/* uihtml — 设计系统：CSS 变量 + 亮/暗双主题（跟随系统 + 手动切换） */

:root{
  color-scheme:light;
  --bg:#f8fafc; --surface:#ffffff; --border:#e2e8f0;
  --text:#1e293b; --muted:#64748b; --faint:#94a3b8;
  --accent:#6366f1; --accent-strong:#4f46e5;
  --accent-soft:#eef2ff; --accent-border:#c7d2fe; --accent-hover:#e0e7ff;
  --code-bg:#0f172a; --code-text:#e2e8f0;
  --shadow:0 6px 20px rgba(99,102,251,.10);
}
html[data-theme="dark"]{
  color-scheme:dark;
  --bg:#0b1220; --surface:#121a2b; --border:#243044;
  --text:#e2e8f0; --muted:#94a3b8; --faint:#64748b;
  --accent:#818cf8; --accent-strong:#a5b4fc;
  --accent-soft:rgba(99,102,251,.14); --accent-border:#3b4770; --accent-hover:rgba(99,102,251,.22);
  --code-bg:#0f172a; --code-text:#e2e8f0;
  --shadow:0 6px 20px rgba(0,0,0,.35);
}
@media (prefers-color-scheme:dark){
  html:not([data-theme="light"]){
    color-scheme:dark;
    --bg:#0b1220; --surface:#121a2b; --border:#243044;
    --text:#e2e8f0; --muted:#94a3b8; --faint:#64748b;
    --accent:#818cf8; --accent-strong:#a5b4fc;
    --accent-soft:rgba(99,102,251,.14); --accent-border:#3b4770; --accent-hover:rgba(99,102,251,.22);
    --code-bg:#0f172a; --code-text:#e2e8f0;
    --shadow:0 6px 20px rgba(0,0,0,.35);
  }
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;color:var(--text);background:var(--bg);line-height:1.6}
a{color:inherit;text-decoration:none}
.wrap{max-width:1040px;margin:0 auto;padding:0 20px}

/* ---------- Header / 主题切换 ---------- */
header.site{background:var(--surface);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:50}
header.site .wrap{display:flex;align-items:center;justify-content:space-between;height:60px}
.logo{font-weight:800;font-size:20px;letter-spacing:-.02em}
.logo span{color:var(--accent)}
nav.main{display:flex;align-items:center;gap:24px;font-size:14.5px;color:var(--muted)}
nav.main a:hover{color:var(--accent)}
/* All Tools 下拉分类菜单 */
.nav-drop{position:relative}
.nav-drop>a{display:inline-flex;align-items:center;gap:4px;cursor:pointer}
.nav-drop .caret{width:12px;height:12px;transition:transform .15s}
.nav-drop:hover .caret,.nav-drop:focus-within .caret{transform:rotate(180deg)}
.drop-panel{position:absolute;top:calc(100% + 10px);right:-10px;min-width:230px;background:var(--surface);border:1px solid var(--border);border-radius:12px;box-shadow:var(--shadow);padding:6px;display:grid;grid-template-columns:1fr 1fr;gap:2px;opacity:0;visibility:hidden;transform:translateY(-6px);transition:.15s;z-index:60}
.nav-drop:hover .drop-panel,.nav-drop:focus-within .drop-panel{opacity:1;visibility:visible;transform:translateY(0)}
.drop-panel a{display:flex;align-items:center;justify-content:space-between;gap:10px;padding:7px 10px;border-radius:8px;font-size:13.5px;white-space:nowrap;color:var(--text)}
.drop-panel a:hover{background:var(--accent-soft);color:var(--accent-strong)}
.drop-panel a span{font-size:11.5px;color:var(--faint)}
.theme-toggle{width:34px;height:34px;border-radius:9px;border:1px solid var(--border);background:var(--surface);cursor:pointer;display:flex;align-items:center;justify-content:center;color:var(--muted);transition:.15s}
.theme-toggle:hover{color:var(--accent);border-color:var(--accent-border)}
.theme-toggle svg{width:16px;height:16px}
.theme-toggle .sun{display:none}
html[data-theme="dark"] .theme-toggle .sun{display:block}
html[data-theme="dark"] .theme-toggle .moon{display:none}
@media (prefers-color-scheme:dark){html:not([data-theme="light"]) .theme-toggle .sun{display:block}html:not([data-theme="light"]) .theme-toggle .moon{display:none}}

/* ---------- Hero ---------- */
.hero{position:relative;text-align:center;padding:64px 0 44px;overflow:hidden}
.hero::before{content:"";position:absolute;inset:-30% -20% auto;height:360px;pointer-events:none;background:
  radial-gradient(38% 62% at 30% 32%,rgba(99,102,251,.16),transparent 70%),
  radial-gradient(34% 55% at 72% 24%,rgba(236,72,153,.10),transparent 70%),
  radial-gradient(30% 50% at 55% 62%,rgba(14,165,233,.10),transparent 70%)}
html[data-theme="dark"] .hero::before{opacity:.55}
@media (prefers-color-scheme:dark){html:not([data-theme="light"]) .hero::before{opacity:.55}}
.hero h1{font-size:38px;line-height:1.15;letter-spacing:-.02em;position:relative}
.hero h1 em{font-style:normal;color:var(--accent)}
.hero p{margin:14px auto 0;max-width:580px;color:var(--muted);font-size:16.5px;position:relative}
.badge{position:relative;display:inline-flex;align-items:center;gap:6px;font-size:12.5px;font-weight:600;color:var(--accent-strong);background:var(--accent-soft);border:1px solid var(--accent-border);border-radius:99px;padding:5px 14px;margin-bottom:18px}
.search{position:relative;max-width:520px;margin:26px auto 0}
.search svg{position:absolute;left:15px;top:50%;transform:translateY(-50%);width:17px;height:17px;color:var(--faint);pointer-events:none}
.search input{width:100%;height:46px;border:1px solid var(--border);border-radius:12px;background:var(--surface);color:var(--text);padding:0 16px 0 42px;font-size:15px;font-family:inherit;outline:none;box-shadow:0 1px 2px rgba(15,23,42,.04)}
.search input:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-soft)}
.search input::placeholder{color:var(--faint)}
.no-results{display:none;text-align:center;color:var(--muted);padding:40px 0;font-size:14.5px}

/* ---------- 首页 sticky 分类条 ---------- */
.cat-chips{position:sticky;top:60px;z-index:40;display:flex;gap:8px;overflow-x:auto;scrollbar-width:none;background:var(--bg);padding:10px 0 12px;margin-bottom:2px}
.cat-chips::-webkit-scrollbar{display:none}
.cat-chips a{flex-shrink:0;font-size:13px;font-weight:500;color:var(--muted);background:var(--surface);border:1px solid var(--border);border-radius:99px;padding:6px 14px;transition:.15s}
.cat-chips a:hover{border-color:var(--accent-border);color:var(--accent-strong)}
.cat-chips a.on{background:var(--accent-soft);border-color:var(--accent-border);color:var(--accent-strong)}

/* ---------- 列表 / 分类 ---------- */
main.wrap{padding:30px 20px 56px}
h1{font-size:28px;letter-spacing:-.01em}
.sub{color:var(--muted);margin:6px 0 20px;font-size:15px}
.cat-section{margin-top:30px;scroll-margin-top:122px}
.cat-section:first-child{margin-top:6px}
.cat-head{display:flex;align-items:center;gap:10px;margin-bottom:12px}
.cat-head h2{font-size:17px;letter-spacing:-.01em}
.cat-head .count{font-size:12px;color:var(--faint);background:var(--surface);border:1px solid var(--border);padding:1px 10px;border-radius:99px}
.cat-head .line{flex:1;height:1px;background:var(--border)}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:14px}
.card{display:block;background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:16px;transition:.15s}
.card:hover{border-color:var(--accent-border);box-shadow:var(--shadow);transform:translateY(-2px)}
.card .ico{width:38px;height:38px;border-radius:10px;display:flex;align-items:center;justify-content:center;margin-bottom:10px;color:var(--c,#6366f1);background:color-mix(in srgb,var(--c,#6366f1) 13%,transparent)}
html[data-theme="dark"] .card .ico{color:var(--cd,#818cf8)}
@media (prefers-color-scheme:dark){html:not([data-theme="light"]) .card .ico{color:var(--cd,#818cf8)}}
.card .ico svg{width:20px;height:20px}
.card h3{font-size:15px;margin:0 0 4px}
.card p{font-size:13px;color:var(--muted)}
/* 分类色板（--c 亮色 / --cd 暗色） */
.cat-css{--c:#6366f1;--cd:#818cf8}
.cat-img{--c:#ec4899;--cd:#f472b6}
.cat-data{--c:#10b981;--cd:#34d399}
.cat-text{--c:#d97706;--cd:#fbbf24}
.cat-dev{--c:#0ea5e9;--cd:#38bdf8}
.cat-seo{--c:#8b5cf6;--cd:#a78bfa}
.cat-calc{--c:#14b8a6;--cd:#2dd4bf}
.cat-pdf{--c:#f43f5e;--cd:#fb7185}

/* ---------- 工具页 ---------- */
.tool{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:20px;margin-top:8px}
.row{display:flex;flex-wrap:wrap;gap:14px;margin-bottom:14px;align-items:center}
.row label{font-size:13.5px;color:var(--muted);min-width:120px}
input[type=text],input[type=url],input[type=number],select,textarea{border:1px solid var(--border);border-radius:8px;padding:8px 12px;font-size:14px;font-family:inherit;outline:none;background:var(--surface);color:var(--text)}
input:focus,select:focus,textarea:focus{border-color:var(--accent)}
textarea{width:100%;min-height:110px;resize:vertical;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:13px}
.btn{border:0;border-radius:8px;background:var(--accent);color:#fff;padding:9px 20px;font-size:14px;cursor:pointer;font-weight:600}
.btn:hover{background:var(--accent-strong)}
html[data-theme="dark"] .btn{color:#0b1220}
@media (prefers-color-scheme:dark){html:not([data-theme="light"]) .btn{color:#0b1220}}
.btn.ghost{background:var(--accent-soft);color:var(--accent-strong)}
.btn.ghost:hover{background:var(--accent-hover)}
.codebox{position:relative;margin-top:14px}
.codebox pre{background:var(--code-bg);color:var(--code-text);border:1px solid var(--border);border-radius:10px;padding:16px;font-size:13px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;overflow-x:auto;white-space:pre-wrap;word-break:break-word;min-height:52px}
.copy{position:absolute;top:10px;right:10px;border:0;border-radius:6px;background:#334155;color:#e2e8f0;padding:5px 12px;font-size:12px;cursor:pointer}
.copy:hover{background:#475569}
.preview{border:1px dashed var(--border);border-radius:10px;padding:18px;margin-top:14px;background:var(--surface)}
section.about,section.faq{max-width:760px;margin-top:36px}
section.about h2,section.faq h2{font-size:20px;margin-bottom:12px}
section.about p,section.faq p{color:var(--muted);font-size:14.5px;margin-bottom:10px}
section.faq h3{font-size:15px;margin:14px 0 4px}
.tip{background:var(--accent-soft);border:1px solid var(--accent-border);color:var(--accent-strong);border-radius:8px;padding:10px 14px;font-size:13.5px;margin-top:12px}

/* ---------- Footer ---------- */
footer.site{background:var(--surface);border-top:1px solid var(--border);padding:22px 0;font-size:13.5px;color:var(--faint)}
footer.site .wrap{display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}
footer.site a:hover{color:var(--accent)}
.foot-cols{display:flex;gap:40px;flex-wrap:wrap;padding:14px 0 18px}
.foot-cols h4{font-size:11.5px;font-weight:700;text-transform:uppercase;letter-spacing:.07em;color:var(--faint);margin-bottom:8px}
.foot-cols a{display:block;font-size:13.5px;color:var(--muted);padding:3px 0}
.foot-cols a:hover{color:var(--accent)}
.foot-base{border-top:1px solid var(--border);padding-top:16px;display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px}

/* ---------- Blog ---------- */
.article{max-width:760px;margin:0 auto}
.crumb{font-size:13px;color:var(--faint);margin-bottom:10px}
.crumb a{color:var(--muted)}
.crumb a:hover{color:var(--accent)}
.article h1{font-size:30px;line-height:1.25;margin-bottom:6px}
.article .meta{font-size:13.5px;color:var(--faint);margin-bottom:10px}
.cats{display:flex;gap:8px;flex-wrap:wrap;margin:8px 0 4px}
.cats a{font-size:12px;font-weight:600;color:var(--accent-strong);background:var(--accent-soft);border-radius:99px;padding:3px 12px}
.cats a:hover{background:var(--accent-hover)}
.post-body{margin-top:18px;font-size:16px;line-height:1.75;color:var(--text)}
.post-body p{margin:0 0 14px}
.post-body h2{font-size:22px;margin:28px 0 10px;letter-spacing:-.01em}
.post-body h3{font-size:17.5px;margin:20px 0 8px}
.post-body ul,.post-body ol{margin:0 0 14px;padding-left:22px}
.post-body li{margin-bottom:6px}
.post-body a{color:var(--accent-strong);text-decoration:underline;text-underline-offset:2px}
.post-body code{background:var(--accent-soft);border:1px solid var(--border);border-radius:5px;padding:1px 6px;font-size:.88em;font-family:ui-monospace,SFMono-Regular,Menlo,monospace}
.post-body pre{background:var(--code-bg);color:var(--code-text);border-radius:10px;padding:14px 16px;overflow-x:auto;font-size:13.5px;margin:0 0 14px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace}
.post-body pre code{background:none;border:0;padding:0;color:inherit}
.post-body blockquote{border-left:3px solid var(--accent-border);margin:0 0 14px;padding:2px 0 2px 16px;color:var(--muted)}
.post-body figure{margin:18px 0}
.post-body img{max-width:100%;height:auto;border-radius:10px;border:1px solid var(--border)}
.post-body figcaption{font-size:12.5px;color:var(--faint);text-align:center;margin-top:6px}
.pager{display:flex;justify-content:space-between;gap:12px;margin-top:30px;padding-top:18px;border-top:1px solid var(--border)}
.pager a{font-size:13.5px;color:var(--accent-strong);line-height:1.4}
.pager .prev{max-width:48%}.pager .next{max-width:48%;text-align:right;margin-left:auto}
.post-list{display:grid;gap:14px;max-width:760px;margin:0 auto}
.post-card{display:flex;gap:16px;background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:16px 18px;transition:.15s}
.post-card:hover{border-color:var(--accent-border);box-shadow:var(--shadow)}
.post-card p{font-size:13.5px;color:var(--muted);margin:0 0 8px}
.pc-cover{width:150px;height:100px;object-fit:cover;border-radius:8px;flex-shrink:0;align-self:center}
.pc-date{font-size:12.5px;color:var(--faint)}
/* 博客卡片：article + 拉伸链接（避免 a 嵌套 a），分类胶囊独立可点 */
.post-card{position:relative}
.pc-title{margin:2px 0 6px;font-size:16.5px;line-height:1.35}
.pc-title a{color:inherit;text-decoration:none}
.pc-title a::after{content:"";position:absolute;inset:0;border-radius:12px}
.post-card .cats a{position:relative;z-index:1}

@media(max-width:640px){
  .hero h1{font-size:27px}
  nav.main{gap:14px}
  .drop-panel{grid-template-columns:1fr;right:auto;left:50%;transform:translate(-50%,-6px)}
  .nav-drop:hover .drop-panel,.nav-drop:focus-within .drop-panel{transform:translate(-50%,0)}
  .article h1{font-size:24px}
  .post-card{flex-direction:column}
  .pc-cover{width:100%;height:150px}
}