:root {
  --bg-deep: #050810;
  --bg-panel: rgba(8, 18, 32, 0.82);
  --border: rgba(0, 212, 255, 0.22);
  --accent: #00d4ff;
  --accent-dim: rgba(0, 212, 255, 0.45);
  --accent-warm: #ff6b35;
  --text: #e8f4fc;
  --text-muted: #7a9bb8;
  --glow: 0 0 24px rgba(0, 212, 255, 0.15);
  --font-display: "Orbitron", sans-serif;
  --font-body: "Noto Sans SC", sans-serif;
  --panel-width: 340px;
}

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

html, body {
  height: 100%;
  overflow: hidden;
  font-family: var(--font-body);
  background: var(--bg-deep);
  color: var(--text);
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 70% 20%, rgba(0, 100, 180, 0.12), transparent),
    radial-gradient(ellipse 60% 40% at 20% 80%, rgba(0, 212, 255, 0.06), transparent);
  pointer-events: none;
  z-index: 0;
}

.app {
  display: grid;
  grid-template-columns: auto 1fr;
  height: 100vh;
  position: relative;
  z-index: 1;
}

/* —— 左侧控制面板（含外侧折叠钮） —— */
.panel-column {
  position: relative;
  width: var(--panel-width);
  flex-shrink: 0;
  min-height: 0;
  overflow: visible;
  transition: width 0.22s ease;
}

.app.panel-collapsed .panel-column {
  width: 0;
  min-width: 0;
}

.panel {
  width: 100%;
  height: 100%;
  min-height: 0;
  border-right: 1px solid var(--border);
  background: var(--bg-panel);
  backdrop-filter: blur(8px);
  box-shadow: var(--glow);
  overflow: hidden;
  transition: opacity 0.18s ease, border-color 0.22s ease;
}

.app.panel-collapsed .panel {
  border-right-color: transparent;
  opacity: 0;
  pointer-events: none;
}

.panel-body {
  display: flex;
  flex-direction: column;
  height: 100%;
  min-height: 0;
  overflow: hidden;
}

.app.panel-collapsed .panel-body {
  display: none;
}

.panel-toggle-btn {
  position: absolute;
  left: 100%;
  top: 50%;
  z-index: 20;
  transform: translateY(-50%);
  box-sizing: border-box;
  width: 28px;
  height: 52px;
  padding: 0;
  margin: 0;
  font-size: 13px;
  line-height: 1;
  border-radius: 0 8px 8px 0;
  border: 1px solid var(--border);
  border-left: none;
  background: rgba(8, 18, 32, 0.95);
  color: var(--text);
  cursor: pointer;
  font-family: inherit;
  box-shadow: 4px 0 16px rgba(0, 0, 0, 0.35);
  transition: background 0.2s, border-color 0.2s, color 0.2s, box-shadow 0.2s;
}

.panel-toggle-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(0, 212, 255, 0.12);
  box-shadow: 4px 0 20px rgba(0, 212, 255, 0.2);
}

.panel-toggle-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.panel-header {
  padding: 20px 22px 16px;
  border-bottom: 1px solid var(--border);
}

.panel-header h1 {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--accent);
  text-transform: uppercase;
}

.panel-tagline-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-top: 10px;
}

.panel-header .panel-tagline {
  margin: 0;
  flex: 1;
  min-width: 0;
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--accent);
  line-height: 1.45;
  text-shadow: 0 0 18px rgba(0, 212, 255, 0.35);
}

.panel-fullscreen-btn {
  flex-shrink: 0;
  padding: 6px 10px;
  font-size: 0.72rem;
  font-family: var(--font-body);
  letter-spacing: 0.04em;
  color: var(--text-muted);
  background: rgba(0, 40, 70, 0.45);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.2s, border-color 0.2s, color 0.2s;
}

.panel-fullscreen-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(0, 212, 255, 0.1);
}

.panel-fullscreen-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.panel-scroll {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 12px 14px 14px;
  scrollbar-width: thin;
  scrollbar-color: var(--accent-dim) transparent;
}

.panel-bottom {
  flex-shrink: 0;
  padding: 10px 14px 18px;
  margin-top: auto;
  border-top: 1px solid var(--border);
  background: rgba(5, 12, 24, 0.45);
}

.panel-bottom .section-label {
  margin-top: 0;
  margin-bottom: 8px;
}

.section-label {
  font-family: var(--font-display);
  font-size: 0.62rem;
  letter-spacing: 0.2em;
  color: var(--accent);
  margin: 14px 0 8px;
  opacity: 0.9;
}

.section-label:first-child { margin-top: 2px; }

.knowledge-select-wrap {
  margin-bottom: 14px;
}

.knowledge-select {
  width: 100%;
  padding: 10px 36px 10px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: rgba(0, 40, 70, 0.5);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 0.84rem;
  cursor: pointer;
  outline: none;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath fill='%2300d4ff' d='M1 1l5 5 5-5'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.knowledge-select:hover,
.knowledge-select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 12px rgba(0, 212, 255, 0.15);
}

.knowledge-select option {
  background: #0a1828;
  color: var(--text);
}

.slider-row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 8px 10px;
  margin-bottom: 10px;
}

.slider-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.slider-val {
  font-family: var(--font-display);
  font-size: 0.7rem;
  color: var(--accent);
  white-space: nowrap;
  text-align: right;
  min-width: 2.8em;
}

.control-row {
  margin-bottom: 10px;
}

.control-row-status {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 8px 10px;
}

.control-row-status .slider-label {
  grid-column: 1;
}

.control-row-status .slider-val {
  grid-column: 3;
  justify-self: end;
}

.control-row .chip {
  grid-column: 1 / -1;
  width: 100%;
  margin-top: 4px;
}

.slider-row input[type="range"],
.control-row input[type="range"] {
  width: 100%;
  min-width: 0;
}

input[type="range"] {
  height: 4px;
  -webkit-appearance: none;
  appearance: none;
  background: rgba(0, 212, 255, 0.2);
  border-radius: 2px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 10px var(--accent);
  cursor: pointer;
}

.slider-row-contour {
  grid-template-columns: auto 1fr auto auto;
}

.slider-row-contour input[type="color"] {
  width: 44px;
  height: 28px;
  padding: 2px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: rgba(0, 40, 70, 0.5);
  cursor: pointer;
  justify-self: end;
}

input[type="color"]::-webkit-color-swatch-wrapper {
  padding: 0;
}

input[type="color"]::-webkit-color-swatch {
  border: none;
  border-radius: 4px;
}

.toggle-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.chip {
  padding: 6px 12px;
  font-size: 0.72rem;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.2s;
}

.chip.on {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(0, 212, 255, 0.1);
}

.landform-btns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.landform-btns button {
  padding: 8px;
  font-size: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 5px;
  background: rgba(0, 30, 50, 0.5);
  color: var(--text);
  cursor: pointer;
  transition: all 0.2s;
}

.landform-btns button:hover,
.landform-btns button.active {
  border-color: var(--accent-warm);
  color: var(--accent-warm);
  background: rgba(255, 107, 53, 0.12);
}

.knowledge-box {
  margin: 0 0 10px;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: rgba(0, 20, 40, 0.5);
  font-size: 0.8rem;
  line-height: 1.75;
  color: var(--text);
  height: auto;
  max-height: min(42vh, 320px);
  overflow-y: auto;
}

.copyright-entry {
  margin: 4px 0 0;
  padding-top: 10px;
  border-top: 1px solid var(--border);
}

.copyright-text-btn {
  display: block;
  width: 100%;
  padding: 10px 12px;
  font-size: 13px;
  font-family: inherit;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  text-align: center;
  transition: background 0.2s, border-color 0.2s, color 0.2s;
}

.copyright-text-btn:hover {
  background: rgba(0, 212, 255, 0.08);
  border-color: var(--accent);
  color: var(--accent);
}

.copyright-text-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.copyright-modal {
  max-width: 440px;
}

.copyright-modal .modal-title {
  text-align: center;
}

.copyright-modal .modal-actions {
  justify-content: center;
}

.copyright-qr-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: flex-start;
  gap: 14px 16px;
  margin-bottom: 14px;
}

.copyright-qr-item {
  margin: 0;
  flex: 1 1 150px;
  max-width: 200px;
  min-width: 0;
  text-align: center;
}

.copyright-qr-caption {
  margin: 8px 0 0;
  font-size: 12px;
  line-height: 1.35;
  color: var(--text-muted);
}

.copyright-qr-image {
  display: block;
  width: 100%;
  max-width: 200px;
  height: auto;
  margin: 0 auto;
  border-radius: 8px;
  border: 1px solid var(--border);
}

.copyright-note {
  margin: 0;
  font-size: 13px;
  line-height: 1.55;
  color: var(--text);
  text-align: center;
}

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 20000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  background: rgba(0, 0, 0, 0.55);
  box-sizing: border-box;
}

.modal-overlay[hidden] {
  display: none !important;
}

.modal-dialog {
  width: 100%;
  max-width: 380px;
  padding: 18px 16px;
  border-radius: 8px;
  background: rgba(8, 18, 32, 0.98);
  border: 1px solid var(--border);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.55);
  color: var(--text);
}

.modal-title {
  margin: 0 0 14px;
  font-size: 17px;
  font-weight: 600;
  color: var(--accent);
}

.modal-actions {
  display: flex;
  gap: 10px;
  margin-top: 18px;
  justify-content: flex-end;
}

.modal-btn {
  padding: 8px 18px;
  font-size: 14px;
  border-radius: 8px;
  cursor: pointer;
  border: 1px solid var(--border);
  background: rgba(0, 40, 70, 0.6);
  color: var(--text);
  font-family: inherit;
  transition: background 0.2s, border-color 0.2s;
}

.modal-btn:hover {
  border-color: var(--accent);
  background: rgba(0, 212, 255, 0.12);
}

.modal-btn-primary {
  border-color: var(--accent);
  color: var(--accent);
}

.knowledge-box h3 {
  font-size: 0.85rem;
  color: var(--accent);
  margin-bottom: 8px;
  font-weight: 600;
}

.knowledge-box ul {
  margin: 8px 0 0 18px;
  color: var(--text-muted);
}

.knowledge-box li { margin-bottom: 4px; }
.knowledge-box strong { color: var(--text); }

/* —— 右侧视口 —— */
.viewport-wrap {
  position: relative;
  overflow: hidden;
  min-height: 0;
  height: 100%;
  background: #182638;
}

#canvas-container {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  background: #182638;
}

#canvas-container canvas {
  display: block;
  width: 100% !important;
  height: 100% !important;
}

.hud {
  position: absolute;
  pointer-events: none;
  inset: 0;
}

.hud-corner {
  position: absolute;
  padding: 12px 16px;
  font-family: var(--font-display);
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  color: var(--accent-dim);
}

.hud-tl {
  top: 0;
  left: 0;
  display: flex;
  flex-direction: row;
  align-items: stretch;
  gap: 0;
  padding: 0;
  border-bottom: 1px solid var(--border);
  border-right: 1px solid var(--border);
  border-radius: 0 0 8px 0;
  background: rgba(5, 12, 24, 0.6);
}
.hud-block {
  padding: 12px 16px;
  border-right: 1px solid var(--border);
}
.hud-block:last-child { border-right: none; }
.hud-label {
  display: block;
  font-size: 0.65rem;
  letter-spacing: 0.06em;
  color: var(--accent-dim);
  white-space: nowrap;
}
.hud-block-elev .hud-label { letter-spacing: 0.04em; }
.hud-bl { bottom: 0; left: 0; border-top: 1px solid var(--border); border-right: 1px solid var(--border); border-radius: 0 8px 0 0; background: rgba(5, 12, 24, 0.6); }
.hud-br { bottom: 0; right: 0; text-align: right; border-top: 1px solid var(--border); border-left: 1px solid var(--border); border-radius: 8px 0 0 0; background: rgba(5, 12, 24, 0.6); }

.hud-stat { color: var(--accent); font-size: 0.85rem; margin-top: 4px; }

.map-overlay {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 248px;
  height: 248px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: rgba(5, 15, 28, 0.85);
  backdrop-filter: blur(8px);
  opacity: 0;
  transform: translateY(-8px);
  transition: opacity 0.35s, transform 0.35s;
  pointer-events: none;
  overflow: hidden;
}

.map-overlay.visible {
  opacity: 1;
  transform: translateY(0);
}

.map-overlay canvas { width: 100%; height: 100%; display: block; }

.map-overlay .map-title {
  position: absolute;
  top: 6px;
  left: 8px;
  font-family: var(--font-display);
  font-size: 0.55rem;
  letter-spacing: 0.15em;
  color: var(--accent);
}

.legend {
  position: absolute;
  bottom: 80px;
  right: 16px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: rgba(5, 15, 28, 0.8);
  font-size: 0.7rem;
  opacity: 0;
  transition: opacity 0.3s;
}

.legend.visible { opacity: 1; }

.profile-chart {
  position: absolute;
  bottom: 56px;
  left: 16px;
  width: 320px;
  height: 120px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: rgba(5, 15, 28, 0.88);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.35s, transform 0.35s;
  pointer-events: none;
}

.profile-chart.visible {
  opacity: 1;
  transform: translateY(0);
}

.profile-chart canvas { width: 100%; height: 100%; display: block; }
.profile-chart .map-title { top: 6px; left: 8px; }

.rel-height-result {
  position: absolute;
  bottom: 56px;
  left: 16px;
  z-index: 12;
  display: none;
  max-width: min(340px, calc(100% - 32px));
  padding: 12px 14px;
  border-radius: 8px;
  border: 1px solid rgba(0, 212, 255, 0.35);
  background: rgba(5, 15, 28, 0.88);
  font-size: 12px;
  line-height: 1.65;
  color: #c8e8f8;
  pointer-events: none;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.35s, transform 0.35s;
}
.rel-height-result.visible {
  display: block;
  opacity: 1;
  transform: translateY(0);
}
.rel-height-result .rel-height-title {
  font-family: var(--font-display);
  font-size: 0.55rem;
  letter-spacing: 0.12em;
  color: #00e5a0;
  margin-bottom: 6px;
}
.rel-height-result strong { color: #00e5ff; }
.rel-height-result .delta { font-size: 14px; font-weight: 600; color: #7affc8; margin-top: 4px; }
.rel-height-result .slope { color: #a8e8d0; margin-top: 2px; }

.legend-item {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 4px;
  color: var(--text-muted);
}

.legend-swatch {
  width: 24px;
  height: 3px;
  border-radius: 1px;
}

.hint-bar {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  padding: 8px 20px;
  border: 1px solid var(--border);
  border-radius: 24px;
  background: rgba(5, 15, 28, 0.75);
  font-size: 0.75rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.scanline {
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(0, 0, 0, 0.03) 2px,
    rgba(0, 0, 0, 0.03) 4px
  );
  pointer-events: none;
}

.grid-deco {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(0, 212, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 212, 255, 0.03) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
  mask-image: radial-gradient(ellipse 70% 70% at 50% 50%, black, transparent);
}

@media (max-width: 900px) {
  .app { grid-template-columns: 1fr; grid-template-rows: auto 1fr; }
  .panel-column {
    width: 100%;
    max-width: none;
  }
  .app.panel-collapsed .panel-column {
    width: 100%;
    max-height: 0;
    overflow: visible;
  }
  .panel { max-height: 42vh; }
  .app.panel-collapsed .panel {
    max-height: 0;
    opacity: 0;
  }
  .panel-toggle-btn {
    left: auto;
    right: 12px;
    top: auto;
    bottom: 12px;
    transform: none;
    border-radius: 8px;
    border-left: 1px solid var(--border);
    width: 36px;
    height: 36px;
  }
}