* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #ff9d00;
    --primary-dark: #ff8800;
    --secondary: #00c3ff;
    --success: #00d664;
    --danger: #ff4757;
    --warning: #ffa502;
    --dark: #2f3542;
    --darker: #1e272e;
    --light: #f1f2f6;
    --text: #2f3542;
    --text-light: #57606f;
    --border: #ced6e0;
    --shadow: rgba(255, 157, 0, 0.3);
    --habbo-blue: #0099cc;
    --habbo-pink: #ff66cc;
    --habbo-green: #00cc66;
}

body {
    font-family: 'Courier New', Courier, monospace;
    background: linear-gradient(135deg, #0099cc 0%, #00c3ff 50%, #ff9d00 100%);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    color: var(--text);
    overflow-x: hidden;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        repeating-linear-gradient(0deg, transparent, transparent 20px, rgba(255,255,255,0.03) 20px, rgba(255,255,255,0.03) 40px),
        repeating-linear-gradient(90deg, transparent, transparent 20px, rgba(255,255,255,0.03) 20px, rgba(255,255,255,0.03) 40px);
    pointer-events: none;
    z-index: 1;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.container {
    width: 100%;
    max-width: 500px;
    position: relative;
    z-index: 2;
}

.screen {
    background: white;
    border-radius: 8px;
    padding: 32px 24px;
    box-shadow: 
        0 8px 0 rgba(0,0,0,0.1),
        0 8px 30px rgba(0,0,0,0.3),
        inset 0 0 0 4px #f1f2f6;
    display: none;
    animation: slideIn 0.4s ease-out;
    border: 4px solid var(--dark);
    image-rendering: pixelated;
}

.screen.active {
    display: block;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Start Screen */
.logo {
    text-align: center;
    margin-bottom: 24px;
}

.habbo-logo {
    font-size: 80px;
    animation: bounce 2s ease-in-out infinite;
    display: inline-block;
    filter: drop-shadow(0 4px 8px rgba(0,0,0,0.2));
}

@keyframes bounce {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

.logo-icon {
    width: 80px;
    height: 80px;
    color: var(--primary);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
        opacity: 1;
    }
    50% {
        transform: scale(1.05);
        opacity: 0.8;
    }
}

h1 {
    text-align: center;
    font-size: 32px;
    color: var(--dark);
    margin-bottom: 8px;
    font-weight: 900;
    letter-spacing: 2px;
    text-transform: uppercase;
    text-shadow: 3px 3px 0 var(--primary), 6px 6px 0 rgba(0,0,0,0.1);
}

.subtitle {
    text-align: center;
    color: var(--habbo-blue);
    font-weight: 700;
    margin-bottom: 24px;
    font-size: 14px;
    letter-spacing: 2px;
    text-transform: uppercase;
}

.instructions {
    text-align: center;
    color: var(--text-light);
    margin-bottom: 32px;
    line-height: 1.6;
    font-size: 15px;
}

.difficulty-selector {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
}

.diff-btn {
    flex: 1;
    padding: 12px;
    border: 3px solid var(--dark);
    background: white;
    border-radius: 4px;
    font-size: 13px;
    font-weight: 700;
    color: var(--text);
    cursor: pointer;
    transition: all 0.2s ease;
    text-transform: uppercase;
    box-shadow: 0 4px 0 var(--border);
}

.diff-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-2px);
    box-shadow: 0 6px 0 var(--border);
}

.diff-btn.active {
    background: var(--primary);
    border-color: var(--dark);
    color: var(--dark);
    box-shadow: 0 4px 0 var(--primary-dark);
}

.primary-btn {
    width: 100%;
    padding: 16px;
    background: var(--primary);
    border: 4px solid var(--dark);
    border-radius: 4px;
    color: var(--dark);
    font-size: 18px;
    font-weight: 900;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 6px 0 var(--primary-dark), 0 8px 20px rgba(0,0,0,0.2);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.primary-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 9px 0 var(--primary-dark), 0 12px 30px rgba(0,0,0,0.3);
}

.primary-btn:active {
    transform: translateY(2px);
    box-shadow: 0 2px 0 var(--primary-dark);
}

/* Game Screen */
.game-header {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 12px;
    margin-bottom: 24px;
}

/* Character Walking Track */
.character-track {
    position: relative;
    width: 100%;
    height: 120px;
    background: linear-gradient(to bottom, #e0f7ff 0%, #b3e5fc 100%);
    border: 3px solid var(--dark);
    border-radius: 4px;
    margin-bottom: 20px;
    overflow: hidden;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
}

.character-track::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 30px;
    background: repeating-linear-gradient(
        90deg,
        #8bc34a 0px,
        #8bc34a 20px,
        #7cb342 20px,
        #7cb342 40px
    );
    border-top: 2px solid var(--dark);
}

.character {
    position: absolute;
    bottom: 30px;
    left: 0%;
    height: 80px;
    width: auto;
    image-rendering: pixelated;
    transition: left 0.5s ease-out;
    z-index: 10;
    filter: drop-shadow(2px 2px 2px rgba(0,0,0,0.3));
}

.character.walking {
    animation: none;
}

.stat-box {
    background: var(--light);
    border-radius: 4px;
    padding: 12px;
    text-align: center;
    border: 3px solid var(--dark);
    box-shadow: 0 3px 0 rgba(0,0,0,0.1);
}

.time-box {
    background: var(--primary);
    border-color: var(--dark);
}

.stat-label {
    font-size: 11px;
    color: var(--text-light);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 4px;
}

.stat-value {
    font-size: 24px;
    font-weight: 800;
    color: var(--dark);
}

.game-content {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.term-card {
    background: linear-gradient(135deg, var(--habbo-blue), var(--secondary));
    border-radius: 4px;
    padding: 24px;
    box-shadow: 0 6px 0 rgba(0,0,0,0.2), 0 8px 24px rgba(0,153,204,0.3);
    position: relative;
    overflow: hidden;
    border: 4px solid var(--dark);
}

.term-card::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: repeating-linear-gradient(
        45deg,
        transparent,
        transparent 10px,
        rgba(255,255,255,0.05) 10px,
        rgba(255,255,255,0.05) 20px
    );
}

@keyframes shimmer {
    0%, 100% {
        transform: translate(0, 0);
    }
    50% {
        transform: translate(-20px, -20px);
    }
}

.card-label {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.8);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 8px;
}

.term-text {
    font-size: 28px;
    font-weight: 800;
    color: white;
    line-height: 1.3;
    position: relative;
    z-index: 1;
}

.options-grid {
    display: grid;
    gap: 12px;
}

.option-btn {
    padding: 18px;
    background: white;
    border: 3px solid var(--dark);
    border-radius: 4px;
    font-size: 14px;
    line-height: 1.5;
    color: var(--text);
    cursor: pointer;
    transition: all 0.2s ease;
    text-align: left;
    font-weight: 600;
    box-shadow: 0 4px 0 var(--border);
}

.option-btn:hover {
    border-color: var(--primary);
    background: var(--light);
    transform: translateX(4px) translateY(-2px);
    box-shadow: 0 6px 0 var(--primary);
}

.option-btn.correct {
    background: var(--success);
    border-color: var(--success);
    color: white;
    animation: successPulse 0.5s ease;
}

.option-btn.wrong {
    background: var(--danger);
    border-color: var(--danger);
    color: white;
    animation: shake 0.5s ease;
}

.option-btn.disabled {
    pointer-events: none;
    opacity: 0.6;
}

@keyframes successPulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

@keyframes shake {
    0%, 100% {
        transform: translateX(0);
    }
    25% {
        transform: translateX(-10px);
    }
    75% {
        transform: translateX(10px);
    }
}

.progress-bar {
    height: 8px;
    background: var(--border);
    border-radius: 8px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: 8px;
    transition: width 0.3s ease;
    width: 0%;
}

/* End Screen */
.result-icon {
    text-align: center;
    font-size: 80px;
    margin-bottom: 16px;
    animation: bounceIn 0.6s ease;
}

@keyframes bounceIn {
    0% {
        transform: scale(0);
        opacity: 0;
    }
    60% {
        transform: scale(1.2);
        opacity: 1;
    }
    100% {
        transform: scale(1);
    }
}

h2 {
    text-align: center;
    font-size: 28px;
    color: var(--dark);
    margin-bottom: 24px;
    font-weight: 800;
}

.final-score {
    background: var(--primary);
    border-radius: 4px;
    padding: 24px;
    text-align: center;
    margin-bottom: 24px;
    border: 4px solid var(--dark);
    box-shadow: 0 6px 0 var(--primary-dark);
}

.score-label {
    font-size: 14px;
    color: var(--dark);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 8px;
}

.score-value {
    font-size: 56px;
    font-weight: 900;
    color: var(--dark);
    text-shadow: 3px 3px 0 rgba(0,0,0,0.2);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-bottom: 24px;
}

.stat-item {
    background: var(--light);
    border-radius: 4px;
    padding: 16px 12px;
    text-align: center;
    border: 3px solid var(--dark);
    box-shadow: 0 3px 0 rgba(0,0,0,0.1);
}

.stat-number {
    font-size: 28px;
    font-weight: 800;
    color: var(--dark);
    margin-bottom: 4px;
}

.stat-desc {
    font-size: 11px;
    color: var(--text-light);
    font-weight: 600;
    text-transform: uppercase;
}

.special-message {
    background: var(--secondary);
    border-radius: 4px;
    padding: 16px;
    text-align: center;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 24px;
    font-size: 14px;
    line-height: 1.5;
    border: 3px solid var(--dark);
    box-shadow: 0 4px 0 rgba(0,0,0,0.1);
}

.special-message:empty {
    display: none;
}

/* Feedback Overlay */
.feedback-overlay {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0);
    font-size: 48px;
    font-weight: 900;
    z-index: 1000;
    pointer-events: none;
    transition: transform 0.3s ease;
    text-shadow: 3px 3px 0 rgba(0,0,0,0.3);
    white-space: nowrap;
    background: white;
    padding: 20px 40px;
    border-radius: 16px;
    border: 4px solid var(--dark);
    box-shadow: 0 8px 24px rgba(0,0,0,0.4);
}

.feedback-overlay.show {
    animation: feedbackPop 0.6s ease;
}

@keyframes feedbackPop {
    0% {
        transform: translate(-50%, -50%) scale(0);
        opacity: 0;
    }
    20% {
        transform: translate(-50%, -50%) scale(1.15);
        opacity: 1;
    }
    70% {
        transform: translate(-50%, -50%) scale(1);
        opacity: 1;
    }
    100% {
        transform: translate(-50%, -50%) scale(0.8);
        opacity: 0;
    }
}

/* Timer warning animation */
.time-box.warning {
    animation: warningFlash 1s ease-in-out infinite;
}

@keyframes warningFlash {
    0%, 100% {
        background: linear-gradient(135deg, #fef3c7, #fde68a);
    }
    50% {
        background: linear-gradient(135deg, #fecaca, #fca5a5);
    }
}

/* Responsive adjustments */
@media (max-width: 400px) {
    .screen {
        padding: 24px 20px;
        border-radius: 20px;
    }
    
    h1 {
        font-size: 28px;
    }
    
    .term-text {
        font-size: 24px;
    }
    
    .stat-value {
        font-size: 20px;
    }
    
    .option-btn {
        padding: 16px;
        font-size: 13px;
    }
    
    .diff-btn {
        padding: 10px;
        font-size: 12px;
    }
}

/* Special effects for correct answers */
@keyframes confetti {
    0% {
        transform: translateY(0) rotate(0deg);
        opacity: 1;
    }
    100% {
        transform: translateY(-100vh) rotate(720deg);
        opacity: 0;
    }
}

.confetti-piece {
    position: fixed;
    width: 12px;
    height: 12px;
    background: var(--primary);
    top: 100%;
    animation: confetti 3s ease-out forwards;
    pointer-events: none;
    border-radius: 2px;
}