/* ═══════════════════════════════════════════════════════════════
   NetAcad Defense Simulator — Dark theme
   ═══════════════════════════════════════════════════════════════ */

:root {
  --bg:        #0d1117;
  --bg-2:      #161b22;
  --bg-3:      #21262d;
  --border:    #30363d;
  --text:      #c9d1d9;
  --muted:     #8b949e;
  --accent:    #58a6ff;
  --accent-h:  #79b8ff;
  --good:      #3fb950;
  --bad:       #f85149;
  --warn:      #d29922;
  --flag:      #e3b341;
  --shadow:    0 2px 8px rgba(0,0,0,.35);
}

* { box-sizing: border-box; }
html, body {
  margin: 0; padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  font-size: 15px;
  line-height: 1.5;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-h); text-decoration: underline; }

h1, h2, h3, h4 { color: var(--text); margin: 0 0 .6em; }
h1 { font-size: 1.8em; font-weight: 600; }
h2 { font-size: 1.4em; font-weight: 600; }
h3 { font-size: 1.1em; font-weight: 600; }

em { color: var(--accent); font-style: normal; font-weight: 600; }
small { color: var(--muted); font-size: .85em; font-weight: normal; }
strong { color: var(--text); }
code { background: var(--bg-3); padding: 1px 5px; border-radius: 3px; font-size: .9em; }

.muted { color: var(--muted); }
.small { font-size: .85em; }

/* ── Topbar ─────────────────────────────────────────────────── */
.topbar {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 24px;
  background: var(--bg-2);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 100;
}
.brand { font-size: 1.05em; font-weight: 600; }
.brand small { display: block; font-weight: normal; margin-top: 2px; }

.topnav { display: flex; gap: 6px; }
.nav-btn {
  background: transparent; color: var(--muted);
  border: 1px solid transparent; padding: 6px 14px;
  border-radius: 6px; cursor: pointer; font-size: .92em;
  transition: all .15s;
}
.nav-btn:hover { color: var(--text); background: var(--bg-3); }
.nav-btn.active { color: var(--text); background: var(--bg-3); border-color: var(--border); }

/* ── Main / Screens ─────────────────────────────────────────── */
#app {
  max-width: 1100px; margin: 0 auto; padding: 24px;
}
.screen { display: none; }
.screen.active { display: block; animation: fadein .25s ease-out; }
@keyframes fadein { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; } }

/* ── Buttons ────────────────────────────────────────────────── */
.btn {
  background: var(--bg-3); color: var(--text);
  border: 1px solid var(--border);
  padding: 8px 16px; border-radius: 6px; cursor: pointer;
  font-size: .92em; font-weight: 500;
  transition: all .15s;
}
.btn:hover:not(:disabled) { background: var(--bg-2); border-color: var(--accent); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 600; }
.btn-primary:hover:not(:disabled) { background: var(--accent-h); border-color: var(--accent-h); }
.btn-ghost { background: transparent; }
.btn-danger { background: var(--bad); border-color: var(--bad); color: #fff; }
.btn-danger:hover:not(:disabled) { background: #c93b30; border-color: #c93b30; }
.btn-sm { padding: 4px 10px; font-size: .85em; }
.btn-lg { padding: 12px 24px; font-size: 1.05em; }

/* ── Cards ──────────────────────────────────────────────────── */
.card {
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
}
.cards-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 18px;
}
@media (max-width: 720px) {
  .cards-grid { grid-template-columns: 1fr; }
}

/* ── Hero ───────────────────────────────────────────────────── */
.hero {
  text-align: center; padding: 36px 20px;
  background: linear-gradient(135deg, rgba(88,166,255,.07), rgba(63,185,80,.05));
  border: 1px solid var(--border); border-radius: 12px;
  margin-bottom: 24px;
}
.hero h1 { font-size: 2em; margin-bottom: 10px; }
.hero p { color: var(--muted); margin-bottom: 22px; }
.hero-actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

/* ── Modlist + Stats ────────────────────────────────────────── */
.modlist { list-style: none; padding: 0; margin: 0; }
.modlist li {
  display: flex; justify-content: space-between;
  padding: 7px 0; border-bottom: 1px solid var(--border);
}
.modlist li:last-child { border-bottom: none; }
.modlist .modnum { color: var(--accent); font-weight: 600; }
.modlist .modcount { color: var(--muted); font-size: .9em; }

.stats-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px;
}
.stat {
  text-align: center; padding: 14px 10px;
  background: var(--bg-3); border-radius: 8px;
}
.stat-val { display: block; font-size: 1.6em; font-weight: 700; color: var(--accent); }
.stat-lbl { display: block; font-size: .8em; color: var(--muted); margin-top: 4px; }

/* ── Config screen ──────────────────────────────────────────── */
.config-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 18px;
}
@media (max-width: 720px) { .config-grid { grid-template-columns: 1fr; } }

.presets { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 14px; }

.module-checks { display: grid; grid-template-columns: 1fr; gap: 6px; }
.module-checks label {
  display: flex; align-items: center; gap: 10px;
  padding: 8px 12px; background: var(--bg-3); border-radius: 6px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: border .15s;
}
.module-checks label:hover { border-color: var(--border); }
.module-checks input[type="checkbox"] { accent-color: var(--accent); }
.module-checks .modtitle { flex: 1; font-size: .92em; }
.module-checks .modcount { color: var(--muted); font-size: .82em; }

.row {
  display: flex; align-items: center; justify-content: space-between;
  padding: 10px 0; border-bottom: 1px solid var(--border);
}
.row:last-child { border-bottom: none; }
.row input[type="number"] {
  background: var(--bg-3); border: 1px solid var(--border); color: var(--text);
  padding: 6px 10px; border-radius: 5px; width: 80px; text-align: right;
}
.row input[type="text"] {
  background: var(--bg-3); border: 1px solid var(--border); color: var(--text);
  padding: 6px 10px; border-radius: 5px; min-width: 220px;
  font-family: monospace; text-transform: uppercase; letter-spacing: .05em;
}
.row input[type="checkbox"] { accent-color: var(--accent); }
.seed-card { border-color: rgba(88,166,255,.30); }
.seed-display {
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
  margin: 12px 0;
}
.seed-display .seed-label { color: var(--muted); font-size: .9em; }
.seed-display input[type="text"] {
  flex: 1; min-width: 180px; max-width: 260px;
  font-size: 1.05em; font-weight: 600; letter-spacing: .08em;
  color: var(--accent);
}

.actions {
  display: flex; gap: 10px; justify-content: center; margin-top: 24px; flex-wrap: wrap;
}

/* ── Exam screen ────────────────────────────────────────────── */
.exam-bar {
  display: flex; align-items: center; justify-content: space-between;
  background: var(--bg-2); border: 1px solid var(--border); border-radius: 10px;
  padding: 12px 18px; margin-bottom: 18px;
}
.exam-progress { font-weight: 600; font-size: 1.05em; }
.exam-flagged { color: var(--flag); margin-left: 12px; font-size: .9em; }
.exam-seed {
  margin-left: 12px; font-size: .85em; font-family: monospace;
  color: var(--accent); cursor: pointer; user-select: all;
  padding: 2px 8px; background: rgba(88,166,255,.08); border-radius: 4px;
  border: 1px solid rgba(88,166,255,.20);
}
.exam-seed:hover { background: rgba(88,166,255,.15); }
.exam-timer {
  font-size: 1.4em; font-weight: 700; font-family: monospace;
  color: var(--accent);
}
.exam-timer.warn { color: var(--warn); }
.exam-timer.danger { color: var(--bad); animation: pulse 1s infinite; }
@keyframes pulse { 50% { opacity: .55; } }

.exam-question {
  background: var(--bg-2); border: 1px solid var(--border); border-radius: 10px;
  padding: 24px; margin-bottom: 18px;
  min-height: 320px;
  box-shadow: var(--shadow);
}
.q-meta { color: var(--muted); font-size: .85em; margin-bottom: 8px; }
.q-text { font-size: 1.08em; margin-bottom: 18px; line-height: 1.55; }
.q-text code { font-size: .95em; }

.q-hint {
  display: inline-block; padding: 5px 12px; margin-bottom: 12px;
  background: rgba(88,166,255,.10); border: 1px solid rgba(88,166,255,.25);
  border-radius: 6px; font-size: .9em;
}
.q-hint strong { color: var(--accent); }

.choices { display: flex; flex-direction: column; gap: 8px; }
.choice {
  display: flex; align-items: flex-start; gap: 10px;
  padding: 11px 14px;
  background: var(--bg-3); border: 1px solid var(--border); border-radius: 7px;
  cursor: pointer; transition: all .12s;
}
.choice:hover { border-color: var(--accent); }
.choice.selected { border-color: var(--accent); background: rgba(88,166,255,.08); }
.choice input { margin-top: 3px; accent-color: var(--accent); }
.choice .ck-text { flex: 1; }
.choice.correct { border-color: var(--good); background: rgba(63,185,80,.10); }
.choice.wrong { border-color: var(--bad); background: rgba(248,81,73,.10); }

/* Drag & drop */
.dragdrop {
  display: grid; grid-template-columns: 1fr 1fr; gap: 16px;
}
@media (max-width: 720px) { .dragdrop { grid-template-columns: 1fr; } }
.dd-pool, .dd-cats {
  background: var(--bg-3); border: 1px solid var(--border); border-radius: 7px;
  padding: 12px; min-height: 80px;
}
.dd-title { font-size: .82em; color: var(--muted); margin-bottom: 8px; text-transform: uppercase; letter-spacing: .04em; }
.dd-item {
  background: var(--bg-2); border: 1px solid var(--border); border-radius: 5px;
  padding: 7px 11px; margin-bottom: 6px; cursor: grab; user-select: none;
}
.dd-item:active { cursor: grabbing; }
.dd-item.dragging { opacity: .4; }
.dd-cat {
  background: var(--bg-2); border: 1px dashed var(--border); border-radius: 6px;
  padding: 8px; margin-bottom: 8px;
}
.dd-cat-title { font-weight: 600; font-size: .92em; margin-bottom: 6px; }
.dd-cat.dragover { border-color: var(--accent); background: rgba(88,166,255,.06); }
.dd-cat .dd-item.placed.correct { border-color: var(--good); }
.dd-cat .dd-item.placed.wrong { border-color: var(--bad); }

.explanation {
  margin-top: 16px; padding: 14px;
  background: rgba(88,166,255,.06); border-left: 3px solid var(--accent);
  border-radius: 5px;
}
.explanation strong { color: var(--accent); }

/* Exam nav + dots */
.exam-nav {
  display: flex; align-items: center; justify-content: space-between; gap: 10px;
}
.exam-dots {
  display: flex; flex-wrap: wrap; gap: 4px; flex: 1; justify-content: center;
  max-width: 70%;
}
.exam-dot {
  width: 22px; height: 22px; border-radius: 5px;
  background: var(--bg-3); border: 1px solid var(--border);
  font-size: .75em; display: flex; align-items: center; justify-content: center;
  cursor: pointer; color: var(--muted);
}
.exam-dot:hover { border-color: var(--accent); }
.exam-dot.answered { background: var(--accent); color: #fff; border-color: var(--accent); }
.exam-dot.current { outline: 2px solid var(--accent); outline-offset: 1px; }
.exam-dot.flagged::after {
  content: ""; position: absolute; width: 6px; height: 6px;
  background: var(--flag); border-radius: 50%; transform: translate(8px, -8px);
}
.exam-dot.flagged { position: relative; }
.exam-dot.correct { background: var(--good); border-color: var(--good); color: #fff; }
.exam-dot.wrong { background: var(--bad); border-color: var(--bad); color: #fff; }
.exam-dot.skipped { background: var(--bg-3); color: var(--muted); }

/* ── Results ────────────────────────────────────────────────── */
.result-summary {
  display: grid; grid-template-columns: 1fr 1.2fr; gap: 24px; align-items: center;
}
@media (max-width: 600px) { .result-summary { grid-template-columns: 1fr; text-align: center; } }
.result-score { text-align: center; }
.score-big { font-size: 4em; font-weight: 700; color: var(--accent); display: block; }
.score-pct { font-size: 1.4em; color: var(--muted); }
.result-meta { line-height: 2; }
.result-status {
  margin-top: 12px; padding: 8px 14px; border-radius: 6px;
  font-weight: 600; display: inline-block;
}
.result-status.pass { background: rgba(63,185,80,.15); color: var(--good); }
.result-status.fail { background: rgba(248,81,73,.15); color: var(--bad); }

.module-bar {
  display: flex; align-items: center; gap: 10px; padding: 8px 0;
  border-bottom: 1px solid var(--border);
}
.module-bar:last-child { border-bottom: none; }
.module-bar-name { flex: 0 0 200px; font-size: .92em; }
.module-bar-track {
  flex: 1; background: var(--bg-3); border-radius: 4px; height: 8px; overflow: hidden;
}
.module-bar-fill {
  height: 100%; background: var(--accent);
  transition: width .4s ease-out;
}
.module-bar-fill.pass { background: var(--good); }
.module-bar-fill.fail { background: var(--bad); }
.module-bar-score {
  flex: 0 0 80px; text-align: right; font-size: .9em; color: var(--muted);
  font-variant-numeric: tabular-nums;
}

/* ── History ────────────────────────────────────────────────── */
.history-row {
  display: grid; grid-template-columns: 1fr auto auto auto;
  gap: 16px; align-items: center;
  padding: 12px 16px;
  background: var(--bg-2); border: 1px solid var(--border); border-radius: 8px;
  margin-bottom: 8px;
}
.history-row .h-date { color: var(--muted); font-size: .9em; }
.history-row .h-mods { font-size: .85em; color: var(--muted); }
.history-row .h-score { font-weight: 600; font-size: 1.1em; }
.history-row .h-score.pass { color: var(--good); }
.history-row .h-score.fail { color: var(--bad); }

.empty-state {
  text-align: center; padding: 40px 20px; color: var(--muted);
}