:root {
  --bg-dark: #0f172a;
  --bg-panel: #1e293b;
  --bg-card: #263349;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --border-color: #334155;
  --accent-blue: #38bdf8;
  --accent-red: #f43f5e;
  --accent-green: #a3e635;
  --accent-amber: #fbbf24;
  --accent-purple: #c084fc;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  user-select: none;
  -webkit-user-select: none;
}

html,
body {
  font-family: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--bg-dark);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  touch-action: manipulation;
  overscroll-behavior: none;
}

.app-container {
  display: flex;
  flex-direction: column;
  height: 100vh;
  max-width: 1680px;
  margin: 0 auto;
  width: 100%;
  padding: 12px 18px;
  gap: 12px;
}

/* 頂部標題列 */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 12px 20px;
  flex-shrink: 0;
  flex-wrap: wrap;
  gap: 12px;
}

.header-title {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.badge {
  display: inline-block;
  width: fit-content;
  background: rgba(56, 189, 248, 0.15);
  color: var(--accent-blue);
  border: 1px solid rgba(56, 189, 248, 0.4);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 999px;
}

.app-header h1 {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: #fff;
}

.subtitle {
  font-size: 0.86rem;
  color: var(--text-muted);
}

.subtitle strong {
  color: #e2e8f0;
}

.stats-bar {
  display: flex;
  gap: 12px;
}

.stat-pill {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 8px 14px;
  border-radius: 12px;
  font-size: 0.85rem;
}

.stat-pill strong {
  font-size: 1.2rem;
  font-variant-numeric: tabular-nums;
  margin-left: 4px;
}

.blood-stat strong {
  color: #fb7185;
}

.lymph-stat strong {
  color: #bef264;
}

.stat-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.blood-dot {
  background: #f43f5e;
  box-shadow: 0 0 8px #f43f5e;
}

.lymph-dot {
  background: #a3e635;
  box-shadow: 0 0 8px #a3e635;
}

/* 主內容區 */
.main-layout {
  display: grid;
  grid-template-columns: 1fr 390px;
  gap: 14px;
  flex: 1;
  min-height: 0;
}

.canvas-wrapper {
  position: relative;
  background: #fdf6e9;
  border-radius: 16px;
  border: 2px solid var(--border-color);
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
}

#sim-canvas {
  width: 100%;
  height: 100%;
  display: block;
  cursor: pointer;
  touch-action: none;
}

/* 畫布浮動控制與提示 */
.canvas-overlay-top-left {
  position: absolute;
  top: 14px;
  left: 14px;
  pointer-events: none;
}

.flow-indicator {
  background: rgba(15, 23, 42, 0.82);
  backdrop-filter: blur(6px);
  color: #fff;
  padding: 7px 14px;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
  border: 1px solid rgba(255, 255, 255, 0.2);
  display: flex;
  align-items: center;
  gap: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.arrow-pulse {
  display: inline-block;
  color: #38bdf8;
  font-weight: 900;
  animation: slideRight 1.2s infinite ease-in-out;
}

@keyframes slideRight {
  0%, 100% { transform: translateX(-2px); opacity: 0.7; }
  50% { transform: translateX(4px); opacity: 1; }
}

.canvas-overlay-bottom-left {
  position: absolute;
  bottom: 14px;
  left: 14px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.toggle-chip {
  background: rgba(15, 23, 42, 0.82);
  backdrop-filter: blur(6px);
  color: #f1f5f9;
  padding: 6px 12px;
  border-radius: 999px;
  font-size: 0.8rem;
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  user-select: none;
  border: 1px solid rgba(255, 255, 255, 0.18);
  transition: background 0.2s;
}

.toggle-chip:hover {
  background: rgba(30, 41, 59, 0.95);
}

.toggle-chip input {
  accent-color: var(--accent-blue);
  cursor: pointer;
}

.structure-tooltip {
  position: absolute;
  pointer-events: none;
  background: rgba(15, 23, 42, 0.94);
  color: #fff;
  padding: 10px 14px;
  border-radius: 10px;
  border: 1px solid rgba(56, 189, 248, 0.5);
  font-size: 0.82rem;
  max-width: 260px;
  line-height: 1.45;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.35);
  z-index: 20;
  transition: opacity 0.15s ease;
}

.structure-tooltip.hidden {
  opacity: 0;
  visibility: hidden;
}

/* 右側控制面板 */
.control-panel {
  display: flex;
  flex-direction: column;
  gap: 12px;
  overflow-y: auto;
  padding-right: 4px;
}

.panel-card {
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.panel-card h2 {
  font-size: 0.98rem;
  font-weight: 700;
  color: #f1f5f9;
  border-left: 3px solid var(--accent-blue);
  padding-left: 8px;
}

.card-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.4;
}

/* 養分投放按鈕 */
.nutrient-buttons {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.btn-nutrient {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 9px 12px;
  color: var(--text-main);
  cursor: pointer;
  text-align: left;
  transition: all 0.16s ease;
}

.btn-nutrient:hover {
  transform: translateY(-1px);
  border-color: var(--accent-blue);
  background: #2d3d56;
}

.btn-nutrient:active {
  transform: translateY(0);
}

.mol-icon {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  flex-shrink: 0;
  position: relative;
}

.carb-icon {
  background: rgba(56, 189, 248, 0.18);
  border: 2px solid #38bdf8;
}
.carb-icon::after {
  content: "⬢⬢";
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #38bdf8;
  font-size: 0.85rem;
}

.protein-icon {
  background: rgba(192, 132, 252, 0.18);
  border: 2px solid #c084fc;
}
.protein-icon::after {
  content: "●●●";
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #c084fc;
  font-size: 0.7rem;
  letter-spacing: -1px;
}

.lipid-icon {
  background: rgba(251, 191, 36, 0.18);
  border: 2px solid #fbbf24;
}
.lipid-icon::after {
  content: "💧";
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}

.btn-text {
  display: flex;
  flex-direction: column;
  flex: 1;
}

.btn-text strong {
  font-size: 0.88rem;
  color: #fff;
}

.btn-text span {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.plus-badge {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 8px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.08);
  color: #e2e8f0;
}

.auto-controls {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 2px;
}

.btn-action.primary {
  background: linear-gradient(135deg, #0284c7, #2563eb);
  color: #fff;
  border: none;
  border-radius: 9px;
  padding: 9px 12px;
  font-weight: 700;
  font-size: 0.86rem;
  cursor: pointer;
  transition: filter 0.15s;
}

.btn-action.primary:hover {
  filter: brightness(1.12);
}

.control-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.82rem;
  color: #cbd5e1;
}

.control-row input[type="range"] {
  width: 140px;
  accent-color: var(--accent-blue);
}

.control-row input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--accent-blue);
  cursor: pointer;
}

.btn-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.btn-secondary {
  background: var(--bg-card);
  color: #e2e8f0;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 7px 10px;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s;
}

.btn-secondary:hover {
  background: #334155;
}

/* 三階段時間軸 */
.stage-timeline {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.stage-item {
  display: flex;
  gap: 10px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 8px 10px;
  transition: border-color 0.25s, background 0.25s;
}

.stage-item.active {
  border-color: var(--accent-blue);
  background: rgba(56, 189, 248, 0.1);
}

.stage-num {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: #334155;
  color: #fff;
  font-size: 0.76rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 2px;
}

.stage-item.active .stage-num {
  background: var(--accent-blue);
  color: #0f172a;
}

.stage-body strong {
  font-size: 0.84rem;
  display: block;
  margin-bottom: 2px;
  color: #f8fafc;
}

.stage-body p {
  font-size: 0.76rem;
  color: #cbd5e1;
  line-height: 1.45;
}

.tag-blood {
  display: inline-block;
  background: rgba(244, 63, 94, 0.2);
  color: #fda4af;
  border: 1px solid rgba(244, 63, 94, 0.45);
  border-radius: 4px;
  padding: 0 5px;
  font-size: 0.7rem;
  font-weight: 700;
}

.tag-lymph {
  display: inline-block;
  background: rgba(163, 230, 53, 0.2);
  color: #d9f99d;
  border: 1px solid rgba(163, 230, 53, 0.45);
  border-radius: 4px;
  padding: 0 5px;
  font-size: 0.7rem;
  font-weight: 700;
}

/* 構造說明盒與圖例 */
.info-box {
  background: var(--bg-card);
  border: 1px solid rgba(56, 189, 248, 0.35);
  border-radius: 10px;
  padding: 10px 12px;
}

.info-title {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--accent-blue);
  margin-bottom: 4px;
}

.info-desc {
  font-size: 0.78rem;
  color: #e2e8f0;
  line-height: 1.48;
}

.legend-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  margin-top: 2px;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  color: #cbd5e1;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
  flex-shrink: 0;
}

.c-glucose { background: #0ea5e9; border: 1px solid #fff; }
.c-amino   { background: #a855f7; border: 1px solid #fff; }
.c-lipid   { background: #eab308; border: 1px solid #fff; }
.c-enzyme  { background: #10b981; border: 1px solid #fff; }
.c-rbc     { background: #dc2626; border: 1px solid #fecdd3; }

@media (max-width: 1080px) {
  .app-container {
    height: auto;
  }
  .main-layout {
    grid-template-columns: 1fr;
  }
  .canvas-wrapper {
    height: 580px;
  }
}