:root{
  --bg:#f6f7fb; --card:#ffffff; --text:#1f2430; --muted:#6b7280; --border:#e5e7eb;
  --primary:#4f46e5; --primary-2:#6366f1; --primary-soft:#eef2ff; --accent:#f59e0b;
  --shadow:0 1px 3px rgba(0,0,0,.08); --shadow-lg:0 8px 24px rgba(0,0,0,.10);
  --radius:14px; --radius-sm:10px;
}
[data-theme="dark"]{
  --bg:#0f1117; --card:#171a24; --text:#e5e7eb; --muted:#9aa1ad; --border:#2a2f3a;
  --primary:#818cf8; --primary-soft:#1e2440; --shadow:0 1px 3px rgba(0,0,0,.5); --shadow-lg:0 8px 24px rgba(0,0,0,.6);
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;font-family:system-ui,-apple-system,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--text);line-height:1.65;transition:background .2s,color .2s}
.container{max-width:1120px;margin:0 auto;padding:0 16px}
a{color:var(--primary);text-decoration:none}
a:hover{text-decoration:underline}
h1,h2,h3{line-height:1.25;margin:.4em 0 .5em}
p{margin:.4em 0}
button{font:inherit;cursor:pointer}

/* ---------- header ---------- */
.site-header{position:sticky;top:0;z-index:50;background:color-mix(in srgb,var(--bg) 88%,transparent);backdrop-filter:blur(8px);border-bottom:1px solid var(--border)}
.header-inner{display:flex;align-items:center;gap:16px;padding:10px 16px}
.brand{display:flex;align-items:center;gap:8px;font-weight:800;font-size:1.15rem;color:var(--text)}
.brand:hover{text-decoration:none}
.brand-logo{font-size:1.4rem}
.main-nav{display:flex;gap:4px;margin-left:8px;flex:1}
.main-nav a{padding:6px 10px;border-radius:8px;color:var(--text);font-weight:500}
.main-nav a:hover{background:var(--primary-soft);text-decoration:none}
.header-actions{display:flex;align-items:center;gap:8px}
.icon-btn{width:36px;height:36px;border-radius:10px;border:1px solid var(--border);background:var(--card);font-size:1rem}
.lang-select{padding:6px 10px;border-radius:10px;border:1px solid var(--border);background:var(--card);color:var(--text);font-size:.9rem;max-width:170px}
.btn-ghost{padding:6px 12px;border-radius:10px;border:1px solid var(--border);background:var(--card);color:var(--text)}

/* ---------- hero ---------- */
.hero{text-align:center;padding:48px 0 32px}
.hero h1{font-size:clamp(1.8rem,4.5vw,3rem);margin:0 0 8px}
.hero-tagline{color:var(--muted);font-size:1.05rem;max-width:640px;margin:0 auto 24px}
.search-box{position:relative;max-width:560px;margin:0 auto}
.search-box .search-icon{position:absolute;left:16px;top:50%;transform:translateY(-50%);opacity:.55}
#tool-search{width:100%;padding:14px 18px 14px 46px;border-radius:999px;border:1px solid var(--border);background:var(--card);color:var(--text);font-size:1rem;outline:none;box-shadow:var(--shadow)}
#tool-search:focus{border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-soft)}
.search-count{color:var(--muted);font-size:.9rem;margin-top:10px}

/* ---------- category chips ---------- */
.cat-chips{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;padding:8px 0 8px}
.chip{padding:7px 14px;border-radius:999px;border:1px solid var(--border);background:var(--card);color:var(--text);font-size:.9rem;transition:.15s}
.chip:hover{border-color:var(--primary)}
.chip.active{background:var(--primary);color:#fff;border-color:var(--primary)}

/* ---------- sections & cards ---------- */
.cat-section{margin:36px 0}
.cat-head{display:flex;align-items:center;gap:12px;margin-bottom:16px}
.cat-icon{font-size:1.8rem}
.cat-head h2{margin:0;font-size:1.4rem}
.cat-head p{margin:0;color:var(--muted);font-size:.9rem}
.tool-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:14px}
.tool-card{display:flex;gap:12px;align-items:flex-start;padding:16px;background:var(--card);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);color:var(--text);transition:transform .12s,box-shadow .12s}
.tool-card:hover{transform:translateY(-2px);box-shadow:var(--shadow-lg);text-decoration:none}
.tool-card-icon{font-size:1.7rem;line-height:1.2}
.tool-card-text{display:flex;flex-direction:column;gap:2px;min-width:0}
.tool-card-name{font-weight:600}
.tool-card-desc{color:var(--muted);font-size:.85rem;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}

/* ---------- tool page ---------- */
.breadcrumb{font-size:.88rem;color:var(--muted);margin:20px 0 8px;display:flex;flex-wrap:wrap;gap:6px;align-items:center}
.breadcrumb a{color:var(--muted)}
.crumb-sep{opacity:.5}
.tool-title{font-size:clamp(1.5rem,3.5vw,2.2rem);margin:8px 0}
.tool-desc{color:var(--muted);max-width:760px;margin-bottom:20px}
.tool-shell{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow);padding:24px;margin:16px 0}
.tool-form{display:flex;flex-direction:column;gap:16px}
.tool-field{display:flex;flex-direction:column;gap:6px}
.tool-label{font-weight:600;font-size:.95rem}
.tool-field input[type=text],.tool-field input[type=number],.tool-field input[type=search],.tool-field select,.tool-field textarea{
  width:100%;padding:11px 13px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--bg);color:var(--text);font:inherit;outline:none}
.tool-field input:focus,.tool-field select:focus,.tool-field textarea:focus{border-color:var(--primary);box-shadow:0 0 0 3px var(--primary-soft)}
.tool-field select option{color:var(--text);background:var(--card)}
.tool-field input::placeholder,.tool-field textarea::placeholder{color:var(--muted);opacity:.85}
.tool-field input[type=color]{width:64px;height:44px;padding:4px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--card)}
.tool-field .inline{display:flex;gap:16px;flex-wrap:wrap}
.tool-hint{color:var(--muted);font-size:.82rem}
.btn-primary{padding:12px 22px;border:none;border-radius:999px;background:var(--primary);color:#fff;font-weight:600;font-size:1rem;align-self:flex-start}
.btn-primary:hover{background:var(--primary-2)}
.tool-outputs{display:grid;gap:14px;margin-top:20px}
.tool-output{display:flex;flex-direction:column;gap:6px}
.tool-output-label{font-weight:600;font-size:.9rem;color:var(--muted)}
.tool-output-value{font-size:1.15rem;font-weight:600;word-break:break-all;background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-sm);padding:12px 14px}
.tool-output-textarea{width:100%;min-height:120px;padding:12px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--bg);color:var(--text);font:inherit;resize:vertical}
.copy-btn{padding:6px 12px;border-radius:8px;border:1px solid var(--border);background:var(--card);color:var(--text);font-size:.85rem;align-self:flex-start}
.copy-btn:hover{border-color:var(--primary);color:var(--primary)}
.tool-error{color:#dc2626;font-weight:600}
[data-theme="dark"] .tool-error{color:#f87171}
.tool-output-table{overflow-x:auto;border:1px solid var(--border);border-radius:var(--radius-sm)}
.tool-output-table table{border-collapse:collapse;width:100%;font-size:.9rem}
.tool-output-table th,.tool-output-table td{border:1px solid var(--border);padding:8px 10px;text-align:right;white-space:nowrap}
.tool-output-table th{background:var(--primary-soft);font-weight:600}
.tool-output-html{overflow-x:auto}
.tool-howto{margin:32px 0 8px}
.tool-howto p{color:var(--muted);max-width:760px}
.related-tools{margin:32px 0}
.tool-note{color:var(--muted);font-size:.85rem;border-left:3px solid var(--border);padding-left:12px;margin:24px 0 40px}

/* ---------- static pages ---------- */
.static-page{max-width:760px;margin:32px auto;background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:28px;box-shadow:var(--shadow)}

/* ---------- ad ---------- */
.ad-slot{min-height:120px;margin:16px 0;display:flex;align-items:center;justify-content:center;background:var(--card);border:1px dashed var(--border);border-radius:var(--radius-sm);color:var(--muted);font-size:.8rem}
.ad-slot:empty{display:none}
.ad-leaderboard{min-height:90px}

/* ---------- footer ---------- */
.site-footer{border-top:1px solid var(--border);margin-top:48px;padding:28px 0 40px;background:var(--card)}
.footer-inner{display:flex;flex-direction:column;gap:10px;align-items:center;text-align:center}
.footer-brand{font-weight:700}
.footer-tagline{color:var(--muted);font-weight:400;font-size:.9rem}
.footer-nav{display:flex;flex-wrap:wrap;gap:16px;justify-content:center}
.footer-nav a{color:var(--muted);font-size:.9rem}
.footer-note{color:var(--muted);font-size:.8rem;max-width:640px}

/* ---------- responsive ---------- */
@media (max-width:720px){
  .main-nav{margin-left:0}
  .main-nav a:nth-child(2){display:none}
  .tool-grid{grid-template-columns:repeat(auto-fill,minmax(160px,1fr))}
  .tool-shell{padding:16px}
  .header-inner{gap:8px}
  .brand-name{display:none}
}
/* ===== 紧凑布局：少滚动、快速完成操作 ===== */
.site-header .header-inner{padding:8px 16px}
.hero{padding:20px 0 14px}
.hero h1{font-size:clamp(1.5rem,3.5vw,2.2rem)}
.hero-tagline{margin-bottom:14px;font-size:1rem}
#tool-search{padding:11px 16px 11px 44px}
.cat-section{margin:18px 0}
.cat-head{margin-bottom:10px}
.cat-head h2{font-size:1.2rem}
.tool-grid{gap:10px;grid-template-columns:repeat(auto-fill,minmax(200px,1fr))}
.tool-card{padding:12px;gap:10px}
.tool-card-icon{font-size:1.4rem}
.breadcrumb{margin:10px 0 4px}
.tool-title{margin:4px 0;font-size:clamp(1.3rem,3vw,1.8rem)}
.tool-desc{margin-bottom:10px;font-size:.95rem}
.tool-shell{padding:16px;margin:10px 0}
.tool-form{gap:10px}
.tool-field{gap:4px}
.tool-field input[type=text],.tool-field input[type=number],.tool-field input[type=search],.tool-field select,.tool-field textarea{padding:9px 11px}
.btn-primary{padding:10px 18px}
.tool-outputs{margin-top:10px;gap:10px}
.tool-output-value{padding:8px 10px;font-size:1.05rem}
.tool-output-textarea{min-height:90px}
.tool-howto{margin:18px 0 4px}
.related-tools{margin:18px 0}
.tool-note{margin:14px 0 24px}
.ad-slot{min-height:80px;margin:10px 0}
.ad-leaderboard{min-height:70px}
.site-footer{margin-top:28px;padding:20px 0 26px}

/* 桌面端：表单与结果同屏双栏，表单吸顶，操作几乎无需滚动 */
@media (min-width:900px){
  #tool{display:grid;grid-template-columns:minmax(280px,400px) minmax(0,1fr);gap:20px;align-items:start}
  .tool-form{position:sticky;top:72px}
  .tool-results{min-width:0}
  .tool-output-table{max-width:100%}
}