.notification {
      position: fixed;
      top: 32px;
      left: 50%;
      transform: translateX(-50%) scale(1);
      min-width: 260px;
      max-width: 90vw;
      background: linear-gradient(135deg, #232a23 60%, #1a1a1a 100%);
      color: #fff;
      border-radius: 14px;
      box-shadow: 0 8px 32px rgba(34,197,94,0.18), 0 2px 8px #22c55e30;
      border: 2.5px solid #22c55e60;
      padding: 18px 32px 16px 22px;
      font-size: 1.13rem;
      font-weight: 500;
      z-index: 9999;
      display: flex;
      align-items: center;
      gap: 12px;
      opacity: 0;
      pointer-events: none;
      transition: opacity 0.35s cubic-bezier(.4,2,.6,1), transform 0.35s cubic-bezier(.4,2,.6,1);
    }
    .notification.show {
      opacity: 1;
      pointer-events: auto;
      transform: translateX(-50%) scale(1.04);
      animation: notif-pop 0.35s cubic-bezier(.4,2,.6,1);
    }
    .notification.success {
      border-color: #22c55e;
      background: linear-gradient(135deg, #1e2e1e 60%, #1a1a1a 100%);
    }
    .notification.warning {
      border-color: #f59e0b;
      background: linear-gradient(135deg, #2e261e 60%, #1a1a1a 100%);
    }
    .notification.error {
      border-color: #ef4444;
      background: linear-gradient(135deg, #2e1e1e 60%, #1a1a1a 100%);
    }
    .notif-icon {
      font-size: 1.5em;
      margin-right: 8px;
      filter: drop-shadow(0 1px 2px #0008);
    }
    .notif-message {
      flex: 1;
      word-break: break-word;
    }
    @keyframes notif-pop {
      0% { transform: translateX(-50%) scale(0.85); opacity: 0; }
      80% { transform: translateX(-50%) scale(1.08); opacity: 1; }
      100% { transform: translateX(-50%) scale(1.04); opacity: 1; }
    }
    
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            background: linear-gradient(135deg, #1a1a1a, #2a2a2a);
            color: white;
            overflow-x: hidden;
            min-height: 100vh;
        }

        /* Header */
        .header {
            text-align: center;
            padding: 40px 20px 30px;
            background: rgba(0, 0, 0, 0.3);
            backdrop-filter: blur(10px);
            position: relative;
        }

        /* Authentication Panel */
        .auth-panel {
            position: absolute;
            top: 20px;
            right: 20px;
            display: flex;
            align-items: center;
            gap: 15px;
            z-index: 1000;
        }

        .auth-buttons {
            display: flex;
            gap: 10px;
            align-items: center;
        }

        .auth-button.profile-btn {
            background: linear-gradient(45deg, #8b5cf6, #a855f7);
            font-size: 0.85rem;
            padding: 8px 16px;
        }

        .auth-button.profile-btn:hover {
            box-shadow: 0 4px 15px rgba(139, 92, 246, 0.3);
        }

        .auth-status {
            display: flex;
            align-items: center;
            gap: 10px;
            background: rgba(0, 0, 0, 0.6);
            padding: 8px 15px;
            border-radius: 25px;
            border: 1px solid #333;
        }

        .user-avatar {
            width: 32px;
            height: 32px;
            border-radius: 50%;
            border: 2px solid #22c55e;
        }

        .user-info {
            display: flex;
            flex-direction: column;
            align-items: flex-start;
            text-align: left;
        }

        .user-name {
            font-size: 0.9rem;
            font-weight: 600;
            color: #fff;
            line-height: 1;
        }

        .user-status {
            font-size: 0.7rem;
            color: #888;
            line-height: 1;
        }

        .auth-button {
            background: linear-gradient(45deg, #4285f4, #34a853);
            color: white;
            border: none;
            padding: 10px 20px;
            border-radius: 25px;
            font-size: 0.9rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .auth-button:hover {
            transform: translateY(-2px);
            box-shadow: 0 4px 15px rgba(66, 133, 244, 0.3);
        }

        .auth-button.sign-out {
            background: linear-gradient(45deg, #dc2626, #ef4444);
        }

        .auth-button.sign-out:hover {
            box-shadow: 0 4px 15px rgba(220, 38, 38, 0.3);
        }

        .anonymous-notice {
            background: rgba(245, 158, 11, 0.1);
            border: 1px solid #f59e0b;
            color: #fbbf24;
            padding: 8px 15px;
            border-radius: 6px;
            font-size: 0.8rem;
            text-align: center;
            margin: 20px auto;
            max-width: 500px;
        }

        @media (max-width: 768px) {
            .auth-panel {
                position: static;
                justify-content: center;
                margin-bottom: 20px;
                flex-wrap: wrap;
            }
            
            .auth-status {
                flex-direction: column;
                text-align: center;
                order: 1;
            }

            .auth-buttons {
                order: 2;
                margin-top: 10px;
            }
        }

        .logo {
            font-size: 7rem;
            font-weight: bold;
            background: linear-gradient(45deg, #06b6d4, #22c55e, #059669);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
            margin-bottom: 15px;
            text-shadow: 0 0 1px rgba(6, 182, 212, 0.3), 0 0 4px rgba(34, 197, 94, 0.2);
            filter: drop-shadow(0 0 1px rgba(6, 182, 212, 0.4)) drop-shadow(0 0 10px rgba(34, 197, 94, 0.3));
            animation: titleGlow 3s ease-in-out infinite alternate;
        }

        @keyframes titleGlow {
            0% {
                filter: drop-shadow(0 0 10px rgba(6, 182, 212, 0.4)) drop-shadow(0 0 20px rgba(34, 197, 94, 0.3));
            }
            100% {
                filter: drop-shadow(0 0 15px rgba(6, 182, 212, 0.6)) drop-shadow(0 0 30px rgba(34, 197, 94, 0.5));
            }
        }

        .subtitle {
            font-size: 1.3rem;
            color: #22c55e;
            margin-bottom: 8px;
            text-shadow: 0 0 1px rgba(34, 197, 94, 0.6), 0 0 20px rgba(34, 197, 94, 0.4), 0 0 30px rgba(34, 197, 94, 0.2);
            filter: drop-shadow(0 0 1px rgba(34, 197, 94, 0.5));
        }

        .description {
            font-size: 1.5rem;
            color: #ccc;
            max-width: 600px;
            margin: 0 auto;
            line-height: 1.5;
        }

        /* Main Content */
        .main-content {
            display: grid;
            grid-template-columns: 1fr 3fr 1fr;
            gap: 20px;
            align-items: start;
            max-width: none; /* Remove max-width to allow full width */
            margin: 0; /* Remove auto margin to stretch to edges */
            padding: 20px 0; /* Remove horizontal padding */
        }

        /* Left Panel: How to Play */
        .how-to-sidebar {
            background: #18181b;
            border-radius: 12px;
            padding: 20px 16px;
            box-shadow: 0 2px 12px rgba(0,0,0,0.12);
        }

        .how-to-title {
            font-size: 1.3rem;
            font-weight: 700;
            margin-bottom: 12px;
            color: #22d3ee;
        }

        .how-to-step {
            margin-bottom: 6px;
            padding-left: 14px;
            position: relative;
            color: #ccc;
            font-size: 0.8rem;
            line-height: 1.3;
        }

        .how-to-step::before {
            content: "•";
            color: #22c55e;
            position: absolute;
            left: 0;
            font-weight: bold;
        }

        /* Center Panel - Game Options */
        .game-panel {
            background: rgba(0, 0, 0, 0.4);
            backdrop-filter: blur(10px);
            border-radius: 12px;
            padding: 20px;
            border: 1px solid #333;
        }

        .panel-title {
            font-size: 1.5rem;
            margin-bottom: 18px;
            color: #fff;
            text-align: center;
        }

        .game-modes-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 24px;
        }

        .game-option {
            background: rgba(255, 255, 255, 0.05);
            border: 1px solid #444;
            border-radius: 8px;
            padding: 6px;
            transition: all 0.3s ease;
            cursor: pointer;
            position: relative;
            outline: none;
            min-height: 240px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
        }

        .game-option:focus {
            border-color: #22c55e;
            box-shadow: 0 0 0 2px rgba(34, 197, 94, 0.2);
        }

        .game-option:focus:not(:hover) {
            transform: none;
        }

        .game-option:hover {
            background: rgba(255, 255, 255, 0.1);
            border-color: #22c55e;
            transform: translateY(-2px);
            box-shadow: 0 4px 20px rgba(34, 197, 94, 0.2);
        }

        .start-button:hover {
            transform: translateY(-1px);
            box-shadow: 0 3px 15px rgba(34, 197, 94, 0.3);
        }

        .start-button:active {
            transform: translateY(0);
        }

        /* Game mode specific styling */
        .game-option#classicMode {
            background: rgba(26, 46, 26, 0.3);
            border-color: #166534;
        }

        .game-option#classicMode:hover {
            background: rgba(26, 46, 26, 0.5);
            border-color: #22c55e;
            box-shadow: 0 4px 20px rgba(34, 197, 94, 0.2);
        }

        .game-option#practiceMode {
            background: rgba(75, 75, 75, 0.3);
            border-color: #6b7280;
        }

        .game-option#practiceMode:hover {
            background: rgba(75, 75, 75, 0.5);
            border-color: #9ca3af;
            box-shadow: 0 4px 20px rgba(156, 163, 175, 0.2);
        }

        .game-option#hardMode {
            background: rgba(46, 26, 26, 0.3);
            border-color: #991b1b;
        }

        .game-option#hardMode:hover {
            background: rgba(46, 26, 26, 0.5);
            border-color: #ef4444;
            box-shadow: 0 4px 20px rgba(239, 68, 68, 0.2);
        }

        .game-option#timeTrialMode {
            background: rgba(26, 26, 26, 0.3);
            border-color: #374151;
        }

        .game-option#timeTrialMode:hover {
            background: rgba(26, 26, 26, 0.5);
            border-color: #6b7280;
            box-shadow: 0 4px 20px rgba(107, 114, 128, 0.2);
        }

        .game-option#quickMode {
            background: rgba(46, 46, 26, 0.3);
            border-color: #a16207;
        }

        .game-option#quickMode:hover {
            background: rgba(46, 46, 26, 0.5);
            border-color: #f59e0b;
            box-shadow: 0 4px 20px rgba(245, 158, 11, 0.2);
        }

        .game-option#marathonMode {
            background: rgba(26, 46, 46, 0.3);
            border-color: #155e75;
        }

        .game-option#marathonMode:hover {
            background: rgba(26, 46, 46, 0.5);
            border-color: #0891b2;
            box-shadow: 0 4px 20px rgba(8, 145, 178, 0.2);
        }

        .game-option#survivalMode {
            background: rgba(46, 42, 26, 0.3);
            border-color: #c2410c;
        }

        .game-option#survivalMode:hover {
            background: rgba(46, 42, 26, 0.5);
            border-color: #ea580c;
            box-shadow: 0 4px 20px rgba(234, 88, 12, 0.2);
        }

        .game-option#practiceMode:hover {
            border-color: #ffffff;
            box-shadow: 0 4px 20px rgba(255, 0, 0, 0.2);
        }

        .option-title {
            font-size: 1.05rem;
            font-weight: bold;
            margin-bottom: 5px;
            color: #22c55e;
        }

        .option-description {
            color: #ccc;
            font-size: 0.8rem;
            margin-bottom: 10px;
            line-height: 1.3;
        }

        .option-details {
            display: flex;
            justify-content: space-between;
            align-items: center;
            font-size: 0.72rem;
            color: #888;
            flex-wrap: wrap;
            gap: 6px;
        }

        .option-stats {
            flex: 1;
            min-width: 0;
        }

        .start-button {
            background: linear-gradient(45deg, #22c55e, #16a34a);
            color: white;
            border: none;
            padding: 6px 12px;
            border-radius: 5px;
            font-size: 11px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            white-space: nowrap;
        }

        /* Right Panel - Daily Scores */
        .daily-scores-panel {
            background: rgba(0, 0, 0, 0.4);
            backdrop-filter: blur(10px);
            border-radius: 12px;
            padding: 20px;
            border: 1px solid #333;
            max-height: 85vh;
            overflow-y: auto;
        }

        .stats-section {
            margin-bottom: 20px;
        }

        .stats-title {
            font-size: 1.1rem;
            margin-bottom: 10px;
            color: #22c55e;
        }

        .stat-item {
            display: flex;
            justify-content: space-between;
            padding: 5px 0;
            border-bottom: 1px solid #333;
            font-size: 0.85rem;
        }

        .stat-item:last-child {
            border-bottom: none;
        }

        .how-to-play {
            margin-top: 20px;
        }

        .how-to-title {
            font-size: 1.1rem;
            margin-bottom: 10px;
            color: #3b82f6;
        }

        .how-to-step {
            margin-bottom: 6px;
            padding-left: 14px;
            position: relative;
            color: #ccc;
            font-size: 0.8rem;
            line-height: 1.3;
        }

        .how-to-step::before {
            content: "•";
            color: #22c55e;
            position: absolute;
            left: 0;
            font-weight: bold;
        }

        /* Footer */
        .footer {
            text-align: center;
            padding: 25px 20px;
            color: #666;
            border-top: 1px solid #333;
            margin-top: 30px;
            font-size: 0.9rem;
        }

        /* Navigation */
        .nav-section {
            background: rgba(0, 0, 0, 0.4);
            backdrop-filter: blur(10px);
            padding: 10px 20px;
            border-radius: 8px;
            margin: 20px 0;
            border: 1px solid #333;
        }

        .nav-links {
            display: flex;
            justify-content: center;
            gap: 15px;
        }

        .nav-links a {
            color: #bbb;
            text-decoration: none;
            font-size: 0.9rem;
            position: relative;
            padding: 5px 10px;
            transition: color 0.3s;
        }

        .nav-links a:hover {
            color: #22c55e;
        }

        .nav-links a.active {
            color: #22c55e;
            font-weight: 600;
        }

        /* Responsive */
        @media (max-width: 1200px) {
            .main-content {
                grid-template-columns: 1fr 2fr 1fr;
                gap: 16px;
                max-width: none;
                margin: 0;
                padding: 20px 0;
            }
            
            .game-modes-grid {
                grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            }
        }

        @media (max-width: 768px) {
            .main-content {
                grid-template-columns: 1fr;
                gap: 20px;
                max-width: none;
                margin: 0;
                padding: 20px 0;
            }

            .logo {
                font-size: 3.25rem;
            }

            .subtitle {
                font-size: 1.2rem;
            }
            
            .game-modes-grid {
                grid-template-columns: 1fr;
            }
        }

        /* Animations */
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(30px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .game-panel, .info-panel {
            animation: fadeInUp 0.6s ease-out;
        }

        .info-panel {
            animation-delay: 0.2s;
        }

        /* Username Modal Styles */
        .username-modal {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.8);
            display: flex;
            justify-content: center;
            align-items: center;
            z-index: 10000;
            animation: fadeIn 0.3s ease-out;
        }

        .username-modal-content {
            background: #1a1a1a;
            border: 2px solid #333;
            border-radius: 12px;
            padding: 30px;
            max-width: 400px;
            width: 90%;
            text-align: center;
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
        }

        .username-modal h3 {
            color: #22c55e;
            margin-bottom: 15px;
            font-size: 1.5rem;
        }

        .username-modal p {
            color: #ccc;
            margin-bottom: 20px;
            line-height: 1.4;
        }

        .username-modal input {
            width: 100%;
            padding: 12px;
            font-size: 1rem;
            border: 2px solid #333;
            border-radius: 8px;
            background: #2a2a2a;
            color: white;
            margin-bottom: 20px;
            outline: none;
            transition: border-color 0.3s;
        }

        .username-modal input:focus {
            border-color: #22c55e;
        }

        .username-modal-buttons {
            display: flex;
            gap: 10px;
            justify-content: center;
        }

        .username-modal button {
            padding: 12px 24px;
            font-size: 1rem;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            transition: all 0.3s;
            font-weight: 600;
        }

        .username-modal .btn-primary {
            background: #22c55e;
            color: white;
            border: none;
            padding: 12px 24px;
            border-radius: 8px;
            cursor: pointer;
            font-size: 1rem;
            font-weight: 600;
            transition: all 0.3s;
        }

        .username-modal .btn-primary:hover {
            background: #16a34a;
        }

        .username-modal .btn-primary:disabled {
            background: #666;
            cursor: not-allowed;
        }

        .username-modal .btn-secondary {
            background: #666;
            color: white;
            border: none;
            padding: 12px 24px;
            border-radius: 8px;
            cursor: pointer;
            font-size: 1rem;
            font-weight: 600;
            transition: all 0.3s;
        }

        .username-modal .btn-secondary:hover {
            background: #555;
        }

        .username-note {
            font-size: 0.85rem;
            color: #888;
            margin-top: 15px;
            margin-bottom: 0;
        }

        @keyframes fadeIn {
            from {
                opacity: 0;
                transform: scale(0.9);
            }
            to {
                opacity: 1;
                transform: scale(1);
            }
        }

        /* Pulse animation for Expert Mode */
        @keyframes pulse {
            0%, 100% { 
                transform: scale(1);
                opacity: 0.1;
            }
            50% { 
                transform: scale(1.1);
                opacity: 0.2;
            }
        }

        /* Expert Mode card pulse animation */
        @keyframes expertCardPulse {
            0%, 100% { 
                box-shadow: 0 0 40px rgba(139, 92, 246, 0.4), inset 0 0 20px rgba(139, 92, 246, 0.1);
                border-color: rgba(139, 92, 246, 0.6);
            }
            50% { 
                box-shadow: 0 0 60px rgba(139, 92, 246, 0.6), inset 0 0 30px rgba(139, 92, 246, 0.2);
                border-color: rgba(139, 92, 246, 0.8);
            }
        }

        /* Expert Mode card styling */
        .expert-mode-card {
            position: relative;
            overflow: hidden;
        }

        .expert-mode-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: linear-gradient(45deg, rgba(139, 92, 246, 0.05), rgba(168, 85, 247, 0.05));
            animation: expertShimmer 3s infinite;
            pointer-events: none;
        }

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