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

:root {
  --bg: #0a0a0a;
  --fg: #e8e8e8;
  --accent: #00d4ff;
  --muted: #666;
  --border: #333;
  --success: #00d4ff;
  --fail: #ff6b6b;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f5f5f5;
    --fg: #1a1a1a;
    --muted: #999;
    --border: #ddd;
  }
}

html, body {
  width: 100%;
  height: 100%;
  background-color: var(--bg);
  color: var(--fg);
  font-family: 'Courier New', monospace;
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -webkit-tap-highlight-color: transparent;
}

#app {
  display: flex;
  flex-direction: column;
  height: 100dvh;
  padding: env(safe-area-inset-top) env(safe-area-inset-right) env(safe-area-inset-bottom) env(safe-area-inset-left);
}

#hud {
  flex-shrink: 0;
  height: auto;
  min-height: 60px;
  padding: 12px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  background-color: rgba(0, 0, 0, 0.2);
}

#screen {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
}

#actions {
  flex-shrink: 0;
  padding: 12px;
  border-top: 1px solid var(--border);
  background-color: rgba(0, 0, 0, 0.2);
}

/* Screen padding utility */
.screen {
  padding: 16px;
}

/* Typography utilities */
.readout {
  font-size: 24px;
  font-weight: bold;
  letter-spacing: 2px;
}

.hint {
  font-size: 12px;
  color: var(--muted);
}

.ticker {
  font-size: 12px;
  color: var(--muted);
  font-family: 'Courier New', monospace;
}

/* Lists and rows */
.list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0;
}

.row {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: 48px;
  padding: 12px;
  border-bottom: 1px solid var(--border);
  transition: background-color 0.15s ease;
}

@media (prefers-reduced-motion: reduce) {
  .row {
    transition: none;
  }
}

.row:active {
  background-color: rgba(0, 212, 255, 0.1);
}

.row.owned {
  opacity: 0.6;
}

.row.locked {
  opacity: 0.4;
}

.row.buyable:active {
  background-color: rgba(0, 212, 255, 0.15);
}

/* Gauge and status */
.gauge {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.gauge-bar {
  width: 100%;
  height: 8px;
  background-color: var(--border);
  border-radius: 2px;
  overflow: hidden;
}

.gauge-fill {
  height: 100%;
  background-color: var(--accent);
  transition: width 0.2s ease;
}

@media (prefers-reduced-motion: reduce) {
  .gauge-fill {
    transition: none;
  }
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 12px 16px;
  border: none;
  border-radius: 4px;
  font-family: 'Courier New', monospace;
  font-size: 14px;
  cursor: pointer;
  transition: background-color 0.15s ease, color 0.15s ease;
  -webkit-tap-highlight-color: transparent;
}

@media (prefers-reduced-motion: reduce) {
  .btn {
    transition: none;
  }
}

.btn-primary {
  display: block;
  width: 100%;
  min-height: 56px;
  padding: 16px;
  background-color: var(--accent);
  color: var(--bg);
  font-weight: bold;
  font-size: 16px;
  letter-spacing: 1px;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  transition: background-color 0.15s ease, opacity 0.15s ease;
  -webkit-tap-highlight-color: transparent;
}

@media (prefers-reduced-motion: reduce) {
  .btn-primary {
    transition: none;
  }
}

.btn-primary:active {
  opacity: 0.8;
  background-color: #00a8cc;
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-secondary {
  display: inline-block;
  padding: 10px 14px;
  background-color: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 4px;
  font-size: 14px;
  cursor: pointer;
  transition: background-color 0.15s ease, color 0.15s ease;
  -webkit-tap-highlight-color: transparent;
}

@media (prefers-reduced-motion: reduce) {
  .btn-secondary {
    transition: none;
  }
}

.btn-secondary:active {
  background-color: var(--accent);
  color: var(--bg);
}

/* Tabs */
.tabs {
  display: flex;
  flex-direction: row;
  gap: 0;
  border-bottom: 1px solid var(--border);
}

.tab {
  flex: 1;
  padding: 12px;
  text-align: center;
  border-bottom: 3px solid transparent;
  cursor: pointer;
  transition: border-color 0.15s ease, color 0.15s ease;
  -webkit-tap-highlight-color: transparent;
}

@media (prefers-reduced-motion: reduce) {
  .tab {
    transition: none;
  }
}

.tab.active {
  border-bottom-color: var(--accent);
  color: var(--accent);
  font-weight: bold;
}

/* Canvas */
canvas {
  display: block;
  width: 100%;
  touch-action: none;
}

/* Scrollbar styling (webkit browsers) */
#screen::-webkit-scrollbar {
  width: 8px;
}

#screen::-webkit-scrollbar-track {
  background-color: transparent;
}

#screen::-webkit-scrollbar-thumb {
  background-color: var(--border);
  border-radius: 4px;
}

#screen::-webkit-scrollbar-thumb:active {
  background-color: var(--muted);
}

/* ==========================================================================
   Phase 0 UI layer (js/ui/*). Appended: everything above is the shell's own
   vocabulary — variables, .row, .tabs, .btn* — and is used, not replaced.
   Rules here are the pieces the screens needed on top of it.
   Target: one thumb on a 360x740 portrait viewport, no horizontal scroll.
   ========================================================================== */

/* Nothing may push the layout sideways. */
#app, #screen, #hud, #actions { max-width: 100vw; }
.screen { padding: 0; }
.pad { padding: 16px; }

/* ---- HUD ---------------------------------------------------------------- */

.hud-item {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0;
  min-width: 0;
}

.hud-label {
  font-size: 10px;
  letter-spacing: 1.5px;
  color: var(--muted);
}

.hud-value {
  font-size: 18px;
  font-weight: bold;
  line-height: 1.2;
  letter-spacing: 1px;
}

/* ---- Type --------------------------------------------------------------- */

.title {
  font-size: 18px;
  font-weight: bold;
  letter-spacing: 1px;
  margin-bottom: 4px;
}

.goal-line { margin-bottom: 12px; }
.foot { margin-top: 12px; }
.good { color: var(--accent); }
.bad { color: var(--fail); }
.muted { color: var(--muted); }

/* ---- Rows (contracts + tree nodes) -------------------------------------- */

.row-main {
  flex: 1 1 auto;
  min-width: 0;
  overflow-wrap: anywhere;
}

.row-title {
  font-size: 14px;
  font-weight: bold;
  letter-spacing: 0.5px;
}

/* The side column is a price tag, not a sentence: cap it so a long note can
   never squeeze the row's title down to one character per line. */
.row-side {
  flex: 0 0 auto;
  max-width: 34%;
  text-align: right;
}

.cost { white-space: nowrap; }

.row-note {
  font-size: 10px;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.row-reason {
  margin-top: 3px;
  color: var(--muted);
  font-style: italic;
}

.cost {
  font-size: 15px;
  font-weight: bold;
  color: var(--accent);
}

.row.owned .cost { color: var(--muted); }
.row-desc { margin-top: 2px; }
.row-effects { margin-top: 2px; color: var(--accent); opacity: 0.8; }
.row.locked .row-effects { color: var(--muted); opacity: 1; }

.row.selected {
  background-color: rgba(0, 212, 255, 0.08);
  box-shadow: inset 3px 0 0 var(--accent);
}

.row.contract, .row.node {
  align-items: flex-start;
  cursor: pointer;
}

.tag {
  font-size: 10px;
  letter-spacing: 1px;
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 0 4px;
  color: var(--muted);
  vertical-align: middle;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-4px); }
  75% { transform: translateX(4px); }
}

.row.shake { animation: shake 0.3s ease; }

@media (prefers-reduced-motion: reduce) {
  .row.shake { animation: none; }
}

/* ---- Stat blocks -------------------------------------------------------- */

.stats {
  margin: 14px 0;
  border-top: 1px solid var(--border);
}

.stats > div {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  padding: 7px 0;
  border-bottom: 1px solid var(--border);
}

.stats dt {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 1px;
}

.stats dd {
  font-size: 15px;
  font-weight: bold;
  text-align: right;
}

/* ---- Delta-v gauge ------------------------------------------------------ */

.gauge { margin: 14px 0; }
.gauge-fill.short { background-color: var(--fail); }

/* ---- Loadout slider ----------------------------------------------------- */

.field { margin-top: 20px; }

.field-label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: 12px;
  letter-spacing: 1px;
  color: var(--muted);
  margin-bottom: 4px;
}

.field-value {
  font-size: 18px;
  font-weight: bold;
  color: var(--accent);
  letter-spacing: 1px;
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 44px; /* thumb target, not track height */
  background: transparent;
  cursor: pointer;
}

input[type="range"]::-webkit-slider-runnable-track {
  height: 4px;
  background: var(--border);
  border-radius: 2px;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 28px;
  height: 28px;
  margin-top: -12px;
  border-radius: 50%;
  background: var(--accent);
  border: none;
}

input[type="range"]::-moz-range-track {
  height: 4px;
  background: var(--border);
  border-radius: 2px;
}

input[type="range"]::-moz-range-thumb {
  width: 28px;
  height: 28px;
  border: none;
  border-radius: 50%;
  background: var(--accent);
}

/* ---- Launch ------------------------------------------------------------- */

.ascent-wrap {
  width: 100%;
  aspect-ratio: 3 / 4;
  /* Clamped so the ticker underneath is on screen without scrolling on a
     360x740 phone; the renderer reads the box it actually gets. */
  max-height: 58vh;
  background-color: #05060a;
  border-bottom: 1px solid var(--border);
}

#ascent {
  width: 100%;
  height: 100%;
  cursor: pointer;
}

ul.ticker {
  list-style: none;
  max-height: 128px;
  overflow-y: auto;
  overflow-x: hidden;
  margin-bottom: 8px;
}

.tick {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  padding: 1px 0;
}

.tick.failure { color: var(--fail); }
.tick.goal, .tick.liftoff { color: var(--accent); }

/* ---- Result / win ------------------------------------------------------- */

.readout {
  margin: 10px 0;
  font-size: 20px;
  letter-spacing: 1px;
  overflow-wrap: anywhere;
}

.readout.success { color: var(--accent); }
.readout.failure { color: var(--fail); }

.points {
  margin: 4px 0;
  padding-left: 10px;
  border-left: 2px solid var(--accent);
}

.ledger {
  display: flex;
  gap: 16px;
  font-size: 15px;
  font-weight: bold;
  margin-bottom: 8px;
}

.win-pad { padding-top: 32px; }

/* ---- Tree --------------------------------------------------------------- */

.branch { margin-bottom: 20px; }

.branch-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: 12px;
  font-weight: bold;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent);
  padding: 8px 0 4px;
  border-bottom: 1px solid var(--accent);
}

/* ---- Actions ------------------------------------------------------------ */

.actions-row {
  display: flex;
  gap: 10px;
  align-items: stretch;
}

.actions-row .btn-primary {
  width: auto;
  flex: 1 1 auto;
  min-width: 0;
}

.actions-row .btn-secondary {
  flex: 0 0 auto;
  min-height: 56px;
}

/* ---- Corrupt-save notice ------------------------------------------------ */

[data-screen="notice"] .btn-primary { margin-top: 16px; }

.notice-msg {
  margin: 8px 0 12px;
  color: var(--fail);
  overflow-wrap: anywhere;
}

/* Light scheme: the shared --accent is a bright cyan, and the shell paints
   .btn-primary's label with --bg, which is near-white there. Darken just the
   label so the primary action stays legible without touching the variable. */
@media (prefers-color-scheme: light) {
  .btn-primary { color: #052a35; }
  .btn-primary:active { background-color: #00b8e0; }
}