:root{--bg:#07101b;--panel:#101c2d;--line:#29415f;--text:#eef4fb;--muted:#9fb0c7;--accent:#58c8ff;--gold:#f7c75d;--green:#74d3a4;--danger:#ff8a8a}*{box-sizing:border-box}body{margin:0;background:radial-gradient(circle at top left,#11233d 0,#07101b 50%,#050a12 100%);color:var(--text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;min-height:100vh}.shell{max-width:1060px;margin:auto;padding:34px 22px 70px}.back{color:var(--muted);text-decoration:none}.login-card{max-width:640px;margin:9vh auto 0;background:linear-gradient(145deg,#111f33,#0b1728);border:1px solid var(--line);border-radius:24px;padding:30px;box-shadow:0 24px 80px rgba(0,0,0,.28)}.eyebrow{font-size:.74rem;letter-spacing:.13em;color:var(--accent);font-weight:850}.login-card h1,.teacher-head h1{margin:8px 0 12px;font-size:clamp(2rem,4vw,3rem)}p{line-height:1.65;color:var(--muted)}label{display:block;font-weight:800;margin:22px 0 7px}.password-row{display:grid;grid-template-columns:1fr auto;gap:8px}.password-row input{min-width:0;background:#08131f;color:#fff;border:1px solid var(--line);border-radius:11px;padding:13px}.password-row button,.primary,.secondary,.tabs button{border:1px solid var(--line);border-radius:11px;padding:11px 14px;cursor:pointer;color:#fff;background:#13243a}.primary{width:100%;margin-top:12px;background:#176b91;font-weight:850}.status{min-height:1.5em;margin:10px 0 0}.status.error{color:#ffb1b1}.security-note{display:grid;gap:5px;margin-top:18px;padding:14px;border-radius:13px;background:#0b1827;border:1px solid var(--line)}.security-note span{color:var(--muted);font-size:.9rem}.teacher-area{margin-top:24px}.teacher-head{display:flex;justify-content:space-between;gap:20px;align-items:flex-start;padding:20px 0;border-bottom:1px solid var(--line)}.teacher-head p{margin:0}.secondary{white-space:nowrap}.tabs{display:flex;gap:8px;flex-wrap:wrap;margin:22px 0}.tabs button.active{background:#18405a;border-color:#39789e}.guide{background:#0d1828;border:1px solid var(--line);border-radius:20px;padding:clamp(20px,4vw,38px);line-height:1.72}.guide h1{font-size:2rem}.guide h2{margin-top:2rem;padding-top:.35rem;border-top:1px solid #233950}.guide h3{margin-top:1.5rem}.guide p,.guide li{color:#c7d4e3}.guide strong{color:#fff}.guide blockquote{margin:18px 0;padding:12px 16px;border-left:3px solid var(--gold);background:#16180f;color:#eadca8}.guide code{background:#07121e;padding:2px 5px;border-radius:5px}.guide ul,.guide ol{padding-left:24px}.guide hr{border:0;border-top:1px solid var(--line);margin:25px 0}button:focus-visible,input:focus-visible,a:focus-visible{outline:3px solid var(--gold);outline-offset:3px}@media(max-width:700px){.teacher-head{display:block}.teacher-head .secondary{margin-top:12px}.tabs button{flex:1 1 100%}.login-card{margin-top:5vh;padding:22px}}