/* Room 1: The Server Vault — iOS dark + Liquid Glass */
:root {
  --bg-base: #000000;
  --bg-elev-1: #0B0B0F;

  --glass-bg: rgba(28, 28, 32, 0.55);
  --glass-bg-strong: rgba(28, 28, 32, 0.78);
  --glass-border: rgba(255, 255, 255, 0.10);
  --glass-highlight: rgba(255, 255, 255, 0.06);

  --text-primary: #F8F5F0;
  --text-secondary: #A8A29A;
  --text-tertiary: #6E6A63;

  --accent: #4FA8E8;
  --accent-glow: rgba(79, 168, 232, 0.35);
  --accent-dim: rgba(79, 168, 232, 0.15);
  --good: #7CD4B8;
  --error: #F08A7C;

  --line: rgba(255, 255, 255, 0.08);
  --line-strong: rgba(255, 255, 255, 0.16);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background:
    radial-gradient(circle at 20% 0%, rgba(79, 168, 232, 0.10), transparent 50%),
    radial-gradient(circle at 80% 100%, rgba(79, 168, 232, 0.06), transparent 50%),
    var(--bg-base);
  color: var(--text-primary);
  font-family: "Cormorant Garamond", Georgia, "Times New Roman", serif;
  min-height: 100vh;
  font-size: 18px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 760px;
  margin: 0 auto;
  padding: 28px 18px 80px;
}

.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border: 1px solid var(--glass-border);
  border-radius: 22px;
  box-shadow:
    inset 0 1px 0 0 var(--glass-highlight),
    0 12px 40px rgba(0, 0, 0, 0.55);
}

.nav-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 16px;
  margin-bottom: 28px;
  background: var(--glass-bg);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid var(--glass-border);
  border-radius: 999px;
}

.nav-link, .nav-btn {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--glass-border);
  padding: 8px 16px;
  font-family: inherit;
  font-size: 0.95rem;
  text-decoration: none;
  cursor: pointer;
  border-radius: 999px;
  transition: background 0.15s, border-color 0.15s;
}
.nav-link:hover, .nav-btn:hover { background: var(--accent-dim); border-color: var(--accent); }
.nav-link:focus-visible, .nav-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.header {
  text-align: center;
  margin-bottom: 32px;
}
.header .pretitle {
  display: inline-block;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 0.72rem;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}
.header h1 {
  font-size: 2.6rem;
  margin: 0 0 10px 0;
  letter-spacing: 0.3px;
  font-weight: 600;
  color: var(--text-primary);
}
.subtitle {
  color: var(--text-secondary);
  margin: 0 0 6px 0;
  font-style: italic;
  font-size: 1.1rem;
}
.lesson-line {
  margin: 8px 0 0 0;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.lock-section {
  padding: 24px 22px;
  margin-bottom: 18px;
}
.lock-section[hidden] { display: none; }

.lock-title {
  margin: 0 0 8px 0;
  font-size: 1.4rem;
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.3px;
}

.lock-prompt {
  margin: 0 0 16px 0;
  color: var(--text-primary);
}

.drag-container {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 16px;
}

.tile {
  background: var(--glass-bg-strong);
  color: var(--text-primary);
  padding: 14px 16px;
  border: 1px solid var(--glass-border);
  border-radius: 14px;
  cursor: grab;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.98rem;
  user-select: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: border-color 0.15s, transform 0.1s, background 0.15s;
}
.tile:hover { background: rgba(28, 28, 32, 0.85); border-color: var(--line-strong); }
.tile:active { cursor: grabbing; }
.tile.dragging { opacity: 0.4; }
.tile.over { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent-glow); }
.tile.shake { animation: shake 0.4s; border-color: var(--error); }
.tile.correct { border-color: var(--good); background: rgba(124, 212, 184, 0.08); }

.tile-controls {
  display: inline-flex;
  gap: 4px;
  margin-left: 12px;
}
.tile-controls button {
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--glass-border);
  color: var(--accent);
  width: 32px;
  height: 32px;
  border-radius: 10px;
  cursor: pointer;
  font-size: 0.9rem;
  transition: background 0.15s;
}
.tile-controls button:hover { background: var(--accent-dim); }

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-6px); }
  75% { transform: translateX(6px); }
}

.button-group {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 8px;
}

.check-btn, .skip-btn {
  font-family: inherit;
  font-size: 0.98rem;
  padding: 11px 20px;
  border-radius: 999px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.15s;
}
.check-btn {
  background: var(--accent);
  color: #001220;
  font-weight: 600;
}
.check-btn:hover { background: #6FB8F0; transform: translateY(-1px); }
.skip-btn {
  background: transparent;
  color: var(--text-secondary);
  border-color: var(--glass-border);
}
.skip-btn:hover { color: var(--text-primary); border-color: var(--line-strong); }

.feedback {
  margin: 8px 0;
  min-height: 1.4em;
  font-style: italic;
  font-size: 0.98rem;
}
.feedback.error { color: var(--error); }
.feedback.success { color: var(--good); }

.led-panel {
  background: rgba(124, 212, 184, 0.08);
  border: 1px solid var(--good);
  color: var(--good);
  padding: 10px 14px;
  border-radius: 14px;
  margin-top: 10px;
  font-family: ui-monospace, monospace;
  letter-spacing: 1px;
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
}
.led-light {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--good);
  box-shadow: 0 0 12px var(--good);
  animation: pulse 1.6s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.city-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 10px;
  margin-bottom: 16px;
}
.city-pin {
  background: var(--glass-bg-strong);
  color: var(--text-primary);
  border: 1px solid var(--glass-border);
  padding: 16px 8px;
  border-radius: 16px;
  cursor: pointer;
  font-family: inherit;
  font-size: 1rem;
  text-align: center;
  transition: all 0.18s;
}
.city-pin:hover { border-color: var(--accent); transform: translateY(-2px); background: rgba(28,28,32,0.85); }
.city-pin.wrong { border-color: var(--error); animation: shake 0.4s; }
.city-pin.correct { border-color: var(--good); background: rgba(124, 212, 184, 0.1); }
.co2-label {
  font-family: ui-monospace, monospace;
  font-size: 0.85rem;
  color: var(--accent);
  display: inline-block;
  margin-top: 4px;
}

.combo-display p { margin: 6px 0; }
.combo-display strong {
  color: var(--accent);
  font-family: ui-monospace, monospace;
}

.combo-input {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin: 10px 0;
}
#combo-code {
  background: var(--glass-bg-strong);
  border: 1px solid var(--glass-border);
  color: var(--accent);
  padding: 12px 16px;
  border-radius: 14px;
  font-family: ui-monospace, monospace;
  font-size: 1.4rem;
  letter-spacing: 6px;
  text-align: center;
  width: 160px;
}
#combo-code:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-dim); }

.citation {
  display: block;
  color: var(--text-tertiary);
  font-size: 0.82rem;
  margin-top: 12px;
  font-style: italic;
}

.win-section {
  padding: 36px 28px;
  text-align: center;
  margin-top: 24px;
  border: 1px solid var(--good);
  background: rgba(124, 212, 184, 0.06);
}
.win-content h2 {
  color: var(--good);
  font-size: 2rem;
  margin: 0 0 16px 0;
  font-weight: 600;
}
.win-message {
  font-size: 1.2rem;
  margin: 0 0 12px 0;
}
.win-subtext { color: var(--text-secondary); font-style: italic; margin-bottom: 20px; }
.win-sources {
  text-align: left;
  background: rgba(0,0,0,0.25);
  padding: 14px 18px;
  border-radius: 14px;
  margin: 20px 0;
}
.win-sources h3 { color: var(--accent); margin: 0 0 8px 0; font-size: 0.95rem; }
.win-sources p { margin: 4px 0; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

@media (max-width: 480px) {
  .container { padding: 18px 12px 60px; }
  .header h1 { font-size: 2rem; }
  .lock-title { font-size: 1.2rem; }
  #combo-code { width: 100%; font-size: 1.2rem; }
}