:root{
  --ink:#141C26;
  --paper:#EEF1F5;
  --surface:#FFFFFF;
  --line:#D3DAE3;
  --muted:#66748A;
  --signal:#2F5BFF;
  --signal-dark:#1E45D8;
  --signal-soft:#E3E9FF;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{background:var(--paper);color:var(--ink);font-family:'Inter',system-ui,sans-serif;line-height:1.65;-webkit-font-smoothing:antialiased}
a{color:inherit}
.wrap{max-width:1040px;margin:0 auto;padding:0 24px}

/* header */
.top{display:flex;align-items:center;justify-content:space-between;padding:26px 0;border-bottom:1px solid var(--line)}
.mark{font-family:'Space Grotesk',sans-serif;font-weight:700;font-size:19px;letter-spacing:-0.02em;text-decoration:none}
.mark span{color:var(--signal)}
.top nav a{margin-left:22px;font-size:14px;color:var(--muted);text-decoration:none}
.top nav a:hover{color:var(--ink)}

/* hero */
.hero{padding:56px 0 34px;max-width:640px}
h1{font-family:'Space Grotesk',sans-serif;font-weight:500;font-size:clamp(32px,5.2vw,56px);line-height:1.04;letter-spacing:-0.035em;margin:0 0 18px}
h1 em{font-style:normal;color:var(--signal)}
.lede{font-size:17px;color:var(--muted);margin:0;max-width:54ch}

/* tool */
.app{display:grid;grid-template-columns:1fr 1fr;background:var(--surface);border:1px solid var(--line);border-radius:18px;overflow:hidden;margin-bottom:18px}
.panel{padding:32px}
.panel.form{border-right:1px solid var(--line)}
.eyebrow{font-family:'IBM Plex Mono',monospace;font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);margin:0 0 20px}
.field{margin-bottom:18px}
label{display:block;font-size:13px;font-weight:500;margin-bottom:7px}
input[type=text],input[type=password],select,textarea{width:100%;padding:11px 13px;font:400 15px 'Inter',sans-serif;color:var(--ink);background:var(--surface);border:1px solid var(--line);border-radius:9px}
input[type=text],input[type=password],select{height:44px;padding:0 13px}
textarea{line-height:1.6;resize:vertical}
input:focus,select:focus,textarea:focus{outline:none;border-color:var(--signal);box-shadow:0 0 0 3px var(--signal-soft)}
input:disabled{background:var(--paper);color:var(--muted)}
.pw{display:flex;gap:8px}
.ghost{flex:0 0 78px;height:44px;border:1px solid var(--line);border-radius:9px;background:var(--surface);cursor:pointer;color:var(--muted);font:400 13px 'IBM Plex Mono',monospace}
.ghost:hover{border-color:var(--muted);color:var(--ink)}
.check{display:flex;align-items:center;gap:9px;font-size:14px;color:var(--muted);cursor:pointer;margin-top:4px}
.check input{width:16px;height:16px;accent-color:var(--signal)}

.stage{display:flex;flex-direction:column;align-items:center;justify-content:center;background:var(--paper);position:relative}
.waves{position:absolute;inset:0;overflow:hidden;pointer-events:none}
.waves i{position:absolute;left:50%;top:44%;border:1px solid var(--line);border-radius:50%;transform:translate(-50%,-50%)}
.qrcard{position:relative;background:#fff;padding:18px;border-radius:14px;border:1px solid var(--line);width:236px;height:236px;display:flex;align-items:center;justify-content:center}
.qrcard canvas,.qrcard img{display:block;width:200px !important;height:200px !important}
.placeholder{font-size:13px;color:var(--muted);text-align:center;max-width:150px}
.caption{position:relative;margin-top:18px;text-align:center;font-size:13px;color:var(--muted)}
.caption strong{display:block;color:var(--ink);font-weight:500;font-size:15px;word-break:break-all;max-width:240px}
.actions{position:relative;display:flex;gap:10px;margin-top:20px}
.btn,button.act{padding:11px 18px;border-radius:9px;cursor:pointer;font:500 14px 'Inter',sans-serif;border:1px solid var(--line);background:var(--surface);color:var(--ink);text-decoration:none;display:inline-block}
.btn:hover,button.act:hover:not(:disabled){border-color:var(--muted)}
.btn.primary,button.act.primary{background:var(--signal);border-color:var(--signal);color:#fff}
.btn.primary:hover,button.act.primary:hover:not(:disabled){background:var(--signal-dark);border-color:var(--signal-dark)}
.btn.danger{color:#B3261E;border-color:#E7C4C1}
button.act:disabled{opacity:.4;cursor:not-allowed}
.payload{display:flex;align-items:center;gap:14px;border:1px dashed var(--line);border-radius:12px;padding:14px 18px;margin-bottom:48px;font-family:'IBM Plex Mono',monospace;font-size:12.5px;color:var(--muted);overflow-x:auto;white-space:nowrap}
.payload b{color:var(--signal);font-weight:400;flex:0 0 auto}
.payload code{color:var(--ink)}

/* blog */
.page-head{padding:48px 0 28px;max-width:640px}
.page-head h1{font-size:clamp(28px,4vw,42px)}
.cats{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:28px}
.cats a{font-size:13px;padding:8px 14px;border:1px solid var(--line);border-radius:999px;background:var(--surface);text-decoration:none;color:var(--muted)}
.cats a.on{background:var(--ink);border-color:var(--ink);color:#fff}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:16px;padding-bottom:56px}
.card{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:22px;text-decoration:none;display:flex;flex-direction:column}
.card:hover{border-color:var(--signal)}
.card .tag{font-family:'IBM Plex Mono',monospace;font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--signal);margin-bottom:10px}
.card h3{font-family:'Space Grotesk',sans-serif;font-weight:500;font-size:18px;line-height:1.25;letter-spacing:-0.015em;margin:0 0 8px}
.card p{margin:0;font-size:14px;color:var(--muted)}
.card .meta{margin-top:14px;font-size:12px;color:var(--muted)}

/* article */
.article{max-width:680px;padding:44px 0 56px}
.crumbs{font-size:13px;color:var(--muted);margin-bottom:18px}
.crumbs a{text-decoration:none;color:var(--muted)}
.crumbs a:hover{color:var(--signal)}
.article .tag{font-family:'IBM Plex Mono',monospace;font-size:11px;letter-spacing:.1em;text-transform:uppercase;color:var(--signal)}
.article h1{margin:14px 0 12px}
.article .meta{font-size:13px;color:var(--muted);margin-bottom:32px;padding-bottom:24px;border-bottom:1px solid var(--line)}
.article .body{font-size:17px}
.article .body h2{font-family:'Space Grotesk',sans-serif;font-weight:500;font-size:21px;letter-spacing:-0.015em;margin:36px 0 10px}
.article .body p{margin:0 0 18px}
.article .lead{font-size:19px;color:var(--muted);margin:0 0 8px}
.backlink{display:inline-block;margin-top:20px;font-size:14px;color:var(--muted);text-decoration:none}
.next{border-top:1px solid var(--line);padding-top:28px;margin-top:8px}
.next h2{font-family:'Space Grotesk',sans-serif;font-size:16px;font-weight:500;margin:0 0 14px}

/* footer */
.site-footer{border-top:1px solid var(--line);padding:44px 0 34px}
.foot-head h2{font-family:'Space Grotesk',sans-serif;font-weight:500;font-size:22px;letter-spacing:-0.02em;margin:0 0 4px}
.foot-head p{margin:0 0 24px;color:var(--muted);font-size:14px}
ol.topics{list-style:none;margin:0;padding:0;columns:2;column-gap:32px}
ol.topics li{break-inside:avoid;border-bottom:1px solid var(--line)}
ol.topics a{display:flex;gap:14px;padding:11px 0;text-decoration:none;font-size:14.5px;align-items:baseline}
ol.topics a:hover .ttl{color:var(--signal)}
ol.topics .rank{font-family:'IBM Plex Mono',monospace;font-size:12px;color:var(--muted);flex:0 0 24px}
.foot-more{display:flex;align-items:center;gap:16px;margin:26px 0 30px}
.foot-more .count{font-size:13px;color:var(--muted)}
.foot-bottom{display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;border-top:1px solid var(--line);padding-top:20px;font-size:13px;color:var(--muted)}
.foot-bottom a{margin-left:16px;text-decoration:none;color:var(--muted)}
.foot-bottom a:hover{color:var(--ink)}

/* admin */
.admin{padding:36px 0 60px}
.admin h1{font-size:30px;margin:0 0 6px}
.admin .sub{color:var(--muted);font-size:14px;margin:0 0 28px}
.panelbox{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:26px;margin-bottom:20px}
.login{max-width:400px;margin:80px auto}
table.list{width:100%;border-collapse:collapse;background:var(--surface);border:1px solid var(--line);border-radius:14px;overflow:hidden;font-size:14px}
table.list th{text-align:left;font-weight:500;font-size:12px;letter-spacing:.06em;text-transform:uppercase;color:var(--muted);padding:14px 16px;border-bottom:1px solid var(--line)}
table.list td{padding:12px 16px;border-bottom:1px solid var(--line);vertical-align:middle}
table.list tr:last-child td{border-bottom:none}
.pill{display:inline-block;font-size:11px;padding:3px 9px;border-radius:999px;background:var(--paper);color:var(--muted)}
.pill.on{background:var(--signal-soft);color:var(--signal-dark)}
.pill.off{background:#FBEAEA;color:#B3261E}
.rowacts{display:flex;gap:6px;justify-content:flex-end}
.rowacts a,.rowacts button{font-size:12.5px;padding:6px 11px;border-radius:7px;border:1px solid var(--line);background:var(--surface);text-decoration:none;color:var(--ink);cursor:pointer}
.notice{background:var(--signal-soft);color:var(--signal-dark);padding:12px 16px;border-radius:10px;font-size:14px;margin-bottom:20px}
.notice.err{background:#FBEAEA;color:#B3261E}
.two{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.hint{font-size:12.5px;color:var(--muted);margin:6px 0 0}
.toolbar{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:20px;flex-wrap:wrap}

@media(max-width:820px){
  .app{grid-template-columns:1fr}
  .panel.form{border-right:none;border-bottom:1px solid var(--line)}
  ol.topics{columns:1}
  .two{grid-template-columns:1fr}
  .foot-bottom a{margin:0 16px 0 0}
}
@media (prefers-reduced-motion:reduce){*{transition:none!important;animation:none!important}}
@media print{.top,.hero,.payload,.site-footer,.actions,.panel.form{display:none}.app{border:none}.waves{display:none}}