@import url('https://fonts.googleapis.com/css2?family=Newsreader:wght@500;600&family=Inter:wght@400;500;600&family=IBM+Plex+Mono&display=swap');
:root{--ink:#16232c;--muted:#526268;--paper:#f4f2eb;--card:#fff;--teal:#3e6f68;--deep:#294d48;--clay:#a85c3f;--line:#d8d2c0;--danger:#8a3b22}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font-family:Inter,sans-serif;line-height:1.5}.topbar{height:72px;display:flex;align-items:center;justify-content:space-between;padding:0 clamp(1rem,4vw,2.5rem);border-bottom:1px solid var(--line)}.brand{font:600 1.4rem Newsreader,serif}.brand span{color:var(--teal)}.toplink{color:var(--teal);font-size:.85rem;text-decoration:none}.auth-shell{width:min(480px,calc(100% - 2rem));margin:8vh auto}.eyebrow{font:400 .75rem 'IBM Plex Mono',monospace;color:var(--clay);text-transform:uppercase;letter-spacing:.08em}.auth-shell h1,.stage h1{font:500 clamp(2rem,5vw,2.7rem) Newsreader,serif;line-height:1.05;margin:.5rem 0}.lead,.muted{color:var(--muted)}.card{background:var(--card);border:1px solid var(--line);border-radius:10px;padding:1.5rem;box-shadow:0 8px 30px #16232c0b;margin-top:1.5rem}label{display:block;color:var(--muted);font-size:.84rem;font-weight:600;margin:.8rem 0 .4rem}input{width:100%;padding:.8rem .9rem;border:1px solid var(--line);border-radius:6px;background:#faf9f5;font:inherit}input:focus{outline:2px solid var(--teal);outline-offset:1px}.code{font:500 1.4rem 'IBM Plex Mono',monospace;letter-spacing:.3em;text-align:center}button{border:0;border-radius:6px;padding:.82rem 1.2rem;background:var(--teal);color:white;font:600 .92rem Inter;cursor:pointer}button:hover{background:var(--deep)}button:disabled{opacity:.55;cursor:wait}.wide{width:100%;margin-top:1rem}.secondary{background:transparent;color:var(--teal);border:1px solid var(--line)}.danger{background:transparent;color:var(--danger);padding:.4rem}.msg{display:none;margin-top:1rem;padding:.7rem .8rem;border-radius:6px;font-size:.88rem}.msg.show{display:block}.msg.error{background:#f6e6e0;color:var(--danger)}.msg.info{background:#e7efec;color:var(--deep)}.hidden{display:none!important}.layout{display:grid;grid-template-columns:290px minmax(0,1fr);min-height:calc(100vh - 72px)}.sidebar{border-right:1px solid var(--line);padding:1.5rem}.sidebar h2{font:600 1.15rem Newsreader;margin:.2rem 0 1rem}.class-button{display:block;width:100%;text-align:left;color:var(--ink);background:transparent;padding:.75rem;border-radius:6px;margin:.2rem 0}.class-button:hover,.class-button.active{background:#e8e5da}.class-button.active{box-shadow:inset 3px 0 var(--clay)}.stage{padding:clamp(1.25rem,4vw,3rem)}.stage h1{font-size:2rem}.player{position:relative;isolation:isolate;aspect-ratio:16/9;max-width:1000px;background:#0d171c;border-radius:10px;overflow:hidden}.player iframe{width:100%;height:100%;border:0;display:block}.wm-layer{position:absolute;inset:0;z-index:10;pointer-events:none;overflow:hidden}.wm{position:absolute;color:#fff9;font:500 clamp(.62rem,1.2vw,.82rem) 'IBM Plex Mono';text-shadow:0 1px 4px #000;padding:.25rem;white-space:nowrap;transition:transform 1s ease}.session-row{display:flex;gap:1rem;align-items:center;justify-content:space-between;max-width:1000px;margin-top:.8rem;color:var(--muted);font-size:.78rem}.privacy-shield{position:absolute;inset:0;z-index:20;display:grid;place-items:center;text-align:center;padding:2rem;background:#0d171c;color:white}.admin-shell{width:min(760px,calc(100% - 2rem));margin:3rem auto}.admin-row{display:flex;gap:.6rem}.student{display:flex;justify-content:space-between;align-items:center;border-top:1px solid var(--line);padding:.7rem 0;font-size:.9rem}@media(max-width:760px){.layout{grid-template-columns:1fr}.sidebar{border-right:0;border-bottom:1px solid var(--line);padding:1rem}.stage{padding:1rem}.admin-row{display:block}.admin-row button{width:100%;margin-top:.6rem}}