:root{--ink:#182230;--muted:#667085;--line:#e4e7ec;--accent:#1769aa;--bg:#f7f8fa}
*{box-sizing:border-box}html{font-size:16px}body{margin:0;background:var(--bg);color:var(--ink);font-family:system-ui,-apple-system,"Segoe UI",sans-serif;line-height:1.55}
.container{width:min(100% - 32px,1120px);margin-inline:auto}.site-header{background:#fff;border-bottom:1px solid var(--line)}.header-inner{min-height:64px;display:flex;align-items:center;justify-content:space-between}.site-title{font-size:1.25rem;font-weight:750;color:var(--ink);text-decoration:none}.link-button{border:0;background:none;color:var(--accent);cursor:pointer;font:inherit}
.site-title--locked{filter:blur(6px);user-select:none}
.page-heading{padding:42px 0 24px}.page-heading h1{margin:0;font-size:clamp(1.8rem,4vw,2.7rem)}.eyebrow{margin:0 0 6px;color:var(--accent);font-weight:700}.muted{color:var(--muted)}.breadcrumbs{padding-top:26px;color:var(--muted);font-size:.92rem}.breadcrumbs a,.lesson-nav a,.legacy-links a{color:var(--accent)}
.card-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px}.card,.lesson-row{display:block;background:#fff;border:1px solid var(--line);border-radius:12px;color:inherit;text-decoration:none}.card{padding:22px;min-height:130px}.card h2{margin:0 0 8px;font-size:1.2rem}.card:hover,.lesson-row:hover{border-color:var(--accent);box-shadow:0 4px 18px #18223012}
.lesson-list{display:grid;gap:10px}.lesson-row{padding:17px 20px;display:flex;justify-content:space-between;gap:16px}.lesson h1{margin:34px 0 10px;font-size:clamp(1.8rem,4vw,2.6rem)}.lead{font-size:1.1rem;color:var(--muted)}.lesson-text{max-width:820px;margin:26px 0}.lesson-text img{max-width:100%;height:auto}.video-section,.legacy-links{margin-top:28px}.video-card{background:#fff;border:1px solid var(--line);border-radius:12px;padding:16px;margin-top:16px}.video-card h3{margin-top:0;font-size:1rem}.video-card video{display:block;width:100%;max-height:70vh;background:#111;border-radius:8px}.legacy-links{display:flex;flex-wrap:wrap;gap:12px}.legacy-links a{padding:8px 12px;border:1px solid var(--line);border-radius:8px;background:#fff}.lesson-nav{border-top:1px solid var(--line);margin-top:34px;padding:20px 0;display:flex;justify-content:space-between;gap:16px}.lesson-nav .next{margin-left:auto;text-align:right}
.materials{margin-top:28px;display:grid;gap:10px}.material-link{display:block;width:max-content;max-width:100%;padding:9px 12px;border:1px solid var(--line);border-radius:8px;background:#fff;color:var(--accent);text-decoration:none}
.auth-card{width:min(100%,420px);margin:12vh auto;background:#fff;border:1px solid var(--line);border-radius:14px;padding:28px}.auth-card h1{margin-top:0}.auth-card form{display:grid;gap:8px}.auth-card input{font:inherit;padding:11px;border:1px solid #cfd4dc;border-radius:8px}.auth-card label{font-weight:650;margin-top:8px}.primary-button{margin-top:12px;border:0;border-radius:8px;background:var(--accent);color:#fff;padding:12px;font:inherit;cursor:pointer}.error{color:#b42318}
@media(max-width:600px){.container{width:min(100% - 24px,1120px)}.page-heading{padding-top:28px}.lesson-row{display:block}.lesson-row .muted{display:block;margin-top:4px}.lesson-nav{display:grid}.lesson-nav .next{margin-left:0;text-align:left}}