:root{--tg-bg: #ffffff;--tg-secondary-bg: #f1f1f4;--tg-text: #000000;--tg-hint: #8a8a8e;--tg-link: #2481cc;--tg-button: #2481cc;--tg-button-text: #ffffff;--brand: #5b8cff;--brand-2: #8a6cff;--success: #2ecc71;--danger: #ff5c5c;--radius: 16px}:root[data-theme=dark]{--tg-secondary-bg: #1c1c1e}*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:var(--tg-bg);color:var(--tg-text)}#root{max-width:640px;margin:0 auto;min-height:100vh}.screen{padding:16px 16px 96px;animation:fade .25s ease}@keyframes fade{0%{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}.h1{font-size:24px;font-weight:800;margin:8px 0 4px}.h2{font-size:18px;font-weight:700;margin:0 0 8px}.hint{color:var(--tg-hint);font-size:14px;line-height:1.5}.card{background:var(--tg-secondary-bg);border-radius:var(--radius);padding:18px;margin-bottom:14px}.btn{display:block;width:100%;border:none;border-radius:14px;padding:16px;font-size:16px;font-weight:700;cursor:pointer;color:var(--tg-button-text);background:linear-gradient(135deg,var(--brand),var(--brand-2));transition:transform .06s ease,opacity .2s ease}.btn:active{transform:scale(.98)}.btn:disabled{opacity:.5;cursor:default}.btn-ghost{background:transparent;color:var(--tg-hint);font-weight:600}.progress{height:8px;background:var(--tg-secondary-bg);border-radius:999px;overflow:hidden;margin:4px 0 18px}.progress>span{display:block;height:100%;background:linear-gradient(90deg,var(--brand),var(--brand-2));border-radius:999px;transition:width .35s ease}.q-meta{font-size:13px;color:var(--tg-hint);margin-bottom:6px;font-weight:600}.q-text{font-size:19px;font-weight:700;line-height:1.35;margin-bottom:18px}.option{display:block;width:100%;text-align:left;background:var(--tg-bg);border:2px solid transparent;outline:1px solid rgba(128,128,128,.18);border-radius:14px;padding:15px 16px;margin-bottom:10px;font-size:16px;color:var(--tg-text);cursor:pointer;transition:border-color .15s ease,transform .06s ease}.option:active{transform:scale(.99)}.option.selected{border-color:var(--brand);outline-color:transparent}.option.dont-know{color:var(--tg-hint);font-weight:600}.result-score{font-size:44px;font-weight:900;text-align:center;background:linear-gradient(135deg,var(--brand),var(--brand-2));-webkit-background-clip:text;background-clip:text;color:transparent;margin:8px 0}.result-sub{text-align:center;color:var(--tg-hint);margin-bottom:20px}.weak-item{display:flex;align-items:center;gap:10px;padding:12px 14px;background:var(--tg-bg);outline:1px solid rgba(128,128,128,.18);border-radius:12px;margin-bottom:8px;font-size:15px}.weak-dot{width:8px;height:8px;border-radius:50%;background:var(--danger);flex:none}.nav{position:fixed;left:0;right:0;bottom:0;max-width:640px;margin:0 auto;display:flex;justify-content:space-around;background:var(--tg-bg);border-top:1px solid rgba(128,128,128,.18);padding:8px 4px calc(8px + env(safe-area-inset-bottom));z-index:10}.nav-item{border:none;background:none;color:var(--tg-hint);font-size:11px;display:flex;flex-direction:column;align-items:center;gap:3px;cursor:pointer;padding:4px 8px;flex:1}.nav-item .ico{font-size:20px}.nav-item.active{color:var(--brand)}.center{min-height:70vh;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:12px;text-align:center;padding:24px}.spinner{width:34px;height:34px;border:3px solid rgba(128,128,128,.25);border-top-color:var(--brand);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.badge{display:inline-block;padding:4px 10px;border-radius:999px;font-size:12px;font-weight:700;background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff}.block-card{display:block;width:100%;text-align:left;border:none;background:var(--tg-secondary-bg);border-radius:var(--radius);padding:16px;margin-bottom:12px;cursor:pointer;color:var(--tg-text);transition:transform .06s ease}.block-card:active{transform:scale(.99)}.block-card-head{display:flex;justify-content:space-between;align-items:center;margin-bottom:8px}.block-card-title{font-size:17px;font-weight:700;margin-bottom:4px}.lesson-title{font-size:21px;font-weight:800;text-align:center;margin:4px 0 14px;line-height:1.25}.section-label{font-size:13px;font-weight:700;color:var(--tg-hint);text-transform:uppercase;letter-spacing:.03em;margin:18px 0 8px}.diff-tag{font-size:11px;font-weight:700;color:var(--tg-hint);background:var(--tg-bg);outline:1px solid rgba(128,128,128,.2);border-radius:999px;padding:3px 9px;white-space:nowrap}.video-btn{display:inline-block;margin-top:12px;padding:10px 16px;border-radius:12px;background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff;font-weight:700;font-size:14px;text-decoration:none}.notes{margin-top:12px;font-size:15px;line-height:1.5;white-space:pre-wrap}.content-img{display:block;width:100%;height:auto;border-radius:12px;margin-top:10px;outline:1px solid rgba(128,128,128,.18)}.task-item{margin-top:14px;padding-top:14px;border-top:1px solid rgba(128,128,128,.18)}.task-q{font-size:15px;font-weight:600;margin-bottom:8px;white-space:pre-wrap}.task-actions{display:flex;gap:16px;flex-wrap:wrap}.toggle{border:none;background:none;color:var(--brand);font-weight:700;font-size:14px;cursor:pointer;padding:0}.task-hint{margin-top:10px;padding:12px 14px;background:var(--tg-bg);outline:1px solid rgba(128,128,128,.18);border-radius:12px;font-size:15px;line-height:1.5}.task-solution{margin-top:10px;padding:12px 14px;background:var(--tg-bg);outline:1px solid rgba(128,128,128,.18);border-radius:12px;font-size:15px;line-height:1.5;white-space:pre-wrap}