:root {
  --bg: #0f1420;
  --panel: #171e2e;
  --panel-light: #1e2740;
  --border: #2a3450;
  --text: #e7ebf5;
  --muted: #93a0bd;
  --accent: #4f8cff;
  --accent-dark: #3a6bd6;
  --good: #33c17a;
  --warn: #e0a934;
  --bad: #e0555a;
  --radius: 10px;
}

* { 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);
  min-height: 100vh;
}

a { color: var(--accent); }

h1, h2, h3 { line-height: 1.25; }
h1 { font-size: 1.6rem; margin: 0 0 0.5rem; }
h2 { font-size: 1.2rem; margin: 2rem 0 0.75rem; }
h3 { font-size: 1rem; margin: 1.5rem 0 0.5rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.04em; }

.muted { color: var(--muted); }

#app-header {
  position: sticky;
  top: 0;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  z-index: 10;
}
.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.75rem 1.25rem;
  display: flex;
  align-items: center;
  gap: 2rem;
}
.brand { font-weight: 700; letter-spacing: 0.02em; }
nav { display: flex; gap: 1.25rem; flex: 1; }
nav a { color: var(--muted); text-decoration: none; font-size: 0.95rem; padding: 0.25rem 0; }
nav a.active { color: var(--text); border-bottom: 2px solid var(--accent); }
.header-right { display: flex; align-items: center; gap: 0.75rem; font-size: 0.9rem; color: var(--muted); }

#app { max-width: 1100px; margin: 0 auto; padding: 2rem 1.25rem 4rem; }

.page { animation: fadein 0.15s ease-in; }
@keyframes fadein { from { opacity: 0; } to { opacity: 1; } }

.centered-card {
  max-width: 420px;
  margin: 3rem auto;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
}

form label { display: block; margin-bottom: 1rem; font-size: 0.9rem; color: var(--muted); }
form input, form select {
  display: block;
  width: 100%;
  margin-top: 0.35rem;
  padding: 0.55rem 0.7rem;
  background: var(--panel-light);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-size: 0.95rem;
}
form input:focus, form select:focus { outline: 2px solid var(--accent); outline-offset: 1px; }

button { font-family: inherit; cursor: pointer; }
button.primary {
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 6px;
  padding: 0.6rem 1.1rem;
  font-size: 0.95rem;
  font-weight: 600;
}
button.primary:hover { background: var(--accent-dark); }
button.secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.6rem 1.1rem;
  font-size: 0.95rem;
}
button.secondary:hover { border-color: var(--accent); }
button.link-button {
  background: none;
  border: none;
  color: var(--muted);
  text-decoration: underline;
  padding: 0;
  font-size: 0.9rem;
}
button.link-button:hover { color: var(--text); }

.error-text { color: var(--bad); font-size: 0.88rem; }
.success-text { color: var(--good); font-size: 0.88rem; }

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
}

.course-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.25rem; margin-top: 1.25rem; }
.course-card .course-title { margin-top: 0; }
.progress-bar { height: 8px; background: var(--panel-light); border-radius: 4px; overflow: hidden; margin: 0.75rem 0 0.35rem; }
.progress-fill { height: 100%; background: var(--accent); }
.card-actions { display: flex; gap: 0.6rem; margin-top: 1rem; }

.back-link { display: inline-block; margin-bottom: 1rem; text-decoration: none; font-size: 0.9rem; }

table.module-table { width: 100%; border-collapse: collapse; margin-top: 0.75rem; }
table.module-table th {
  text-align: left; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.03em;
  color: var(--muted); padding: 0.5rem 0.6rem; border-bottom: 1px solid var(--border);
}
table.module-table td { padding: 0.6rem; border-bottom: 1px solid var(--border); font-size: 0.92rem; }
table.module-table tr:hover td { background: var(--panel-light); }

.status-pill {
  display: inline-block; padding: 0.15rem 0.6rem; border-radius: 999px; font-size: 0.78rem; font-weight: 600;
}
.status-pill.not_started { background: #2a3450; color: var(--muted); }
.status-pill.in_progress { background: rgba(224,169,52,0.15); color: var(--warn); }
.status-pill.completed { background: rgba(51,193,122,0.15); color: var(--good); }

.module-topics { padding-left: 1.2rem; }
.module-topics li { margin-bottom: 0.3rem; }

.module-resources { margin: 1rem 0; }
.module-resources a.resource-link {
  display: inline-block; margin-right: 0.75rem; padding: 0.4rem 0.8rem;
  border: 1px solid var(--border); border-radius: 6px; text-decoration: none; font-size: 0.88rem;
}

.video-note-box {
  background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1rem 1.25rem; margin: 1rem 0;
}
.video-player-slot video { width: 100%; max-height: 480px; margin-top: 0.75rem; border-radius: 6px; background: black; }

.quiz-question { margin-bottom: 1rem; }
.quiz-question .options label {
  display: block; margin: 0.4rem 0; font-size: 0.94rem; color: var(--text); cursor: pointer;
}
.quiz-question .options input { width: auto; display: inline-block; margin-right: 0.5rem; }
.quiz-question.correct { border-color: var(--good); }
.quiz-question.incorrect { border-color: var(--bad); }
.explanation { margin-top: 0.75rem; padding-top: 0.75rem; border-top: 1px solid var(--border); font-size: 0.9rem; color: var(--muted); }

.exam-header { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 0.5rem; }
.exam-timer { font-size: 0.9rem; color: var(--muted); }

.exam-score-banner { text-align: center; margin: 1.5rem 0; }
.score-number { font-size: 3rem; font-weight: 700; }
.score-pass-fail { font-size: 1.1rem; font-weight: 600; margin-top: 0.25rem; }
.score-pass-fail.pass { color: var(--good); }
.score-pass-fail.fail { color: var(--bad); }

.inline-form { display: flex; gap: 0.6rem; flex-wrap: wrap; align-items: center; margin-top: 0.75rem; }
.inline-form input, .inline-form select { width: auto; margin-top: 0; }

#btn-submit-exam { margin-top: 1.5rem; }