/* Learn DeepSeek Harness — 复刻 learn.shareai.run/zh 风格 */
* { box-sizing: border-box; }
:root {
  --bg: #fafafa;
  --bg-soft: #f4f4f5;
  --card: #ffffff;
  --text: #18181b;
  --muted: #71717a;
  --faint: #a1a1aa;
  --border: #e4e4e7;
  --accent: #4f46e5;
  --accent-soft: #eef2ff;
  --code-bg: #0c0c0e;
  --code-text: #e4e4e7;
  --code-border: #27272a;
  --invert-bg: #18181b;
  --invert-text: #fafafa;
}
html.dark {
  --bg: #18181b;
  --bg-soft: #212124;
  --card: #18181b;
  --text: #f4f4f5;
  --muted: #a1a1aa;
  --faint: #71717a;
  --border: #3f3f46;
  --accent: #818cf8;
  --accent-soft: #312e81;
  --invert-bg: #fafafa;
  --invert-text: #18181b;
}
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
code, pre { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace; }

/* ---- header ---- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
}
.header-inner {
  max-width: 1200px; margin: 0 auto; height: 56px;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 20px;
}
.brand { font-size: 17px; font-weight: 700; letter-spacing: -0.01em; }
.site-nav { display: flex; gap: 24px; }
.site-nav a { font-size: 14px; font-weight: 500; color: var(--muted); transition: color .15s; }
.site-nav a:hover { color: var(--text); }
.header-actions { display: flex; align-items: center; gap: 10px; }
.lang-pill { font-size: 12px; padding: 3px 10px; border: 1px solid var(--border); border-radius: 999px; color: var(--muted); }
.theme-toggle {
  border: 1px solid var(--border); background: var(--card); color: var(--text);
  width: 34px; height: 34px; border-radius: 999px; cursor: pointer;
  display: grid; place-items: center; font-size: 15px; transition: border-color .15s;
}
.theme-toggle:hover { border-color: var(--faint); }
.theme-toggle .icon-dark { display: none; }
html.dark .theme-toggle .icon-light { display: none; }
html.dark .theme-toggle .icon-dark { display: inline; }

/* ---- hero ---- */
.hero { max-width: 780px; margin: 0 auto; padding: 76px 24px 36px; text-align: center; }
.hero h1 { font-size: 44px; line-height: 1.15; letter-spacing: -0.03em; margin: 0 0 14px; }
.hero-tagline { font-size: 20px; color: var(--muted); margin: 0 0 12px; }
.hero-sub { font-size: 15px; color: var(--muted); margin: 0 auto 30px; max-width: 640px; }
.hero .cta {
  display: inline-block; background: var(--invert-bg); color: var(--invert-text);
  font-size: 15px; font-weight: 500; padding: 11px 26px; border-radius: 10px; transition: opacity .15s;
}
.hero .cta:hover { opacity: .85; }
.hero-stats { display: flex; justify-content: center; gap: 10px; margin-top: 26px; flex-wrap: wrap; }
.hero-stats span { font-size: 12px; color: var(--muted); border: 1px solid var(--border); border-radius: 999px; padding: 4px 12px; }

/* ---- home sections ---- */
.home-main { max-width: 1000px; margin: 0 auto; padding: 0 24px 90px; }
.home-section { margin-top: 64px; }
.home-section h2 { font-size: 26px; letter-spacing: -0.02em; margin: 0 0 10px; }
.home-section > p { color: var(--muted); margin: 0 0 20px; }
.home-section h3 { font-size: 16px; font-weight: 600; margin: 0 0 12px; }

/* ---- lesson cards ---- */
.layer-block { margin-top: 28px; }
.layer-block h3 { font-size: 15px; font-weight: 600; color: var(--muted); margin: 0 0 12px; }
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; }
.lesson-card {
  display: flex; flex-direction: column; gap: 8px;
  border: 1px solid var(--border); background: var(--card); border-radius: 12px; padding: 16px;
  transition: border-color .15s, transform .15s, box-shadow .15s;
}
.lesson-card:hover { border-color: var(--faint); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.06); }
.s-badge { font-size: 12px; font-weight: 600; color: var(--accent); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
.lesson-card h4 { font-size: 16px; margin: 0; }
.lesson-card p { font-size: 13.5px; color: var(--muted); margin: 0; flex: 1; }
.card-meta { font-size: 12px; color: var(--faint); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }

/* ---- layers ---- */
.layer-list { display: flex; flex-direction: column; gap: 10px; margin-top: 12px; }
.layer-row {
  display: grid; grid-template-columns: 150px 1fr auto; gap: 18px; align-items: center;
  border: 1px solid var(--border); border-radius: 12px; padding: 14px 18px; background: var(--card);
}
.layer-name { font-weight: 600; font-size: 15px; }
.layer-desc { font-size: 13.5px; color: var(--muted); }
.layer-chips { display: flex; flex-wrap: wrap; gap: 6px; justify-content: flex-end; }
.layer-chip {
  font-size: 12px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  color: var(--muted); border: 1px solid var(--border); border-radius: 999px; padding: 3px 10px; transition: all .15s;
}
.layer-chip:hover { color: var(--accent); border-color: var(--accent); }
@media (max-width: 760px) {
  .layer-row { grid-template-columns: 1fr; gap: 8px; }
  .layer-chips { justify-content: flex-start; }
}

/* ---- code ---- */
pre {
  background: var(--code-bg); color: var(--code-text); border: 1px solid var(--code-border);
  border-radius: 12px; padding: 16px 20px; overflow-x: auto;
  font-size: 13px; line-height: 1.65; margin: 16px 0;
}
pre code { background: none; border: none; padding: 0; font-size: inherit; }
code { background: var(--bg-soft); border: 1px solid var(--border); border-radius: 5px; padding: 1px 5px; font-size: 0.9em; }

/* ---- tables ---- */
table { width: 100%; border-collapse: collapse; font-size: 14px; margin: 16px 0; display: block; overflow-x: auto; }
th { text-align: left; font-weight: 500; color: var(--muted); border-bottom: 1px solid var(--border); padding: 8px 12px; white-space: nowrap; }
td { border-bottom: 1px solid var(--border); padding: 8px 12px; vertical-align: top; }
tr:last-child td { border-bottom: none; }
table a { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; }

/* ---- lesson page ---- */
.lesson-layout {
  max-width: 1200px; margin: 0 auto; padding: 32px 20px 80px;
  display: grid; grid-template-columns: 235px minmax(0, 1fr); gap: 44px;
}
.sidebar { position: sticky; top: 76px; align-self: start; max-height: calc(100vh - 96px); overflow-y: auto; padding-right: 6px; }
.side-home { display: block; font-size: 13px; color: var(--muted); margin-bottom: 14px; }
.side-home:hover { color: var(--text); }
.side-group { margin-bottom: 18px; }
.side-layer { font-size: 12px; font-weight: 600; color: var(--faint); margin-bottom: 6px; }
.side-item { display: block; font-size: 13px; color: var(--muted); padding: 4px 10px; border-radius: 8px; margin: 2px 0; transition: all .12s; }
.side-item:hover { color: var(--text); background: var(--bg-soft); }
.side-item.active { color: var(--accent); background: var(--accent-soft); font-weight: 500; }
.lesson-main { max-width: 800px; min-width: 0; }
@media (max-width: 900px) {
  .lesson-layout { grid-template-columns: 1fr; }
  .sidebar { display: none; }
}
.lesson-header { margin-bottom: 22px; }
.breadcrumb { font-size: 13px; color: var(--muted); display: flex; gap: 8px; margin-bottom: 10px; }
.breadcrumb a:hover { color: var(--text); }
.lesson-header h1 { font-size: 34px; letter-spacing: -0.02em; margin: 0 0 10px; }
.tagline { font-size: 17px; font-weight: 500; margin: 0 0 6px; }
.lesson-desc { font-size: 15px; color: var(--muted); margin: 0 0 16px; }
.stats { display: flex; gap: 8px; flex-wrap: wrap; }
.chip { font-size: 12px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; border: 1px solid var(--border); border-radius: 999px; padding: 3px 11px; color: var(--muted); }

/* ---- tabs ---- */
.tabs { display: flex; gap: 2px; border-bottom: 1px solid var(--border); margin-bottom: 6px; }
.tab {
  appearance: none; background: none; border: none; cursor: pointer; font: inherit;
  font-size: 14px; font-weight: 500; color: var(--muted); padding: 10px 14px;
  border-bottom: 2px solid transparent; margin-bottom: -1px; transition: color .15s;
}
.tab:hover { color: var(--text); }
.tab.active { color: var(--text); border-bottom-color: var(--text); }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ---- lesson prose ---- */
.lesson-section h2 { font-size: 20px; margin: 30px 0 8px; letter-spacing: -0.01em; }
.lesson-section p { margin: 10px 0; }
.lesson-section ul, .lesson-section ol { padding-left: 22px; margin: 10px 0; }
.lesson-section li { margin: 4px 0; }
.lesson-section blockquote { border-left: 3px solid var(--border); margin: 14px 0; padding: 2px 16px; color: var(--muted); }
.lesson-section a, .site-footer a, .tab-panel a { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; text-decoration-color: color-mix(in srgb, var(--accent) 45%, transparent); }
strong { font-weight: 600; }

/* ---- lesson nav ---- */
.lesson-nav { display: flex; justify-content: space-between; gap: 16px; margin-top: 44px; padding-top: 20px; border-top: 1px solid var(--border); }
.nav-prev, .nav-next {
  font-size: 14px; font-weight: 500; color: var(--text);
  border: 1px solid var(--border); border-radius: 10px; padding: 10px 16px; background: var(--card);
  transition: border-color .15s; max-width: 48%;
}
.nav-prev:hover, .nav-next:hover { border-color: var(--faint); }

/* ---- growth widget ---- */
.growth-widget { border: 1px solid var(--border); border-radius: 12px; padding: 18px 20px; background: var(--card); margin: 20px 0; }
.growth-title { font-size: 13px; color: var(--muted); margin-bottom: 14px; }
.growth-rows { display: flex; flex-direction: column; gap: 9px; }
.growth-row { display: grid; grid-template-columns: 26px 46px minmax(90px, 1fr) auto; gap: 10px; align-items: center; }
.growth-len { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; color: var(--accent); font-weight: 600; text-align: right; }
.growth-who { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; color: var(--muted); font-size: 12.5px; }
.growth-bar-wrap { height: 10px; background: var(--bg-soft); border-radius: 999px; overflow: hidden; }
.growth-bar {
  height: 100%; width: 0; border-radius: 999px;
  background: linear-gradient(90deg, var(--accent), color-mix(in srgb, var(--accent) 55%, transparent));
  animation: grow 1.1s ease-out forwards; animation-delay: var(--d, 0s);
}
@keyframes grow { from { width: 0; } to { width: var(--w, 100%); } }
.growth-label { font-size: 12px; color: var(--muted); white-space: nowrap; }
@media (max-width: 640px) { .growth-row { grid-template-columns: 22px 42px 1fr; } .growth-label { display: none; } }

/* ---- footer ---- */
.site-footer { border-top: 1px solid var(--border); padding: 34px 24px 40px; text-align: center; font-size: 13.5px; color: var(--muted); }
.site-footer p { margin: 4px 0; }
.muted { color: var(--faint); font-size: 12.5px; }