:root {
  --sky-top: #5b9bd4;
  --sky-mid: #8ec5e8;
  --sky-bot: #c5e4f5;
  --apron: #3d4654;
  --apron-deep: #2c3340;
  --tarmac: #4a5564;
  --line: rgba(255, 255, 255, 0.22);
  --runway: #232830;
  --runway-paint: #f4e8c1;
  --panel: rgba(20, 28, 38, 0.72);
  --text: #f2f6fa;
  --muted: #a8b4c2;
  --accent: #f0a202;
  --accent-deep: #d48900;
  --good: #3ecf8e;
  --land: #4ea8d8;
  --depart: #3ecf8e;
  --shadow: 0 18px 40px rgba(12, 20, 32, 0.35);
  --font-display: "Bebas Neue", sans-serif;
  --font-body: "DM Sans", sans-serif;
}

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

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--sky-bot);
  overflow-x: hidden;
}

.sky {
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 15% 12%, rgba(255, 255, 255, 0.45), transparent 55%),
    radial-gradient(ellipse 60% 40% at 78% 18%, rgba(255, 255, 255, 0.28), transparent 50%),
    linear-gradient(180deg, var(--sky-top) 0%, var(--sky-mid) 42%, var(--sky-bot) 100%);
  z-index: -1;
}

.app {
  max-width: 540px;
  margin: 0 auto;
  padding: 1.25rem 1rem 2rem;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.top-bar {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1rem;
}

.brand-block {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  min-width: 0;
}

.brand {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 8vw, 3rem);
  letter-spacing: 0.04em;
  line-height: 0.9;
  text-shadow: 0 2px 0 rgba(20, 40, 70, 0.15);
}

.airport-title {
  margin: 0;
  font-size: 0.82rem;
  font-weight: 700;
  color: #27405c;
  letter-spacing: 0.02em;
}

.airport-switcher {
  display: flex;
  gap: 0.4rem;
  overflow-x: auto;
  padding-bottom: 0.15rem;
  -webkit-overflow-scrolling: touch;
}

.airport-chip {
  flex: 0 0 auto;
  border: 1px solid rgba(20, 40, 70, 0.12);
  background: rgba(255, 255, 255, 0.55);
  color: #1d2f44;
  border-radius: 999px;
  padding: 0.45rem 0.75rem;
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease;
}

.airport-chip:hover:not(:disabled) {
  transform: translateY(-1px);
}

.airport-chip.completed {
  border-color: rgba(62, 207, 142, 0.55);
  background: rgba(62, 207, 142, 0.2);
}

.airport-chip.completed.active {
  background: rgba(20, 28, 38, 0.88);
  border-color: transparent;
}

.airport-chip:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.stats {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.stat {
  min-width: 4.6rem;
  padding: 0.45rem 0.7rem;
  background: var(--panel);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 12px;
  backdrop-filter: blur(10px);
  text-align: right;
}

.stat-label {
  display: block;
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.stat-value {
  display: block;
  font-family: var(--font-display);
  font-size: 1.55rem;
  letter-spacing: 0.03em;
  line-height: 1;
  color: var(--accent);
}

.apron {
  position: relative;
  display: grid;
  gap: 0.55rem;
  aspect-ratio: 4 / 5;
  margin: 0.25rem 0;
  padding: 0.7rem 0.65rem;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.04) 25%, transparent 25%),
    linear-gradient(225deg, rgba(255, 255, 255, 0.04) 25%, transparent 25%),
    linear-gradient(45deg, rgba(255, 255, 255, 0.04) 25%, transparent 25%),
    linear-gradient(315deg, rgba(255, 255, 255, 0.04) 25%, transparent 25%),
    linear-gradient(160deg, var(--tarmac), var(--apron-deep));
  background-size: 18px 18px, 18px 18px, 18px 18px, 18px 18px, auto;
  background-position: 0 0, 0 9px, 9px -9px, -9px 0, 0 0;
  border-radius: 22px;
  box-shadow: var(--shadow), inset 0 0 0 2px rgba(255, 255, 255, 0.08);
  overflow: hidden;
}

.apron.layout-single {
  grid-template-rows: 1fr auto;
}

.apron.layout-dual {
  grid-template-rows: auto 1fr auto;
}

.apron.layout-side {
  grid-template-columns: auto 1fr;
  grid-template-rows: 1fr;
  aspect-ratio: 5 / 4;
}

.apron.layout-cross {
  grid-template-columns: 1fr auto;
  grid-template-rows: auto 1fr;
  aspect-ratio: 5 / 4;
}

.apron.layout-cross .runway-landing {
  grid-column: 1 / 2;
  grid-row: 1;
}

.apron.layout-cross .terminal {
  grid-column: 1 / 2;
  grid-row: 2;
}

.apron.layout-cross .runway-takeoff {
  grid-column: 2 / 3;
  grid-row: 1 / 3;
}

.runway {
  position: relative;
  z-index: 1;
  transition: filter 0.25s ease, transform 0.25s ease;
}

.runway.active .runway-surface {
  box-shadow:
    0 0 0 2px rgba(244, 232, 193, 0.45),
    0 0 28px rgba(240, 162, 2, 0.35);
}

.runway-landing.active .runway-surface {
  box-shadow:
    0 0 0 2px rgba(78, 168, 216, 0.55),
    0 0 28px rgba(78, 168, 216, 0.4);
}

.runway-takeoff.active .runway-surface {
  box-shadow:
    0 0 0 2px rgba(62, 207, 142, 0.55),
    0 0 28px rgba(62, 207, 142, 0.4);
}

.runway-surface {
  position: relative;
  height: clamp(58px, 14vw, 74px);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.05), transparent 35%),
    repeating-linear-gradient(
      90deg,
      #1d2229 0 34px,
      #252b34 34px 36px
    );
  border: 2px solid #161a20;
  border-radius: 10px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 0.55rem;
}

.runway-centerline {
  position: absolute;
  left: 12%;
  right: 12%;
  top: 50%;
  height: 3px;
  transform: translateY(-50%);
  background: repeating-linear-gradient(
    90deg,
    var(--runway-paint) 0 18px,
    transparent 18px 30px
  );
  opacity: 0.9;
  pointer-events: none;
}

.runway-threshold {
  position: absolute;
  top: 18%;
  bottom: 18%;
  width: 28px;
  background: repeating-linear-gradient(
    90deg,
    var(--runway-paint) 0 3px,
    transparent 3px 6px
  );
  opacity: 0.75;
  pointer-events: none;
}

.runway-threshold-start {
  left: 11%;
}

.runway-threshold-end {
  right: 11%;
}

.runway-num {
  position: relative;
  z-index: 1;
  font-family: var(--font-display);
  font-size: 1.35rem;
  letter-spacing: 0.08em;
  color: var(--runway-paint);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.55);
  line-height: 1;
}

.runway-badge {
  position: absolute;
  top: -0.55rem;
  left: 0.75rem;
  padding: 0.18rem 0.55rem;
  border-radius: 999px;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  z-index: 2;
}

.badge-land {
  background: rgba(78, 168, 216, 0.95);
  color: #062033;
}

.badge-depart {
  background: rgba(62, 207, 142, 0.95);
  color: #062617;
}

.runway-surface.vertical {
  height: auto;
  width: clamp(58px, 14vw, 74px);
  min-height: 100%;
  flex-direction: column;
  padding: 0.55rem 0;
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.05), transparent 35%),
    repeating-linear-gradient(
      180deg,
      #1d2229 0 34px,
      #252b34 34px 36px
    );
}

.runway-surface.vertical .runway-centerline {
  left: 50%;
  right: auto;
  top: 12%;
  bottom: 12%;
  width: 3px;
  height: auto;
  transform: translateX(-50%);
  background: repeating-linear-gradient(
    180deg,
    var(--runway-paint) 0 18px,
    transparent 18px 30px
  );
}

.runway-surface.vertical .runway-threshold {
  left: 18%;
  right: 18%;
  width: auto;
  height: 28px;
  background: repeating-linear-gradient(
    180deg,
    var(--runway-paint) 0 3px,
    transparent 3px 6px
  );
}

.runway-surface.vertical .runway-threshold-start {
  top: 11%;
  bottom: auto;
  left: 18%;
  right: 18%;
}

.runway-surface.vertical .runway-threshold-end {
  bottom: 11%;
  top: auto;
  left: 18%;
  right: 18%;
}

.runway-shared.active .runway-surface {
  box-shadow:
    0 0 0 2px rgba(240, 162, 2, 0.55),
    0 0 28px rgba(240, 162, 2, 0.35);
}

.badge-shared {
  background: rgba(240, 162, 2, 0.95);
  color: #2a1c00;
}

.terminal {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-rows: 1fr;
  gap: 0;
  min-height: 0;
}

.apron-stands {
  display: grid;
  grid-template-columns: 14px minmax(0, 1fr) 14px;
  gap: 0.4rem;
  min-height: 0;
  height: 100%;
  align-items: stretch;
}

.side-taxi {
  border-radius: 5px;
  background:
    repeating-linear-gradient(
      180deg,
      rgba(244, 232, 193, 0.7) 0 7px,
      transparent 7px 14px
    ),
    #2a303a;
  opacity: 0.9;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.08);
}

.apron.layout-side .apron-stands {
  grid-template-columns: 1fr;
  grid-template-rows: 12px minmax(0, 1fr) 12px;
}

.apron.layout-side .side-taxi-l {
  grid-row: 1;
  background:
    repeating-linear-gradient(
      90deg,
      rgba(244, 232, 193, 0.7) 0 7px,
      transparent 7px 14px
    ),
    #2a303a;
}

.apron.layout-side .grid {
  grid-row: 2;
}

.apron.layout-side .side-taxi-r {
  grid-row: 3;
  background:
    repeating-linear-gradient(
      90deg,
      rgba(244, 232, 193, 0.7) 0 7px,
      transparent 7px 14px
    ),
    #2a303a;
}

.grid {
  display: grid;
  gap: 0.4rem;
  min-height: 0;
  height: 100%;
  width: 100%;
}

.cell.inactive {
  visibility: hidden;
  pointer-events: none;
  border: none;
  background: transparent;
}

.flight-layer {
  position: absolute;
  inset: 0;
  z-index: 5;
  pointer-events: none;
  overflow: visible;
}

.cell {
  position: relative;
  background: rgba(0, 0, 0, 0.22);
  border: 1.5px dashed var(--line);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s ease, border-color 0.2s ease;
  min-height: 0;
  overflow: visible;
  padding: 0.2rem;
}

.cell.drop-target {
  background: rgba(240, 162, 2, 0.18);
  border-color: var(--accent);
  border-style: solid;
}

.cell.merge-ok {
  background: rgba(62, 207, 142, 0.2);
  border-color: var(--good);
  border-style: solid;
}

.cell.reserved {
  border-style: solid;
  border-color: rgba(78, 168, 216, 0.65);
  background: rgba(78, 168, 216, 0.14);
}

.plane,
.flight-plane {
  position: relative;
  width: 100%;
  height: 100%;
  max-width: 100%;
  max-height: 100%;
  aspect-ratio: auto;
  border: none;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.45rem 0.3rem 0.9rem;
  color: #141c28;
  font-family: var(--font-display);
  box-shadow:
    0 8px 16px rgba(0, 0, 0, 0.28),
    inset 0 1px 0 rgba(255, 255, 255, 0.35);
  user-select: none;
  -webkit-user-select: none;
  overflow: visible;
}

.plane-art {
  width: auto;
  height: auto;
  max-width: 92%;
  max-height: 88%;
  aspect-ratio: 4 / 5;
  display: block;
  flex: 0 1 auto;
  filter: drop-shadow(0 2px 2px rgba(0, 0, 0, 0.2));
  transform-origin: center;
  overflow: visible;
}

.plane-art .fuse,
.plane-art .nose,
.plane-art .fuse-tail,
.plane-art .deck {
  fill: #f4f7fb;
  stroke: rgba(20, 28, 40, 0.35);
  stroke-width: 0.8;
}

.plane-art .deck {
  fill: rgba(255, 255, 255, 0.55);
}

.plane-art .wing,
.plane-art .tail,
.plane-art .fin {
  fill: #d9e3ef;
  stroke: rgba(20, 28, 40, 0.3);
  stroke-width: 0.7;
}

.plane-art .fin {
  fill: #c5d0dd;
}

.plane-art .wing-edge {
  fill: rgba(255, 255, 255, 0.35);
}

.plane-art .cockpit {
  fill: #2a6f9a;
  stroke: rgba(10, 30, 50, 0.35);
  stroke-width: 0.5;
}

.plane-art .eng {
  fill: #4a5564;
  stroke: rgba(0, 0, 0, 0.25);
  stroke-width: 0.5;
}

.plane-art .intake {
  fill: #1b222c;
}

.plane-art .window,
.plane-art .door {
  fill: #1d4f6e;
  opacity: 0.85;
}

.plane-art .prop line {
  stroke: #2c3340;
  stroke-width: 1.6;
  stroke-linecap: round;
}

.plane-art .prop circle {
  fill: #f0a202;
  stroke: #2c3340;
  stroke-width: 0.6;
}

.plane-art .spinning {
  transform-box: view-box;
  animation: prop-spin 0.55s linear infinite;
}

.plane-airline {
  position: absolute;
  left: 50%;
  top: 0.2rem;
  transform: translateX(-50%);
  max-width: 72%;
  font-family: var(--font-body);
  font-size: clamp(0.42rem, 1.7vw, 0.58rem);
  font-weight: 700;
  letter-spacing: 0.01em;
  line-height: 1.1;
  padding: 0.08rem 0.28rem;
  border-radius: 999px;
  background: rgba(20, 28, 40, 0.72);
  color: #fff;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  pointer-events: none;
  z-index: 2;
}

.plane-form {
  position: absolute;
  left: 0.28rem;
  bottom: 0.22rem;
  max-width: 48%;
  font-family: var(--font-body);
  font-size: clamp(0.42rem, 1.7vw, 0.55rem);
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.1;
  padding: 0.08rem 0.24rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.78);
  color: #1d2f44;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  pointer-events: none;
}

.flight-plane .plane-form {
  font-size: clamp(0.42rem, 1.8vw, 0.55rem);
}

.plane {
  cursor: grab;
  transition: transform 0.18s ease, box-shadow 0.18s ease;
  touch-action: none;
  max-height: 94%;
}

.plane:active {
  cursor: grabbing;
}

.plane.selected {
  transform: scale(1.06);
  box-shadow:
    0 0 0 3px rgba(240, 162, 2, 0.85),
    0 10px 20px rgba(0, 0, 0, 0.35);
}

.plane.dragging {
  opacity: 0.55;
  transform: scale(0.96);
}

.flight-plane {
  position: absolute;
  width: 14%;
  height: auto;
  max-height: none;
  aspect-ratio: 4 / 5;
  margin: 0;
  z-index: 6;
  will-change: transform, left, top, opacity, filter;
  filter: drop-shadow(0 10px 12px rgba(0, 0, 0, 0.35));
  overflow: visible;
}

.flight-plane.airborne {
  filter: drop-shadow(0 18px 16px rgba(0, 0, 0, 0.28));
}

.plane-flag-wrap {
  position: absolute;
  right: 0.28rem;
  top: 0.22rem;
  width: clamp(0.95rem, 22%, 1.35rem);
  line-height: 0;
  border-radius: 2px;
  overflow: hidden;
  box-shadow:
    0 1px 2px rgba(0, 0, 0, 0.35),
    0 0 0 1px rgba(255, 255, 255, 0.4);
  pointer-events: none;
  z-index: 2;
}

.plane-flag {
  width: 100%;
  height: auto;
  display: block;
  aspect-ratio: 3 / 2;
}

.plane-level {
  position: absolute;
  right: 0.28rem;
  bottom: 0.18rem;
  font-size: clamp(0.75rem, 3vw, 1rem);
  letter-spacing: 0.04em;
  line-height: 1;
  padding: 0.12rem 0.28rem;
  border-radius: 999px;
  background: rgba(20, 28, 40, 0.72);
  color: #fff;
  pointer-events: none;
}

.flight-plane .plane-level {
  font-size: clamp(0.7rem, 2.8vw, 0.9rem);
  right: 0.2rem;
  bottom: 0.12rem;
}

/* Level-tinted airframes */
.lvl-1 .plane-art .fuse,
.lvl-1 .plane-art .nose,
.lvl-1 .plane-art .fuse-tail,
.lvl-1 .plane-art .deck { fill: #eef3f8; }
.lvl-1 .plane-art .wing,
.lvl-1 .plane-art .tail,
.lvl-1 .plane-art .fin { fill: #b7c7d8; }

.lvl-2 .plane-art .fuse,
.lvl-2 .plane-art .nose,
.lvl-2 .plane-art .fuse-tail,
.lvl-2 .plane-art .deck { fill: #e8f6fc; }
.lvl-2 .plane-art .wing,
.lvl-2 .plane-art .tail,
.lvl-2 .plane-art .fin { fill: #7ec3df; }

.lvl-3 .plane-art .fuse,
.lvl-3 .plane-art .nose,
.lvl-3 .plane-art .fuse-tail,
.lvl-3 .plane-art .deck { fill: #e7faf4; }
.lvl-3 .plane-art .wing,
.lvl-3 .plane-art .tail,
.lvl-3 .plane-art .fin { fill: #63c3ab; }

.lvl-4 .plane-art .fuse,
.lvl-4 .plane-art .nose,
.lvl-4 .plane-art .fuse-tail,
.lvl-4 .plane-art .deck { fill: #f3f9e6; }
.lvl-4 .plane-art .wing,
.lvl-4 .plane-art .tail,
.lvl-4 .plane-art .fin { fill: #9bc455; }

.lvl-5 .plane-art .fuse,
.lvl-5 .plane-art .nose,
.lvl-5 .plane-art .fuse-tail,
.lvl-5 .plane-art .deck { fill: #fff8dc; }
.lvl-5 .plane-art .wing,
.lvl-5 .plane-art .tail,
.lvl-5 .plane-art .fin { fill: #e0bc3a; }

.lvl-6 .plane-art .fuse,
.lvl-6 .plane-art .nose,
.lvl-6 .plane-art .fuse-tail,
.lvl-6 .plane-art .deck { fill: #fff0df; }
.lvl-6 .plane-art .wing,
.lvl-6 .plane-art .tail,
.lvl-6 .plane-art .fin { fill: #e89840; }

.lvl-7 .plane-art .fuse,
.lvl-7 .plane-art .nose,
.lvl-7 .plane-art .fuse-tail,
.lvl-7 .plane-art .deck { fill: #ffe8e3; }
.lvl-7 .plane-art .wing,
.lvl-7 .plane-art .tail,
.lvl-7 .plane-art .fin { fill: #db6a58; }

.lvl-8 .plane-art .fuse,
.lvl-8 .plane-art .nose,
.lvl-8 .plane-art .fuse-tail,
.lvl-8 .plane-art .deck { fill: #fbeaf8; }
.lvl-8 .plane-art .wing,
.lvl-8 .plane-art .tail,
.lvl-8 .plane-art .fin { fill: #c068b4; }

.lvl-9 .plane-art .fuse,
.lvl-9 .plane-art .nose,
.lvl-9 .plane-art .fuse-tail,
.lvl-9 .plane-art .deck { fill: #eee8ff; }
.lvl-9 .plane-art .wing,
.lvl-9 .plane-art .tail,
.lvl-9 .plane-art .fin { fill: #8772d8; }

.lvl-10 .plane-art .fuse,
.lvl-10 .plane-art .nose,
.lvl-10 .plane-art .fuse-tail,
.lvl-10 .plane-art .deck { fill: #fff6cc; }
.lvl-10 .plane-art .wing,
.lvl-10 .plane-art .tail,
.lvl-10 .plane-art .fin { fill: #f0a202; }
.lvl-10 .plane-art .cockpit { fill: #8a5a00; }

.plane.lvl-1,
.flight-plane.lvl-1 { background: linear-gradient(145deg, #d7e3ef, #9fb4c9); }
.plane.lvl-2,
.flight-plane.lvl-2 { background: linear-gradient(145deg, #bfe3f2, #6eb8d8); }
.plane.lvl-3,
.flight-plane.lvl-3 { background: linear-gradient(145deg, #9fd9c8, #4faf96); }
.plane.lvl-4,
.flight-plane.lvl-4 { background: linear-gradient(145deg, #c9e09a, #89b84a); }
.plane.lvl-5,
.flight-plane.lvl-5 { background: linear-gradient(145deg, #f2e08a, #d4b132); }
.plane.lvl-6,
.flight-plane.lvl-6 { background: linear-gradient(145deg, #f5c78a, #e08a2f); }
.plane.lvl-7,
.flight-plane.lvl-7 { background: linear-gradient(145deg, #f0a898, #d45d4a); }
.plane.lvl-8,
.flight-plane.lvl-8 { background: linear-gradient(145deg, #e0a8d8, #b85aab); }
.plane.lvl-9,
.flight-plane.lvl-9 { background: linear-gradient(145deg, #c2b4f0, #7d68d4); }
.plane.lvl-10,
.flight-plane.lvl-10 {
  background: linear-gradient(145deg, #f8e7a0, #f0a202 55%, #ffd56a);
  color: #2a1c00;
}

.hint {
  margin: 0;
  text-align: center;
  color: #27405c;
  font-size: 0.92rem;
  font-weight: 500;
}

.controls {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.65rem;
}

.btn {
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 700;
  border: none;
  border-radius: 14px;
  padding: 0.85rem 0.9rem;
  cursor: pointer;
  transition: transform 0.15s ease, filter 0.15s ease, background 0.15s ease;
}

.btn:hover:not(:disabled) {
  transform: translateY(-1px);
}

.btn:active:not(:disabled) {
  transform: translateY(1px);
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.btn-primary {
  background: linear-gradient(180deg, #ffc23a, var(--accent));
  color: #2a1c00;
  box-shadow: 0 8px 0 var(--accent-deep);
}

.btn-primary:active:not(:disabled) {
  box-shadow: 0 3px 0 var(--accent-deep);
}

.btn-launch {
  background: linear-gradient(180deg, #5fd4a0, #2fb87a);
  color: #062617;
  box-shadow: 0 8px 0 #1f8a5a;
}

.btn-launch:active:not(:disabled) {
  box-shadow: 0 3px 0 #1f8a5a;
}

.btn-secondary {
  background: rgba(20, 28, 38, 0.78);
  color: var(--text);
  border: 1px solid rgba(255, 255, 255, 0.16);
}

.btn-upgrade {
  background: linear-gradient(180deg, #7ec8ef, #3a8fbe);
  color: #062033;
  box-shadow: 0 8px 0 #2a6f96;
}

.btn-upgrade:active:not(:disabled) {
  box-shadow: 0 3px 0 #2a6f96;
}

.btn-upgrade.owned {
  background: rgba(20, 28, 38, 0.55);
  color: var(--muted);
  box-shadow: none;
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 1.25rem;
  transform: translateX(-50%) translateY(12px);
  margin: 0;
  padding: 0.7rem 1rem;
  background: rgba(20, 28, 38, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 999px;
  font-size: 0.88rem;
  font-weight: 500;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
  z-index: 20;
  white-space: nowrap;
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

@keyframes merge-pop {
  0% { transform: scale(0.72) rotate(-6deg); }
  45% { transform: scale(1.16) rotate(3deg); }
  100% { transform: scale(1) rotate(0deg); }
}

@keyframes evolve-flash {
  0% {
    filter: drop-shadow(0 0 0 rgba(240, 162, 2, 0)) brightness(1);
    transform: scale(0.85);
  }
  40% {
    filter: drop-shadow(0 0 12px rgba(240, 162, 2, 0.9)) brightness(1.35);
    transform: scale(1.12);
  }
  100% {
    filter: drop-shadow(0 2px 2px rgba(0, 0, 0, 0.2)) brightness(1);
    transform: scale(1);
  }
}

@keyframes prop-spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.plane.merged {
  animation: merge-pop 0.45s cubic-bezier(0.2, 0.9, 0.3, 1.15);
}

.plane.evolving .plane-art.evolve-flash {
  animation: evolve-flash 0.55s ease;
}

@media (max-width: 420px) {
  .controls {
    grid-template-columns: 1fr;
  }

  .top-bar {
    flex-direction: column;
    align-items: stretch;
  }

  .stats {
    justify-content: flex-end;
    flex-wrap: wrap;
  }

  .apron {
    aspect-ratio: 3 / 4;
  }
}