/* ==========================================================================
   xuzhi.tech — 个人技术主页
   科技蓝 + 白 · 扁平化 · 语义图形优先
   ========================================================================== */

:root {
  /* 品牌色 */
  --blue-900: #06213f;
  --blue-800: #093465;
  --blue-700: #0b4ea2;
  --blue-600: #1268d3;
  --blue-500: #2b8ae8;
  --blue-300: #8cc0f5;
  --blue-100: #e6f0fc;
  --blue-050: #f3f8fe;

  /* 中性色 */
  --ink:      #0e1a2b;
  --ink-2:    #2c3d54;
  --muted:    #61748c;
  --line:     #dfe7f1;
  --line-2:   #eef3f9;
  --bg:       #ffffff;
  --bg-soft:  #f7fafd;

  /* 语义强调 */
  --accent-red:   #d64545;
  --accent-violet:#7b52d1;

  /* 排版 */
  --font-sans: "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
               "Source Han Sans SC", "Noto Sans CJK SC", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Cascadia Code", "SFMono-Regular", Consolas,
               "Liberation Mono", monospace;

  /* 尺度 */
  --maxw: 1160px;
  --r-sm: 6px;
  --r-md: 10px;
  --r-lg: 16px;
  --gap: 24px;

  /* 扁平阴影（极克制） */
  --sh-1: 0 1px 2px rgba(9, 52, 101, .06);
  --sh-2: 0 4px 16px rgba(9, 52, 101, .08);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { max-width: 100%; display: block; }
a { color: var(--blue-700); text-decoration: none; }
a:hover { color: var(--blue-600); }
h1, h2, h3, h4 { line-height: 1.28; margin: 0 0 .5em; font-weight: 700; letter-spacing: -.01em; }
p { margin: 0 0 1em; }
ul, ol { margin: 0 0 1em; padding-left: 1.25em; }
li { margin-bottom: .4em; }
code, kbd, pre { font-family: var(--font-mono); font-size: .875em; }

::selection { background: var(--blue-100); color: var(--blue-900); }

/* ---------- 布局容器 ---------- */
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 28px; }
.wrap-narrow { max-width: 820px; }
section { padding: 72px 0; }
section + section { border-top: 1px solid var(--line-2); }

/* ---------- 通用小组件 ---------- */
.eyebrow {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--font-mono); font-size: 12px; letter-spacing: .14em;
  text-transform: uppercase; color: var(--blue-700);
  margin-bottom: 14px; font-weight: 600;
}
.eyebrow::before {
  content: ""; width: 22px; height: 2px; background: var(--blue-600); flex: none;
}
.h-sec { font-size: clamp(24px, 3vw, 34px); color: var(--blue-900); }
.lede { font-size: 17px; color: var(--muted); max-width: 66ch; }

.tag {
  display: inline-block; padding: 2px 10px; border-radius: 999px;
  background: var(--blue-050); border: 1px solid var(--blue-100);
  color: var(--blue-700); font-size: 12.5px; font-weight: 600;
  font-family: var(--font-mono); letter-spacing: .02em;
}
.tag-row { display: flex; flex-wrap: wrap; gap: 8px; }

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 22px; border-radius: var(--r-sm);
  font-weight: 600; font-size: 15px; border: 1px solid transparent;
  transition: background .18s ease, border-color .18s ease, color .18s ease;
  cursor: pointer;
}
.btn-primary { background: var(--blue-700); color: #fff; }
.btn-primary:hover { background: var(--blue-600); color: #fff; }
.btn-ghost { background: transparent; color: var(--blue-700); border-color: var(--blue-300); }
.btn-ghost:hover { background: var(--blue-050); border-color: var(--blue-600); color: var(--blue-700); }
.btn-row { display: flex; flex-wrap: wrap; gap: 12px; }

/* ==========================================================================
   Header / Nav
   ========================================================================== */
.site-head {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.94);
  backdrop-filter: saturate(160%) blur(8px);
  border-bottom: 1px solid var(--line);
}
.head-in {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px; gap: 20px;
}
.brand { display: flex; align-items: center; gap: 11px; color: var(--blue-900); }
.brand:hover { color: var(--blue-900); }
.brand-mark { width: 30px; height: 30px; flex: none; }
.brand-txt { display: flex; flex-direction: column; line-height: 1.15; }
.brand-txt b { font-size: 15.5px; letter-spacing: -.01em; }
.brand-txt span {
  font-family: var(--font-mono); font-size: 10.5px; color: var(--muted);
  letter-spacing: .1em; text-transform: uppercase;
}

.nav { display: flex; align-items: center; gap: 4px; }
.nav a {
  position: relative; padding: 8px 14px; border-radius: var(--r-sm);
  color: var(--ink-2); font-size: 15px; font-weight: 500;
}
.nav a:hover { color: var(--blue-700); background: var(--blue-050); }
.nav a[aria-current="page"] { color: var(--blue-700); font-weight: 700; }
.nav a[aria-current="page"]::after {
  content: ""; position: absolute; left: 14px; right: 14px; bottom: 2px;
  height: 2px; background: var(--blue-600); border-radius: 2px;
}

.nav-toggle {
  display: none; width: 40px; height: 40px; padding: 0;
  background: none; border: 1px solid var(--line); border-radius: var(--r-sm);
  cursor: pointer; align-items: center; justify-content: center;
}
.nav-toggle span { display: block; width: 18px; height: 2px; background: var(--blue-800); position: relative; }
.nav-toggle span::before, .nav-toggle span::after {
  content: ""; position: absolute; left: 0; width: 18px; height: 2px; background: var(--blue-800);
}
.nav-toggle span::before { top: -6px; }
.nav-toggle span::after { top: 6px; }

/* ==========================================================================
   Hero
   ========================================================================== */
.hero {
  position: relative; overflow: hidden;
  background:
    linear-gradient(180deg, #ffffff 0%, var(--blue-050) 100%);
  border-bottom: 1px solid var(--line);
  padding: 0;
}
.hero-grid-bg {
  position: absolute; inset: 0; pointer-events: none; opacity: .5;
  background-image:
    linear-gradient(to right, rgba(18,104,211,.07) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(18,104,211,.07) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: linear-gradient(to bottom, #000 0%, transparent 78%);
  -webkit-mask-image: linear-gradient(to bottom, #000 0%, transparent 78%);
}
.hero-in {
  position: relative; display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
  gap: 56px; align-items: center; padding: 84px 0 88px;
}
.hero h1 {
  font-size: clamp(32px, 4.6vw, 52px); color: var(--blue-900);
  letter-spacing: -.025em; margin-bottom: 18px;
}
.hero h1 .accent { color: var(--blue-600); }
.hero-sub {
  font-size: clamp(16px, 1.6vw, 19px); color: var(--ink-2);
  max-width: 54ch; margin-bottom: 14px;
}
.hero-meta {
  font-family: var(--font-mono); font-size: 13px; color: var(--muted);
  margin-bottom: 30px; letter-spacing: .02em;
}
.hero-meta b { color: var(--blue-700); font-weight: 600; }

/* Hero 右侧：结构化密度曲线卡片 */
.curve-card {
  background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--r-lg); padding: 22px 22px 16px; box-shadow: var(--sh-2);
}
.curve-card h3 {
  font-size: 14px; color: var(--blue-900); margin-bottom: 4px;
  display: flex; align-items: center; gap: 8px;
}
.curve-card > svg { width: 100%; height: auto; }
.curve-card .cap {
  font-family: var(--font-mono); font-size: 11.5px; color: var(--muted);
  letter-spacing: .04em; margin-bottom: 14px;
}
.legend {
  display: flex; flex-wrap: wrap; gap: 6px 16px; margin-top: 14px;
  padding-top: 14px; border-top: 1px dashed var(--line);
  font-size: 12.5px; color: var(--ink-2);
}
.legend i { display: inline-block; width: 16px; height: 0; vertical-align: middle; margin-right: 6px; }
.legend .l-raw  i { border-top: 2px solid var(--accent-red); }
.legend .l-in   i { border-top: 2px dashed #9aa9bb; }
.legend .l-out  i { border-top: 2px solid var(--blue-600); }
.legend .l-cmp  i { border-top: 2px dashed var(--accent-violet); }

/* ==========================================================================
   卡片网格
   ========================================================================== */
.grid { display: grid; gap: var(--gap); }
.grid-2 { grid-template-columns: repeat(2, minmax(0,1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0,1fr)); }
.grid-4 { grid-template-columns: repeat(4, minmax(0,1fr)); }

.card {
  background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--r-md); padding: 24px;
  transition: border-color .18s ease, box-shadow .18s ease, transform .18s ease;
  display: flex; flex-direction: column;
}
.card:hover { border-color: var(--blue-300); box-shadow: var(--sh-2); transform: translateY(-2px); }
.card-idx {
  font-family: var(--font-mono); font-size: 11.5px; color: var(--blue-500);
  letter-spacing: .12em; margin-bottom: 12px; font-weight: 600;
}
.card h3 { font-size: 18px; color: var(--blue-900); margin-bottom: 8px; }
.card p { color: var(--muted); font-size: 14.5px; margin-bottom: 14px; flex: 1; }
.card-foot { margin-top: auto; }

/* 项目卡：带图标 */
.proj-card { position: relative; overflow: hidden; }
.proj-card::before {
  content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
  background: var(--blue-600); opacity: 0; transition: opacity .18s ease;
}
.proj-card:hover::before { opacity: 1; }
.proj-ico {
  width: 40px; height: 40px; border-radius: var(--r-sm);
  background: var(--blue-050); border: 1px solid var(--blue-100);
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 16px; color: var(--blue-700);
}
.proj-stat {
  display: flex; gap: 20px; flex-wrap: wrap;
  padding-top: 14px; margin-top: 4px; border-top: 1px solid var(--line-2);
}
.proj-stat div { min-width: 0; }
.proj-stat b {
  display: block; font-family: var(--font-mono); font-size: 17px;
  color: var(--blue-700); font-weight: 700; letter-spacing: -.01em;
}
.proj-stat span { font-size: 12px; color: var(--muted); }

/* ==========================================================================
   语义图：因果 / 汇聚 / 展开
   ========================================================================== */
.figure {
  background: var(--bg-soft); border: 1px solid var(--line);
  border-radius: var(--r-lg); padding: 28px; margin: 8px 0 4px;
}
.figure svg { width: 100%; height: auto; }
.figure-cap {
  margin-top: 16px; padding-top: 14px; border-top: 1px dashed var(--line);
  font-size: 13.5px; color: var(--muted);
}
.figure-cap b { color: var(--ink-2); font-weight: 600; }

/* SVG 内文本样式 */
.svg-t   { font-family: var(--font-sans); font-size: 13px; fill: var(--ink); }
.svg-ts  { font-family: var(--font-sans); font-size: 11.5px; fill: var(--muted); }
.svg-tm  { font-family: var(--font-mono); font-size: 11px; fill: var(--muted); letter-spacing: .06em; }
.svg-tb  { font-family: var(--font-sans); font-size: 13.5px; fill: #fff; font-weight: 600; }
.svg-th  { font-family: var(--font-sans); font-size: 14px; fill: var(--blue-900); font-weight: 700; }

/* ==========================================================================
   时间线 / 列表
   ========================================================================== */
.tl { position: relative; padding-left: 26px; margin-top: 8px; }
.tl::before {
  content: ""; position: absolute; left: 5px; top: 8px; bottom: 8px;
  width: 2px; background: linear-gradient(to bottom, var(--blue-300), var(--line));
}
.tl-item { position: relative; padding-bottom: 26px; }
.tl-item:last-child { padding-bottom: 0; }
.tl-item::before {
  content: ""; position: absolute; left: -26px; top: 8px;
  width: 12px; height: 12px; border-radius: 50%;
  background: var(--bg); border: 3px solid var(--blue-600);
}
.tl-when {
  font-family: var(--font-mono); font-size: 12px; color: var(--blue-600);
  letter-spacing: .06em; font-weight: 600;
}
.tl-item h4 { font-size: 16px; color: var(--blue-900); margin: 2px 0 6px; }
.tl-item p { font-size: 14.5px; color: var(--muted); margin: 0; }

/* 定义式条目 */
.deflist { margin: 0; }
.deflist > div {
  display: grid; grid-template-columns: 190px minmax(0,1fr);
  gap: 20px; padding: 16px 0; border-top: 1px solid var(--line-2);
}
.deflist > div:first-child { border-top: 0; padding-top: 0; }
.deflist dt {
  font-family: var(--font-mono); font-size: 12.5px; color: var(--blue-700);
  letter-spacing: .04em; font-weight: 600; padding-top: 3px;
}
.deflist dd { margin: 0; color: var(--ink-2); font-size: 15px; }

/* 数据表 */
.tbl-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: var(--r-md); margin: 8px 0; }
table.tbl { width: 100%; border-collapse: collapse; font-size: 14.5px; min-width: 520px; }
table.tbl caption {
  caption-side: top; text-align: left; padding: 14px 18px; font-size: 13px;
  color: var(--muted); border-bottom: 1px solid var(--line-2); background: var(--bg-soft);
  font-family: var(--font-mono); letter-spacing: .04em;
}
table.tbl th, table.tbl td { padding: 12px 18px; text-align: left; border-bottom: 1px solid var(--line-2); }
table.tbl thead th {
  background: var(--blue-050); color: var(--blue-800); font-weight: 700; font-size: 13px;
  letter-spacing: .04em; border-bottom: 1px solid var(--blue-100); white-space: nowrap;
}
table.tbl tbody tr:last-child td { border-bottom: 0; }
table.tbl tbody tr:hover { background: var(--blue-050); }
table.tbl td.num, table.tbl th.num {
  font-family: var(--font-mono); text-align: right; color: var(--blue-700); font-weight: 600;
  white-space: nowrap;
}
table.tbl td.mut { color: var(--muted); }
.pill-ok  { display:inline-block; padding:1px 8px; border-radius:999px; background:#e8f6ee; color:#1d7a45; font-size:12px; font-weight:600; }
.pill-run { display:inline-block; padding:1px 8px; border-radius:999px; background:#fdecec; color:#b23b3b; font-size:12px; font-weight:600; font-family:var(--font-mono); }

/* 命题 / 编号论点 */
.prop { border-left: 3px solid var(--blue-600); padding: 4px 0 4px 20px; margin-bottom: 22px; }
.prop h4 { font-size: 16px; color: var(--blue-900); margin-bottom: 6px; }
.prop p { font-size: 14.5px; color: var(--muted); margin: 0; }
.prop .how {
  display: block; margin-top: 8px; font-family: var(--font-mono); font-size: 12.5px;
  color: var(--blue-700); letter-spacing: .02em;
}

/* 代码块 */
pre.code {
  margin: 12px 0; padding: 18px 20px; overflow-x: auto;
  background: var(--blue-900); color: #cfe0f3; border-radius: var(--r-md);
  font-family: var(--font-mono); font-size: 13px; line-height: 1.75;
  border: 1px solid #0a2c52;
}
pre.code .k { color: #8cc0f5; font-weight: 600; }
pre.code .c { color: #6f8bab; font-style: italic; }
pre.code .s { color: #ffd9a0; }
p code, li code, dd code {
  background: var(--blue-050); border: 1px solid var(--blue-100);
  padding: 1px 6px; border-radius: 4px; color: var(--blue-800); font-size: .86em;
}

/* 分层堆叠（L0-L3） */
.stack { display: flex; flex-direction: column; gap: 10px; margin-top: 8px; }
.stack-row {
  display: grid; grid-template-columns: 76px minmax(0,1fr); gap: 16px; align-items: center;
  border: 1px solid var(--line); border-radius: var(--r-sm); padding: 14px 18px; background: var(--bg);
}
.stack-row .lv {
  font-family: var(--font-mono); font-weight: 700; font-size: 15px; color: #fff;
  background: var(--blue-700); border-radius: var(--r-sm); text-align: center; padding: 5px 0;
}
.stack-row:nth-child(2) .lv { background: var(--blue-600); }
.stack-row:nth-child(3) .lv { background: var(--blue-500); }
.stack-row:nth-child(4) .lv { background: var(--blue-300); color: var(--blue-900); }
.stack-row b { display: block; color: var(--blue-900); font-size: 15px; margin-bottom: 2px; }
.stack-row span { color: var(--muted); font-size: 14px; }

/* 引用块 */
.note {
  border-left: 3px solid var(--blue-600); background: var(--blue-050);
  padding: 16px 20px; border-radius: 0 var(--r-sm) var(--r-sm) 0;
  color: var(--ink-2); font-size: 15px; margin: 20px 0;
}
.note b { color: var(--blue-800); }

/* 数据条 */
.metric-row { display: grid; grid-template-columns: repeat(4, minmax(0,1fr)); gap: 20px; }
.metric {
  border: 1px solid var(--line); border-radius: var(--r-md);
  padding: 20px; background: var(--bg);
}
.metric b {
  display: block; font-family: var(--font-mono); font-size: 28px;
  color: var(--blue-700); font-weight: 700; letter-spacing: -.02em; line-height: 1.1;
}
.metric span { display: block; font-size: 13px; color: var(--muted); margin-top: 6px; }

/* ==========================================================================
   页面标题条（内页）
   ========================================================================== */
.page-head {
  background: linear-gradient(180deg, var(--blue-050) 0%, #fff 100%);
  border-bottom: 1px solid var(--line); padding: 56px 0 48px;
}
.page-head h1 { font-size: clamp(28px, 4vw, 42px); color: var(--blue-900); margin-bottom: 12px; }
.page-head p { color: var(--muted); font-size: 17px; max-width: 70ch; margin: 0; }
.crumb {
  font-family: var(--font-mono); font-size: 12px; color: var(--muted);
  letter-spacing: .06em; margin-bottom: 16px;
}
.crumb a { color: var(--blue-600); }

/* ==========================================================================
   Footer
   ========================================================================== */
.site-foot {
  background: var(--blue-900); color: #c7d7ea; padding: 52px 0 28px; margin-top: 0;
}
.foot-grid {
  display: grid; grid-template-columns: minmax(0,1.4fr) repeat(2, minmax(0,.8fr));
  gap: 40px; padding-bottom: 32px; border-bottom: 1px solid rgba(255,255,255,.14);
}
.foot-grid h4 {
  color: #fff; font-size: 13px; letter-spacing: .1em; text-transform: uppercase;
  font-family: var(--font-mono); margin-bottom: 14px;
}
.foot-grid ul { list-style: none; padding: 0; margin: 0; }
.foot-grid li { margin-bottom: 9px; }
.foot-grid a { color: #a8c1de; font-size: 14.5px; }
.foot-grid a:hover { color: #fff; }
.foot-brand p { font-size: 14.5px; color: #9fb9d6; max-width: 44ch; margin-top: 12px; }
.foot-brand .brand-txt b, .foot-brand .brand-txt span { color: #fff; }
.foot-brand .brand-txt span { color: #8fabc9; }
.foot-bot {
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  padding-top: 22px; font-size: 13px; color: #7f9cbd;
  font-family: var(--font-mono); letter-spacing: .02em;
}

/* ==========================================================================
   动效：滚动淡入
   默认内容完全可见；只有 JS 成功运行并给 <html> 加上 .reveal-on 后，
   才启用「先隐藏再淡入」。这样无 JS、打印、爬虫、截图环境都不会丢内容。
   ========================================================================== */
html.reveal-on .reveal { opacity: 0; transform: translateY(14px); transition: opacity .5s ease, transform .5s ease; }
html.reveal-on .reveal.is-in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  html.reveal-on .reveal { opacity: 1; transform: none; transition: none; }
  .card:hover { transform: none; }
}

/* 跳到主内容（无障碍） */
.skip {
  position: absolute; left: -9999px; top: 0; z-index: 100;
  background: var(--blue-700); color: #fff; padding: 10px 18px; border-radius: 0 0 var(--r-sm) 0;
}
.skip:focus { left: 0; color: #fff; }

:focus-visible { outline: 2px solid var(--blue-600); outline-offset: 2px; border-radius: 3px; }

/* ==========================================================================
   响应式
   ========================================================================== */
@media (max-width: 1000px) {
  .hero-in { grid-template-columns: minmax(0,1fr); gap: 40px; padding: 60px 0 64px; }
  .grid-4 { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .metric-row { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .foot-grid { grid-template-columns: minmax(0,1fr) minmax(0,1fr); }
}
@media (max-width: 780px) {
  section { padding: 52px 0; }
  .grid-3, .grid-2 { grid-template-columns: minmax(0,1fr); }
  .deflist > div { grid-template-columns: minmax(0,1fr); gap: 4px; }
  .nav-toggle { display: flex; }
  .nav {
    position: absolute; left: 0; right: 0; top: 64px;
    flex-direction: column; align-items: stretch; gap: 0;
    background: #fff; border-bottom: 1px solid var(--line);
    box-shadow: var(--sh-2); padding: 8px 20px 14px;
    display: none;
  }
  .nav.is-open { display: flex; }
  .nav a { padding: 12px 10px; border-bottom: 1px solid var(--line-2); border-radius: 0; }
  .nav a[aria-current="page"]::after { display: none; }
  .nav a[aria-current="page"] { background: var(--blue-050); }
  .figure { padding: 18px 14px; }
}
@media (max-width: 560px) {
  .wrap { padding: 0 18px; }
  .grid-4 { grid-template-columns: minmax(0,1fr); }
  .metric-row { grid-template-columns: minmax(0,1fr); }
  .foot-grid { grid-template-columns: minmax(0,1fr); gap: 28px; }
  .hero h1 { font-size: 32px; }
}

/* ==========================================================================
   打印
   ========================================================================== */
@media print {
  .site-head, .site-foot, .btn-row, .nav-toggle { display: none !important; }
  body { font-size: 11.5pt; color: #000; }
  .hero, .page-head { background: #fff !important; padding: 12pt 0; }
  section { padding: 14pt 0; }
  .card, .figure, .metric { box-shadow: none !important; break-inside: avoid; }
  a { color: #000; text-decoration: underline; }
  h2, h3 { break-after: avoid; page-break-after: avoid; }
}