:root {
  --bg: #0b1220;
  --panel: #121b2e;
  --panel-2: #18233a;
  --border: #24324f;
  --text: #e6ecf7;
  --muted: #8d9bb8;
  --accent: #2fd3a6;
  --accent-2: #3b82f6;
  --danger: #f05d6c;
  --warn: #f5b545;
  --radius: 12px;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}
a { color: var(--accent-2); }
h1, h2, h3 { margin: 0 0 .5em; line-height: 1.25; }
.muted { color: var(--muted); }
.hidden { display: none !important; }
.small-text { font-size: 13px; }
.mt-8 { margin: 8px 0 0; }
.mt-14 { margin-top: 14px; }

/* ---------- Header ---------- */
.topbar {
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 12px 24px; background: var(--panel); border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 10;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; letter-spacing: .3px; }
.brand .logo {
  width: 32px; height: 32px; border-radius: 8px; display: grid; place-items: center;
  background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #06101f; font-size: 16px;
}
.topbar nav { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.topbar nav a { color: var(--muted); text-decoration: none; font-size: 14px; }
.topbar nav a.active, .topbar nav a:hover { color: var(--text); }
.user-chip { font-size: 14px; color: var(--muted); }

/* ---------- Bottoni / form ---------- */
.btn {
  appearance: none; border: 1px solid transparent; border-radius: 8px; cursor: pointer;
  padding: 10px 18px; font-size: 15px; font-weight: 600; font-family: inherit;
  background: var(--accent); color: #05261c; transition: filter .15s, opacity .15s;
}
.btn:hover { filter: brightness(1.08); }
.btn:disabled { opacity: .45; cursor: not-allowed; filter: none; }
.btn.secondary { background: transparent; color: var(--text); border-color: var(--border); }
.btn.small { padding: 6px 12px; font-size: 13px; }
label { display: block; font-size: 14px; color: var(--muted); margin-bottom: 6px; }
input[type=text], input[type=email], input[type=password] {
  width: 100%; padding: 11px 12px; border-radius: 8px; border: 1px solid var(--border);
  background: var(--bg); color: var(--text); font-size: 15px; font-family: inherit;
}
input:focus-visible, .btn:focus-visible, .video-item:focus-visible { outline: 2px solid var(--accent-2); outline-offset: 2px; }
.alert { padding: 10px 14px; border-radius: 8px; font-size: 14px; margin-bottom: 14px; }
.alert.error { background: rgba(240, 93, 108, .12); border: 1px solid rgba(240, 93, 108, .4); color: #ffb3bb; }
.alert.ok { background: rgba(47, 211, 166, .12); border: 1px solid rgba(47, 211, 166, .4); color: #9ff0d8; }
.alert.info { background: rgba(59, 130, 246, .12); border: 1px solid rgba(59, 130, 246, .4); color: #b9d3ff; }

/* ---------- Login ---------- */
.login-wrap { min-height: 100vh; display: grid; place-items: center; padding: 16px; }
.login-card {
  width: 100%; max-width: 400px; background: var(--panel); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 32px;
}
.login-card .brand { justify-content: center; margin-bottom: 8px; font-size: 18px; }
.login-card p.sub { text-align: center; margin: 0 0 24px; }
.field { margin-bottom: 16px; }
.login-card .btn { width: 100%; margin-top: 8px; }

/* ---------- Corso ---------- */
.layout { display: grid; grid-template-columns: 340px 1fr; gap: 24px; padding: 24px; max-width: 1400px; margin: 0 auto; }
.panel { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; }
.progress { height: 8px; background: var(--panel-2); border-radius: 99px; overflow: hidden; }
.progress > span { display: block; height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-2)); border-radius: 99px; transition: width .4s; }
.progress-label { display: flex; justify-content: space-between; font-size: 13px; color: var(--muted); margin: 6px 0 16px; }

.video-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 6px; }
.video-item {
  display: flex; gap: 12px; align-items: center; width: 100%; text-align: left;
  padding: 10px 12px; border-radius: 10px; border: 1px solid transparent;
  background: transparent; color: var(--text); font: inherit; cursor: pointer;
}
.video-item:hover:not(:disabled) { background: var(--panel-2); }
.video-item.current { background: var(--panel-2); border-color: var(--accent-2); }
.video-item:disabled { cursor: not-allowed; opacity: .5; }
.video-item .num {
  flex: 0 0 30px; height: 30px; border-radius: 50%; display: grid; place-items: center;
  font-size: 13px; font-weight: 700; background: var(--panel-2); border: 1px solid var(--border);
}
.video-item.done .num { background: var(--accent); color: #05261c; border-color: var(--accent); }
.video-item .t { font-size: 14px; flex: 1; }
.video-item .s { font-size: 12px; color: var(--muted); }

.quiz-cta { margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--border); }
.quiz-cta .btn { width: 100%; }

.player-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 12px; margin-bottom: 14px; }
.player-head h2 { font-size: 20px; }
video { width: 100%; max-height: 70vh; background: #000; border-radius: 10px; display: block; }
.player-foot { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-top: 14px; flex-wrap: wrap; }
.badge { display: inline-block; font-size: 12px; font-weight: 600; padding: 3px 10px; border-radius: 99px; background: var(--panel-2); color: var(--muted); border: 1px solid var(--border); white-space: nowrap; }
.badge.ok { background: rgba(47, 211, 166, .15); color: var(--accent); border-color: rgba(47, 211, 166, .4); }
.badge.ko { background: rgba(240, 93, 108, .15); color: var(--danger); border-color: rgba(240, 93, 108, .4); }
.badge.warn { background: rgba(245, 181, 69, .15); color: var(--warn); border-color: rgba(245, 181, 69, .4); }

/* ---------- Quiz ---------- */
.container { max-width: 860px; margin: 0 auto; padding: 24px; }
.question { margin-bottom: 16px; }
.question h3 { font-size: 16px; display: flex; gap: 10px; }
.question h3 .qn { color: var(--accent); flex: 0 0 auto; }
.option {
  display: flex; gap: 12px; align-items: flex-start; padding: 12px 14px; margin: 8px 0 0;
  border: 1px solid var(--border); border-radius: 10px; cursor: pointer; color: var(--text); font-size: 15px;
}
.option:hover { background: var(--panel-2); }
.option input { margin-top: 4px; accent-color: var(--accent); }
.option:has(input:checked) { border-color: var(--accent); background: rgba(47, 211, 166, .07); }
.result { text-align: center; padding: 32px; }
.result .score { font-size: 48px; font-weight: 800; margin: 8px 0; }
.sticky-submit { position: sticky; bottom: 0; padding: 16px 0; background: linear-gradient(transparent, var(--bg) 35%); display: flex; justify-content: space-between; align-items: center; gap: 12px; }

fieldset { min-width: 0; margin: 0 0 16px; }
.container.admin { max-width: 1300px; }
details.attempt summary { cursor: pointer; font-weight: 600; }
details.attempt[open] summary { margin-bottom: 10px; }

/* ---------- Admin ---------- */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 16px; margin-bottom: 24px; }
.stat .v { font-size: 30px; font-weight: 800; }
.stat .l { font-size: 13px; color: var(--muted); }
.tabs { display: flex; gap: 8px; margin-bottom: 16px; flex-wrap: wrap; }
.tabs button { background: transparent; border: 1px solid var(--border); color: var(--muted); padding: 8px 14px; border-radius: 8px; cursor: pointer; font: inherit; font-size: 14px; }
.tabs button.active { color: var(--text); background: var(--panel-2); border-color: var(--accent-2); }
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--border); vertical-align: top; }
th { color: var(--muted); font-weight: 600; font-size: 12px; text-transform: uppercase; letter-spacing: .4px; white-space: nowrap; }
tbody tr.clickable { cursor: pointer; }
tbody tr.clickable:hover { background: var(--panel-2); }
td .progress { width: 120px; display: inline-block; vertical-align: middle; margin-right: 8px; }
.exports { display: flex; gap: 8px; flex-wrap: wrap; }
.detail-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.section-title { display: flex; justify-content: space-between; align-items: center; margin: 24px 0 12px; gap: 12px; flex-wrap: wrap; }
.attempt { border: 1px solid var(--border); border-radius: 10px; padding: 12px; margin-bottom: 12px; }
.ans-ok { color: var(--accent); }
.ans-ko { color: var(--danger); }

@media (max-width: 900px) {
  .layout { grid-template-columns: 1fr; padding: 16px; }
  .detail-grid { grid-template-columns: 1fr; }
  .container { padding: 16px; }
  .topbar { padding: 10px 16px; }
}