/* ========== Design System ========== */
:root {
  --bg-primary: #0f0f23;
  --bg-secondary: #1a1a2e;
  --bg-tertiary: #16213e;
  --bg-card: #1a1a2e;
  --bg-card-hover: #222244;

  --color-primary: #00d4ff;
  --color-primary-dim: #007a99;
  --color-accent: #e94560;
  --color-accent-dim: #a8324a;
  --color-miss: #555577;
  --color-hit: #e94560;
  --color-sunk: #8b1a2b;
  --color-ship: #1e5f8a;
  --color-ship-glow: #2980b9;
  --color-valid: #2ecc71;
  --color-invalid: #e74c3c;
  --color-warning: #f39c12;
  --color-success: #2ecc71;

  --text-primary: #e0e0e0;
  --text-secondary: #9999aa;
  --text-muted: #6a6a7e;

  --border-color: #2a2a4a;
  --border-glow: rgba(0, 212, 255, 0.3);

  --cell-size: 38px;
  --cell-gap: 2px;
  --grid-border: #334;
  --radius: 8px;
  --radius-lg: 12px;

  --font-main: 'Segoe UI', system-ui, -apple-system, sans-serif;
  --font-mono: 'Fira Code', 'Cascadia Code', 'Consolas', monospace;

  --transition: 0.2s ease;
}

[data-theme="light"] {
  --bg-primary: #f5f5f8;
  --bg-secondary: #ffffff;
  --bg-tertiary: #ecedf2;
  --bg-card: #ffffff;
  --bg-card-hover: #f0f0f6;
  --color-primary: #0091b3;
  --color-primary-dim: #006680;
  --color-accent: #d63852;
  --color-accent-dim: #a8324a;
  --color-miss: #b0b0c0;
  --color-hit: #d63852;
  --color-sunk: #9f1239;
  --color-ship: #3b82f6;
  --color-ship-glow: #60a5fa;
  --color-valid: #16a34a;
  --color-invalid: #dc2626;
  --color-warning: #ca8a04;
  --color-success: #16a34a;
  --text-primary: #1a1a2e;
  --text-secondary: #555566;
  --text-muted: #888899;
  --border-color: #d8d8e4;
  --border-glow: rgba(0, 145, 179, 0.3);
  --grid-border: #c8c8d8;
}


/* ========== Home Button ========== */
#home-btn {
  position: fixed;
  top: 16px;
  left: 16px;
  z-index: 999;
  align-items: center;
  gap: 4px;
  padding: 6px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.8rem;
  font-family: inherit;
  transition: all 0.2s ease;
}
#home-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ========== Reset & Base ========== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
  overflow-x: hidden;
}

body {
  font-family: var(--font-main);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  background-image:
    radial-gradient(ellipse at 20% 80%, rgba(0, 60, 120, 0.15) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 20%, rgba(0, 80, 140, 0.1) 0%, transparent 50%);
}

#app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

/* ========== Typography ========== */
h1, h2, h3 {
  color: var(--text-primary);
  font-weight: 600;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.15rem; }

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  border: 2px solid transparent;
  border-radius: var(--radius);
  font-family: var(--font-main);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  gap: 8px;
}

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

.btn-primary {
  background: var(--color-primary);
  color: var(--bg-primary);
  border-color: var(--color-primary);
}
.btn-primary:hover:not(:disabled) {
  background: transparent;
  color: var(--color-primary);
  box-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
}

.btn-accent {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}
.btn-accent:hover:not(:disabled) {
  background: transparent;
  color: var(--color-accent);
  box-shadow: 0 0 20px rgba(233, 69, 96, 0.3);
}

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border-color: var(--border-color);
}
.btn-outline:hover:not(:disabled) {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-success {
  background: var(--color-success);
  color: var(--bg-primary);
  border-color: var(--color-success);
}
.btn-success:hover:not(:disabled) {
  background: transparent;
  color: var(--color-success);
  box-shadow: 0 0 20px rgba(46, 204, 113, 0.3);
}

.btn-sm {
  padding: 6px 14px;
  font-size: 0.8rem;
}

.btn-lg {
  padding: 14px 36px;
  font-size: 1.1rem;
}

/* ========== Inputs ========== */
.input {
  width: 100%;
  padding: 10px 16px;
  background: var(--bg-tertiary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-family: var(--font-main);
  font-size: 0.95rem;
  transition: border-color var(--transition);
  outline: none;
}

.input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 10px var(--border-glow);
}

.input::placeholder {
  color: var(--text-muted);
}

.input-code {
  font-family: var(--font-mono);
  font-size: 1.3rem;
  text-align: center;
  letter-spacing: 4px;
  text-transform: uppercase;
}

/* ========== Cards ========== */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: border-color var(--transition);
}

.card:hover {
  border-color: rgba(0, 212, 255, 0.2);
}

/* ========== Grid ========== */
.grid-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.grid-label {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.grid-wrapper {
  display: inline-block;
  position: relative;
}

.grid-col-labels {
  display: grid;
  grid-template-columns: 28px repeat(10, var(--cell-size));
  gap: var(--cell-gap);
  margin-bottom: 2px;
}

.grid-col-label {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  height: 20px;
}

.grid-row {
  display: grid;
  grid-template-columns: 28px repeat(10, var(--cell-size));
  gap: var(--cell-gap);
  margin-bottom: var(--cell-gap);
}

.grid-row-label {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  width: 28px;
}

.cell {
  width: var(--cell-size);
  height: var(--cell-size);
  background: var(--bg-tertiary);
  border: 1px solid var(--grid-border);
  border-radius: 3px;
  cursor: default;
  transition: all 0.15s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.cell.clickable {
  cursor: crosshair;
}

.cell.clickable:hover {
  background: rgba(0, 212, 255, 0.15);
  border-color: var(--color-primary);
  box-shadow: 0 0 8px var(--border-glow);
}

/* Cell States */
.cell.ship {
  background: var(--color-ship);
  border-color: var(--color-ship-glow);
  box-shadow: inset 0 0 8px rgba(41, 128, 185, 0.3);
}

.cell.hit {
  background: var(--color-hit);
  border-color: var(--color-accent);
  animation: hitFlash 0.5s ease;
}

.cell.hit::after {
  content: '\u2716';
  font-size: 18px;
  color: #fff;
  font-weight: bold;
  text-shadow: 0 0 6px rgba(255,255,255,0.5);
}

.cell.miss {
  background: var(--bg-tertiary);
  border-color: var(--color-miss);
}

.cell.miss::after {
  content: '';
  width: 10px;
  height: 10px;
  background: var(--color-miss);
  border-radius: 50%;
  animation: missRipple 0.4s ease;
}

.cell.sunk {
  background: var(--color-sunk);
  border-color: #a0213a;
  animation: sunkShake 0.6s ease;
}

.cell.sunk::after {
  content: '\u2716';
  font-size: 18px;
  color: #ffaaaa;
  font-weight: bold;
}

/* Preview states for placement */
.cell.preview-valid {
  background: rgba(46, 204, 113, 0.3);
  border-color: var(--color-valid);
  box-shadow: 0 0 8px rgba(46, 204, 113, 0.3);
}

.cell.preview-invalid {
  background: rgba(231, 76, 60, 0.3);
  border-color: var(--color-invalid);
  box-shadow: 0 0 8px rgba(231, 76, 60, 0.3);
}

/* ========== Animations ========== */
@keyframes hitFlash {
  0% { transform: scale(1.2); background: #fff; }
  50% { transform: scale(0.95); }
  100% { transform: scale(1); background: var(--color-hit); }
}

@keyframes missRipple {
  0% { transform: scale(0); opacity: 0; }
  50% { transform: scale(1.5); opacity: 0.5; }
  100% { transform: scale(1); opacity: 1; }
}

@keyframes sunkShake {
  0%, 100% { transform: translateX(0); }
  10% { transform: translateX(-4px); }
  20% { transform: translateX(4px); }
  30% { transform: translateX(-4px); }
  40% { transform: translateX(4px); }
  50% { transform: translateX(-2px); }
  60% { transform: translateX(2px); }
  70% { transform: translateX(-1px); }
  80% { transform: translateX(1px); }
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
  from { opacity: 0; transform: translateX(100%); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes slideOut {
  from { opacity: 1; transform: translateX(0); }
  to { opacity: 0; transform: translateX(100%); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

@keyframes borderGlow {
  0%, 100% { box-shadow: 0 0 5px var(--border-glow); }
  50% { box-shadow: 0 0 20px var(--border-glow), 0 0 40px rgba(0,212,255,0.1); }
}

/* ========== Landing View ========== */
.landing {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 40px;
  animation: fadeIn 0.5s ease;
}

.landing-title {
  text-align: center;
}

.landing-title h1 {
  font-size: 3rem;
  color: var(--color-primary);
  text-shadow: 0 0 30px rgba(0, 212, 255, 0.3);
  letter-spacing: 4px;
}

.landing-title p {
  color: var(--text-secondary);
  margin-top: 8px;
  font-size: 1.05rem;
}

.landing-cards {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  justify-content: center;
}

.landing-card {
  width: 320px;
  padding: 32px;
  text-align: center;
}

.landing-card h2 {
  margin-bottom: 20px;
  color: var(--color-primary);
}

.landing-card .form-group {
  margin-bottom: 16px;
}

.landing-card label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 6px;
  text-align: left;
}

.ship-decoration {
  display: flex;
  justify-content: center;
  gap: 4px;
  margin-top: 30px;
  opacity: 0.3;
}

.ship-block {
  width: 20px;
  height: 20px;
  background: var(--color-primary);
  border-radius: 3px;
}

/* ========== Lobby View ========== */
.lobby {
  width: 100%;
  max-width: 600px;
  animation: fadeIn 0.5s ease;
}

.lobby-header {
  text-align: center;
  margin-bottom: 30px;
}

.lobby-header h1 {
  color: var(--color-primary);
  margin-bottom: 10px;
}

.room-code-display {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--bg-tertiary);
  padding: 10px 20px;
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: all var(--transition);
}

.room-code-display:hover {
  border-color: var(--color-primary);
}

.room-code-display .code {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--color-primary);
  letter-spacing: 4px;
}

.room-code-display .copy-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.player-slots {
  display: flex;
  gap: 16px;
  margin-bottom: 24px;
  flex-wrap: wrap;
  justify-content: center;
}

.player-slot {
  flex: 1;
  min-width: 240px;
  padding: 20px;
  text-align: center;
}

.player-slot.empty {
  border-style: dashed;
  opacity: 0.5;
}

.player-slot .player-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 8px;
}

.player-slot .player-name {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.player-slot .player-name.waiting {
  color: var(--text-muted);
  font-style: italic;
}

.ready-badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
}

.ready-badge.ready {
  background: rgba(46, 204, 113, 0.2);
  color: var(--color-success);
  border: 1px solid var(--color-success);
}

.ready-badge.not-ready {
  background: rgba(136, 136, 153, 0.15);
  color: var(--text-muted);
  border: 1px solid var(--text-muted);
}

.spectator-section {
  margin-top: 20px;
  padding: 16px;
  border-radius: var(--radius);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
}

.spectator-section h3 {
  color: var(--text-secondary);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 8px;
}

.spectator-list {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.spectator-tag {
  padding: 4px 10px;
  background: var(--bg-secondary);
  border-radius: 20px;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.lobby-actions {
  text-align: center;
  margin-top: 24px;
  display: flex;
  gap: 12px;
  justify-content: center;
}

/* ========== Placement View ========== */
.placement {
  display: flex;
  gap: 40px;
  align-items: flex-start;
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeIn 0.5s ease;
  width: 100%;
  max-width: 1000px;
}

.placement-header {
  width: 100%;
  text-align: center;
  margin-bottom: 10px;
}

.placement-header h2 {
  color: var(--color-primary);
}

.placement-header p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 4px;
}

.placement-grid-section {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.placement-controls {
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-width: 220px;
}

.placement-info {
  text-align: center;
  padding: 12px;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
}

.placement-info .count {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--color-primary);
}

.rotation-indicator {
  text-align: center;
  padding: 10px;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.rotation-indicator kbd {
  display: inline-block;
  padding: 2px 8px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-primary);
}

.opponent-status {
  text-align: center;
  padding: 10px;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  font-size: 0.85rem;
  color: var(--text-secondary);
  animation: pulse 2s ease infinite;
}

/* ========== Ship Palette ========== */
.ship-palette {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.ship-palette-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: var(--bg-tertiary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition);
}

.ship-palette-item:hover:not(.placed) {
  border-color: var(--color-primary);
  background: var(--bg-card-hover);
}

.ship-palette-item.selected {
  border-color: var(--color-primary);
  box-shadow: 0 0 12px var(--border-glow);
  background: rgba(0, 212, 255, 0.08);
}

.ship-palette-item.placed {
  border-color: var(--color-success);
  opacity: 0.6;
  cursor: default;
}

.ship-palette-item .ship-name {
  font-weight: 600;
  font-size: 0.85rem;
  min-width: 85px;
}

.ship-palette-item .ship-blocks {
  display: flex;
  gap: 2px;
}

.ship-palette-item .ship-block-small {
  width: 18px;
  height: 18px;
  background: var(--color-ship);
  border-radius: 2px;
  border: 1px solid var(--color-ship-glow);
}

.ship-palette-item.selected .ship-block-small {
  background: var(--color-primary);
  border-color: var(--color-primary);
}

.ship-palette-item.placed .ship-block-small {
  background: var(--color-success);
  border-color: var(--color-success);
}

.ship-palette-item .ship-status-icon {
  margin-left: auto;
  font-size: 1rem;
}

/* ========== Battle View ========== */
.battle {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  width: 100%;
  max-width: 1100px;
  animation: fadeIn 0.5s ease;
}

.turn-indicator {
  text-align: center;
  padding: 12px 32px;
  border-radius: var(--radius-lg);
  font-size: 1.2rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
}

.turn-indicator.your-turn {
  background: rgba(46, 204, 113, 0.15);
  color: var(--color-success);
  border: 2px solid var(--color-success);
  animation: borderGlow 2s ease infinite;
}

.turn-indicator.opponent-turn {
  background: rgba(243, 156, 18, 0.15);
  color: var(--color-warning);
  border: 2px solid var(--color-warning);
}

.battle-grids {
  display: flex;
  gap: 40px;
  flex-wrap: wrap;
  justify-content: center;
  width: 100%;
}

.battle-grid-panel {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.battle-grid-panel .grid-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.ship-status-panel {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  justify-content: center;
}

.ship-status-group {
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
}

.ship-status-group h4 {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 6px;
}

.ship-status-list {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.ship-status-entry {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
}

.ship-status-entry.sunk {
  text-decoration: line-through;
  opacity: 0.5;
  color: var(--color-accent);
}

.ship-status-entry .status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-success);
}

.ship-status-entry.sunk .status-dot {
  background: var(--color-accent);
}

/* ========== Mobile Tabs ========== */
.mobile-tabs {
  display: none;
  width: 100%;
  justify-content: center;
  gap: 4px;
  margin-bottom: 10px;
}

.mobile-tab {
  padding: 10px 24px;
  background: var(--bg-tertiary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius) var(--radius) 0 0;
  color: var(--text-secondary);
  cursor: pointer;
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
  transition: all var(--transition);
  font-family: var(--font-main);
}

.mobile-tab.active {
  background: var(--bg-card);
  border-color: var(--color-primary);
  color: var(--color-primary);
  border-bottom-color: var(--bg-card);
}

/* ========== Spectator View ========== */
.spectator-banner {
  text-align: center;
  padding: 10px 24px;
  background: rgba(243, 156, 18, 0.1);
  border: 1px solid var(--color-warning);
  border-radius: var(--radius);
  color: var(--color-warning);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-size: 0.85rem;
}

/* ========== Game Over View ========== */
.game-over {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  animation: fadeIn 0.5s ease;
  width: 100%;
  max-width: 1100px;
}

.victory-banner {
  text-align: center;
  padding: 24px 40px;
  border-radius: var(--radius-lg);
}

.victory-banner.winner {
  background: rgba(46, 204, 113, 0.1);
  border: 2px solid var(--color-success);
}

.victory-banner.loser {
  background: rgba(233, 69, 96, 0.1);
  border: 2px solid var(--color-accent);
}

.victory-banner.spectator-result {
  background: rgba(0, 212, 255, 0.1);
  border: 2px solid var(--color-primary);
}

.victory-banner h1 {
  font-size: 2.5rem;
  margin-bottom: 8px;
}

.victory-banner.winner h1 { color: var(--color-success); }
.victory-banner.loser h1 { color: var(--color-accent); }
.victory-banner.spectator-result h1 { color: var(--color-primary); }

.victory-banner p {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

.game-stats {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
}

.stat-card {
  padding: 16px 24px;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  text-align: center;
  min-width: 120px;
}

.stat-card .stat-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
}

.stat-card .stat-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-top: 4px;
}

.game-over-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: center;
}

.rematch-status {
  font-size: 0.85rem;
  color: var(--text-secondary);
  text-align: center;
}

/* ========== Toasts ========== */
#toast-container {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
}

.toast {
  padding: 12px 20px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  font-weight: 500;
  pointer-events: auto;
  animation: slideIn 0.3s ease;
  max-width: 350px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}

.toast.removing {
  animation: slideOut 0.3s ease forwards;
}

.toast.info {
  background: var(--bg-tertiary);
  border: 1px solid var(--color-primary);
  color: var(--color-primary);
}

.toast.success {
  background: rgba(46, 204, 113, 0.15);
  border: 1px solid var(--color-success);
  color: var(--color-success);
}

.toast.error {
  background: rgba(233, 69, 96, 0.15);
  border: 1px solid var(--color-accent);
  color: var(--color-accent);
}

.toast.warning {
  background: rgba(243, 156, 18, 0.15);
  border: 1px solid var(--color-warning);
  color: var(--color-warning);
}

/* ========== Responsive ========== */
@media (max-width: 768px) {
  :root {
    --cell-size: 32px;
  }

  #app {
    padding: 10px;
  }

  .landing-title h1 {
    font-size: 2rem;
  }

  .landing-cards {
    flex-direction: column;
    align-items: center;
  }

  .landing-card {
    width: 100%;
    max-width: 350px;
  }

  .battle-grids {
    flex-direction: column;
    align-items: center;
  }

  .mobile-tabs {
    display: flex;
  }

  .battle-grid-panel.hidden-mobile {
    display: none;
  }

  .placement {
    gap: 20px;
  }
}

@media (max-width: 480px) {
  :root {
    --cell-size: 28px;
  }

  .grid-col-labels {
    grid-template-columns: 20px repeat(10, var(--cell-size));
  }

  .grid-row {
    grid-template-columns: 20px repeat(10, var(--cell-size));
  }

  .grid-row-label, .grid-col-label {
    font-size: 0.65rem;
    width: 20px;
  }
}

/* ========== Utility ========== */
.text-center { text-align: center; }
.text-muted { color: var(--text-secondary); }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mb-8 { margin-bottom: 8px; }
.mb-16 { margin-bottom: 16px; }
.gap-8 { gap: 8px; }
.gap-16 { gap: 16px; }
.flex-center {
  display: flex;
  align-items: center;
  justify-content: center;
}
.hidden { display: none !important; }