:root{
  --bg:#f4f6f8;
  --panel:#ffffff;
  --panel-2:#eef2f6;
  --panel-3:#e2e8f0;
  --border:#dde3ea;
  --fg:#1f2937;
  --muted:#64748b;
  --accent:#0e7490;
  --accent-strong:#0b5e75;
  --accent-ink:#ffffff;
  --good:#047857;
  --info:#0369a1;
  --warn:#b45309;
  --bad:#b91c1c;
  --shadow:0 1px 2px rgba(15,23,42,.06),0 1px 1px rgba(15,23,42,.04);
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;font-family:"Segoe UI",system-ui,-apple-system,"Microsoft YaHei",Roboto,sans-serif;background:var(--bg);color:var(--fg);font-size:14px;line-height:1.45}
.hidden{display:none!important}
.muted{color:var(--muted)}
.err{color:var(--bad);min-height:18px;margin:8px 0}
.btn{display:inline-flex;align-items:center;gap:6px}
button{cursor:pointer;border:1px solid transparent;border-radius:8px;padding:8px 14px;background:var(--accent);color:var(--accent-ink);font-weight:600;font-size:14px;transition:background .15s ease,border-color .15s ease}
button:hover{background:var(--accent-strong)}
button:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
button.secondary{background:var(--panel);color:var(--fg);border-color:var(--border)}
button.secondary:hover{background:var(--panel-2)}
button.small{padding:4px 9px;font-size:12px;font-weight:500}
button.small.danger{background:#fef2f2;color:var(--bad);border-color:#fecaca}
button.small.danger:hover{background:#fee2e2}
svg.ic{width:16px;height:16px;flex:none}

/* login */
.login{max-width:400px;margin:9vh auto;background:var(--panel);border:1px solid var(--border);border-radius:8px;box-shadow:var(--shadow);padding:32px 28px}
.login .brand{display:flex;align-items:center;gap:10px;justify-content:center;margin-bottom:4px}
.login .brand .mark{width:34px;height:34px;border-radius:8px;background:var(--accent);display:grid;place-items:center;color:#fff}
.login h2{text-align:center;margin:6px 0 2px;font-size:20px;letter-spacing:0}
.login p.muted{text-align:center;margin:0 0 16px}
.login input{display:block;width:100%;margin:8px 0;padding:10px 12px;border-radius:8px;border:1px solid var(--border);background:#fbfdff;color:var(--fg);font-size:14px}
.login input:focus{outline:2px solid var(--accent);outline-offset:1px;border-color:var(--accent)}
.login button{width:100%;margin-top:6px}

/* header */
header{display:flex;justify-content:space-between;align-items:center;gap:16px;padding:12px 24px;background:var(--panel);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:20}
header .brand{display:flex;align-items:center;gap:10px;min-width:0}
header .mark{width:32px;height:32px;border-radius:8px;background:var(--accent);display:grid;place-items:center;color:#fff;flex:none}
header h1{font-size:17px;margin:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.subtitle{font-size:12px;color:var(--muted);white-space:nowrap}
.user{display:flex;gap:8px;align-items:center;flex:none}
.user .who{font-weight:600;white-space:nowrap}

/* nav */
nav{display:flex;gap:2px;padding:8px 24px;background:#fbfdff;border-bottom:1px solid var(--border);overflow-x:auto}
.tab{background:transparent;color:var(--muted);font-weight:600;padding:8px 14px;border-radius:8px;border:none}
.tab:hover{background:var(--panel-2);color:var(--fg)}
.tab.active{color:var(--accent);background:var(--panel-2)}

/* layout */
main{padding:24px;max-width:1200px;margin:0 auto}
.panel{display:none}
.panel.active{display:block}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(170px,1fr));gap:14px;margin-bottom:22px}
.card{background:var(--panel);border:1px solid var(--border);border-radius:8px;box-shadow:var(--shadow);padding:16px}
.card h3{margin:0 0 12px;font-size:14px;color:var(--muted);font-weight:600;text-transform:uppercase;letter-spacing:.02em}
.card .big{font-size:28px;font-weight:700;line-height:1.15}
.grid2{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-bottom:18px}

/* tables */
table{width:100%;border-collapse:collapse;background:var(--panel);border:1px solid var(--border);border-radius:8px;overflow:hidden;font-size:13px}
th,td{padding:9px 11px;text-align:left;border-bottom:1px solid var(--border);vertical-align:top}
th{background:var(--panel-2);color:var(--muted);font-weight:600;white-space:nowrap}
tbody tr:last-child td{border-bottom:none}
tr.clickable{cursor:pointer}
tr.clickable:hover{background:var(--panel-2)}
td{word-break:break-word}
td .em{word-break:break-all}

/* badges */
.badge{display:inline-block;padding:2px 9px;border-radius:999px;font-size:12px;font-weight:700;line-height:1.4}
.grade-Ap{background:#d1fae5;color:var(--good)}
.grade-A{background:#e0f2fe;color:var(--info)}
.grade-B{background:#fef3c7;color:var(--warn)}
.grade-C{background:#f1f5f9;color:var(--muted)}

/* misc */
.note{background:#fffbeb;border-left:3px solid #f59e0b;border-radius:6px;padding:12px 14px;margin:16px 0;color:#78350f}
.bar{background:var(--panel-3);border-radius:6px;height:12px;overflow:hidden}
.bar>span{display:block;height:100%;background:var(--accent);border-radius:6px}
input.search,select.search{padding:8px 11px;border-radius:8px;border:1px solid var(--border);background:#fbfdff;color:var(--fg);width:220px;font-size:14px}
input.search:focus,select.search:focus{outline:2px solid var(--accent);outline-offset:1px;border-color:var(--accent)}
input.search::placeholder{color:#9aa5b1}
textarea.preview,pre.preview{width:100%;background:#fbfdff;color:var(--fg);border:1px solid var(--border);border-radius:8px;padding:12px;font-size:13px;white-space:pre-wrap}
.toolbar{display:flex;gap:10px;flex-wrap:wrap;margin-bottom:14px;align-items:center}
.crumbs{display:inline-flex;align-items:center;font-size:13px;color:var(--muted);margin-bottom:14px}

@media(max-width:820px){
  .grid2,.cards{grid-template-columns:1fr}
  header{flex-wrap:wrap}
  header h1{font-size:15px}
  .user .who{display:none}
  main{padding:16px}
  input.search,select.search{width:100%}
}