:root{--ink:#172033;--muted:#64748b;--line:#dce4ee;--surface:#fff;--soft:#f3f7fb;--nav:#102a43;--nav2:#184e77;--brand:#0f8f83;--brand2:#23b3a2;--danger:#dc3545;--warning:#f4a261}
*{box-sizing:border-box}body{margin:0;background:var(--soft);color:var(--ink);font-family:"Segoe UI",Arial,sans-serif}a{text-decoration:none}.app-shell{min-height:100vh;display:grid;grid-template-columns:264px minmax(0,1fr)}.sidebar{position:sticky;top:0;height:100vh;overflow:auto;background:linear-gradient(180deg,var(--nav),var(--nav2));padding:20px 16px;color:#fff;display:flex;flex-direction:column}.brand{display:flex;align-items:center;gap:12px;padding:4px 4px 20px;border-bottom:1px solid #ffffff28}.brand img{width:46px;height:46px;object-fit:contain;background:#fff;border-radius:10px;padding:4px}.brand strong,.brand small{display:block}.brand small{color:#ffffffb3}.nav-group{margin-top:22px}.nav-caption{padding:0 12px 7px;font-size:.69rem;letter-spacing:.09em;text-transform:uppercase;color:#ffffff8f;font-weight:800}.app-nav{display:grid;gap:4px}.app-nav a{display:flex;align-items:center;gap:11px;color:#ffffffc7;padding:11px 12px;border-radius:9px;font-weight:650}.app-nav a:hover,.app-nav a.active{background:#ffffff1c;color:#fff}.sidebar-footer{margin-top:auto;padding-top:20px}.main{min-width:0}.topbar{height:74px;background:#fffffff0;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 28px;position:sticky;top:0;z-index:30;backdrop-filter:blur(12px)}.topbar h1{font-size:1.22rem;margin:0}.topbar p{margin:2px 0 0;color:var(--muted);font-size:.82rem}.user-chip{display:flex;align-items:center;gap:10px}.avatar{width:38px;height:38px;border-radius:12px;background:#d7f5f0;color:#08776e;display:grid;place-items:center;font-weight:800}.content{padding:26px;max-width:1500px;margin:0 auto}.panel{background:#fff;border:1px solid var(--line);border-radius:16px;padding:22px;box-shadow:0 8px 28px #16324a0a}.metric-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:15px}.metric{background:#fff;border:1px solid var(--line);border-radius:15px;padding:18px;position:relative;overflow:hidden}.metric:after{content:"";position:absolute;width:70px;height:70px;border-radius:50%;background:#1b998b12;right:-20px;top:-25px}.metric span,.metric small{display:block;color:var(--muted)}.metric strong{font-size:1.8rem;display:block;margin:5px 0}.section-head{display:flex;justify-content:space-between;align-items:center;gap:16px;margin-bottom:17px}.section-head h2{font-size:1.1rem;margin:0}.empty{padding:38px;text-align:center;color:var(--muted)}.empty i{font-size:2rem;display:block;margin-bottom:10px}.question-card{border:1px solid var(--line);border-radius:13px;padding:16px;margin-bottom:11px}.question-meta{display:flex;gap:7px;flex-wrap:wrap;margin-bottom:8px}.question-stem{white-space:pre-wrap}.badge-soft{background:#e8f7f5;color:#08776e;border:1px solid #bdeae4}.import-source{border:1px solid var(--line);border-radius:14px;padding:18px;height:100%}.import-source i{font-size:1.6rem;color:var(--brand)}.preview-question{display:grid;grid-template-columns:34px 1fr;gap:12px;border:1px solid var(--line);border-radius:13px;padding:15px;margin-bottom:10px}.math-hint{background:#f5f2ff;border:1px solid #ded5ff;border-radius:11px;padding:12px;color:#51409a}.editor-toolbar{display:flex;gap:5px;flex-wrap:wrap;border:1px solid var(--line);border-bottom:0;padding:8px;border-radius:10px 10px 0 0;background:#f8fafc}.rich-editor{min-height:150px;border:1px solid var(--line);border-radius:0 0 10px 10px;padding:12px;background:#fff}.rich-editor:focus{outline:2px solid #0d6efd33}.option-row{display:grid;grid-template-columns:36px 1fr 45px;gap:8px;align-items:center;margin-bottom:8px}.option-letter{width:34px;height:34px;border-radius:9px;background:#e8f7f5;display:grid;place-items:center;font-weight:800;color:#08776e}.setup-alert{border-left:4px solid var(--warning)}.login-shell{min-height:100vh;background:linear-gradient(135deg,#102a43,#184e77 60%,#0f8f83);display:grid;place-items:center;padding:22px}.login-card{width:min(960px,100%);display:grid;grid-template-columns:1.15fr .85fr;background:#fff;border-radius:24px;overflow:hidden;box-shadow:0 30px 80px #06152280}.login-visual{padding:48px;background:linear-gradient(145deg,#e9faf7,#f4f8fc);display:flex;flex-direction:column;justify-content:space-between}.login-visual img{width:74px}.login-visual h1{font-size:2.6rem;line-height:1.05;margin:24px 0 14px}.login-visual p{color:var(--muted);font-size:1.05rem}.feature-pills{display:flex;gap:8px;flex-wrap:wrap}.feature-pills span{background:#fff;border:1px solid var(--line);border-radius:99px;padding:7px 11px;font-size:.8rem}.login-actions{padding:48px;display:flex;flex-direction:column;justify-content:center}.login-actions h2{margin-bottom:6px}.exam-shell{min-height:100vh;background:#eef3f8}.exam-topbar{height:68px;background:#fff;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 24px;position:sticky;top:0;z-index:20}.exam-grid{display:grid;grid-template-columns:minmax(0,1fr) 270px;gap:18px;max-width:1200px;margin:22px auto;padding:0 18px}.exam-question{background:#fff;border:1px solid var(--line);border-radius:16px;padding:24px}.answer-option{display:flex;gap:11px;padding:12px;border:1px solid var(--line);border-radius:11px;margin-top:9px;cursor:pointer}.answer-option:has(input:checked){border-color:var(--brand);background:#effbf9}.exam-nav{background:#fff;border:1px solid var(--line);border-radius:16px;padding:17px;position:sticky;top:90px;height:max-content}.number-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:7px}.number-grid button{aspect-ratio:1;border:1px solid var(--line);background:#fff;border-radius:8px}.number-grid button.answered{background:#d7f5f0;border-color:#59c8ba}.save-state{font-size:.8rem;color:var(--muted)}.mobile-menu{display:none}
@media(max-width:960px){.app-shell{grid-template-columns:1fr}.sidebar{position:fixed;left:-280px;z-index:50;width:264px;transition:left .2s}.menu-open .sidebar{left:0}.mobile-menu{display:inline-flex}.metric-grid{grid-template-columns:repeat(2,1fr)}.exam-grid{grid-template-columns:1fr}.exam-nav{position:static}.login-card{grid-template-columns:1fr}.login-visual{display:none}}
@media(max-width:560px){.content{padding:16px}.topbar{padding:0 14px}.user-chip>div:last-child{display:none}.metric-grid{grid-template-columns:1fr}.section-head{align-items:flex-start;flex-direction:column}.exam-topbar{padding:0 12px}.login-actions{padding:30px}}