body {
            margin: 0;
            overflow: hidden;
            background-color: #050510; /* Deep space dark blue/black */
            font-family: 'Inter', sans-serif;
            touch-action: none; /* Prevent default touch actions on mobile */
            color: white;
        }
        /* Visually hidden but still in the accessibility tree and readable
           by search/AI crawlers — standard "sr-only" clip technique, not
           display:none (which some tools weight as less trustworthy/ignore). */
        .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;
        }
        canvas {
            display: block;
            width: 100vw;
            height: 100vh;
        }
        #ui-layer {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            pointer-events: none; /* Let clicks pass through to canvas container */
            display: flex;
            flex-direction: column;
            justify-content: space-between;
            padding: 20px;
            box-sizing: border-box;
        }
        .hud-text {
            text-shadow: 1px 1px 2px rgba(0,0,0,0.8);
        }
        #message-overlay {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            text-align: center;
            pointer-events: auto; /* Allow clicking the buttons */
            background: rgba(10, 15, 30, 0.85);
            padding: 2rem;
            border-radius: 1rem;
            border: 1px solid rgba(255,255,255,0.1);
            backdrop-filter: blur(5px);
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 1rem;
        }
        .hidden {
            display: none !important;
        }
        /* Custom button styling */
        .game-btn {
            background: linear-gradient(135deg, #3b82f6, #2563eb);
            color: white;
            font-weight: bold;
            padding: 0.75rem 2rem;
            border-radius: 9999px;
            border: none;
            cursor: pointer;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.5), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
            transition: transform 0.1s, box-shadow 0.1s;
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }
        .game-btn:active {
            transform: scale(0.95);
            box-shadow: 0 1px 2px rgba(0,0,0,0.5);
        }
        .game-btn:hover {
            background: linear-gradient(135deg, #60a5fa, #3b82f6);
        }
        .ships-btn {
            background: transparent;
            color: #94a3b8;
            border: 1px solid rgba(255,255,255,0.15);
            padding: 0.5rem 1.5rem;
            border-radius: 9999px;
            cursor: pointer;
            font-size: 0.85rem;
            letter-spacing: 0.05em;
            text-transform: uppercase;
            transition: color 0.1s, border-color 0.1s;
        }
        .ships-btn:hover {
            color: #e2e8f0;
            border-color: rgba(255,255,255,0.35);
        }
        #ship-picker {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            text-align: center;
            pointer-events: auto;
            background: rgba(10, 15, 30, 0.92);
            padding: 2rem;
            border-radius: 1rem;
            border: 1px solid rgba(255,255,255,0.1);
            backdrop-filter: blur(5px);
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 0.75rem;
            max-width: 90vw;
            max-height: 85vh;
        }
        .ship-picker-title {
            font-size: 1.5rem;
            font-weight: 800;
            color: #e2e8f0;
        }
        .ship-picker-hint {
            font-size: 0.8rem;
            color: #64748b;
            margin-bottom: 0.5rem;
        }
        .ship-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 12px;
            overflow-y: auto;
            max-height: 50vh;
            padding: 4px;
            width: 100%;
        }
        .ship-tile {
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 4px;
            cursor: pointer;
            padding: 6px;
            border-radius: 0.5rem;
            border: 2px solid transparent;
            background: rgba(255,255,255,0.03);
        }
        .ship-tile:hover {
            background: rgba(255,255,255,0.08);
        }
        .ship-tile.selected {
            border-color: #3b82f6;
            background: rgba(59,130,246,0.15);
        }
        .ship-tile canvas {
            display: block;
        }
        .ship-tile .ship-name {
            font-size: 0.6rem;
            text-transform: uppercase;
            letter-spacing: 0.05em;
            color: #94a3b8;
        }
        .ship-tile.locked {
            opacity: 0.35;
            cursor: default;
        }
        .unlock-preview {
            width: 72px;
            height: 72px;
            margin: -0.5rem auto 0;
            display: block;
        }

        /* ---- Developer mode (only ever created when ?dev is in the URL —
           see game.js) ---- */
        #dev-toggle {
            position: fixed;
            bottom: 14px;
            right: 14px;
            z-index: 30;
            background: rgba(15,20,32,0.85);
            color: #14b8a6;
            border: 1px solid rgba(20,184,166,0.4);
            border-radius: 6px;
            padding: 5px 10px;
            font-size: 11px;
            font-weight: 700;
            letter-spacing: 0.05em;
            text-transform: uppercase;
            cursor: pointer;
        }
        #dev-toggle:hover { background: rgba(20,184,166,0.15); }
        #dev-panel {
            position: fixed;
            top: 14px;
            right: 14px;
            z-index: 31;
            width: 250px;
            max-height: calc(100vh - 28px);
            overflow-y: auto;
            background: rgba(10, 15, 30, 0.95);
            border: 1px solid rgba(20,184,166,0.35);
            border-radius: 10px;
            padding: 14px;
            font-size: 12px;
            color: #cbd5e1;
        }
        #dev-panel h3 {
            margin: 0 0 8px;
            font-size: 12px;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 0.06em;
            color: #14b8a6;
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        #dev-panel .dev-close {
            cursor: pointer;
            color: #64748b;
            font-weight: 400;
        }
        #dev-panel .dev-row {
            display: flex;
            align-items: center;
            gap: 6px;
            margin-bottom: 8px;
        }
        #dev-panel .dev-row label {
            flex: 1;
            color: #94a3b8;
            font-size: 11px;
        }
        #dev-panel input[type=number] {
            width: 64px;
            background: #0f1420;
            border: 1px solid rgba(255,255,255,0.15);
            color: #e2e8f0;
            border-radius: 4px;
            padding: 3px 5px;
            font-size: 12px;
        }
        #dev-panel select {
            width: 100%;
            background: #0f1420;
            border: 1px solid rgba(255,255,255,0.15);
            color: #e2e8f0;
            border-radius: 4px;
            padding: 3px 5px;
            font-size: 12px;
            margin-bottom: 8px;
        }
        #dev-panel button {
            background: #14b8a6;
            color: #04201c;
            border: none;
            border-radius: 4px;
            padding: 4px 8px;
            font-size: 11px;
            font-weight: 700;
            cursor: pointer;
        }
        #dev-panel button:hover { background: #2dd4bf; }
        #dev-panel .dev-actions {
            display: flex;
            flex-wrap: wrap;
            gap: 6px;
            margin: 6px 0 10px;
        }
        #dev-panel .dev-actions button {
            flex: 1 1 auto;
            background: rgba(255,255,255,0.08);
            color: #cbd5e1;
        }
        #dev-panel .dev-actions button:hover { background: rgba(255,255,255,0.15); }
        #dev-panel .dev-divider {
            border: none;
            border-top: 1px solid rgba(255,255,255,0.1);
            margin: 10px 0;
        }
        #dev-panel .dev-danger {
            width: 100%;
            background: rgba(239,68,68,0.15) !important;
            color: #fca5a5 !important;
        }
        #dev-panel .dev-danger:hover { background: rgba(239,68,68,0.3) !important; }
        #dev-panel .dev-hint {
            font-size: 10px;
            color: #475569;
            margin-top: 8px;
            line-height: 1.4;
        }