:root{
  --primary:#4f46e5; --accent:#0f172a;
  --bg:#0b1020; --surface:#141a2e; --surface2:#1c2440;
  --text:#e6e8f0; --muted:#9aa3bd; --border:#2a3357;
  --ok:#22c55e; --warn:#f59e0b; --danger:#ef4444; --radius:14px;
}
*{box-sizing:border-box}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  background:var(--bg);color:var(--text);line-height:1.55}
a{color:inherit;text-decoration:none}
img{max-width:100%}
.container{max-width:1140px;margin:0 auto;padding:0 20px}
.muted{color:var(--muted)}
.small{font-size:13px}

/* Header */
.topbar{position:sticky;top:0;z-index:20;background:rgba(11,16,32,.9);backdrop-filter:blur(8px);
  border-bottom:1px solid var(--border)}
.topbar .inner{display:flex;align-items:center;gap:20px;height:62px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700}
.brand .logo{width:34px;height:34px;border-radius:9px;background:var(--primary);display:grid;place-items:center;color:#fff;font-weight:800}
.nav{display:flex;gap:18px;margin-left:auto;align-items:center}
.nav a{color:var(--muted);font-size:14px;font-weight:600}
.nav a:hover,.nav a.active{color:var(--text)}
.avatar{width:34px;height:34px;border-radius:50%;background:var(--surface2);display:grid;place-items:center;font-weight:700;border:1px solid var(--border)}

/* Buttons */
.btn{display:inline-flex;align-items:center;gap:8px;justify-content:center;border:0;cursor:pointer;
  background:var(--primary);color:#fff;padding:10px 16px;border-radius:10px;font-weight:600;font-size:14px}
.btn:hover{filter:brightness(1.08)}
.btn.ghost{background:transparent;border:1px solid var(--border);color:var(--text)}
.btn.sm{padding:6px 11px;font-size:13px}
.btn.ok{background:var(--ok)} .btn.danger{background:var(--danger)} .btn.warn{background:var(--warn);color:#111}
.btn.block{width:100%}

/* Cards / grid */
.grid{display:grid;gap:18px}
.grid.c3{grid-template-columns:repeat(3,1fr)}
.grid.c4{grid-template-columns:repeat(4,1fr)}
.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden}
.card .body{padding:16px}
.course-cover{aspect-ratio:16/9;background:linear-gradient(135deg,var(--primary),var(--accent));
  display:grid;place-items:center;color:#fff;font-size:34px;font-weight:800}
.badge{display:inline-block;font-size:11px;font-weight:700;padding:3px 9px;border-radius:999px;background:var(--surface2);color:var(--muted)}
.badge.ok{background:rgba(34,197,94,.15);color:#4ade80}
.badge.warn{background:rgba(245,158,11,.15);color:#fbbf24}
.badge.danger{background:rgba(239,68,68,.15);color:#f87171}

/* Progress bar */
.progress{height:8px;background:var(--surface2);border-radius:999px;overflow:hidden}
.progress > span{display:block;height:100%;background:var(--primary)}

/* Layout with sidebar (lesson + admin) */
.split{display:grid;grid-template-columns:1fr 320px;gap:24px;align-items:start}
.admin-shell{display:grid;grid-template-columns:230px 1fr;min-height:100vh}
.sidebar{background:var(--surface);border-right:1px solid var(--border);padding:18px 14px}
.sidebar a{display:block;padding:10px 12px;border-radius:9px;color:var(--muted);font-weight:600;font-size:14px}
.sidebar a:hover,.sidebar a.active{background:var(--surface2);color:var(--text)}
.content{padding:26px 30px}

/* Player */
.player{position:relative;aspect-ratio:16/9;background:#000;border-radius:12px;overflow:hidden}
.player iframe{position:absolute;inset:0;width:100%;height:100%;border:0}

/* Lesson list */
.mod{border:1px solid var(--border);border-radius:12px;margin-bottom:12px;overflow:hidden;background:var(--surface)}
.mod > h4{margin:0;padding:12px 15px;background:var(--surface2);font-size:14px}
.mod ul{list-style:none;margin:0;padding:0}
.mod li a{display:flex;align-items:center;gap:10px;padding:11px 15px;border-top:1px solid var(--border);font-size:14px}
.mod li a:hover{background:var(--surface2)}
.check{width:20px;height:20px;border-radius:50%;border:2px solid var(--border);display:grid;place-items:center;flex:0 0 auto;font-size:12px}
.check.done{background:var(--ok);border-color:var(--ok);color:#062b12}

/* Tables */
table{width:100%;border-collapse:collapse}
th,td{text-align:left;padding:10px 12px;border-bottom:1px solid var(--border);font-size:14px}
th{color:var(--muted);font-weight:600;font-size:12px;text-transform:uppercase;letter-spacing:.04em}

/* Forms */
label{display:block;font-size:13px;color:var(--muted);margin:12px 0 6px;font-weight:600}
input,select,textarea{width:100%;background:var(--surface2);border:1px solid var(--border);color:var(--text);
  padding:10px 12px;border-radius:10px;font-size:14px;font-family:inherit}
textarea{min-height:90px;resize:vertical}
.row{display:flex;gap:14px}.row>*{flex:1}

/* Alerts */
.alert{padding:12px 15px;border-radius:10px;margin-bottom:16px;font-size:14px;font-weight:500}
.alert.success{background:rgba(34,197,94,.14);color:#86efac;border:1px solid rgba(34,197,94,.3)}
.alert.error{background:rgba(239,68,68,.14);color:#fca5a5;border:1px solid rgba(239,68,68,.3)}

/* Auth */
.auth-wrap{min-height:100vh;display:grid;place-items:center;padding:20px;
  background:radial-gradient(1200px 600px at 50% -10%,rgba(79,70,229,.25),transparent)}
.auth-card{width:100%;max-width:400px;background:var(--surface);border:1px solid var(--border);
  border-radius:18px;padding:30px}

/* Fingerprint (anti-pirataria, forense) */
.fingerprint{position:fixed;bottom:6px;right:10px;font-size:10px;color:rgba(255,255,255,.16);
  pointer-events:none;z-index:5;user-select:none;letter-spacing:.05em}

/* Stats */
.stat{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:16px}
.stat b{font-size:26px;display:block}
.stat span{color:var(--muted);font-size:13px}

h1{font-size:24px;margin:0 0 4px} h2{font-size:19px} .page-head{margin-bottom:22px}
.banner{border-radius:14px;overflow:hidden;margin-bottom:22px;border:1px solid var(--border)}
.section-title{margin:26px 0 12px;font-size:16px;color:var(--muted);text-transform:uppercase;letter-spacing:.05em;font-size:12px}

@media(max-width:900px){
  .grid.c3,.grid.c4{grid-template-columns:1fr 1fr}
  .split{grid-template-columns:1fr}
  .admin-shell{grid-template-columns:1fr}
  .sidebar{border-right:0;border-bottom:1px solid var(--border)}
}
@media(max-width:560px){ .grid.c3,.grid.c4{grid-template-columns:1fr} .nav{gap:12px} }