.app-header {
            width: calc(100% - 24px);
            max-width: 360px;
            display: grid;
            grid-template-columns: 1fr auto 1fr;
            align-items: center;
            padding: 8px 16px;
            margin-bottom: 12px;
            border-radius: 16px;
            background: var(--header-bg);
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
            border: 1px solid var(--card-border);
            z-index: 100;
            box-shadow: 0 4px 12px var(--shadow-color);
            transition: background 0.5s ease, border-color 0.5s ease;
        }

        .logo {
            font-size: 20px;
            font-weight: 800;
            letter-spacing: -0.5px;
            background: var(--btn-bg);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            text-align: left;
            filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.35));
            cursor: pointer;
            user-select: none;
            transition: transform 0.2s ease, background 0.5s ease;
            display: inline-block;
        }

        .logo:hover {
            transform: scale(1.05);
        }

        .logo:active {
            transform: scale(0.95);
        }

        .score-wrapper {
            display: flex;
            align-items: center;
            gap: 8px;
            justify-self: center;
        }

        .score-container {
            font-weight: 600;
            font-size: 16px;
            background: rgba(255, 255, 255, 0.15);
            padding: 4px 12px;
            border-radius: 20px;
            border: 1px solid var(--card-border);
            transition: transform 0.2s ease, background 0.3s ease, border-color 0.3s ease, color 0.3s ease, box-shadow 0.3s ease;
        }

        @keyframes scoreBounce {
            0%, 100% { transform: scale(1); }
            50% { transform: scale(1.3); }
        }

        .score-container.bounce {
            animation: scoreBounce 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
        }

        .score-container.on-streak {
            background: rgba(255, 120, 0, 0.15);
            border-color: rgba(255, 90, 0, 0.4);
            color: #FF5A00;
            box-shadow: 0 0 15px rgba(255, 90, 0, 0.4);
            animation: streakPulse 1s infinite alternate;
        }

        @keyframes streakPulse {
            0% { transform: scale(1); box-shadow: 0 0 8px rgba(255, 90, 0, 0.3); }
            100% { transform: scale(1.03); box-shadow: 0 0 20px rgba(255, 90, 0, 0.6); }
        }

        .controls {
            display: flex;
            gap: 8px;
            align-items: center;
            justify-self: end;
        }

        .control-btn {
            background: none;
            border: none;
            cursor: pointer;
            padding: 6px;
            border-radius: 50%;
            color: var(--text-color);
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background 0.3s, transform 0.2s;
            width: 30px;
            height: 30px;
        }

        .control-btn:hover {
            background: rgba(255, 255, 255, 0.15);
            transform: scale(1.15);
        }

        .control-btn svg {
            width: 16px;
            height: 16px;
        }

        .card-container {
            position: relative;
            width: calc(100% - 24px);
            max-width: 360px;
            flex: 1;
            display: flex;
            justify-content: center;
            align-items: center;
            margin-top: 16px;
            margin-bottom: 12px;
            z-index: 10;
        }

        .card {
            background: var(--card-bg);
            backdrop-filter: blur(20px);
            -webkit-backdrop-filter: blur(20px);
            border: 1px solid var(--card-border);
            padding: 30px 24px;
            border-radius: 28px;
            box-shadow: 0 15px 35px var(--shadow-color);
            width: 100%;
            height: 100%;
            box-sizing: border-box;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
            position: absolute;
            cursor: grab;
            user-select: none;
            transform-origin: center bottom;
            transition: transform 0.1s ease-out, opacity 0.1s ease-out, background 0.5s ease;
            touch-action: none;
            z-index: 10;
            opacity: 1;
            overflow: hidden;
        }

        .card:active { cursor: grabbing; }

        .card.shake {
            animation: shake 0.5s cubic-bezier(.36,.07,.19,.97) both;
            transform: translate3d(0, 0, 0);
            backface-visibility: hidden;
            perspective: 1000px;
        }

        @keyframes shake {
            10%, 90% { transform: translate3d(-4px, 0, 0); }
            20%, 80% { transform: translate3d(8px, 0, 0); }
            30%, 50%, 70% { transform: translate3d(-10px, 0, 0); }
            40%, 60% { transform: translate3d(10px, 0, 0); }
        }

        #question {
            font-family: 'Fira Code', monospace;
            font-size: 46px;
            margin: 20px 0;
            font-weight: 700;
            letter-spacing: -2px;
            color: var(--text-color);
        }

        .options-container {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 12px;
            width: 100%;
            margin-top: 15px;
            margin-bottom: 20px;
        }

        .option-btn {
            background: rgba(255, 255, 255, 0.1);
            border: 1px solid var(--card-border);
            color: var(--text-color);
            padding: 14px 10px;
            border-radius: 16px;
            font-family: 'Outfit', sans-serif;
            font-weight: 700;
            font-size: 18px;
            cursor: pointer;
            transition: background 0.2s, border-color 0.2s, transform 0.1s, box-shadow 0.2s;
            outline: none;
            text-align: center;
        }

        .option-btn:hover {
            background: rgba(255, 255, 255, 0.2);
            transform: translateY(-1px);
        }

        .option-btn:active {
            transform: translateY(1px);
        }

        .option-btn.selected {
            background: rgba(255, 255, 255, 0.25);
            border-color: #FF0844;
            box-shadow: 0 0 12px rgba(255, 8, 68, 0.3);
            transform: scale(1.03);
        }

        [data-theme="dark"] .option-btn.selected {
            border-color: #E94057;
            box-shadow: 0 0 12px rgba(233, 64, 87, 0.4);
        }

        .btn-hint {
            border: none;
            padding: 14px 20px;
            font-size: 15px;
            font-weight: 600;
            border-radius: 16px;
            cursor: pointer;
            color: var(--btn-text);
            background: var(--btn-bg);
            width: 100%;
            box-shadow: 0 6px 20px var(--shadow-color);
            transition: transform 0.2s, box-shadow 0.2s;
            font-family: 'Outfit', sans-serif;
        }

        .btn-hint:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 24px var(--shadow-color);
        }

        .btn-hint:active {
            transform: translateY(1px);
        }

        .feedback {
            font-weight: 600;
            font-size: 18px;
            min-height: 40px;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: opacity 0.3s;
            letter-spacing: 0.5px;
        }

        .swipe-indicator {
            position: absolute;
            top: 25px;
            font-weight: 800;
            font-size: 20px;
            padding: 6px 14px;
            border-radius: 8px;
            border: 3px solid;
            opacity: 0;
            pointer-events: none;
            z-index: 100;
            letter-spacing: 1px;
            font-family: 'Outfit', sans-serif;
            transition: opacity 0.1s ease-out;
        }

        .indicator-right {
            right: 25px;
            border-color: #10B981;
            color: #10B981;
            transform: rotate(12deg);
        }

        .indicator-left {
            left: 25px;
            border-color: #EF4444;
            color: #EF4444;
            transform: rotate(-12deg);
        }

        #confetti-canvas {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            pointer-events: none;
            z-index: 1000;
        }

        .footer-text {
            font-size: 13px;
            font-weight: 500;
            color: var(--text-muted);
            margin-bottom: 16px;
            opacity: 0.8;
            z-index: 10;
        }

        @media (min-width: 600px) {
            .app-header {
                width: 440px;
                max-width: 440px;
                padding: 10px 20px;
            }
            .control-btn {
                width: 34px;
                height: 34px;
            }
            .control-btn svg {
                width: 19px;
                height: 19px;
            }
            .card-container {
                width: 440px;
                max-width: 440px;
                height: 540px;
                flex: none;
                margin-top: auto;
                margin-bottom: auto;
            }
            #question {
                font-size: 62px;
                margin: 25px 0;
            }
            .btn-hint {
                font-size: 17px;
                padding: 16px 24px;
                border-radius: 18px;
            }
            .swipe-indicator {
                font-size: 24px;
                top: 30px;
            }
            .indicator-right {
                right: 30px;
            }
            .indicator-left {
                left: 30px;
            }
        }

        /* Review Mode Styling */
        .review-badge {
            display: none;
            position: absolute;
            top: 16px;
            left: 50%;
            transform: translateX(-50%);
            background: rgba(233, 64, 87, 0.15);
            border: 1px solid rgba(233, 64, 87, 0.4);
            color: #E94057;
            padding: 4px 12px;
            border-radius: 20px;
            font-size: 11px;
            font-weight: 700;
            text-transform: uppercase;
            letter-spacing: 1px;
            pointer-events: none;
            z-index: 10;
        }

        .review-mode .review-badge {
            display: block;
        }

        .review-mode #card {
            border-color: rgba(233, 64, 87, 0.4);
            box-shadow: 0 10px 35px rgba(233, 64, 87, 0.2);
        }

        .control-btn.active {
            color: #E94057;
            filter: drop-shadow(0 0 4px rgba(233, 64, 87, 0.5));
        }

        /* Full Width Preference Button */
        .preference-btn.full-width-btn {
            grid-column: span 2;
        }

        /* Leaderboard Styling */
        .leaderboard-container {
            background: rgba(0, 0, 0, 0.05);
            border: 1px solid var(--card-border);
            border-radius: 16px;
            padding: 8px 12px;
            display: flex;
            flex-direction: column;
            gap: 2px;
        }
        
        .leaderboard-row {
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-size: 13px;
            padding: 6px 0;
            border-bottom: 1px solid rgba(255, 255, 255, 0.05);
        }
        
        .leaderboard-row:last-child {
            border-bottom: none;
        }
        
        .leaderboard-rank {
            font-weight: 800;
            color: var(--text-muted);
            width: 24px;
            text-align: left;
        }
        
        .leaderboard-name {
            flex: 1;
            text-align: left;
            font-weight: 600;
            padding-left: 4px;
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
        }
        
        .leaderboard-score {
            font-weight: 800;
            background: var(--header-bg);
            padding: 2px 8px;
            border-radius: 10px;
            font-size: 12px;
        }

        /* Card Liquid Draining Style */
        .card-liquid {
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: var(--timer-percent, 0%);
            pointer-events: none;
            z-index: 0;
            display: none; /* hidden by default, toggled in JS */
            transition: height 0.1s linear;
        }

        .liquid-wave {
            position: absolute;
            top: -20px;
            left: 0;
            width: 200%;
            height: 28px;
            color: var(--liquid-color, rgba(16, 185, 129, 0.15));
            opacity: 1;
            pointer-events: none;
            animation: waveMove 4s linear infinite;
            filter: drop-shadow(0 -4px 6px var(--liquid-glow, rgba(16, 185, 129, 0.5)));
            transition: color 0.3s ease, filter 0.3s ease;
        }

        .liquid-body {
            position: absolute;
            top: 7px; /* overlaps the SVG wave bottom nicely */
            left: 0;
            width: 100%;
            height: 100%;
            background: var(--liquid-color, rgba(16, 185, 129, 0.15));
            box-shadow: inset 0 2px 4px rgba(255, 255, 255, 0.05);
            transition: background 0.3s ease;
        }

        @keyframes waveMove {
            0% { transform: translateX(0); }
            100% { transform: translateX(-50%); }
        }

        /* Ensure card contents sit on top of liquid layer */
        #question, .options-container, .btn-hint, .feedback, .review-badge {
            position: relative;
            z-index: 2;
        }

        /* Supporter Zone & Wallet Styles */
        .supporter-container {
            display: flex;
            flex-direction: column;
            gap: 12px;
            background: rgba(0, 0, 0, 0.08);
            border: 1px solid var(--card-border);
            border-radius: 18px;
            padding: 14px;
            margin-top: 6px;
        }

        .supporter-buttons {
            display: flex;
            gap: 10px;
            width: 100%;
        }

        .supporter-link {
            flex: 1;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 10px 0;
            border-radius: 12px;
            font-size: 13px;
            font-weight: 600;
            text-decoration: none;
            color: var(--text-color);
            background: var(--header-bg);
            border: 1px solid var(--card-border);
            transition: transform 0.2s ease, background 0.2s ease;
        }

        .supporter-link:hover {
            transform: translateY(-1px);
            background: rgba(255, 255, 255, 0.08);
        }

        .premium-badge {
            background: linear-gradient(135deg, #BF953F 0%, #FCF6BA 50%, #AA771C 100%);
            color: #231207;
            padding: 2px 8px;
            border-radius: 6px;
            font-size: 10px;
            font-weight: 800;
            letter-spacing: 0.5px;
            margin-left: 8px;
            display: inline-block;
            box-shadow: 0 0 8px rgba(212, 175, 55, 0.4);
            vertical-align: middle;
        }

        .wallet-box {
            background: rgba(0, 0, 0, 0.06);
            border: 1px solid var(--card-border);
            border-radius: 12px;
            padding: 10px 12px;
            display: flex;
            flex-direction: column;
            text-align: left;
        }

        .wallet-title {
            font-size: 11px;
            font-weight: 800;
            color: var(--text-muted);
            text-transform: uppercase;
            letter-spacing: 0.5px;
            margin-bottom: 6px;
        }

        .wallet-row {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        .wallet-addr {
            font-family: 'Fira Code', monospace;
            font-size: 13px;
            font-weight: 600;
            color: var(--text-color);
            overflow: hidden;
            text-overflow: ellipsis;
            white-space: nowrap;
        }

        .wallet-action-btn {
            background: var(--header-bg);
            border: 1px solid var(--card-border);
            color: var(--text-color);
            padding: 3px 10px;
            border-radius: 8px;
            font-size: 11px;
            font-weight: 600;
            cursor: pointer;
            transition: background 0.2s, transform 0.1s;
        }

        .wallet-action-btn:hover {
            background: rgba(255, 255, 255, 0.08);
        }

        .wallet-action-btn:active {
            transform: scale(0.95);
        }

        .supporter-input-wrapper {
            display: flex;
            align-items: center;
            width: 100%;
            margin-top: 4px;
        }