/* ───────────────────────────────────
   ALTITUDE EXPLORER — Style Sheet
   Dark Topographic Terminal Aesthetic
   ─────────────────────────────────── */

:root {
  --bg-deep: #060a12;
  --bg-panel: rgba(8, 14, 28, 0.92);
  --bg-input: rgba(15, 25, 50, 0.7);
  --bg-hover: rgba(25, 40, 70, 0.6);
  --border: rgba(60, 90, 140, 0.25);
  --border-bright: rgba(80, 130, 200, 0.35);
  --text-primary: #e2e8f0;
  --text-secondary: #7a8ba8;
  --text-dim: #4a5a74;
  --accent: #e8b931;
  --accent-glow: rgba(232, 185, 49, 0.15);
  --teal: #2dd4bf;
  --teal-dim: rgba(45, 212, 191, 0.12);
  --red: #f87171;
  --font-display: 'Outfit', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', monospace;
  --radius: 10px;
  --radius-sm: 6px;
  --panel-width: 340px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

/* ── Loader ── */
#loader {
  position: fixed;
  inset: 0;
  z-index: 10000;
  background: var(--bg-deep);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.6s ease, visibility 0.6s ease;
}
#loader.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}
.loader-content {
  text-align: center;
}
.loader-rings {
  position: relative;
  width: 64px;
  height: 64px;
  margin: 0 auto 20px;
}
.ring {
  position: absolute;
  inset: 0;
  border: 2px solid transparent;
  border-radius: 50%;
  animation: spin 1.8s linear infinite;
}
.ring:nth-child(1) {
  border-top-color: var(--accent);
  animation-duration: 1.6s;
}
.ring:nth-child(2) {
  inset: 6px;
  border-right-color: var(--teal);
  animation-duration: 2.2s;
  animation-direction: reverse;
}
.ring:nth-child(3) {
  inset: 12px;
  border-bottom-color: var(--text-secondary);
  animation-duration: 1.4s;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}
.loader-text {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-secondary);
  letter-spacing: 0.08em;
}

/* ── Map ── */
#map {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: var(--bg-deep);
}
.leaflet-control-zoom {
  border: none !important;
  box-shadow: 0 2px 12px rgba(0,0,0,0.5) !important;
}
.leaflet-control-zoom a {
  background: var(--bg-panel) !important;
  color: var(--text-primary) !important;
  border: 1px solid var(--border) !important;
  backdrop-filter: blur(20px);
  width: 36px !important;
  height: 36px !important;
  line-height: 36px !important;
  font-size: 16px !important;
}
.leaflet-control-zoom a:hover {
  background: var(--bg-hover) !important;
}
.leaflet-control-attribution {
  background: rgba(6, 10, 18, 0.8) !important;
  color: var(--text-dim) !important;
  font-size: 10px !important;
  backdrop-filter: blur(10px);
}
.leaflet-control-attribution a {
  color: var(--text-secondary) !important;
}

/* ── Panel ── */
#panel {
  position: fixed;
  top: 16px;
  left: 16px;
  bottom: 16px;
  width: var(--panel-width);
  z-index: 1000;
  background: var(--bg-panel);
  backdrop-filter: blur(30px) saturate(1.2);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  overflow-y: auto;
  transition: transform var(--transition);
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}
#panel::-webkit-scrollbar {
  width: 4px;
}
#panel::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 4px;
}

.panel-header {
  display: flex;
  align-items: center;
  gap: 14px;
}
.logo-mark {
  color: var(--accent);
  flex-shrink: 0;
}
.panel-header h1 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.2;
}
.subtitle {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-dim);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-top: 2px;
}

.divider {
  height: 1px;
  background: var(--border);
  margin: 2px 0;
}

/* ── Controls ── */
.control-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.control-group label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  color: var(--text-secondary);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  display: flex;
  align-items: center;
  gap: 8px;
}
.label-icon {
  color: var(--teal);
  font-size: 0.6rem;
}

/* Select */
.select-wrapper {
  position: relative;
}
.select-wrapper::after {
  content: '▾';
  position: absolute;
  right: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-dim);
  pointer-events: none;
  font-size: 0.8rem;
}
#country-select {
  width: 100%;
  padding: 10px 36px 10px 14px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-display);
  font-size: 0.88rem;
  appearance: none;
  cursor: pointer;
  transition: border-color var(--transition);
  outline: none;
}
#country-select:hover {
  border-color: var(--border-bright);
}
#country-select:focus {
  border-color: var(--teal);
  box-shadow: 0 0 0 2px var(--teal-dim);
}
#country-select option {
  background: #0c1424;
  color: var(--text-primary);
}

/* Slider */
.slider-container {
  padding: 0 2px;
}
#altitude-slider {
  width: 100%;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}
#altitude-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-deep);
  box-shadow: 0 0 8px var(--accent-glow), 0 2px 6px rgba(0,0,0,0.4);
  cursor: grab;
  transition: transform 0.15s ease;
}
#altitude-slider::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}
#altitude-slider::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 2px solid var(--bg-deep);
  box-shadow: 0 0 8px var(--accent-glow), 0 2px 6px rgba(0,0,0,0.4);
  cursor: grab;
}
.slider-labels {
  display: flex;
  justify-content: space-between;
  margin-top: 4px;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: var(--text-dim);
}

.altitude-display {
  display: flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 14px;
  background: var(--accent-glow);
  border: 1px solid rgba(232, 185, 49, 0.2);
  border-radius: var(--radius-sm);
}
.altitude-value {
  font-family: var(--font-mono);
  font-size: 1.8rem;
  font-weight: 600;
  color: var(--accent);
  line-height: 1;
}
.altitude-unit {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-dim);
  letter-spacing: 0.05em;
}

/* Button */
#apply-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  padding: 12px 20px;
  background: linear-gradient(135deg, var(--teal), #0ea5e9);
  border: none;
  border-radius: var(--radius-sm);
  color: #0a0e17;
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}
#apply-btn::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent, rgba(255,255,255,0.15));
  opacity: 0;
  transition: opacity var(--transition);
}
#apply-btn:hover:not(:disabled)::before {
  opacity: 1;
}
#apply-btn:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(45, 212, 191, 0.3);
}
#apply-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}
#apply-btn.loading .btn-text::after {
  content: '';
  display: inline-block;
  width: 14px;
  height: 14px;
  margin-left: 8px;
  border: 2px solid rgba(10,14,23,0.3);
  border-top-color: #0a0e17;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  vertical-align: middle;
}

/* Legend */
.legend {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.legend-bar {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.legend-gradient {
  height: 14px;
  border-radius: 3px;
  background: linear-gradient(90deg,
    #166534 0%,
    #22c55e 15%,
    #eab308 35%,
    #f97316 55%,
    #dc2626 75%,
    #fecaca 90%,
    #ffffff 100%
  );
  border: 1px solid var(--border);
}
.legend-labels {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: var(--text-dim);
}

/* Info box */
.info-box {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 12px 14px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
}
.info-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.info-label {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.info-value {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-primary);
  font-weight: 500;
}

/* Footer */
.panel-footer {
  margin-top: auto;
  padding-top: 8px;
}
.panel-footer p {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  color: var(--text-dim);
  line-height: 1.8;
}
.panel-footer a {
  color: var(--text-secondary);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: color var(--transition), border-color var(--transition);
}
.panel-footer a:hover {
  color: var(--teal);
  border-color: var(--teal);
}

/* Panel toggle (mobile) */
#panel-toggle {
  display: none;
  position: fixed;
  top: 16px;
  left: 16px;
  z-index: 1001;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--bg-panel);
  backdrop-filter: blur(20px);
  border: 1px solid var(--border);
  color: var(--text-primary);
  cursor: pointer;
  align-items: center;
  justify-content: center;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(0);
  z-index: 2000;
  padding: 10px 20px;
  background: var(--bg-panel);
  backdrop-filter: blur(20px);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
  transition: all 0.4s ease;
  pointer-events: none;
}
.toast.hidden {
  opacity: 0;
  transform: translateX(-50%) translateY(10px);
}

/* ── Responsive ── */
@media (max-width: 768px) {
  #panel {
    top: 0;
    left: 0;
    bottom: 0;
    width: 300px;
    border-radius: 0 16px 16px 0;
    transform: translateX(-100%);
    padding: 20px 16px;
  }
  #panel.open {
    transform: translateX(0);
  }
  #panel-toggle {
    display: flex;
  }
  #panel-toggle.shifted {
    left: 308px;
  }
  .leaflet-control-zoom {
    margin-top: 70px !important;
  }
}

/* ── Animations ── */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
.control-group {
  animation: fadeInUp 0.5s ease backwards;
}
.control-group:nth-child(1) { animation-delay: 0.1s; }
.control-group:nth-child(2) { animation-delay: 0.2s; }
#apply-btn { animation: fadeInUp 0.5s ease 0.3s backwards; }