/* ============================================================
   Relativistic Space Travel — main.css
   Dark theme, purple/blue gradient, cyan accents.
   ============================================================ */

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

html, body {
  height: 100%;
  font-family: 'Segoe UI', Tahoma, sans-serif;
  color: #e8ecff;
  background: #0f0f23;
  overflow-x: hidden;
}

body {
  min-height: 100vh;
  background:
    radial-gradient(circle at 20% 10%, rgba(102, 126, 234, 0.35) 0%, transparent 40%),
    radial-gradient(circle at 85% 85%, rgba(118, 75, 162, 0.35) 0%, transparent 45%),
    linear-gradient(135deg, #1a1a3e 0%, #2a1a4a 100%);
}

/* ---------- Top Nav ---------- */
.top-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 28px;
  background: rgba(10, 10, 30, 0.75);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
.nav-brand {
  font-weight: 600;
  font-size: 15px;
  background: linear-gradient(135deg, #00d9ff 0%, #a88bff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: 0.3px;
}
.nav-links {
  display: flex;
  gap: 4px;
}
.nav-link {
  background: transparent;
  color: rgba(232, 236, 255, 0.7);
  border: 0;
  padding: 8px 16px;
  border-radius: 20px;
  font-family: inherit;
  font-size: 13px;
  cursor: pointer;
  transition: all 0.2s;
}
.nav-link:hover {
  color: #e8ecff;
  background: rgba(255, 255, 255, 0.06);
}
.nav-link.active {
  color: #00d9ff;
  background: rgba(0, 217, 255, 0.12);
  box-shadow: 0 0 0 1px rgba(0, 217, 255, 0.3);
}

/* ---------- View switching ---------- */
.view { display: none; }
.view.active { display: block; }

/* ---------- Home / Landing ---------- */
.view-home {
  padding: 40px 32px 48px;
  max-width: 1400px;
  margin: 0 auto;
}
.home-hero {
  text-align: center;
  margin-bottom: 42px;
}
.home-hero h1 {
  font-size: 42px;
  font-weight: 600;
  letter-spacing: 0.2px;
  background: linear-gradient(135deg, #00d9ff 0%, #a88bff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 14px;
  line-height: 1.2;
}
.home-hero p {
  color: rgba(232, 236, 255, 0.75);
  font-size: 16px;
}
.menu-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}
.menu-card {
  background: rgba(10, 10, 30, 0.55);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 18px;
  padding: 28px 26px 24px;
  text-align: left;
  cursor: pointer;
  font-family: inherit;
  color: inherit;
  transition: all 0.25s;
  position: relative;
  overflow: hidden;
}
.menu-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: linear-gradient(135deg, rgba(0, 217, 255, 0), rgba(168, 139, 255, 0));
  transition: all 0.25s;
  pointer-events: none;
}
.menu-card:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 217, 255, 0.35);
  box-shadow: 0 14px 40px rgba(0, 0, 0, 0.4), 0 0 30px rgba(0, 217, 255, 0.1);
}
.menu-card:hover::before {
  background: linear-gradient(135deg, rgba(0, 217, 255, 0.07), rgba(168, 139, 255, 0.07));
}
.menu-card-icon {
  font-size: 36px;
  margin-bottom: 12px;
}
.menu-card h2 {
  font-size: 20px;
  font-weight: 600;
  color: #00d9ff;
  margin-bottom: 10px;
}
.menu-card p {
  color: rgba(232, 236, 255, 0.75);
  font-size: 13.5px;
  line-height: 1.55;
}
.home-footer {
  margin-top: 48px;
  text-align: center;
  color: rgba(232, 236, 255, 0.4);
  font-size: 12px;
}
.home-footer code {
  background: rgba(0, 217, 255, 0.12);
  padding: 2px 6px;
  border-radius: 4px;
  color: #00d9ff;
  font-family: Consolas, monospace;
  font-size: 11px;
}

/* ---------- Space View Layout ---------- */
.view-space { padding: 18px 0 28px; }
.app-main {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 18px;
  padding: 4px 28px 24px;
  max-width: 1800px;
  margin: 0 auto;
}
.panel-space    { grid-column: 1; }
.panel-controls { grid-column: 2; }

/* ---------- Data view ---------- */
.view-data, .view-fuel {
  padding: 18px 28px 36px;
  max-width: 1800px;
  margin: 0 auto;
}
.data-intro {
  margin-bottom: 18px;
  text-align: center;
}
.data-intro h1 {
  font-size: 28px;
  font-weight: 600;
  background: linear-gradient(135deg, #00d9ff 0%, #a88bff 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 6px;
}
.data-intro p {
  color: rgba(232, 236, 255, 0.7);
  font-size: 14px;
  max-width: 760px;
  margin: 0 auto;
}
.graphs-grid-large {
  grid-template-columns: 1fr 1fr;
}
.graphs-grid-large .graph-card:first-child {
  grid-column: span 2;
}
.graphs-grid-quad {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.graph-canvas-large { height: 300px !important; }
.graph-readout {
  font-size: 11px;
  color: rgba(220,230,255,0.8);
  margin-top: 2px;
}
.graph-readout .mono {
  font-family: Consolas, monospace;
  color: #00d9ff;
  font-size: 11px;
}
.graph-header {
  margin-bottom: 8px;
}

/* ---------- Fuel section ---------- */
.fuel-layout {
  display: grid;
  grid-template-columns: 320px 1fr;
  grid-template-rows: auto auto;
  gap: 18px;
}
.panel-fuel-inputs  { grid-column: 1; grid-row: 1 / 3; }
.panel-fuel-results { grid-column: 2; grid-row: 1; }
.panel-fuel-chart   { grid-column: 2; grid-row: 2; }

.fuel-results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 14px;
  margin-bottom: 10px;
}
.fuel-result {
  background: rgba(0, 0, 0, 0.28);
  padding: 12px 14px;
  border-radius: 10px;
  border-left: 3px solid rgba(0, 217, 255, 0.4);
}
.fuel-result-label {
  color: rgba(232, 236, 255, 0.65);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.4px;
  margin-bottom: 4px;
}
.fuel-result-value {
  font-family: Consolas, monospace;
  color: #00d9ff;
  font-size: 18px;
  font-weight: 600;
}
.fuel-result-value.warn { color: #ff6060; }
.fuel-result-hint {
  color: rgba(232, 236, 255, 0.55);
  font-size: 11px;
  margin-top: 4px;
}
.equation-block {
  background: rgba(0, 217, 255, 0.06);
  border-left: 2px solid #00d9ff;
  border-radius: 5px;
  padding: 12px 14px;
}
.equation-sub {
  margin-top: 6px;
  font-size: 12px;
  color: rgba(232, 236, 255, 0.7);
}
.hint-inline {
  margin-top: 6px;
  font-size: 11px;
}

/* ---------- Panels ---------- */
.panel {
  background: rgba(10, 10, 30, 0.55);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 15px;
  padding: 18px 20px 20px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  display: flex;
  flex-direction: column;
  min-height: 0;
}
.panel-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: 12px;
}
.panel-header h2 {
  font-size: 16px;
  color: #00d9ff;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}
.hint {
  font-size: 11px;
  color: rgba(232, 236, 255, 0.5);
}

/* ---------- Space View ---------- */
.panel-space {
  min-height: 520px;
  position: relative;
}
#space-canvas {
  flex: 1;
  width: 100%;
  height: 480px;
  border-radius: 10px;
  background:
    radial-gradient(circle at 30% 40%, rgba(102, 126, 234, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 70% 60%, rgba(168, 139, 255, 0.08) 0%, transparent 55%),
    #050510;
  cursor: grab;
  display: block;
}
#space-canvas:active { cursor: grabbing; }
.space-overlay {
  position: absolute;
  bottom: 30px;
  left: 32px;
  pointer-events: none;
}
.selection-info {
  background: rgba(0, 0, 0, 0.65);
  border: 1px solid rgba(0, 217, 255, 0.3);
  padding: 10px 14px;
  border-radius: 8px;
  font-family: Consolas, monospace;
  font-size: 12px;
  max-width: 320px;
  color: #e8ecff;
  display: none;
}
.selection-info.visible { display: block; }

/* ---------- Controls ---------- */
.panel-controls {
  gap: 0;
  max-height: 520px;
  overflow-y: auto;
}
.control-group {
  margin-bottom: 14px;
}
.control-group label {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: rgba(232, 236, 255, 0.85);
  margin-bottom: 6px;
  letter-spacing: 0.3px;
}
.control-group input[type="range"] {
  width: 100%;
  -webkit-appearance: none;
  appearance: none;
  height: 4px;
  border-radius: 2px;
  background: rgba(255, 255, 255, 0.12);
  outline: none;
  cursor: pointer;
}
.control-group input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: linear-gradient(135deg, #00d9ff, #a88bff);
  cursor: pointer;
  box-shadow: 0 0 8px rgba(0, 217, 255, 0.5);
}
.control-group input[type="range"]::-moz-range-thumb {
  width: 16px;
  height: 16px;
  border: 0;
  border-radius: 50%;
  background: linear-gradient(135deg, #00d9ff, #a88bff);
  cursor: pointer;
  box-shadow: 0 0 8px rgba(0, 217, 255, 0.5);
}
.control-group select {
  width: 100%;
  background: rgba(255, 255, 255, 0.07);
  color: #e8ecff;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 13px;
  font-family: inherit;
  cursor: pointer;
}
.control-group select:focus { outline: 1px solid #00d9ff; }

.mono { font-family: Consolas, monospace; color: #00d9ff; font-size: 11px; }

.divider {
  border: 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  margin: 16px 0 14px;
}

/* Radio row */
.radio-row {
  display: flex;
  gap: 6px;
}
.radio-option {
  flex: 1;
  display: flex !important;
  align-items: center;
  justify-content: center;
  gap: 4px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  padding: 6px 8px;
  font-size: 11px !important;
  cursor: pointer;
  margin-bottom: 0 !important;
}
.radio-option input { accent-color: #00d9ff; }

/* Buttons */
.playback-row, .btn-row {
  display: flex;
  gap: 8px;
  margin-bottom: 14px;
}
.btn-primary, .btn-secondary {
  border: 0;
  color: white;
  padding: 9px 16px;
  border-radius: 25px;
  cursor: pointer;
  font-size: 13px;
  font-family: inherit;
  font-weight: 500;
  transition: all 0.25s;
  flex: 1;
}
.btn-primary {
  background: linear-gradient(135deg, #00d9ff, #a88bff);
  box-shadow: 0 4px 14px rgba(0, 217, 255, 0.25);
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(0, 217, 255, 0.4);
}
.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
}
.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.14);
  transform: translateY(-1px);
}
.btn-secondary.small {
  padding: 6px 10px;
  font-size: 11px;
  border-radius: 18px;
}

/* Inline forms (Add Location / Rocket / Message) */
.inline-form {
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid rgba(0, 217, 255, 0.22);
  border-radius: 10px;
  padding: 10px 12px;
  margin-top: 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  animation: formFadeIn 0.15s ease-out;
}
.inline-form[hidden] { display: none; }
.inline-form-title {
  color: #00d9ff;
  font-size: 11px;
  letter-spacing: 0.4px;
  text-transform: uppercase;
  margin-bottom: 2px;
}
.inline-label {
  font-size: 10.5px;
  color: rgba(232, 236, 255, 0.6);
  margin-top: 2px;
  text-transform: none;
  letter-spacing: 0.2px;
}
.inline-form input[type="text"],
.inline-form input[type="number"],
.inline-form select {
  width: 100%;
  background: rgba(255, 255, 255, 0.07);
  color: #e8ecff;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 6px;
  padding: 7px 9px;
  font-size: 12.5px;
  font-family: inherit;
  box-sizing: border-box;
}
.inline-form input:focus,
.inline-form select:focus {
  outline: 1px solid #00d9ff;
  border-color: rgba(0, 217, 255, 0.6);
}
/* Safari/WebKit draws native selects white and ignores the dark background,
   leaving the light text invisible. Drop the native look and draw our own arrow.
   (Placed after the select rules above so their `background` shorthand
   doesn't wipe the arrow image.) */
.control-group select,
.inline-form select {
  -webkit-appearance: none;
  appearance: none;
  color-scheme: dark;
  padding-right: 30px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'%3E%3Cpath d='M1 1l4 4 4-4' fill='none' stroke='%2300d9ff' stroke-width='1.5'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 11px center;
}
.control-group select option,
.inline-form select option {
  background: #1a1a3e;
  color: #e8ecff;
}
.form-row {
  display: flex;
  gap: 6px;
}
.form-row > * { flex: 1; min-width: 0; }
.form-actions {
  display: flex;
  gap: 6px;
  margin-top: 4px;
}
.form-actions > * { flex: 1; }
@keyframes formFadeIn {
  from { opacity: 0; transform: translateY(-4px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* Object list */
.object-list {
  background: rgba(0, 0, 0, 0.3);
  border-radius: 8px;
  padding: 6px;
  max-height: 180px;
  overflow-y: auto;
  font-size: 12px;
}
.object-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 5px 8px;
  border-radius: 5px;
  margin-bottom: 2px;
}
.object-row:hover { background: rgba(255, 255, 255, 0.05); }
.object-row .dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  margin-right: 8px;
  display: inline-block;
  vertical-align: middle;
  box-shadow: 0 0 8px currentColor;
}
.object-name {
  flex: 1;
  display: flex;
  align-items: center;
}
.object-del {
  background: transparent;
  border: 0;
  color: rgba(255, 100, 100, 0.6);
  cursor: pointer;
  font-size: 14px;
  padding: 0 4px;
}
.object-del:hover { color: #ff6060; }

/* ---------- Graphs ---------- */
.panel-graphs {
  min-height: 300px;
}
.graphs-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
}
.graph-card {
  background: rgba(0, 0, 0, 0.25);
  border: 1px solid rgba(255, 255, 255, 0.07);
  border-radius: 10px;
  padding: 12px 14px 14px;
  display: flex;
  flex-direction: column;
}
.graph-header {
  margin-bottom: 8px;
}
.graph-header h3 {
  font-size: 13px;
  color: #a88bff;
  letter-spacing: 0.4px;
  text-transform: uppercase;
  margin-bottom: 4px;
}
.equation {
  font-family: 'Cambria Math', 'Times New Roman', serif;
  font-size: 13px;
  color: #00d9ff;
  background: rgba(0, 217, 255, 0.07);
  padding: 4px 8px;
  border-radius: 5px;
  border-left: 2px solid #00d9ff;
}
.graph-canvas {
  width: 100%;
  height: 200px;
  background: #060612;
  border-radius: 6px;
  display: block;
}
.graph-explanation {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.5;
  color: rgba(232, 236, 255, 0.75);
}

/* ---------- Responsive ---------- */
@media (max-width: 1200px) {
  .app-main {
    grid-template-columns: 1fr;
  }
  .panel-space    { grid-column: 1; grid-row: 1; }
  .panel-controls { grid-column: 1; grid-row: 2; max-height: none; }
  .graphs-grid { grid-template-columns: 1fr; }
  .graphs-grid-large { grid-template-columns: 1fr; }
  .graphs-grid-large .graph-card:first-child { grid-column: 1; }
  .graphs-grid-quad { grid-template-columns: 1fr; }
  .fuel-layout {
    grid-template-columns: 1fr;
  }
  .panel-fuel-inputs  { grid-column: 1; grid-row: 1; }
  .panel-fuel-results { grid-column: 1; grid-row: 2; }
  .panel-fuel-chart   { grid-column: 1; grid-row: 3; }
}

/* ---------- Scrollbars ---------- */
*::-webkit-scrollbar { width: 8px; height: 8px; }
*::-webkit-scrollbar-track { background: rgba(255, 255, 255, 0.03); }
*::-webkit-scrollbar-thumb {
  background: rgba(0, 217, 255, 0.25);
  border-radius: 4px;
}
*::-webkit-scrollbar-thumb:hover { background: rgba(0, 217, 255, 0.45); }