:root { 
            --primary: #0003c3; 
            --secondary: #1700e6; 
            --bg: #001954; 
            --card: #ffffff; 
            --text: #1e293b; 
            --success: #10b981; 
            --danger: #ef4444; 
            --warning: #f59e0b;
        }

        body { 
            font-family: 'Signika Negative', sans-serif; 
            background: var(--bg); 
            background-image: url('../images/background.png');
            color: var(--text); 
            margin: 0; 
            display: flex; 
            justify-content: center; 
            align-items: center; 
            min-height: 100vh; 
            overflow-x: hidden;
        }

        .game-card { 
            background: var(--card); 
            width: 90%; 
            max-width: 550px; 
            padding: 2rem; 
            border-radius: 32px; 
            box-shadow: 0 25px 50px -12px rgba(0,0,0,0.5); 
            position: relative; 
            min-height: 580px;
            display: flex;
            flex-direction: column;
        }

        .top-nav { 
            display: flex; 
            justify-content: space-between; 
            align-items: center; 
            margin-bottom: 1.5rem; 
        }

        .nav-icon { 
            cursor: pointer; 
            color: #94a3b8; 
            font-size: 1.3rem; 
            transition: 0.3s; 
        }

        .nav-icon:hover { 
            color: var(--primary); 
        }

        .mission-label { 
            font-weight: 700; 
            font-size: 0.8rem; 
            color: #64748b; 
            letter-spacing: 2px; 
            text-transform: uppercase; 
        }

        .timer-bar { 
            height: 8px; 
            background: #f1f5f9; 
            border-radius: 10px; 
            margin-bottom: 25px; 
            overflow: hidden; 
        }
        
        #timer-fill { 
            height: 100%; 
            background: linear-gradient(to right, var(--primary), var(--secondary)); 
            width: 100%; 
            transition: 1s linear; 
        }

        .step-row { 
            display: flex; 
            justify-content: space-between; 
            margin-bottom: 30px; 
            position: relative; 
        }
        
        .step-row::before { 
            content: ''; 
            position: absolute; 
            top: 50%; 
            left: 0; 
            right: 0; 
            height: 2px; 
            background: #e2e8f0; 
            z-index: 1; 
            transform: translateY(-50%); 
        }
        
        .step { 
            width: 35px; 
            height: 35px; 
            border-radius: 50%; 
            background: #e2e8f0; 
            display: flex; 
            align-items: center; 
            justify-content: center; 
            font-size: 14px; 
            font-weight: 700; 
            color: #64748b; 
            z-index: 2; 
            border: 3px solid white; 
            transition: 0.3s; 
        }
        
        .step.active { 
            background: var(--primary); 
            color: white; 
            border-color: #e0e7ff; 
            transform: scale(1.2); 
        }
        
        .step.done { 
            background: var(--success); 
            color: white; 
        }

        h1 { 
            font-size: 2.2rem; 
            font-weight: 800; 
            margin-bottom: 0.5rem; 
            background: linear-gradient(to right, var(--primary), var(--secondary)); 
            -webkit-background-clip: text; 
            -webkit-text-fill-color: transparent; 
            text-align: center; 
        }
        
        h3 { 
            font-weight: 700; 
            color: #0f172a; 
            margin-top: 0; 
            margin-bottom: 1rem; 
        }

        .study-box { 
            background: #f8fafc; 
            border-left: 5px solid var(--primary); 
            padding: 1.2rem; 
            border-radius: 12px; 
            margin: 15px 0; 
            font-size: 0.9rem; 
            line-height: 1.6; 
            border: 1px solid #e2e8f0;
            display: flex;
            gap: 15px;
            align-items: flex-start;
        }
        
        .anime-avatar {
            width: 50px;
            height: 50px;
            border-radius: 12px;
            background: #e2e8f0;
            flex-shrink: 0;
            border: 2px solid var(--primary);
            overflow: hidden;
        }

        .math-tag { 
            background: #e0e7ff; 
            color: var(--primary); 
            padding: 2px 6px; 
            border-radius: 4px; 
            font-family: monospace; 
            font-weight: 700; 
        }

        .btn { 
            width: 100%; 
            padding: 16px; 
            border: none; 
            border-radius: 16px; 
            background: var(--primary); 
            color: white; 
            font-weight: 700; 
            font-size: 1rem; 
            cursor: pointer; 
            transition: 0.3s; 
            margin-top: 10px; 
            display: flex; 
            justify-content: center; 
            align-items: center; 
            gap: 10px; 
            border-bottom: 4px solid rgba(0,0,0,0.1); 
        }

        .btn:hover { 
            transform: translateY(-2px); 
            filter: brightness(1.1); 
        }

        .btn:active { 
            transform: translateY(1px); 
            border-bottom-width: 1px; 
        }
        
        .btn-outline { 
            background: transparent; 
            border: 2px solid #e2e8f0; 
            color: #64748b; 
        }

        .btn-outline:hover { 
            background: #f8fafc; 
        }

        input { 
            width: 100%; 
            padding: 14px; 
            border: 2px solid #e2e8f0; 
            border-radius: 12px; 
            outline: none; 
            font-size: 1rem; 
            font-family: inherit; 
            margin-bottom: 10px; 
            box-sizing: border-box; 
        }
        
        input:focus { 
            border-color: var(--primary); 
        }

        .chip-container { 
            display: flex; 
            flex-wrap: wrap; 
            gap: 10px; 
            margin: 20px 0; 
            justify-content: center; 
        }

        .chip { 
            padding: 10px 18px; 
            background: #f1f5f9; 
            border-radius: 12px; 
            cursor: pointer; 
            font-weight: 700; 
            transition: 0.2s; 
            border: 2px solid transparent; 
        }

        .chip:hover { 
            background: #e2e8f0; 
        }

        .chip.selected { 
            background: var(--primary); 
            color: white; 
        }

        .chip.wrong { 
            background: var(--danger); 
            color: white; 
            animation: shake 0.4s; 
        }

        .modal-overlay { 
            position: fixed; 
            top: 0; 
            left: 0; 
            width: 100%; 
            height: 100%; 
            background: rgba(15, 23, 42, 0.8); 
            backdrop-filter: blur(8px); 
            display: flex; 
            align-items: center; 
            justify-content: center; 
            z-index: 1000; 
        }

        .modal-box { 
            background: white; 
            padding: 2.5rem; 
            border-radius: 32px; 
            width: 85%; 
            max-width: 400px; 
            text-align: center; 
        }

        @keyframes shake { 
            0%, 100% { 
                transform: translateX(0); 
            } 25% { 
                transform: translateX(-6px); 
            } 75% { 
                transform: translateX(6px); 
            } 
        }

        .hidden { 
            display: none; 
        }

        .fade-in { 
            animation: fadeIn 0.4s ease-out forwards; 
        }

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

        .leaderboard-table { 
            width: 100%; 
            margin-top: 1rem; 
            border-spacing: 0; 
        }

        .leaderboard-table td { 
            padding: 10px; 
            border-bottom: 1px solid #f1f5f9; 
            font-size: 0.9rem; 
        }
        
        .hero-icon { 
            font-size: 4rem; 
            margin-bottom: 1rem; 
            color: var(--primary); 
            text-shadow: 0 10px 20px rgba(99,102,241,0.2); 
            position: relative; 
            display: inline-block; 
        }

        .audio-toggle { 
            font-size: 1.2rem; 
            cursor: pointer; 
            color: var(--primary); 
            margin-left: 10px; 
        }

        .footer { 
            margin-top: auto; 
            text-align: center; 
            padding-top: 15px; 
        }