/* ============================================================
   LEY·LINES — HUD stylesheet  v2
   All HUD panels, toasts, abilities bar, chain indicator,
   sandbox panel, and animation tokens.
   Depends on CSS custom properties defined in styles.css (:root).
   ============================================================ */

/* ---- Shared glass tokens ---- */
:root {
  --glass-bg:        rgba(10, 7, 18, 0.72);
  --glass-bg-light:  rgba(14, 10, 28, 0.60);
  --glass-border:    1px solid rgba(233, 196, 106, 0.18);
  --glass-border-hi: 1px solid rgba(233, 196, 106, 0.40);
  --glass-blur:      blur(14px) saturate(1.4);
  --glass-glow:      0 0 28px rgba(123, 108, 246, 0.12), 0 2px 12px rgba(0,0,0,0.55);
  --radius-panel:    12px;
  --radius-btn:      8px;
  --trans-fast:      150ms ease-out;
  --trans-med:       220ms ease-out;
}

/* ================================================================
   WRAPPER
   ================================================================ */
#hud {
  position: absolute;
  inset: 0;
  pointer-events: none;
  display: grid;
  grid-template-rows: auto 1fr auto;
  grid-template-columns: auto 1fr auto;
  gap: 0;
  font-family: var(--font-body);
  color: var(--ink);
}

/* ================================================================
   SHARED: glass panel
   ================================================================ */
.hud-panel {
  background: var(--glass-bg);
  border: var(--glass-border);
  border-radius: var(--radius-panel);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  box-shadow: var(--glass-glow);
  position: relative;
  overflow: hidden;
}

.hud-panel::before {
  content: '';
  position: absolute;
  inset: 0;
  top: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(233,196,106,0.35), transparent);
  pointer-events: none;
}

/* Universal hidden helper */
.is-hidden { display: none !important; }

/* ================================================================
   TOP BAR
   ================================================================ */
#hud-top {
  grid-column: 1 / -1;
  grid-row: 1;
  pointer-events: none;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 10px 14px 0;
  gap: 10px;
}

.hud-top-inner {
  display: flex;
  gap: 10px;
  align-items: stretch;
  flex-wrap: wrap;
  justify-content: center;
}

/* Individual stat chips */
.hud-stat {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 16px 7px 12px;
  min-width: 110px;
}

.hud-stat__glyph {
  font-size: 1.05rem;
  line-height: 1;
  flex-shrink: 0;
  filter: drop-shadow(0 0 6px currentColor);
}

.hud-stat__body {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.hud-stat__label {
  font-family: var(--font-body);
  font-size: 0.62rem;
  font-variant: small-caps;
  letter-spacing: 0.16em;
  color: var(--ink-dim);
  text-transform: uppercase;
  line-height: 1;
}

.hud-stat__value {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(0.95rem, 2vw, 1.15rem);
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--ink);
  transition: color var(--trans-fast);
  font-variant-numeric: tabular-nums;
}

/* Essence */
.hud-stat--essence .hud-stat__glyph { color: var(--gold); }
.hud-stat--essence .hud-stat__value { color: var(--gold); text-shadow: 0 0 10px rgba(233,196,106,0.5); }

/* Integrity: pulses red when low */
.hud-stat--integrity .hud-stat__glyph { color: var(--danger); }
.hud-stat--integrity .hud-stat__value { color: var(--ink); }
.hud-stat--integrity.is-critical .hud-stat__glyph,
.hud-stat--integrity.is-critical .hud-stat__value {
  color: var(--danger);
  animation: hud-pulse-danger 1.1s ease-in-out infinite;
}

@keyframes hud-pulse-danger {
  0%, 100% { opacity: 1; text-shadow: 0 0 8px rgba(255,84,112,0.6); }
  50%       { opacity: 0.65; text-shadow: 0 0 18px rgba(255,84,112,0.9); }
}

/* Wave chip */
.hud-stat--wave .hud-stat__glyph { color: var(--arcane); }
.hud-stat--wave .hud-stat__value { color: var(--arcane-bright, #b3a7ff); }

/* Score chip */
.hud-stat--score .hud-stat__glyph { color: var(--gold); }
.hud-stat__value--score {
  font-family: var(--font-display);
  color: var(--gold);
  text-shadow: 0 0 10px rgba(233,196,106,0.4);
}

/* Essence count-up flash */
@keyframes hud-essence-bump {
  0%   { transform: scale(1.0); color: var(--gold); }
  35%  { transform: scale(1.18); color: #ffe7a8; text-shadow: 0 0 18px rgba(255,231,168,0.9); }
  100% { transform: scale(1.0); color: var(--gold); }
}
.hud-stat__value.is-bumping {
  animation: hud-essence-bump 0.4s ease-out forwards;
}

/* ================================================================
   LEFT: SELECTED TOWER PANEL
   ================================================================ */
#hud-selected {
  grid-column: 1;
  grid-row: 2;
  pointer-events: auto;
  align-self: center;
  margin: 10px 0 10px 12px;
  width: clamp(200px, 22vw, 260px);
}

.sel-header {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 12px 8px;
  border-bottom: 1px solid rgba(233,196,106,0.12);
}

.sel-element-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 4px;
  box-shadow: 0 0 8px currentColor;
}

.sel-title-block { flex: 1; min-width: 0; }

.sel-name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.92rem;
  letter-spacing: 0.06em;
  color: var(--ink);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sel-role {
  font-size: 0.62rem;
  font-variant: small-caps;
  letter-spacing: 0.14em;
  color: var(--ink-dim);
  margin-top: 2px;
}

.sel-close {
  background: none;
  border: none;
  color: var(--ink-dim);
  cursor: pointer;
  font-size: 1.1rem;
  line-height: 1;
  padding: 2px 4px;
  border-radius: 4px;
  pointer-events: auto;
  transition: color var(--trans-fast), background var(--trans-fast);
}
.sel-close:hover { color: var(--ink); background: rgba(255,84,112,0.15); }

/* Level pips */
.sel-level {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
}
.sel-level__label {
  font-size: 0.62rem;
  font-variant: small-caps;
  letter-spacing: 0.14em;
  color: var(--ink-dim);
}
.sel-pips { display: flex; gap: 4px; }
.sel-pip {
  width: 16px;
  height: 5px;
  border-radius: 3px;
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.1);
  transition: background var(--trans-fast), border-color var(--trans-fast), box-shadow var(--trans-fast);
}
.sel-pip.is-active {
  background: var(--pip-color, var(--gold));
  border-color: var(--pip-color, var(--gold));
  box-shadow: 0 0 6px var(--pip-color, var(--gold));
}

/* Stats grid */
.sel-stats {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 1px;
  padding: 0 12px 8px;
}
.sel-stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 6px 4px;
}
.sel-stat__label {
  font-size: 0.58rem;
  font-variant: small-caps;
  letter-spacing: 0.12em;
  color: var(--ink-dim);
}
.sel-stat__val {
  font-family: var(--font-display);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

/* Targeting row */
.sel-targeting {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 12px 8px;
}
.sel-targeting__label {
  font-size: 0.62rem;
  font-variant: small-caps;
  letter-spacing: 0.13em;
  color: var(--ink-dim);
  flex-shrink: 0;
}

/* Action buttons */
.sel-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  padding: 0 10px 10px;
}

.sel-actions .hud-btn-full,
.hud-btn-full {
  grid-column: 1 / -1;
}

/* ================================================================
   SHARED BUTTON STYLES
   ================================================================ */
.hud-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  padding: 7px 10px;
  border-radius: var(--radius-btn);
  border: 1px solid rgba(233,196,106,0.2);
  background: rgba(233,196,106,0.07);
  color: var(--ink);
  cursor: pointer;
  pointer-events: auto;
  transition: background var(--trans-fast), border-color var(--trans-fast), box-shadow var(--trans-fast), transform var(--trans-fast);
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}

.hud-btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255,255,255,0);
  transition: background var(--trans-fast);
}
.hud-btn:hover::after { background: rgba(255,255,255,0.04); }
.hud-btn:active { transform: scale(0.96); }

.hud-btn:hover:not(:disabled) {
  border-color: rgba(233,196,106,0.45);
  box-shadow: 0 0 14px rgba(233,196,106,0.2);
}

.hud-btn:disabled {
  opacity: 0.38;
  cursor: not-allowed;
  pointer-events: none;
}

/* Upgrade — gold accent */
.hud-btn--upgrade {
  border-color: rgba(233,196,106,0.35);
  background: rgba(233,196,106,0.1);
  color: var(--gold);
}
.hud-btn--upgrade:hover:not(:disabled) {
  background: rgba(233,196,106,0.2);
  box-shadow: 0 0 18px rgba(233,196,106,0.35);
}
.hud-btn--upgrade.is-unaffordable {
  opacity: 0.45;
  filter: saturate(0.4);
}

/* Sell — danger tint */
.hud-btn--sell {
  border-color: rgba(255,84,112,0.25);
  background: rgba(255,84,112,0.07);
  color: var(--ink);
}
.hud-btn--sell:hover:not(:disabled) {
  background: rgba(255,84,112,0.14);
  border-color: rgba(255,84,112,0.45);
  box-shadow: 0 0 14px rgba(255,84,112,0.2);
}

/* Targeting cycle */
.hud-btn--target {
  background: rgba(123,108,246,0.08);
  border-color: rgba(123,108,246,0.25);
  color: var(--arcane-bright, #b3a7ff);
  font-size: 0.65rem;
}
.hud-btn--target:hover:not(:disabled) {
  background: rgba(123,108,246,0.18);
  box-shadow: 0 0 14px rgba(123,108,246,0.25);
}

/* Icon-only small button */
.hud-btn--icon {
  padding: 7px;
  min-width: 34px;
  min-height: 34px;
  font-size: 0.9rem;
}
.hud-btn--icon.is-active {
  border-color: rgba(233,196,106,0.45);
  background: rgba(233,196,106,0.12);
  color: var(--gold);
  box-shadow: 0 0 10px rgba(233,196,106,0.2);
}

/* Cost sub-label inside buttons */
.hud-btn__cost {
  font-family: var(--font-body);
  font-size: 0.65rem;
  opacity: 0.8;
  margin-left: 3px;
}

/* ================================================================
   SPECIALIZATION — branch badge · synergy chips · fork chooser
   ================================================================ */
.sel-branch {
  margin-left: auto;
  font-family: var(--font-display);
  font-size: 0.6rem;
  font-variant: small-caps;
  letter-spacing: 0.1em;
  padding: 2px 9px;
  border-radius: 999px;
  color: var(--gold);
  border: 1px solid rgba(233,196,106,0.4);
  background: rgba(233,196,106,0.12);
  box-shadow: 0 0 10px rgba(233,196,106,0.15);
  white-space: nowrap;
}

.sel-synergies {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  padding: 0 12px 8px;
}
.sel-syn__chip {
  font-family: var(--font-body);
  font-size: 0.6rem;
  letter-spacing: 0.03em;
  padding: 2px 8px;
  border-radius: 999px;
  color: #d2ffee;
  border: 1px solid rgba(110,231,183,0.42);
  background: rgba(110,231,183,0.12);
  box-shadow: 0 0 10px rgba(110,231,183,0.12);
}

.sel-fork { padding: 2px 10px 10px; }
.sel-fork__title {
  font-size: 0.62rem;
  font-variant: small-caps;
  letter-spacing: 0.16em;
  color: var(--gold);
  text-align: center;
  margin-bottom: 6px;
  opacity: 0.92;
}
.sel-fork__opts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}
.sel-fork__opt {
  display: flex;
  flex-direction: column;
  gap: 3px;
  text-align: left;
  padding: 8px 9px;
  border-radius: var(--radius-btn);
  cursor: pointer;
  pointer-events: auto;
  color: var(--ink);
  border: 1px solid color-mix(in srgb, var(--fork-color, var(--gold)) 55%, transparent);
  background: color-mix(in srgb, var(--fork-color, var(--gold)) 10%, rgba(10,7,18,0.6));
  transition: background var(--trans-fast), box-shadow var(--trans-fast), transform var(--trans-fast);
}
.sel-fork__opt--a { --fork-color: #7fe9ff; }
.sel-fork__opt--b { --fork-color: #ff8a4a; }
.sel-fork__opt:hover:not(:disabled) {
  background: color-mix(in srgb, var(--fork-color, var(--gold)) 22%, rgba(10,7,18,0.6));
  box-shadow: 0 0 16px color-mix(in srgb, var(--fork-color, var(--gold)) 40%, transparent);
}
.sel-fork__opt:active:not(:disabled) { transform: scale(0.97); }
.sel-fork__opt.is-unaffordable { opacity: 0.45; filter: saturate(0.5); cursor: not-allowed; }
.sel-fork__name {
  font-family: var(--font-display);
  font-size: 0.74rem;
  font-weight: 600;
  color: var(--fork-color, var(--gold));
  letter-spacing: 0.04em;
}
.sel-fork__desc {
  font-family: var(--font-body);
  font-size: 0.62rem;
  line-height: 1.25;
  color: var(--ink-dim);
}
.sel-fork__cost {
  font-family: var(--font-body);
  font-size: 0.62rem;
  color: var(--gold);
  margin-top: 1px;
}

/* ================================================================
   BUILD PALETTE (bottom-center)
   ================================================================ */
#hud-palette {
  grid-column: 2;
  grid-row: 3;
  pointer-events: none;
  display: flex;
  justify-content: center;
  padding: 0 0 12px;
  align-self: end;
}

.palette-inner {
  display: flex;
  gap: 8px;
  padding: 10px 12px;
  align-items: flex-end;
}

/* Build card */
.build-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px;
  padding: 10px 10px 8px;
  min-width: clamp(72px, 9vw, 90px);
  cursor: pointer;
  pointer-events: auto;
  border-radius: var(--radius-panel);
  border: 1px solid rgba(255,255,255,0.08);
  background: rgba(10,7,18,0.65);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: border-color var(--trans-med), box-shadow var(--trans-med), background var(--trans-med), transform var(--trans-fast), filter var(--trans-med);
  position: relative;
  overflow: hidden;
  outline: none;
}

.build-card::before {
  content: '';
  position: absolute;
  inset: 0 0 auto 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  transition: opacity var(--trans-med);
  opacity: 0.5;
}

.build-card:hover {
  transform: translateY(-3px);
  border-color: rgba(255,255,255,0.22);
  background: rgba(14,10,28,0.8);
}
.build-card:active { transform: translateY(0) scale(0.97); }

.build-card:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 2px;
}

.build-card.is-selected { transform: translateY(-2px); }

.build-card.is-unaffordable {
  filter: saturate(0.25) brightness(0.7);
}
.build-card.is-unaffordable:not(.is-selected) {
  opacity: 0.7;
}

.build-icon {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
  position: relative;
}

.build-crystal {
  display: block;
  width: 32px;
  height: 32px;
  filter: drop-shadow(0 0 6px currentColor);
  transition: filter var(--trans-med), transform var(--trans-med);
}

.build-card:hover .build-crystal { filter: drop-shadow(0 0 12px currentColor); transform: scale(1.08); }
.build-card.is-selected .build-crystal { filter: drop-shadow(0 0 14px currentColor); transform: scale(1.05); }

/* Key badge */
.build-key {
  position: absolute;
  top: -2px;
  left: -2px;
  font-family: var(--font-display);
  font-size: 0.52rem;
  font-weight: 600;
  color: var(--ink-dim);
  background: rgba(0,0,0,0.5);
  border-radius: 3px;
  padding: 1px 4px;
  letter-spacing: 0.05em;
}

.build-name {
  font-family: var(--font-display);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.07em;
  color: var(--ink);
  text-align: center;
  line-height: 1.2;
}

.build-role {
  font-family: var(--font-body);
  font-size: 0.55rem;
  font-variant: small-caps;
  letter-spacing: 0.14em;
  color: var(--ink-dim);
}

.build-cost {
  display: flex;
  align-items: center;
  gap: 3px;
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--gold);
}
.build-cost__gem {
  font-size: 0.7rem;
  filter: drop-shadow(0 0 4px var(--gold));
}

/* Selected ring glow */
.build-card.is-selected::after {
  content: '';
  position: absolute;
  inset: -1px;
  border-radius: var(--radius-panel);
  border: 2px solid var(--card-color, var(--gold));
  box-shadow:
    inset 0 0 10px rgba(0,0,0,0.3),
    0 0 16px var(--card-color, var(--gold)),
    0 0 32px color-mix(in srgb, var(--card-color, var(--gold)) 40%, transparent);
  pointer-events: none;
}

/* Tooltip */
.build-tooltip {
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%);
  width: 180px;
  background: rgba(8,5,18,0.96);
  border: var(--glass-border-hi);
  border-radius: 8px;
  padding: 8px 10px;
  font-size: 0.72rem;
  line-height: 1.5;
  color: var(--ink-dim);
  pointer-events: none;
  z-index: 100;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--trans-fast), visibility var(--trans-fast);
  box-shadow: 0 4px 20px rgba(0,0,0,0.7);
  text-align: left;
  backdrop-filter: blur(8px);
}
.build-tooltip::after {
  content: '';
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  border: 5px solid transparent;
  border-top-color: rgba(233,196,106,0.35);
}
.build-card:hover .build-tooltip {
  opacity: 1;
  visibility: visible;
}

/* ================================================================
   ABILITIES BAR (bottom-center, above palette on mobile;
                   positioned via grid on desktop)
   ================================================================ */
#hud-abilities {
  grid-column: 2;
  grid-row: 2;
  pointer-events: none;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding: 0 0 8px;
  gap: 8px;
  align-self: end;
}

.ability-btn {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  border: 2px solid rgba(255,255,255,0.12);
  background: rgba(10,7,18,0.75);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  cursor: pointer;
  pointer-events: auto;
  outline: none;
  transition: border-color var(--trans-med), box-shadow var(--trans-med), transform var(--trans-fast), background var(--trans-med);
  overflow: visible; /* ring sits on top */
}

.ability-btn:hover:not(:disabled) {
  transform: scale(1.08);
  border-color: rgba(255,255,255,0.3);
}
.ability-btn:active { transform: scale(0.95); }

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

/* Glow when ready */
.ability-btn.is-ready {
  border-color: var(--ab-color, var(--gold));
  box-shadow: 0 0 14px color-mix(in srgb, var(--ab-color, var(--gold)) 55%, transparent),
              0 0 4px  var(--ab-color, var(--gold));
  animation: ability-ready-pulse 2.2s ease-in-out infinite;
}

@keyframes ability-ready-pulse {
  0%, 100% { box-shadow: 0 0 14px color-mix(in srgb, var(--ab-color, var(--gold)) 55%, transparent); }
  50%       { box-shadow: 0 0 26px color-mix(in srgb, var(--ab-color, var(--gold)) 80%, transparent),
                          0 0 8px  var(--ab-color, var(--gold)); }
}

/* Strong highlight when casting */
.ability-btn.is-casting {
  border-color: var(--ab-color, var(--gold));
  background: color-mix(in srgb, var(--ab-color, var(--gold)) 18%, rgba(10,7,18,0.8));
  box-shadow: 0 0 28px var(--ab-color, var(--gold)), 0 0 8px rgba(255,255,255,0.2);
  animation: ability-casting-throb 0.6s ease-in-out infinite alternate;
}

@keyframes ability-casting-throb {
  from { transform: scale(1.0); }
  to   { transform: scale(1.10); }
}

/* Casting hint label */
.ability-btn.is-casting::after {
  content: 'targeting…';
  position: absolute;
  bottom: calc(100% + 6px);
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--font-display);
  font-size: 0.55rem;
  letter-spacing: 0.13em;
  color: var(--ab-color, var(--gold));
  white-space: nowrap;
  text-shadow: 0 0 8px var(--ab-color, var(--gold));
  pointer-events: none;
}

/* Glyph */
.ability-glyph {
  font-size: 1.3rem;
  line-height: 1;
  color: var(--ab-color, var(--gold));
  filter: drop-shadow(0 0 5px var(--ab-color, var(--gold)));
  transition: filter var(--trans-med);
  position: relative;
  z-index: 1;
}
.ability-btn:disabled .ability-glyph { filter: none; color: var(--ink-dim); }

/* Key label */
.ability-key {
  position: absolute;
  top: -2px;
  right: -2px;
  font-family: var(--font-display);
  font-size: 0.5rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--ink-dim);
  background: rgba(0,0,0,0.55);
  border-radius: 3px;
  padding: 1px 3px;
  z-index: 2;
}

/* Cooldown remaining text (centered overlay) */
.ability-cd-text {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 0.68rem;
  font-weight: 700;
  color: var(--ink);
  text-shadow: 0 1px 3px rgba(0,0,0,0.9);
  z-index: 2;
  pointer-events: none;
}

/* Radial SVG cooldown ring */
.ability-cd-ring {
  position: absolute;
  inset: -4px;
  width: calc(100% + 8px);
  height: calc(100% + 8px);
  pointer-events: none;
  z-index: 0;
  overflow: visible;
  transform: rotate(-90deg);
}

.ability-cd-ring__track {
  fill: none;
  stroke: rgba(255,255,255,0.07);
  stroke-width: 3;
}

.ability-cd-ring__fill {
  fill: none;
  stroke: var(--ab-color, var(--gold));
  stroke-width: 3;
  stroke-linecap: round;
  transition: stroke-dashoffset 0.25s linear;
}

/* ================================================================
   WAVE CONTROL (bottom-right)
   ================================================================ */
#hud-wave {
  grid-column: 3;
  grid-row: 3;
  pointer-events: auto;
  align-self: end;
  margin: 0 12px 12px 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: clamp(160px, 19vw, 220px);
}

/* Utility row */
.wave-utils {
  display: flex;
  gap: 6px;
  justify-content: flex-end;
}

/* Wave main panel */
.wave-panel {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 10px 12px;
}

/* Enemy preview */
.wave-preview {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.wave-preview-chip {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 0.68rem;
  color: var(--ink-dim);
  background: rgba(255,255,255,0.05);
  border-radius: 4px;
  padding: 2px 6px;
}
.wave-preview-chip__icon { font-size: 0.75rem; }
.wave-preview-chip__count {
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

/* Blind / veiled wave */
.wave-preview-veil {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-display);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--ink-dim);
  opacity: 0.7;
}
.wave-preview-veil__glyph {
  font-size: 1.1rem;
  color: var(--arcane);
  filter: drop-shadow(0 0 6px var(--arcane));
}
.wave-preview-veil__label {
  font-variant: small-caps;
  letter-spacing: 0.18em;
  font-style: italic;
}

/* Boss flair */
.wave-boss-badge {
  display: flex;
  align-items: center;
  gap: 5px;
  font-family: var(--font-display);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--danger);
  text-shadow: 0 0 12px rgba(255,84,112,0.6);
  animation: boss-flicker 1.6s ease-in-out infinite;
}

@keyframes boss-flicker {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.7; }
}

/* Active wave info */
.wave-active-info {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}
.wave-active-label {
  font-size: 0.68rem;
  font-variant: small-caps;
  letter-spacing: 0.13em;
  color: var(--ink-dim);
}
.wave-enemy-count {
  font-family: var(--font-display);
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--danger);
  font-variant-numeric: tabular-nums;
}

/* Call wave button */
.hud-btn--callwave {
  width: 100%;
  padding: 11px 14px;
  font-size: 0.82rem;
  letter-spacing: 0.1em;
  background: linear-gradient(135deg, rgba(123,108,246,0.18), rgba(233,196,106,0.1));
  border: 1px solid rgba(233,196,106,0.35);
  color: var(--gold);
  text-shadow: 0 0 10px rgba(233,196,106,0.4);
  box-shadow: 0 0 18px rgba(123,108,246,0.15), inset 0 1px 0 rgba(255,255,255,0.08);
  overflow: hidden;
}
.hud-btn--callwave::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent, rgba(233,196,106,0.08), transparent);
  transform: translateX(-100%);
  transition: transform 0.6s ease;
}
.hud-btn--callwave:hover:not(:disabled)::before {
  transform: translateX(100%);
}
.hud-btn--callwave:hover:not(:disabled) {
  background: linear-gradient(135deg, rgba(123,108,246,0.28), rgba(233,196,106,0.18));
  box-shadow: 0 0 28px rgba(233,196,106,0.3), 0 0 14px rgba(123,108,246,0.25);
  border-color: rgba(233,196,106,0.6);
}
.hud-btn--callwave:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

/* Speed display */
.speed-indicator {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
}

/* ================================================================
   CHAIN INDICATOR
   ================================================================ */
#hud-chain {
  position: absolute;
  top: 80px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 72;
  pointer-events: none;
  display: flex;
  align-items: center;
  justify-content: center;
}

#hud-chain-label {
  display: inline-block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(0.85rem, 2.5vw, 1.1rem);
  letter-spacing: 0.2em;
  padding: 5px 18px;
  border-radius: 20px;
  background: rgba(10,7,18,0.82);
  border: 1px solid rgba(233,196,106,0.3);
  backdrop-filter: blur(10px);
  white-space: nowrap;
  transition: color var(--trans-med), border-color var(--trans-med), box-shadow var(--trans-med), font-size var(--trans-med);
}

/* Tier colour ramps */
#hud-chain[data-tier="chain-gold"]   #hud-chain-label {
  color: var(--gold);
  border-color: rgba(233,196,106,0.5);
  box-shadow: 0 0 18px rgba(233,196,106,0.35);
}
#hud-chain[data-tier="chain-orange"] #hud-chain-label {
  color: #ff9f40;
  border-color: rgba(255,159,64,0.5);
  box-shadow: 0 0 22px rgba(255,159,64,0.4);
}
#hud-chain[data-tier="chain-violet"] #hud-chain-label {
  color: #d070ff;
  border-color: rgba(208,112,255,0.55);
  box-shadow: 0 0 28px rgba(208,112,255,0.45);
}

/* Pop animation triggered from JS */
@keyframes chain-pop-anim {
  0%   { transform: scale(1.0); }
  35%  { transform: scale(1.22); }
  70%  { transform: scale(0.95); }
  100% { transform: scale(1.0); }
}
#hud-chain.chain-pop #hud-chain-label {
  animation: chain-pop-anim 0.38s cubic-bezier(0.22,1,0.36,1);
}

/* Continuous gentle pulse when visible */
#hud-chain:not(.is-hidden) #hud-chain-label {
  animation: chain-idle-pulse 2s ease-in-out infinite;
}
#hud-chain.chain-pop #hud-chain-label {
  animation: chain-pop-anim 0.38s cubic-bezier(0.22,1,0.36,1);
}

@keyframes chain-idle-pulse {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.78; }
}

/* ================================================================
   SANDBOX PANEL (bottom-left, below selected panel)
   ================================================================ */
#hud-sandbox {
  grid-column: 1;
  grid-row: 3;
  pointer-events: auto;
  align-self: end;
  margin: 0 0 12px 12px;
  width: clamp(180px, 22vw, 240px);
}
#hud-sandbox.is-hidden { display: none !important; }

.sandbox-title {
  font-family: var(--font-display);
  font-size: 0.62rem;
  font-variant: small-caps;
  letter-spacing: 0.18em;
  color: var(--ink-dim);
  padding: 8px 12px 4px;
  border-bottom: 1px solid rgba(233,196,106,0.1);
}

.sandbox-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 4px;
  padding: 8px 10px;
}

.sandbox-spawn-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: 6px 4px;
  border-radius: 6px;
  border: 1px solid rgba(255,255,255,0.08);
  background: rgba(255,255,255,0.04);
  cursor: pointer;
  pointer-events: auto;
  font-family: var(--font-body);
  transition: background var(--trans-fast), border-color var(--trans-fast), transform var(--trans-fast);
}
.sandbox-spawn-btn:hover {
  background: rgba(255,255,255,0.1);
  border-color: rgba(233,196,106,0.3);
  transform: translateY(-1px);
}
.sandbox-spawn-btn:active { transform: scale(0.93); }

.sandbox-spawn-icon {
  font-size: 0.9rem;
  color: var(--arcane-bright, #b3a7ff);
  line-height: 1;
}
.sandbox-spawn-label {
  font-size: 0.48rem;
  font-variant: small-caps;
  letter-spacing: 0.1em;
  color: var(--ink-dim);
  text-align: center;
  line-height: 1;
}

/* ================================================================
   TOASTS
   ================================================================ */
#hud-toasts {
  position: absolute;
  top: 80px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 80;
  pointer-events: none;
  display: flex;
  flex-direction: column-reverse;
  align-items: center;
  gap: 6px;
  width: max-content;
  max-width: 90vw;
}

.hud-toast {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 16px;
  border-radius: 20px;
  font-family: var(--font-display);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  border: 1px solid rgba(255,255,255,0.15);
  background: rgba(10,7,18,0.88);
  backdrop-filter: blur(10px);
  box-shadow: 0 4px 20px rgba(0,0,0,0.5), 0 0 12px var(--toast-glow, transparent);
  animation: toast-in 0.25s ease-out;
  white-space: nowrap;
}

@keyframes toast-in {
  from { opacity: 0; transform: translateY(12px) scale(0.9); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes toast-out {
  from { opacity: 1; transform: translateY(0) scale(1); }
  to   { opacity: 0; transform: translateY(-10px) scale(0.92); }
}

.hud-toast.is-leaving {
  animation: toast-out 0.3s ease-in forwards;
}

/* Reaction colors */
.hud-toast--shatter      { --toast-glow: rgba(191,234,255,0.4); border-color: rgba(191,234,255,0.3); color: #bfeaff; }
.hud-toast--wildfire     { --toast-glow: rgba(255,106,42,0.45);  border-color: rgba(255,106,42,0.3);  color: #ff8c5a; }
.hud-toast--thermalshock { --toast-glow: rgba(255,213,106,0.4);  border-color: rgba(255,213,106,0.3); color: #ffd56a; }
.hud-toast--conduction   { --toast-glow: rgba(174,240,160,0.4);  border-color: rgba(174,240,160,0.3); color: #aef0a0; }

/* ================================================================
   WAVE BANNERS (large, centered)
   ================================================================ */
.hud-banner {
  position: absolute;
  top: 28%;
  left: 50%;
  transform: translateX(-50%);
  z-index: 75;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  animation: banner-in 0.4s cubic-bezier(0.22,1,0.36,1), banner-out 0.5s ease-in 2s forwards;
}

@keyframes banner-in {
  from { opacity: 0; transform: translateX(-50%) scale(0.8); }
  to   { opacity: 1; transform: translateX(-50%) scale(1); }
}
@keyframes banner-out {
  from { opacity: 1; }
  to   { opacity: 0; }
}

.hud-banner__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  letter-spacing: 0.3em;
  text-indent: 0.3em;
  color: var(--gold);
  text-shadow: 0 0 30px rgba(233,196,106,0.6), 0 0 6px rgba(255,255,255,0.3);
  white-space: nowrap;
}

.hud-banner__sub {
  font-family: var(--font-display);
  font-size: 0.8rem;
  letter-spacing: 0.25em;
  color: var(--arcane-bright, #b3a7ff);
  opacity: 0.9;
}

.hud-banner.is-boss .hud-banner__title    { color: var(--danger); text-shadow: 0 0 30px rgba(255,84,112,0.7); }
.hud-banner.is-cleared .hud-banner__title { color: #a8ffb8; text-shadow: 0 0 24px rgba(100,255,140,0.5); }

/* ================================================================
   RESPONSIVE
   ================================================================ */
@media (max-width: 760px) {
  #hud {
    grid-template-rows: auto 1fr auto auto auto;
    grid-template-columns: 1fr 1fr;
  }

  #hud-selected {
    grid-column: 1;
    grid-row: 3;
    margin: 4px 4px 4px 8px;
    width: auto;
  }

  #hud-wave {
    grid-column: 2;
    grid-row: 3;
    margin: 4px 8px 4px 4px;
    min-width: 0;
  }

  #hud-abilities {
    grid-column: 1 / -1;
    grid-row: 4;
    padding: 4px 8px;
    justify-content: center;
    gap: 10px;
  }

  #hud-palette {
    grid-column: 1 / -1;
    grid-row: 5;
    padding: 0 0 8px;
  }

  #hud-sandbox {
    grid-column: 1 / -1;
    grid-row: 6;
    width: auto;
    margin: 0 8px 8px;
  }

  .palette-inner {
    gap: 5px;
    padding: 8px;
    flex-wrap: nowrap;
    overflow-x: auto;
  }

  .build-card {
    min-width: 68px;
    padding: 8px 8px 6px;
  }

  .build-tooltip { display: none; }

  .ability-btn { width: 46px; height: 46px; }
}

@media (max-width: 500px) {
  .hud-stat { min-width: 90px; padding: 6px 10px; }
  .hud-stat__value { font-size: 0.9rem; }

  #hud-wave { min-width: 0; }

  .build-name { font-size: 0.6rem; }
  .build-cost { font-size: 0.65rem; }

  .ability-btn { width: 40px; height: 40px; }
  .ability-glyph { font-size: 1.1rem; }
}

/* ================================================================
   ENTRANCE ANIMATIONS
   ================================================================ */
@keyframes slide-up {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}

#hud-top        { animation: slide-up 0.5s ease-out 0.1s both; }
#hud-palette    { animation: slide-up 0.5s ease-out 0.2s both; }
#hud-wave       { animation: slide-up 0.5s ease-out 0.25s both; }
#hud-abilities  { animation: slide-up 0.5s ease-out 0.3s both; }
#hud-sandbox    { animation: slide-up 0.5s ease-out 0.15s both; }
#hud-selected   { animation: none; } /* appears on demand */

/* ================================================================
   ACCESSIBILITY
   ================================================================ */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}