:root{ --bg:#0b1722; --panel:#122333; --ink:#ecf2f8; --muted:#9eb2c2; --brand:#d62828; --accent:#f6aa1c; --radius:18px; --gap:14px; --shadow:0 8px 30px rgba(0,0,0,.35); }
:root.light{ --bg:#f6f9fc; --panel:#ffffff; --ink:#0d1b2a; --muted:#5b6b79; --brand:#d62828; --accent:#ff9800; }
*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;background:radial-gradient(1200px 500px at 50% 10%,#142638,#091521), var(--bg);color:var(--ink);font:16px/1.45 system-ui, Segoe UI, Roboto, sans-serif}
img{max-width:100%;display:block}
.card{background:linear-gradient(180deg, rgba(255,255,255,.06), rgba(255,255,255,.02));border:1px solid rgba(255,255,255,.08);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px}
.topbar{display:flex;justify-content:space-between;align-items:center;padding:12px 20px;border-bottom:1px solid rgba(255,255,255,.08);backdrop-filter:blur(6px);position:sticky;top:0;background:rgba(9,21,33,.7)}
.brand{display:flex;align-items:center;gap:12px}
.brand h1{font-size:20px;margin:0}
.brand-logo{width:110px;filter:drop-shadow(0 6px 18px rgba(255,176,46,.35))}
.brand-logo.sm{width:48px}
.layout{display:grid;grid-template-columns:320px 1fr;gap:var(--gap);padding:var(--gap)}
.sidebar{height:calc(100dvh - 92px);overflow:auto}
.section-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:10px}
.list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:8px}
.list-item{display:flex;justify-content:space-between;align-items:center;padding:10px;border:1px solid rgba(255,255,255,.08);border-radius:12px;background:rgba(255,255,255,.03)}
.content{display:flex;flex-direction:column;gap:var(--gap)}
.grid{display:grid;grid-template-columns:1fr 1fr;gap:var(--gap)}
.calendar-wrap{overflow:hidden}
.calendar-header{display:flex;align-items:center;justify-content:center;gap:12px;margin-bottom:10px}
#calendar-title{margin:0}
.calendar{display:grid;grid-template-columns:repeat(7,1fr);gap:6px}
.calendar .dow{opacity:.8;font-weight:600;text-align:center;padding:8px}
.calendar .cell{min-height:86px;border:1px solid rgba(255,255,255,.08);border-radius:12px;padding:8px;background:rgba(0,0,0,.15);position:relative}
.calendar .cell .num{position:absolute;top:6px;right:8px;opacity:.6;font-size:12px}
.calendar .cell.active{outline:2px solid var(--accent);}
.calendar .cell.has-lesson{background:linear-gradient(180deg, rgba(255,176,46,.15), rgba(0,0,0,.15))}
label{display:flex;flex-direction:column;gap:6px;margin:8px 0}
input, select, textarea{background:rgba(255,255,255,.06);border:1px solid rgba(255,255,255,.12);border-radius:10px;color:var(--ink);padding:10px}
textarea{resize:vertical}
.row{display:flex;gap:10px;align-items:center}
.row.space{justify-content:space-between}
.row.end{justify-content:flex-end}
.btn{background:var(--brand);border:none;border-radius:12px;color:white;padding:10px 14px;cursor:pointer;box-shadow:0 4px 14px rgba(214,40,40,.35)}
.btn:hover{filter:brightness(1.1)}
.btn.ghost{background:transparent;border:1px solid rgba(255,255,255,.18)}
.btn.sm{padding:6px 10px;font-size:14px}
.btn.danger{border-color:rgba(231,76,60,.4)}
.muted{color:var(--muted)}
.error{color:#ff7b7b;margin-top:8px;min-height:22px}
.auth-body{display:grid;place-items:center;min-height:100dvh;padding:24px}
.auth-container{width:min(520px, 92vw);text-align:center}
.tabs{display:flex;gap:6px;justify-content:center;margin:6px 0 12px}
.tab{background:transparent;border:1px solid rgba(255,255,255,.18);color:var(--ink);padding:8px 12px;border-radius:10px;cursor:pointer}
.tab.active{background:rgba(255,255,255,.08)}
.auth-form{display:none}
.auth-form.visible{display:flex;flex-direction:column}
@media (max-width: 980px){ .grid{grid-template-columns:1fr} .layout{grid-template-columns:1fr} }
@media print{ body{ background:#fff; color:#000; } .topbar, .sidebar, #theme-toggle, #print-view, #export-csv{ display:none !important; } .content{ grid-template-columns:1fr !important; } .card{ box-shadow:none; border-color:#ccc; } }