/* ============================================================
   BRAIN BRIDGE – bridge.css
   ============================================================ */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --font: 'Outfit', system-ui, sans-serif;
  --bg-dark: #08101a;
  --bg-panel: #111d2e;
  --border: rgba(255,255,255,0.12);
  --text: #e8eef8;
  --text-muted: #94a3b8;
  --accent: #ffd060;
  
  --wood: #c07b46;
  --steel: #8a9ba8;
  --road: #334155;
  
  --correct: #2ec97a;
  --error: #e84040;
}

body {
  font-family: var(--font);
  background: var(--bg-dark);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  padding: 20px;
}

.bb-layout {
  width: 100%;
  max-width: 1200px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* ── Header ── */
.bb-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 16px 24px;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 20px;
}

.hub-btn {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  color: var(--text);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.9rem;
  padding: 8px 16px;
  border-radius: 100px;
  transition: all 0.2s;
}
.hub-btn:hover { background: rgba(255,255,255,0.15); }

.bb-title {
  font-size: 1.8rem;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: #fff;
  line-height: 1;
}

.bb-sub {
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 600;
  margin-top: 4px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.header-right {
  display: flex;
  gap: 12px;
}

.action-btn {
  font-family: var(--font);
  font-size: 0.95rem;
  font-weight: 800;
  padding: 10px 20px;
  border-radius: 10px;
  cursor: pointer;
  border: none;
  transition: transform 0.15s, opacity 0.15s;
}
.action-btn:active { transform: scale(0.95); }
.action-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.action-btn.primary { background: var(--correct); color: #000; box-shadow: 0 4px 15px rgba(46,201,122,0.3); }
.action-btn.secondary { background: rgba(255,255,255,0.1); color: #fff; }

/* ── Canvas Area ── */
.bb-canvas-wrapper {
  position: relative;
  width: 100%;
  background: #1e293b;
  border: 1px solid var(--border);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: inset 0 0 40px rgba(0,0,0,0.5);
}

#bridgeCanvas {
  display: block;
  width: 100%;
  background: linear-gradient(180deg, #1e293b 0%, #0f172a 100%);
  cursor: crosshair;
}

.bb-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.7);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
}

.bb-modal {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 32px 40px;
  max-width: 500px;
  box-shadow: 0 20px 50px rgba(0,0,0,0.6);
  text-align: center;
}

.bb-modal h2 {
  font-size: 2rem;
  font-weight: 900;
  color: var(--accent);
  margin-bottom: 12px;
}

.bb-modal p {
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 24px;
}

.role-list {
  text-align: left;
  list-style: none;
  background: rgba(0,0,0,0.2);
  padding: 16px;
  border-radius: 12px;
  margin-bottom: 24px;
}
.role-list li { margin-bottom: 12px; font-size: 0.95rem; color: #cbd5e1; }
.role-list li:last-child { margin-bottom: 0; }
.role-list strong { color: #fff; display: block; margin-bottom: 4px; }

.difficulty-select {
  margin-bottom: 24px;
  text-align: left;
}
.difficulty-select label {
  display: block;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-muted);
  margin-bottom: 8px;
}
.difficulty-select select {
  width: 100%;
  background: rgba(0,0,0,0.3);
  border: 1px solid var(--border);
  color: #fff;
  font-family: var(--font);
  font-size: 1rem;
  font-weight: 600;
  padding: 12px;
  border-radius: 8px;
  outline: none;
}

.start-btn {
  background: var(--accent);
  color: #000;
  border: none;
  font-family: var(--font);
  font-size: 1.1rem;
  font-weight: 800;
  width: 100%;
  padding: 14px;
  border-radius: 10px;
  cursor: pointer;
  box-shadow: 0 6px 20px rgba(255,208,96,0.3);
  transition: transform 0.15s;
}
.start-btn:active { transform: scale(0.97); }

/* ── Stations Area ── */
.bb-stations {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 20px;
}

.station {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px;
  display: flex;
  flex-direction: column;
}

.station-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
}

.station-icon {
  font-size: 1.8rem;
  background: rgba(255,255,255,0.05);
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
}

.station-header h3 { font-size: 1.2rem; font-weight: 800; color: #fff; }
.station-hint { font-size: 0.8rem; color: var(--text-muted); font-weight: 600; }

/* Solver Station */
.solver-screen {
  background: #0f172a;
  border: 2px solid #1e293b;
  border-radius: 12px;
  padding: 24px;
  text-align: center;
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.math-problem {
  font-size: 3.5rem;
  font-weight: 900;
  color: var(--accent);
  font-family: monospace;
  margin-bottom: 20px;
  letter-spacing: -0.05em;
}

.math-input {
  background: #1e293b;
  border: 2px solid #334155;
  color: #fff;
  font-family: monospace;
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
  width: 180px;
  padding: 10px;
  border-radius: 8px;
  outline: none;
  transition: border-color 0.2s;
}
.math-input:focus { border-color: var(--accent); }
/* hide arrows */
.math-input::-webkit-outer-spin-button, .math-input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.math-input[type=number] { -moz-appearance: textfield; }

.feedback-text {
  margin-top: 16px;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  min-height: 1.2rem;
}
.feedback-text.good { color: var(--correct); }
.feedback-text.bad { color: var(--error); }

/* Engineer Inventory */
.inventory-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  flex: 1;
}

.inv-item {
  background: #0f172a;
  border: 2px solid #1e293b;
  border-radius: 12px;
  padding: 16px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  transition: all 0.2s;
  position: relative;
}

.inv-item:hover { border-color: #334155; background: #152033; }
.inv-item.active { border-color: var(--accent); background: rgba(255,208,96,0.05); }

.inv-visual {
  width: 100%;
  height: 40px;
  border-radius: 6px;
  position: relative;
}

.visual-wood {
  background: repeating-linear-gradient(90deg, #c07b46, #c07b46 10px, #a86b3c 10px, #a86b3c 12px);
  border: 2px solid #8c552a;
}
.visual-steel {
  background: #8a9ba8;
  border: 2px solid #5a6b78;
  /* dots for rivets */
  background-image: radial-gradient(#5a6b78 15%, transparent 16%), radial-gradient(#5a6b78 15%, transparent 16%);
  background-size: 16px 16px;
  background-position: 0 0, 8px 8px;
}
.visual-road {
  background: #334155;
  border: 2px solid #1e293b;
  /* dashed line */
}
.visual-road::after {
  content: '';
  position: absolute;
  top: 50%; left: 0; right: 0; height: 2px;
  background: repeating-linear-gradient(90deg, transparent, transparent 10px, #fff 10px, #fff 20px);
  transform: translateY(-50%);
}

.inv-info { text-align: center; }
.inv-name { font-size: 0.9rem; font-weight: 700; color: #fff; margin-bottom: 4px; }
.inv-count {
  font-size: 1.5rem; font-weight: 900; font-family: monospace; color: var(--accent);
  background: rgba(0,0,0,0.3); padding: 2px 10px; border-radius: 6px; display: inline-block;
}

.inv-key {
  position: absolute;
  top: -8px; left: 50%;
  transform: translateX(-50%);
  background: var(--bg-panel);
  border: 1px solid var(--border);
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.65rem;
  font-weight: 800;
  color: var(--text-muted);
  text-transform: uppercase;
}
.inv-item.active .inv-key { color: var(--accent); border-color: var(--accent); }

.engineer-feedback { text-align: center; margin-top: 20px; }