:root{color-scheme:light;font-family:system-ui,-apple-system,Segoe UI,Arial,sans-serif;--navy:#142a43;--dark:#0e1c2c;--teal:#006d77;--bg:#f3f7fa;--line:#d7e2e8;--text:#183044;--muted:#526676}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--text);line-height:1.55;min-height:100vh}
a{color:#005b68;text-decoration:none}a:hover{text-decoration:underline}
button,input,select{font:inherit}
button{border:1px solid var(--teal);background:#fff;color:var(--teal);border-radius:9px;padding:.65rem .9rem;cursor:pointer;font-weight:650}
button:hover{background:#e6f3f4}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #095c68;outline-offset:3px}
button.primary{background:var(--teal);color:#fff}button.primary:hover{background:#055861}
button:disabled{opacity:.5;cursor:not-allowed}
.topbar{background:var(--navy);color:#f6fbff;display:flex;align-items:center;justify-content:space-between;gap:1rem;padding:1rem max(4vw,1rem)}
.topbar a,.topbar button{color:#f2f8fc}.topbar a:focus-visible,.topbar button:focus-visible{outline-color:#ffdf80}.topbar nav{display:flex;gap:1.3rem;align-items:center;flex-wrap:wrap}
.brand{display:flex;align-items:center;gap:.75rem;font-size:1.1rem;font-weight:750}
.brand-logo{display:block;width:105px;height:70px;object-fit:contain;flex:none}
.brand-caption{font-size:.76rem;font-weight:650;letter-spacing:.1em;text-transform:uppercase;color:#f0f7ff}
.brand small{display:block;font-size:.7rem;font-weight:500;letter-spacing:.08em;text-transform:uppercase}
.link-btn{border:0;padding:.25rem;background:transparent;color:inherit}
.shell{max-width:1180px;margin:0 auto;padding:2rem max(1rem,2vw);min-height:70vh}
.footer{text-align:center;color:var(--muted);font-size:.8rem;border-top:1px solid var(--line);padding:1.4rem}
h1{font-size:clamp(1.65rem,3vw,2.6rem);line-height:1.15;margin:.3rem 0 1rem}h2{font-size:1.15rem;line-height:1.3;margin:0 0 1rem}
.eyebrow{font-weight:750;letter-spacing:.13em;font-size:.75rem;color:var(--teal);margin:0 0 .5rem}
.muted{color:var(--muted)}.small{font-size:.87rem}.section{margin:1.7rem 0}.back{display:inline-block;margin-bottom:1.4rem}
.auth-card{max-width:460px;margin:2rem auto 3rem;background:#fff;border:1px solid var(--line);border-radius:18px;padding:clamp(1.4rem,3vw,2.5rem);box-shadow:0 15px 40px rgba(16,41,67,.06)}
form{display:grid;gap:1rem}label{display:grid;gap:.4rem;font-weight:600;font-size:.91rem}
input,select{display:block;width:100%;min-height:44px;padding:.6rem .75rem;border-radius:8px;border:1px solid #a8b8c6;background:#fff;color:var(--text)}
.feedback{min-height:1.5rem;font-size:.9rem;font-weight:620}.feedback[data-kind="error"]{color:#a42b2b}.feedback[data-kind="ok"]{color:#096f47}
.hero{background:#fff;border:1px solid var(--line);border-radius:18px;padding:2rem;margin-bottom:1.7rem}
.course-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(245px,1fr));gap:1rem}
.course-card,.panel,.lesson{background:#fff;border:1px solid var(--line);border-radius:14px;padding:1.35rem}
.course-card h2{margin-bottom:.5rem}.course-card p{margin-top:0}
.course-card a{display:inline-block;margin-top:.75rem;font-weight:750}
.lesson{margin:1rem 0}.lesson h2{margin-bottom:.5rem}.lesson p{margin:0}
.admin-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1rem;margin-bottom:1rem}
.panel{min-width:0}.panel button{margin-top:.35rem}
.three{display:grid;grid-template-columns:repeat(3,1fr);gap:.5rem}
.actions{display:flex;flex-wrap:wrap;gap:.5rem;margin-top:1rem}
.once{background:#fff9db;border:1px solid #e9bb54;border-radius:10px;padding:1rem;margin-top:1rem}
.once output{display:block;overflow-wrap:anywhere;font-family:ui-monospace,monospace;font-size:1.05rem;padding:.8rem 0}
.list{padding-left:1.1rem}.list li{padding:.35rem 0;border-bottom:1px solid var(--line)}
.notice{background:#f0fbf7;border-left:4px solid #088c75;border-radius:8px;padding:1rem}
[hidden]{display:none!important}
@media(max-width:820px){.admin-grid{grid-template-columns:1fr}}
@media(max-width:640px){.topbar{align-items:flex-start;flex-direction:column}.shell{padding:1.2rem 1rem}.three{grid-template-columns:1fr}.admin-grid{grid-template-columns:1fr}}