:root{color:#102033;font-synthesis:none;text-rendering:optimizelegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;background:#f7fbff;font-family:Pretendard,Inter,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}*{box-sizing:border-box}body{min-width:320px;min-height:100vh;margin:0}button,input{font:inherit}a{color:inherit;text-decoration:none}#root{min-height:100vh}:root{--bg:#f7fbff;--surface:#fff;--ink:#102033;--muted:#64748b;--line:#dbe7f3;--blue:#2563eb;--mint:#12b981;--violet:#7c3aed;--amber:#f59e0b;--red:#ef4444;--shadow:0 18px 48px #1e40af1a}.page{width:min(1180px,100% - 40px);margin:0 auto;padding:28px 0 44px}.topbar{justify-content:space-between;align-items:center;gap:18px;margin-bottom:34px;display:flex}.brand{align-items:center;gap:12px;min-width:0;display:flex}.brandMark{color:#fff;background:linear-gradient(135deg,#2563eb,#12b981);border-radius:14px;place-items:center;width:44px;height:44px;display:grid;box-shadow:0 14px 30px 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1.2fr;align-items:center;gap:16px;display:grid}.aiCard{background:linear-gradient(135deg,#2563eb1f,#12b98124),#f8fbff;border:1px solid #cfe0f5;border-radius:8px;flex-direction:column;justify-content:space-between;min-height:180px;padding:18px;display:flex}.aiCard i{width:42px;height:42px;color:var(--blue);background:#fff;border-radius:13px;place-items:center;display:grid;box-shadow:0 12px 24px #2563eb1f}.aiCard strong{font-size:17px;font-weight:900;line-height:1.35}.checkList{gap:12px;display:grid}.checkRow{color:#334155;align-items:flex-start;gap:10px;font-size:14px;font-weight:800;line-height:1.5;display:flex}.checkRow i{color:#0f766e;background:#dcfce7;border-radius:999px;flex:none;place-items:center;width:22px;height:22px;margin-top:1px;display:grid}body{background:radial-gradient(circle at 18% 8%, #2563eb1f, transparent 30%), radial-gradient(circle at 88% 12%, #14b8a624, transparent 28%), linear-gradient(180deg, #fbfdff 0%, var(--bg) 48%, #eef7ff 100%)}@media (width<=980px){.shell,.bottomGrid,.homeworkPreview,.activeRoomPanel{grid-template-columns:1fr}}@media (width<=720px){.page{width:min(100% - 24px,1180px);padding-top:18px}.topbar{align-items:flex-start}.topActions{flex-direction:column;align-items:flex-end}.topActions .iconBtn{display:none}.userMenu{grid-template-columns:auto minmax(0,1fr);max-width:184px}.userMenu .ghostBtn{grid-column:1/-1;width:100%}.heroPanel{min-height:auto;padding:24px}.rolePanel,.roleActions{grid-template-columns:1fr}h1{font-size:40px}.heroCopy{font-size:16px}.heroActions,.joinBox,.flowStrip,.videoGrid,.studentStatus{grid-template-columns:1fr}.primaryBtn,.secondaryBtn,.joinBox button{width:100%}.studentTiles{grid-template-columns:repeat(2,minmax(0,1fr))}.barRow{grid-template-columns:32px 1fr 38px}.lessonItem{grid-template-columns:auto 1fr}.lessonScore{grid-column:2}}