/* ============================================================
   DeepSeek Harness Desktop — 下载介绍页
   设计系统参照 deepseek.com/harness/：
   深蓝黑底 #0d1017 · Montserrat 标题 · Host Grotesk 正文 ·
   品牌蓝 #4d6bfe · 玻璃面板 · 旋转 conic 描边 · hero 入场动效
   ============================================================ */

:root {
  --bg: #0d1017;
  --bg-panel: rgba(255, 255, 255, 0.04);
  --bg-panel-2: rgba(255, 255, 255, 0.08);
  --text: #ffffff;
  --text-desc: #8691a1;
  --text-dim: #5b6577;
  --brand: #4d6bfe;
  --brand-deep: #4176e6;
  --brand-glow: rgba(120, 170, 255, 0.7);
  --border: rgba(255, 255, 255, 0.12);
  --border-strong: rgba(255, 255, 255, 0.22);
  --radius-panel: 20px;
  --radius-card: 12px;
  --radius-pill: 9999px;
  --font-display: "Montserrat", "Host Grotesk", ui-sans-serif, system-ui, sans-serif;
  --font-sans: "Host Grotesk", "DM Sans", ui-sans-serif, system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "Fragment Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --ease-out: cubic-bezier(0.22, 0.61, 0.36, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection { background: rgba(77, 107, 254, 0.35); }

a { color: inherit; text-decoration: none; }

img { max-width: 100%; display: block; }

.container {
  width: min(100% - 48px, 1140px);
  margin-inline: auto;
}

/* ---------- 字体 ---------- */
.font-display { font-family: var(--font-display); }
.mono { font-family: var(--font-mono); }

/* ---------- 文字 ---------- */
.hero-title {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: clamp(44px, 8vw, 76px);
  letter-spacing: -0.02em;
  line-height: 1.15;
  color: var(--text);
}

.section-title {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: clamp(28px, 4vw, 40px);
  letter-spacing: -0.02em;
  line-height: 1.25;
}

.section-sub { color: var(--text-desc); font-size: 16px; line-height: 1.7; text-wrap: pretty; }

.preview-label {
  font-size: 17px;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--text);
}

/* ---------- 按钮（参照 ds-btn-*） ---------- */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border-radius: var(--radius-pill);
  font-family: var(--font-sans);
  font-weight: 500;
  font-size: 15px;
  line-height: 1.2;
  padding: 12px 22px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.25s var(--ease-out), background 0.25s, border-color 0.25s, box-shadow 0.25s;
  white-space: nowrap;
}
.btn svg { flex-shrink: 0; }
.btn:active { transform: translateY(0) scale(0.98); }

.btn-primary {
  background: #fff;
  color: #0a0a0a;
}
.btn-primary:hover {
  background: rgba(255, 255, 255, 0.88);
  transform: translateY(-1px);
  box-shadow: 0 8px 30px rgba(120, 170, 255, 0.25);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.15);
  color: #fff;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: rgba(255, 255, 255, 0.6);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  border-color: rgba(255, 255, 255, 0.2);
  color: #fff;
}
.btn-ghost:hover { background: rgba(255, 255, 255, 0.08); border-color: rgba(255, 255, 255, 0.35); }

.btn-brand {
  background: var(--brand);
  color: #fff;
}
.btn-brand:hover {
  background: #5b77ff;
  transform: translateY(-1px);
  box-shadow: 0 8px 30px rgba(77, 107, 254, 0.35);
}

.btn-sm { padding: 9px 16px; font-size: 14px; }
.btn-lg { padding: 15px 30px; font-size: 16px; }

/* ---------- 导航 ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  transition: background 0.3s, border-color 0.3s, backdrop-filter 0.3s;
  border-bottom: 1px solid transparent;
}
.nav.scrolled {
  background: rgba(13, 16, 23, 0.72);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-color: rgba(255, 255, 255, 0.08);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 16px;
}
.nav-brand .mark {
  width: 28px; height: 28px;
  border-radius: 7px;
  background: #0b0e14;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.14);
  display: flex; align-items: center; justify-content: center;
}
.nav-brand .mark img { width: 18px; height: auto; }
.nav-brand em { font-style: normal; color: var(--text-desc); font-weight: 400; margin-left: 2px; }

.nav-links { display: flex; align-items: center; gap: 4px; }
.nav-link {
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  font-size: 14.5px;
  color: #c7d0de;
  transition: background 0.2s, color 0.2s;
}
.nav-link:hover { background: rgba(255, 255, 255, 0.08); color: #fff; }
.nav-link.primary { color: #fff; background: rgba(255, 255, 255, 0.1); }
.nav-link.primary:hover { background: rgba(255, 255, 255, 0.18); }

.nav-toggle { display: none; background: none; border: 0; color: #fff; cursor: pointer; padding: 8px; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100svh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

/* 背景：网格 + 品牌辉光（对应官方 hero 的 canvas 氛围层） */
.hero-bg-grid {
  position: absolute; inset: 0; z-index: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: linear-gradient(#000000fc 0%, #000000e8 9%, transparent 100%);
  -webkit-mask-image: linear-gradient(#000000fc 0%, #000000e8 9%, transparent 100%);
}
.hero-glow {
  position: absolute; z-index: 0;
  width: 760px; height: 760px;
  right: -160px; top: 50%;
  transform: translateY(-50%);
  background: radial-gradient(closest-side, rgba(77, 107, 254, 0.22), rgba(65, 118, 230, 0.08) 55%, transparent 75%);
  filter: blur(30px);
  pointer-events: none;
}
.hero-glow.left { right: auto; left: -260px; top: 12%; width: 520px; height: 520px; opacity: 0.5; }

.hero-inner {
  position: relative; z-index: 1;
  display: grid;
  grid-template-columns: 60fr 40fr;
  gap: 48px;
  align-items: center;
  padding: 120px 0 80px;
}

.hero-copy { display: flex; flex-direction: column; gap: 20px; align-items: flex-start; }
.hero-copy .preview-label { display: flex; align-items: center; gap: 10px; }
.hero-copy .preview-label::before {
  content: ""; width: 8px; height: 8px; border-radius: 50%;
  background: var(--brand); box-shadow: 0 0 12px var(--brand-glow);
}
.hero-copy .desc { color: var(--text-desc); font-size: 17px; line-height: 1.7; max-width: 560px; text-wrap: pretty; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 6px; }

.platform-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.chip {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 13px; color: #9fb0cc;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.03);
}
.chip svg { opacity: 0.85; }

/* ---------- 入场动效（对应 ds-hero-enter） ---------- */
.hero-enter {
  animation: ds-hero-enter 0.9s var(--ease-out) backwards;
  --enter-y: 24px;
  --enter-blur: 10px;
}
@keyframes ds-hero-enter {
  from { opacity: 0; transform: translateY(var(--enter-y, 20px)); filter: blur(var(--enter-blur, 8px)); }
  to { opacity: 1; transform: none; filter: none; }
}

/* ---------- 窗口模拟（hero 右侧） ---------- */
.window {
  position: relative;
  border-radius: var(--radius-panel);
  background: rgba(18, 22, 32, 0.92);
  border: 1px solid var(--border);
  box-shadow: 0 40px 90px rgba(0, 0, 0, 0.5), 0 0 60px rgba(77, 107, 254, 0.08);
  overflow: hidden;
}
.window::before {
  content: "";
  position: absolute; inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: conic-gradient(
    from var(--border-angle, 0deg),
    rgba(58, 101, 194, 0.15) 0%,
    rgba(120, 170, 255, 0.7) 25%,
    rgba(58, 101, 194, 0.15) 50%,
    rgba(120, 170, 255, 0.7) 75%,
    rgba(58, 101, 194, 0.15) 100%
  );
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  animation: rotating-border 6s linear infinite;
  pointer-events: none;
}
@property --border-angle {
  syntax: "<angle>";
  initial-value: 0deg;
  inherits: false;
}
@keyframes rotating-border {
  to { --border-angle: 360deg; }
}

.window-bar {
  display: flex; align-items: center; gap: 8px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
}
.window-dot { width: 12px; height: 12px; border-radius: 50%; }
.window-dot.r { background: #ff5f57; }
.window-dot.y { background: #febc2e; }
.window-dot.g { background: #28c840; }
.window-title {
  flex: 1; text-align: center;
  font-size: 13px; color: var(--text-desc);
  letter-spacing: 0.01em;
}

.window-body {
  padding: 26px 24px 30px;
  min-height: 340px;
  display: flex; flex-direction: column; gap: 18px;
  font-family: var(--font-mono);
  font-size: 13.5px;
  line-height: 1.7;
}
.window-brand { display: flex; align-items: center; gap: 10px; }
.window-brand .mark {
  width: 34px; height: 34px; border-radius: 9px;
  background: #0b0e14;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.14);
  display: flex; align-items: center; justify-content: center;
}
.window-brand .mark img { width: 22px; height: auto; }
.window-brand .name { font-family: var(--font-sans); font-weight: 600; font-size: 15px; }

.boot-line { color: #8fa3c8; white-space: pre-wrap; word-break: break-all; }
.boot-line .ok { color: #4ade80; }
.boot-line .dim { color: #5b6577; }
.boot-line .url { color: var(--brand-glow); }
.boot-cursor {
  display: inline-block; width: 8px; height: 15px;
  background: var(--brand-glow);
  vertical-align: -2px;
  animation: blink 1.1s steps(1) infinite;
}
@keyframes blink { 50% { opacity: 0; } }

.window-status {
  display: flex; align-items: center; gap: 8px;
  font-family: var(--font-sans);
  font-size: 13px; color: var(--text-desc);
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px dashed var(--border);
}
.window-status .pulse {
  width: 8px; height: 8px; border-radius: 50%;
  background: #4ade80;
  box-shadow: 0 0 10px rgba(74, 222, 128, 0.8);
  animation: blink 2s steps(1) infinite;
}

/* ---------- 区块通用 ---------- */
.section { position: relative; padding: 110px 0; }
.section-head { max-width: 720px; margin-bottom: 56px; }
.section-head .preview-label { color: var(--text-desc); font-size: 15px; margin-bottom: 14px; }
.section-head h2 { margin-bottom: 16px; }
.section-head p { max-width: 640px; }

/* 滚动显现 */
.reveal { opacity: 0; transform: translateY(28px); filter: blur(6px); transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out), filter 0.8s var(--ease-out); }
.reveal.in { opacity: 1; transform: none; filter: none; }
.reveal[data-delay="1"] { transition-delay: 0.1s; }
.reveal[data-delay="2"] { transition-delay: 0.2s; }
.reveal[data-delay="3"] { transition-delay: 0.3s; }

/* ---------- 特性卡片 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.feature-card {
  position: relative;
  border-radius: var(--radius-panel);
  border: 1px solid var(--border);
  background: var(--bg-panel);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 34px 28px;
  transition: transform 0.35s var(--ease-out), border-color 0.3s, background 0.3s, box-shadow 0.35s;
}
.feature-card:hover {
  transform: translateY(-6px);
  border-color: rgba(120, 170, 255, 0.4);
  background: rgba(255, 255, 255, 0.06);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.35), 0 0 40px rgba(77, 107, 254, 0.1);
}
.feature-icon {
  width: 44px; height: 44px;
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(77, 107, 254, 0.14);
  border: 1px solid rgba(120, 170, 255, 0.25);
  color: #8fabff;
  margin-bottom: 20px;
}
.feature-card h3 { font-family: var(--font-display); font-weight: 500; font-size: 19px; margin-bottom: 10px; }
.feature-card p { color: var(--text-desc); font-size: 14.5px; line-height: 1.7; text-wrap: pretty; }

/* ---------- 工作原理（编号步骤） ---------- */
.how-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  counter-reset: step;
}
.step-card {
  border-radius: var(--radius-card);
  border: 1px solid var(--border);
  background: var(--bg-panel);
  padding: 26px 22px;
  transition: border-color 0.3s, transform 0.3s var(--ease-out);
}
.step-card:hover { border-color: rgba(120, 170, 255, 0.4); transform: translateY(-4px); }
.step-num {
  font-family: var(--font-mono);
  font-size: 13px; color: var(--brand-glow);
  margin-bottom: 14px;
  display: flex; align-items: center; gap: 8px;
}
.step-num::before {
  counter-increment: step;
  content: "0" counter(step);
  font-size: 12px;
  padding: 3px 8px;
  border-radius: var(--radius-pill);
  background: rgba(77, 107, 254, 0.15);
  border: 1px solid rgba(120, 170, 255, 0.3);
}
.step-card h3 { font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.step-card p { color: var(--text-desc); font-size: 13.5px; line-height: 1.7; text-wrap: pretty; }

/* ---------- 下载区 ---------- */
.download-wrap {
  position: relative;
  border-radius: 28px;
  padding: 56px 48px;
  border: 1px solid var(--border);
  background:
    radial-gradient(1000px 400px at 20% 0%, rgba(77, 107, 254, 0.12), transparent 60%),
    rgba(255, 255, 255, 0.025);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  overflow: hidden;
}
.download-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; flex-wrap: wrap; margin-bottom: 34px; }
.version-badge {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-mono); font-size: 13px;
  color: #c7d0fe;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(120, 170, 255, 0.35);
  background: rgba(77, 107, 254, 0.12);
}
.version-badge::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: #4ade80; box-shadow: 0 0 8px rgba(74, 222, 128, 0.9); }

.tabs { display: flex; gap: 6px; padding: 5px; border-radius: var(--radius-pill); background: rgba(255, 255, 255, 0.06); border: 1px solid var(--border); width: fit-content; }
.tab {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 20px;
  border-radius: var(--radius-pill);
  border: 0; background: transparent;
  color: #9fb0cc; font-family: var(--font-sans); font-size: 14.5px; font-weight: 500;
  cursor: pointer;
  transition: background 0.25s, color 0.25s;
}
.tab:hover { color: #fff; }
.tab.active { background: #fff; color: #0a0a0a; }

.tab-panel { display: none; margin-top: 30px; }
.tab-panel.active { display: block; animation: panel-in 0.5s var(--ease-out); }
@keyframes panel-in {
  from { opacity: 0; transform: translateY(14px); }
  to { opacity: 1; transform: none; }
}

.artifact-list { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; }
.artifact-card {
  display: flex; align-items: center; gap: 16px;
  padding: 20px 22px;
  border-radius: var(--radius-card);
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.03);
  transition: border-color 0.3s, background 0.3s, transform 0.3s var(--ease-out);
}
.artifact-card:hover { border-color: rgba(120, 170, 255, 0.45); background: rgba(255, 255, 255, 0.055); transform: translateY(-3px); }
.artifact-icon {
  width: 42px; height: 42px; flex-shrink: 0;
  border-radius: 11px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(77, 107, 254, 0.13);
  border: 1px solid rgba(120, 170, 255, 0.25);
  color: #8fabff;
}
.artifact-meta { flex: 1; min-width: 0; }
.artifact-name { font-weight: 600; font-size: 15px; display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.artifact-tag {
  font-size: 11px; font-weight: 500;
  padding: 2px 8px; border-radius: var(--radius-pill);
  background: rgba(77, 107, 254, 0.16);
  border: 1px solid rgba(120, 170, 255, 0.3);
  color: #a9bcff;
}
.artifact-desc { color: var(--text-desc); font-size: 13px; margin-top: 3px; }
.artifact-download {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 13.5px; font-weight: 500; color: #d6ddf2;
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border-strong);
  transition: background 0.25s, color 0.25s, border-color 0.25s;
  white-space: nowrap;
}
.artifact-download:hover { background: var(--brand); border-color: var(--brand); color: #fff; }

.download-notes { margin-top: 26px; color: var(--text-dim); font-size: 13px; line-height: 1.8; }
.download-notes a { color: #8fabff; border-bottom: 1px dashed rgba(143, 171, 255, 0.5); }
.download-notes a:hover { color: #a9bcff; }

/* ---------- 源码构建 ---------- */
.code-block {
  margin-top: 30px;
  border-radius: var(--radius-card);
  border: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.35);
  overflow: hidden;
}
.code-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 16px;
  border-bottom: 1px solid var(--border);
  font-family: var(--font-mono); font-size: 12px; color: var(--text-dim);
}
.code-copy {
  display: inline-flex; align-items: center; gap: 6px;
  border: 1px solid var(--border); background: rgba(255,255,255,0.05);
  color: #c7d0de; font-size: 12px; font-family: var(--font-sans);
  padding: 5px 12px; border-radius: var(--radius-pill); cursor: pointer;
  transition: background 0.2s, color 0.2s;
}
.code-copy:hover { background: rgba(255,255,255,0.12); color: #fff; }
.code-copy.copied { border-color: rgba(74, 222, 128, 0.5); color: #4ade80; }
.code-body { padding: 18px 20px; font-family: var(--font-mono); font-size: 13.5px; line-height: 1.9; color: #c7d0fe; overflow-x: auto; white-space: pre; }
.code-body .cm { color: #5b6577; }
.code-body .c1 { color: #f9f8f8; }
.code-body .c2 { color: #febc2e; }

/* ---------- 生态 CTA ---------- */
.cta-band {
  position: relative;
  text-align: center;
  padding: 90px 24px;
  border-radius: 28px;
  border: 1px solid var(--border);
  background:
    radial-gradient(700px 300px at 50% 0%, rgba(77, 107, 254, 0.16), transparent 70%),
    rgba(255, 255, 255, 0.02);
  overflow: hidden;
}
.cta-band h2 { margin-bottom: 14px; }
.cta-band p { color: var(--text-desc); max-width: 560px; margin: 0 auto 30px; text-wrap: pretty; }
.cta-actions { display: flex; justify-content: center; gap: 14px; flex-wrap: wrap; }

/* ---------- 页脚 ---------- */
.footer {
  border-top: 1px solid var(--border);
  padding: 64px 0 40px;
  background: rgba(0, 0, 0, 0.25);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1.6fr;
  gap: 48px;
  margin-bottom: 48px;
}
.footer h4 {
  font-family: var(--font-display); font-weight: 500;
  font-size: 14px; letter-spacing: 0.02em;
  color: #aab6cc; margin-bottom: 16px;
}
.footer .about p { color: var(--text-dim); font-size: 13.5px; line-height: 1.8; max-width: 340px; text-wrap: pretty; }
.footer .about .mark-row { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; }
.footer .about .mark {
  width: 34px; height: 34px; border-radius: 9px;
  background: #0b0e14; box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.14);
  display: flex; align-items: center; justify-content: center;
}
.footer .about .mark img { width: 22px; height: auto; }
.footer .about .mark-row .name { font-weight: 600; font-size: 15px; }
.footer-links { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.footer-links a { color: var(--text-desc); font-size: 14px; transition: color 0.2s; }
.footer-links a:hover { color: #fff; }
.footer-links a .ext { opacity: 0.5; font-size: 11px; margin-left: 4px; }

.footer-bottom {
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap;
  padding-top: 28px;
  border-top: 1px solid var(--border);
  color: var(--text-dim); font-size: 13px;
}
.footer-bottom a { color: #8fabff; }
.footer-bottom a:hover { color: #a9bcff; }

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .hero-inner { grid-template-columns: 1fr; gap: 56px; padding-top: 110px; }
  .window { max-width: 560px; }
  .feature-grid { grid-template-columns: 1fr; }
  .how-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; gap: 36px; }
  .download-wrap { padding: 40px 26px; }
}

@media (max-width: 640px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex; flex-direction: column; align-items: stretch; gap: 2px;
    position: absolute; top: 64px; left: 0; right: 0;
    background: rgba(13, 16, 23, 0.96);
    backdrop-filter: blur(16px);
    padding: 14px 16px 20px;
    border-bottom: 1px solid var(--border);
  }
  .nav-link { padding: 12px 14px; }
  .nav-toggle { display: block; }
  .how-grid { grid-template-columns: 1fr; }
  .tabs { width: 100%; }
  .tab { flex: 1; justify-content: center; padding: 10px 8px; }
  .artifact-list { grid-template-columns: 1fr; }
  .hero { padding-top: 0; }
  .container { width: min(100% - 32px, 1140px); }
}

/* ---------- 无障碍 / 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001s !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001s !important;
  }
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; filter: none; }
}

:focus-visible {
  outline: 2px solid var(--brand);
  outline-offset: 3px;
  border-radius: 4px;
}