.2fr 1.05fr; border-block: 1px solid var(--border); }
.problem-flow article { position: relative; min-height: 250px; padding: 32px 40px 36px 0; }
.problem-flow article + article { border-left: 1px solid var(--border); padding-left: 40px; }
.problem-flow span { display: block; margin-bottom: 38px; color: var(--muted); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 11.5px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; }
.problem-flow h3 { max-width: 18ch; margin-bottom: 12px; font-size: clamp(1.2rem, 1.9vw, 1.55rem); font-weight: 650; letter-spacing: -0.025em; line-height: 1.35; }
.problem-flow p { max-width: 28ch; margin-bottom: 0; color: var(--muted); font-size: 13.5px; }

blockquote {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: end;
  gap: 30px;
  margin: 72px 0 0;
  padding-left: clamp(0px, 14vw, 180px);
}
blockquote p { margin-bottom: 0; color: var(--fg); font-size: clamp(1.7rem, 3.6vw, 3.2rem); font-weight: 700; letter-spacing: -0.04em; line-height: 1.14; }
blockquote footer { padding-bottom: 12px; color: var(--muted-2); font-size: 12px; }

/* ---------- agents ---------- */
.agents-section { width: 100%; background: var(--surface); border-block: 1px solid var(--border); }
.agent-workbench { display: grid; grid-template-columns: minmax(250px, 0.72fr) minmax(0, 1.85fr); overflow: hidden; border: 1px solid var(--border); border-radius: var(--r-lg); background: var(--bg); }
.agent-list { border-right: 1px solid var(--border); }
.agent-tab {
  display: grid;
  width: 100%;
  min-height: 74px;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 12px;
  border: 0;
  border-bottom: 1px solid var(--border);
  background: transparent;
  color: var(--fg);
  padding: 15px 20px;
  text-align: left;
  cursor: pointer;
  transition: background-color 0.18s ease, color 0.18s ease;
}
.agent-tab:last-child { border-bottom: 0; }
.agent-tab b { font-size: 14px; font-weight: 600; }
.agent-tab span { color: var(--muted-2); font-size: 12px; }
.agent-tab:hover, .agent-tab:focus-visible { background: var(--surface); }
.agent-tab.is-active { background: var(--surface-2); color: var(--fg); }
.agent-tab.is-active b { font-weight: 700; }

.agent-detail { position: relative; min-height: 460px; padding: clamp(32px, 5vw, 70px); outline: none; }
.agent-detail.switching { opacity: 0; transform: translateY(6px); }
.agent-detail { transition: opacity 0.28s var(--ease), transform 0.28s var(--ease); }
.agent-index { position: absolute; top: 26px; right: 32px; color: color-mix(in srgb, var(--fg) 10%, transparent); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: clamp(4rem, 9vw, 8rem); font-weight: 800; letter-spacing: -0.06em; line-height: 1; }
.agent-role { position: relative; margin-bottom: 12px; color: var(--muted); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 12px; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; }
.agent-detail h3 { position: relative; margin-bottom: 16px; font-size: clamp(1.7rem, 3.4vw, 3rem); font-weight: 750; letter-spacing: -0.04em; line-height: 1.06; }
.agent-description { position: relative; max-width: 52ch; margin-bottom: 38px; color: var(--fg-soft); font-size: 15px; }
.agent-io { position: relative; display: grid; grid-template-columns: 1fr 1fr; gap: 1px; overflow: hidden; border: 1px solid var(--border); border-radius: var(--r); background: var(--border); }
.agent-io > div { min-height: 124px; background: var(--bg); padding: 20px; }
.agent-io h4 { margin: 0 0 9px; color: var(--muted-2); font-size: 11px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; }
.agent-io p { margin-bottom: 0; font-size: 14px; font-weight: 550; }
.agent-boundary { position: relative; margin: 20px 0 0; color: var(--muted); font-size: 13px; }
.agent-boundary b { color: var(--fg-soft); }

/* ---------- method strip ---------- */
.method-strip { display: grid; grid-template-columns: repeat(3, 1fr); margin-bottom: 24px; overflow: hidden; border: 1px solid var(--border); border-radius: var(--r-lg); background: var(--surface); }
.method-strip > div { padding: 24px 28px; }
.method-strip > div + div { border-left: 1px solid var(--border); }
.method-strip strong { display: block; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: clamp(1.35rem, 2.2vw, 1.9rem); font-weight: 700; letter-spacing: -0.03em; line-height: 1.2; }
.method-strip span { color: var(--muted); font-size: 12.5px; }

/* ---------- evidence figures ---------- */
.evidence-figures { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.evidence-figure { margin: 0; }
.evidence-figure.wide { grid-column: 1 / -1; }
.evidence-figure a { display: block; overflow: hidden; border: 1px solid var(--border); border-radius: var(--r); background: var(--bg); box-shadow: var(--shadow-sm); transition: transform 0.3s var(--ease), border-color 0.2s ease, box-shadow 0.3s ease; }
.evidence-figure a:hover { transform: translateY(-3px); border-color: var(--border-strong); box-shadow: var(--shadow); }
.evidence-figure img { width: 100%; height: auto; }
.evidence-figure figcaption { margin-top: 10px; color: var(--muted-2); font-size: 12px; }

/* ---------- tables ---------- */
.table-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.table-stack { display: grid; gap: 32px; }
.table-scroll { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--r); background: var(--bg); }

.metric-table {
  width: 100%;
  height: max-content;
  border-collapse: separate;
  border-spacing: 0;
  border: 1px solid var(--border);
  border-radius: var(--r);
  overflow: hidden;
  background: var(--bg);
  font-size: 13.5px;
}
.table-scroll .metric-table { min-width: 1000px; border: 0; border-radius: 0; }

.metric-table caption { padding: 16px 20px 14px; color: var(--fg); font-size: 13px; font-weight: 650; text-align: left; }
.metric-table th, .metric-table td { padding: 12px 20px; border-top: 1px solid var(--border); text-align: left; vertical-align: top; }
.metric-table thead th { color: var(--muted-2); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 11px; font-weight: 600; letter-spacing: 0.04em; text-transform: uppercase; }
.metric-table td:first-child { font-weight: 600; }
.metric-table tbody tr { transition: background-color 0.15s ease; }
.metric-table tbody tr:hover { background: var(--surface); }
.metric-table td.up { color: var(--pos); font-weight: 650; }
.metric-table tr.total td { border-top: 1px solid var(--border-strong); font-weight: 700; }
.table-scroll .metric-table td:first-child, .table-scroll .metric-table th:first-child { word-break: keep-all; }

/* ---------- grids: result / retro / toc / duty / other ---------- */
.result-grid { display: grid; grid-template-columns: repeat(4, 1fr); border-block: 1px solid var(--border); }
.result-grid > div { padding: 30px 28px; transition: background-color 0.2s ease; }
.result-grid > div + div { border-left: 1px solid var(--border); }
.result-grid > div:hover { background: var(--surface); }
.result-grid strong { display: block; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: clamp(1.6rem, 2.9vw, 2.4rem); font-weight: 750; letter-spacing: -0.04em; line-height: 1.12; }
.result-grid span { color: var(--muted); font-size: 12.5px; }

.retro-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.retro-grid article { border-top: 1px solid var(--fg); padding-top: 18px; }
.retro-grid h3 { margin-bottom: 10px; font-size: 15px; font-weight: 650; }
.retro-grid p { margin-bottom: 0; color: var(--muted); font-size: 14px; }

.toc-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.toc-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  border: 1px solid var(--border);
  border-radius: var(--r);
  background: var(--bg);
  padding: 22px 24px;
  transition: transform 0.24s var(--ease), border-color 0.2s ease, box-shadow 0.24s ease;
}
.toc-card:hover, .toc-card:focus-visible { transform: translateY(-3px); border-color: var(--border-strong); box-shadow: var(--shadow); }
.toc-card em { color: var(--muted-2); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 11px; font-style: normal; font-weight: 600; letter-spacing: 0.06em; text-transform: uppercase; }
.toc-card b { font-size: 15px; font-weight: 650; }
.toc-card span { color: var(--muted); font-size: 13px; }

.duty-card { border: 1px solid var(--border); border-radius: var(--r); background: var(--bg); padding: 26px 28px; }
.duty-card h3 { margin-bottom: 14px; font-size: 15px; font-weight: 650; }
.duty-list { display: grid; margin: 0; padding: 0; gap: 10px; list-style: none; }
.duty-list li { display: flex; gap: 10px; color: var(--fg-soft); font-size: 14px; }
.duty-list li::before { content: "→"; color: var(--muted-2); font-weight: 600; }

.other-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.other-card { display: block; border: 1px solid var(--border); border-radius: var(--r); background: var(--bg); padding: 28px 30px; transition: transform 0.24s var(--ease), border-color 0.2s ease, box-shadow 0.24s ease; }
.other-card:hover { transform: translateY(-3px); border-color: var(--border-strong); box-shadow: var(--shadow); }
.other-card h3 { margin-bottom: 6px; font-size: 17px; font-weight: 700; letter-spacing: -0.02em; }
.other-card .role { margin-bottom: 16px; color: var(--muted-2); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 11.5px; letter-spacing: 0.04em; text-transform: uppercase; }
.other-card ul { display: grid; margin: 0; padding-left: 18px; gap: 8px; color: var(--muted); font-size: 13.5px; }
.other-card strong { color: var(--fg); }

.contact-list { display: grid; margin: 0; padding: 0; gap: 12px; list-style: none; }
.contact-list a { display: inline-flex; width: max-content; align-items: center; gap: 10px; font-weight: 600; font-size: 14px; transition: color 0.18s ease; }
.contact-list a:hover, .contact-list a:focus-visible { color: var(--link); }

/* ---------- page hero (sub pages) ---------- */
.page-hero { padding-block: 72px 8px; }
.page-hero .eyebrow { margin-bottom: 16px; }
.page-title { max-width: 22ch; margin-bottom: 20px; font-size: clamp(2.1rem, 4.4vw, 3.4rem); font-weight: 800; letter-spacing: -0.045em; line-height: 1.05; }
.page-lede { max-width: 62ch; margin-bottom: 0; color: var(--muted); font-size: 15.5px; }

/* ---------- page nav ---------- */
.page-nav { display: flex; width: min(calc(100% - 44px), var(--max)); margin: 0 auto; padding: 28px 0 60px; border-top: 1px solid var(--border); gap: 14px; }
.page-nav:empty { display: none; }
.page-nav-link { display: flex; min-width: 190px; flex-direction: column; gap: 3px; border: 1px solid var(--border); border-radius: var(--r); background: var(--bg); padding: 14px 18px; transition: transform 0.22s var(--ease), border-color 0.18s ease, box-shadow 0.22s ease; }
.page-nav-link:hover, .page-nav-link:focus-visible { transform: translateY(-2px); border-color: var(--border-strong); box-shadow: var(--shadow); }
.page-nav-link span { color: var(--muted-2); font-size: 11px; letter-spacing: 0.06em; text-transform: uppercase; }
.page-nav-link b { font-size: 14px; }
.page-nav-link.next { margin-left: auto; align-items: flex-end; text-align: right; }

/* ---------- misc ---------- */
.data-note { margin: 40px 0 0; color: var(--muted-2); font-size: 12.5px; line-height: 1.7; }
.brief-band { margin-top: 26px; border: 1px solid var(--border); border-left: 3px solid var(--fg); border-radius: var(--r-sm); background: var(--surface); padding: 18px 22px; color: var(--muted); font-size: 13.5px; }
.skip-link { position: fixed; left: 16px; top: -60px; z-index: 80; border-radius: var(--r-sm); background: var(--fg); color: var(--bg); padding: 9px 14px; transition: top 0.2s ease; }
.skip-link:focus { top: 16px; }

.site-footer { border-top: 1px solid var(--border); background: var(--surface); }
.site-footer .shell { display: flex; min-height: 92px; align-items: center; justify-content: space-between; gap: 24px; }
.site-footer p { margin: 0; color: var(--muted-2); font-size: 12.5px; }

:focus-visible { outline: 2px solid var(--link); outline-offset: 2px; }

/* ---------- motion (Linear-ish) ---------- */
.reveal { opacity: 0; transform: translateY(12px); transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease); transition-delay: var(--d, 0ms); }
.reveal.is-in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1 !important; transform: none !important; transition: none !important; }
  * { transition-duration: 0.001ms !important; animation-duration: 0.001ms !important; }
}

/* ---------- responsive ---------- */
@media (max-width: 960px) {
  nav { display: none; }
  .nav-shell { grid-template-columns: 1fr auto; }
  .hero { min-height: auto; grid-template-columns: 1fr; padding-block: 64px 44px; }
  h1 { max-width: 14ch; }
  .project-facts, .signal-grid { grid-template-columns: 1fr 1fr; }
  .project-facts > div:nth-child(3) { grid-column: 1 / -1; border-left: 0; border-top: 1px solid var(--border); margin-top: 16px; padding-left: 0; }
  .signal-grid > *:nth-child(3) { border-left: 0; border-top: 1px solid var(--border); }
  .signal-grid > *:nth-child(4) { border-top: 1px solid var(--border); }
  .problem-flow { grid-template-columns: 1fr; }
  .problem-flow article { min-height: auto; padding: 26px 0; }
  .problem-flow article + article { border-left: 0; border-top: 1px solid var(--border); padding-left: 0; }
  .problem-flow span { margin-bottom: 16px; }
  .problem-flow p, .problem-flow h3 { max-width: none; }
  blockquote { grid-template-columns: 1fr; padding-left: 0; }
  blockquote footer { padding-bottom: 0; }
  .agent-workbench { grid-template-columns: 1fr; }
  .agent-list { display: grid; grid-template-columns: 1fr 1fr; border-right: 0; border-bottom: 1px solid var(--border); }
  .agent-tab:nth-child(odd) { border-right: 1px solid var(--border); }
  .toc-grid, .note-grid, .other-grid, .retro-grid, .evidence-figures, .table-wrap { grid-template-columns: 1fr; }
  .method-strip { grid-template-columns: 1fr; }
  .method-strip > div + div { border-left: 0; border-top: 1px solid var(--border); }
  .result-grid { grid-template-columns: 1fr 1fr; }
  .result-grid > div:nth-child(3) { border-left: 0; border-top: 1px solid var(--border); }
  .result-grid > div:nth-child(4) { border-top: 1px solid var(--border); }
}

@media (max-width: 620px) {
  .shell { width: min(calc(100% - 32px), var(--max)); }
  .section { padding-block: 76px; }
  .section-heading { margin-bottom: 34px; }
  .agent-list { display: flex; overflow-x: auto; }
  .agent-tab { min-width: 180px; border-right: 1px solid var(--border); }
  .agent-detail { min-height: 520px; padding: 30px 20px; }
  .agent-io { grid-template-columns: 1fr; }
  .result-grid { grid-template-columns: 1fr; }
  .result-grid > div + div, .result-grid > div:nth-child(3) { border-left: 0; border-top: 1px solid var(--border); }
  .metric-table caption, .metric-table th, .metric-table td { padding-inline: 14px; }
  .page-nav { flex-direction: column; }
  .page-nav-link, .page-nav-link.next { min-width: 0; width: 100%; align-items: flex-start; margin-left: 0; text-align: left; }
  .site-footer .shell { flex-direction: column; align-items: flex-start; justify-content: center; gap: 4px; }
}

@media (prefers-reduced-transparency: reduce) {
  .site-header { background: var(--bg); backdrop-filter: none; -webkit-backdrop-filter: none; }
}

/* ---------- home / project cards ---------- */
.home-hero { padding-block: 84px 18px; }
.home-hero h1 { max-width: 16ch; margin-bottom: 22px; }
.home-hero .hero-summary { max-width: 56ch; }

.project-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }

.project-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: var(--bg);
  padding: 30px;
  transition: transform 0.3s var(--ease), border-color 0.2s ease, box-shadow 0.3s ease;
}

.project-card:hover,
.project-card:focus-visible {
  transform: translateY(-4px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow);
}

.project-card .p-eyebrow {
  margin: 0;
  color: var(--muted-2);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.project-card h3 { margin: 0; font-size: clamp(1.25rem, 1.9vw, 1.55rem); font-weight: 750; letter-spacing: -0.03em; line-height: 1.15; }
.project-card .p-meta { margin: 0; color: var(--muted-2); font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 11.5px; letter-spacing: 0.03em; }
.project-card .p-sum { margin: 0; color: var(--muted); font-size: 14px; }

.project-card .p-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  margin: 4px 0;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--r);
  background: var(--border);
}
.project-card .p-stats > div { background: var(--bg); padding: 14px 16px; }
.project-card .p-stats strong { display: block; font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: 1.2rem; font-weight: 750; letter-spacing: -0.03em; line-height: 1.2; }
.project-card .p-stats span { color: var(--muted-2); font-size: 11.5px; }

.project-card .p-link { margin-top: auto; padding-top: 6px; color: var(--fg); font-size: 14px; font-weight: 650; }
.project-card:hover .p-link { color: var(--link); }
.project-card .p-actions { display: flex; flex-wrap: wrap; gap: 6px 20px; margin-top: auto; padding-top: 6px; }
.project-card .p-actions .p-link { margin-top: 0; padding-top: 0; }

@media (max-width: 960px) {
  .project-grid { grid-template-columns: 1fr; }
}

/* ---------- file preview modal ---------- */
.preview-modal { position: fixed; inset: 0; z-index: 100; display: none; }
.preview-modal.open { display: grid; place-items: center; }
.preview-backdrop { position: absolute; inset: 0; background: rgba(0, 0, 0, 0.5); }
.preview-panel {
  position: relative;
  display: flex;
  width: min(1120px, 94vw);
  height: min(88vh, 900px);
  flex-direction: column;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: var(--bg);
  box-shadow: var(--shadow-lg);
  animation: preview-in 0.24s var(--ease);
}
@keyframes preview-in { from { opacity: 0; transform: translateY(10px) scale(0.99); } to { opacity: 1; transform: none; } }
.preview-head { display: flex; align-items: center; gap: 12px; border-bottom: 1px solid var(--border); padding: 12px 14px 12px 18px; }
.preview-title { flex: 1; min-width: 0; font-size: 14px; font-weight: 650; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.preview-actions { display: flex; gap: 8px; flex: none; }
.preview-btn {
  display: inline-flex; align-items: center; gap: 6px; min-height: 32px;
  padding: 6px 12px; border: 1px solid var(--border); border-radius: var(--r-sm);
  background: var(--bg); color: var(--fg); font: inherit; font-size: 13px; font-weight: 500;
  white-space: nowrap; cursor: pointer;
  transition: background-color 0.18s ease, border-color 0.18s ease, transform 0.12s ease;
}
.preview-btn:hover { border-color: var(--border-strong); background: var(--surface); }
.preview-btn:active { transform: translateY(1px); }
.preview-btn.primary { background: var(--accent); color: var(--accent-fg); border-color: transparent; }
.preview-btn.primary:hover { filter: brightness(1.08); background: var(--accent); }
.preview-body { position: relative; flex: 1; background: var(--surface); }
.preview-body iframe { width: 100%; height: 100%; border: 0; background: #fff; }
@media (max-width: 640px) {
  .preview-panel { width: 100vw; height: 100dvh; border-radius: 0; border: 0; }
}

/* ---------- side table of contents ---------- */
.side-toc {
  position: fixed;
  right: 20px;
  top: 50%;
  z-index: 30;
  display: grid;
  gap: 9px;
  padding: 10px 0;
  transform: translateY(-50%);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}
.side-toc.visible { opacity: 1; pointer-events: auto; }
.side-toc a { display: flex; align-items: center; justify-content: flex-end; gap: 10px; text-decoration: none; }
.side-toc .bar {
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: var(--border-strong);
  transition: width 0.22s var(--ease), background-color 0.22s ease;
}
.side-toc .label {
  max-width: 0;
  overflow: hidden;
  opacity: 0;
  white-space: nowrap;
  color: var(--muted);
  font-size: 12.5px;
  transition: max-width 0.32s var(--ease), opacity 0.2s ease, color 0.2s ease;
}
.side-toc:hover .label { max-width: 300px; opacity: 1; }
.side-toc a.is-active .label { max-width: 300px; opacity: 1; color: var(--fg); font-weight: 600; }
.side-toc a.is-active .bar { width: 32px; background: var(--fg); }
.side-toc a:hover .bar { width: 32px; background: var(--fg); }
@media (max-width: 1180px) { .side-toc { display: none; } }

/* ---------- left chapter nav（项目章节：概览 / 需求与方案 / ...） ---------- */
.side-chapters {
  position: fixed;
  left: max(12px, calc((100vw - var(--max)) / 2 - 168px));
  top: 104px;
  z-index: 30;
  display: grid;
  width: 150px;
  gap: 3px;
}
.side-chapters .sc-title {
  margin: 0 0 8px;
  color: var(--muted-2);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.07em;
  text-transform: uppercase;
}
.side-chapters a {
  position: relative;
  padding: 5px 0 5px 12px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 500;
  transition: color 0.18s ease;
}
.side-chapters a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 2px;
  height: 0;
  border-radius: 2px;
  background: var(--fg);
  transform: translateY(-50%);
  transition: height 0.22s var(--ease);
}
.side-chapters a:hover { color: var(--fg); }
.side-chapters a.is-active { color: var(--fg); font-weight: 700; }
.side-chapters a.is-active::before { height: 18px; }
@media (max-width: 1499px) { .side-chapters { display: none; } }

/* ---------- UI gallery（产品界面截图） ---------- */
.ui-gallery { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.ui-shot { margin: 0; }
.ui-shot.wide { grid-column: 1 / -1; }
.ui-shot a {
  display: block;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--r);
  background: var(--bg);
  box-shadow: var(--shadow-sm);
  transition: transform 0.3s var(--ease), border-color 0.2s ease, box-shadow 0.3s ease;
}
.ui-shot a:hover { transform: translateY(-3px); border-color: var(--border-strong); box-shadow: var(--shadow); }
.ui-shot img { display: block; width: 100%; height: auto; }
.ui-shot figcaption { display: flex; align-items: baseline; gap: 10px; margin-top: 11px; color: var(--muted); font-size: 12.5px; }
.ui-shot figcaption em {
  flex: none;
  color: var(--muted-2);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 11px;
  font-style: normal;
  letter-spacing: 0.06em;
}
.ui-shot figcaption b { flex: none; color: var(--fg); font-size: 13px; font-weight: 650; }
@media (max-width: 760px) { .ui-gallery { grid-template-columns: 1fr; } }