:root{--bg: var(--tg-theme-bg-color, #ffffff);--text: var(--tg-theme-text-color, #17181a);--hint: var(--tg-theme-hint-color, #707579);--link: var(--tg-theme-link-color, #2f6fed);--button: var(--tg-theme-button-color, #2f6fed);--button-text: var(--tg-theme-button-text-color, #ffffff);--secondary-bg: var(--tg-theme-secondary-bg-color, #f4f4f6);--success: #17875a;--success-tint: rgba(23, 135, 90, .12);--danger: #d1433f;--danger-tint: rgba(209, 67, 63, .1);--hairline: color-mix(in srgb, var(--text) 10%, transparent);--hairline-soft: color-mix(in srgb, var(--text) 6%, transparent);--card-shadow: 0 1px 2px color-mix(in srgb, var(--text) 6%, transparent);--radius-sm: 10px;--radius: 14px}*{box-sizing:border-box}html{-webkit-text-size-adjust:100%}body{margin:0;background:var(--bg);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;font-size:15.5px;line-height:1.5;-webkit-font-smoothing:antialiased}a{color:var(--link)}h1{font-size:1.3rem;font-weight:700;letter-spacing:-.01em;margin:2px 0 16px;text-wrap:balance}h2{font-size:1.05rem;font-weight:600;margin:0 0 4px}h3{font-size:.72rem;font-weight:700;letter-spacing:.04em;text-transform:uppercase;color:var(--hint);margin:22px 0 10px}h3:first-child{margin-top:0}p{margin:0 0 10px}.screen-padded{padding:16px 16px 56px;max-width:640px;margin:0 auto}.screen-center{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:16px}.muted{color:var(--hint)}.error{color:var(--danger);background:var(--danger-tint);border-radius:var(--radius-sm);padding:10px 13px;font-size:.9rem}.back-link{display:inline-flex;align-items:center;margin-bottom:14px;font-size:.88rem;text-decoration:none;color:var(--hint);font-weight:500}.stack{display:flex;flex-direction:column;gap:10px;margin:0 0 16px}.card{background:var(--secondary-bg);border:1px solid var(--hairline-soft);border-radius:var(--radius);padding:16px;margin:0 0 16px}.card:last-child{margin-bottom:0}.button{display:inline-flex;align-items:center;justify-content:center;gap:6px;width:100%;background:var(--button);color:var(--button-text);border:none;border-radius:var(--radius-sm);padding:13px 18px;font:inherit;font-size:.98rem;font-weight:600;text-decoration:none;text-align:center;cursor:pointer;transition:opacity .12s ease,transform .05s ease}.button:active{transform:scale(.98);opacity:.9}.button:disabled{opacity:.5;cursor:default;transform:none}.badge{display:inline-flex;align-items:center;gap:4px;padding:5px 12px;border-radius:999px;background:var(--hairline-soft);color:var(--hint);font-size:.82rem;font-weight:600}.badge-success{background:var(--success-tint);color:var(--success)}.course-card h2{margin-bottom:6px}.course-card .muted{margin-bottom:14px}.course-card .button,.course-card .badge{margin-top:2px}.module-block{margin-bottom:22px}.lesson-row{display:flex;align-items:center;gap:12px;padding:12px 14px;border-radius:var(--radius-sm);background:var(--secondary-bg);border:1px solid var(--hairline-soft);text-decoration:none;color:var(--text);margin-bottom:8px}.lesson-row:last-child{margin-bottom:0}.lesson-row.locked{opacity:.5}.lesson-order{flex-shrink:0;width:26px;height:26px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.78rem;font-weight:700;background:var(--hairline);color:var(--hint)}.lesson-row.completed .lesson-order{background:var(--success-tint);color:var(--success)}.lesson-row.in_progress .lesson-order{background:color-mix(in srgb,var(--link) 16%,transparent);color:var(--link)}.lesson-title{flex:1;min-width:0;font-size:.95rem;font-weight:500;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.lesson-chevron{flex-shrink:0;color:var(--hint);font-size:.85rem}.lesson-content{white-space:pre-wrap;font-size:.98rem;line-height:1.65;margin:0 0 20px}.material-list{display:flex;flex-direction:column;gap:8px;margin:0 0 8px}.material-link{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);background:var(--secondary-bg);border:1px solid var(--hairline-soft);border-radius:var(--radius-sm);padding:11px 13px;font-size:.9rem;font-weight:500}.material-icon{flex-shrink:0;width:30px;height:30px;border-radius:8px;background:var(--hairline);display:flex;align-items:center;justify-content:center;font-size:.95rem}.video-wrap{position:relative;width:100%;aspect-ratio:16 / 9;background:#000;border-radius:var(--radius);overflow:hidden;margin:0 0 20px;box-shadow:var(--card-shadow)}.video-wrap iframe,.video-wrap>div{width:100%;height:100%}form label{display:flex;flex-direction:column;gap:6px;margin-bottom:12px;font-size:.85rem;font-weight:500;color:var(--hint)}form label:last-of-type{margin-bottom:0}input,textarea{font:inherit;font-size:.95rem;padding:11px 13px;border-radius:var(--radius-sm);border:1px solid var(--hairline);background:var(--bg);color:var(--text)}input:focus,textarea:focus{outline:none;border-color:var(--link)}input::placeholder,textarea::placeholder{color:var(--hint);opacity:.7}textarea{font-family:inherit;resize:vertical}input[type=file]{padding:10px 13px;font-size:.86rem}input[type=file]::file-selector-button{border:none;background:var(--hairline);color:var(--text);padding:7px 12px;border-radius:7px;font:inherit;font-size:.85rem;font-weight:600;margin-right:10px;cursor:pointer}.homework-card{border-color:color-mix(in srgb,var(--link) 22%,var(--hairline-soft))}.accent-card{background:color-mix(in srgb,var(--link) 8%,var(--secondary-bg));border-color:color-mix(in srgb,var(--link) 25%,var(--hairline-soft))}