* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Lexend', 'Arial', sans-serif;
}

body {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 10px;
    color: #333;
    overflow-x: hidden;
    -webkit-text-size-adjust: 100%;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: 15px;
    padding: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    width: 100%;
    box-sizing: border-box;
}

h1 {
    text-align: center;
    color: #4a5568;
    margin-bottom: 10px;
    font-size: 2.5rem;
    font-weight: bold;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.instructions {
    text-align: center;
    color: #666;
    margin-bottom: 30px;
    font-size: 1.1rem;
    font-style: italic;
}

.bingo-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 8px;
    max-width: 600px;
    margin: 0 auto;
    background: #f7fafc;
    padding: 15px;
    border-radius: 10px;
    box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.1);
}

.bingo-square {
    aspect-ratio: 1;
    background: linear-gradient(145deg, #ffffff, #f0f4f7);
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    padding: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    min-height: 80px;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

.bingo-square:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    border-color: #667eea;
}

.bingo-square.completed {
    background: linear-gradient(145deg, #48bb78, #38a169);
    border-color: #2f855a;
    color: white;
    justify-content: flex-start;
    align-items: stretch;
    padding: 4px;
}

.bingo-square.free-space {
    background: linear-gradient(145deg, #ffd700, #ffb347);
    border-color: #ff8c00;
    color: #8b4513;
    font-weight: bold;
    justify-content: center;
    align-items: center;
}

.bingo-square.free-space .question-text {
    display: none !important;
}

.question-text {
    text-align: center;
    font-size: 0.8rem;
    font-weight: 500;
    line-height: 1.2;
    padding: 4px;
    word-wrap: break-word;
    overflow-wrap: break-word;
    hyphens: auto;
}

.question-text.question-small {
    font-size: 0.55rem;
    line-height: 1.1;
    padding: 2px;
    flex: 0 0 25%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 400;
}

.bingo-square.completed .question-text {
    color: white;
}

.name-input {
    width: 100%;
    max-width: 90%;
    padding: 8px 6px;
    border: 1px solid #cbd5e0;
    border-radius: 4px;
    font-size: 0.8rem;
    text-align: center;
    background: white;
    outline: none;
    transition: border-color 0.2s ease;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    touch-action: manipulation;
}

.name-input.name-display {
    flex: 1;
    max-width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.85rem;
    margin-top: 2px;
}

.name-input:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 2px rgba(102, 126, 234, 0.2);
}

.bingo-square.completed .name-input {
    background: rgba(255, 255, 255, 0);
    border-color: rgba(255, 255, 255, 0);
    color: #ffffff;
    font-weight: 500;
    text-align: center;
    justify-content: center;
}

.bingo-square.free-space .name-input {
    color: #8b4513;
    font-weight: bold;
    background: rgba(255, 255, 255, 0);
    border: none;
    width: 100%;
    height: 100%;
    display: flex !important;
    align-items: center;
    justify-content: center;
    font-size: auto;
    padding: 0;
    text-align: center;
}

/* Mobile-first responsive design */
@media (max-width: 768px) {
    body {
        padding: 5px;
    }
    
    .container {
        padding: 15px;
        margin: 0;
        border-radius: 10px;
    }
    
    h1 {
        font-size: 1.8rem;
        margin-bottom: 8px;
    }
    
    .instructions {
        font-size: 0.95rem;
        margin-bottom: 20px;
    }
    
    .bingo-grid {
        gap: 4px;
        padding: 8px;
        max-width: 100%;
    }
    
    .bingo-square {
        min-height: 70px;
        padding: 4px;
    }
    
    .question-text {
        font-size: 0.65rem;
        line-height: 1.1;
        padding: 2px;
    }
    
    .question-text.question-small {
        font-size: 0.45rem;
        line-height: 1.0;
        padding: 1px;
    }
    
    .name-input {
        font-size: 0.7rem;
        padding: 6px 4px;
    }
    
    .name-input.name-display {
        font-size: 0.75rem;
        padding: 4px 2px;
    }
    
    .bingo-square.free-space .name-input {
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    body {
        padding: 2px;
    }
    
    .container {
        padding: 10px;
        margin: 0;
        border-radius: 8px;
    }
    
    h1 {
        font-size: 1.6rem;
        margin-bottom: 5px;
    }
    
    .instructions {
        font-size: 0.9rem;
        margin-bottom: 15px;
    }
    
    .bingo-grid {
        gap: 3px;
        padding: 6px;
    }
    
    .bingo-square {
        min-height: 60px;
        padding: 3px;
        border-radius: 6px;
    }
    
    .question-text {
        font-size: 0.6rem;
        line-height: 1.0;
        padding: 1px;
    }
    
    .question-text.question-small {
        font-size: 0.4rem;
        line-height: 0.9;
        padding: 1px;
    }
    
    .name-input {
        font-size: 0.65rem;
        padding: 5px 3px;
        border-radius: 3px;
    }
    
    .name-input.name-display {
        font-size: 0.7rem;
        padding: 3px 2px;
    }
    
    .bingo-square.free-space .name-input {
        font-size: 0.9rem;
    }
}

@media (max-width: 360px) {
    h1 {
        font-size: 1.4rem;
    }
    
    .instructions {
        font-size: 0.85rem;
    }
    
    .bingo-square {
        min-height: 55px;
        padding: 2px;
    }
    
    .question-text {
        font-size: 0.55rem;
    }
    
    .question-text.question-small {
        font-size: 0.35rem;
        line-height: 0.8;
    }
    
    .name-input {
        font-size: 0.6rem;
        padding: 4px 2px;
    }
    
    .name-input.name-display {
        font-size: 0.65rem;
        padding: 2px 1px;
    }
    
    .bingo-square.free-space .name-input {
        font-size: 0.8rem;
    }
}

/* Ultra-thin screens (like 344px width) */
@media (max-width: 350px) {
    body {
        padding: 1px;
    }
    
    .container {
        padding: 8px;
        border-radius: 6px;
        margin: 1px;
    }
    
    h1 {
        font-size: 1.2rem;
        margin-bottom: 4px;
        line-height: 1.2;
    }
    
    .instructions {
        font-size: 0.8rem;
        margin-bottom: 12px;
        line-height: 1.2;
        padding: 0 4px;
    }
    
    .bingo-grid {
        gap: 2px;
        padding: 4px;
        border-radius: 6px;
    }
    
    .bingo-square {
        min-height: 50px;
        padding: 1px;
        border-radius: 4px;
        border-width: 1px;
    }
    
    .question-text {
        font-size: 0.5rem;
        line-height: 0.9;
        padding: 1px;
        font-weight: 600;
        letter-spacing: -0.02em;
    }
    
    .question-text.question-small {
        font-size: 0.32rem;
        line-height: 0.75;
        font-weight: 700;
        letter-spacing: -0.03em;
    }
    
    .name-input {
        font-size: 0.55rem;
        padding: 3px 1px;
        border-radius: 2px;
        max-width: 95%;
    }
    
    .name-input.name-display {
        font-size: 0.6rem;
        padding: 2px 1px;
        max-width: 100%;
    }
    
    .bingo-square.free-space .name-input {
        font-size: 0.7rem;
    }
}

/* Extra ultra-thin screens (320px and below) */
@media (max-width: 320px) {
    .container {
        padding: 6px;
        margin: 0;
    }
    
    h1 {
        font-size: 1.1rem;
        margin-bottom: 3px;
    }
    
    .instructions {
        font-size: 0.75rem;
        margin-bottom: 10px;
    }
    
    .bingo-grid {
        gap: 1px;
        padding: 3px;
    }
    
    .bingo-square {
        min-height: 45px;
        padding: 1px;
    }
    
    .question-text {
        font-size: 0.45rem;
        line-height: 0.85;
        font-weight: 700;
        letter-spacing: -0.03em;
    }
    
    .question-text.question-small {
        font-size: 0.3rem;
        line-height: 0.7;
        font-weight: 800;
        letter-spacing: -0.04em;
    }
    
    .name-input {
        font-size: 0.5rem;
        padding: 2px 1px;
        max-width: 98%;
    }
    
    .name-input.name-display {
        font-size: 0.55rem;
        padding: 1px;
        max-width: 100%;
    }
    
    .bingo-square.free-space .name-input {
        font-size: 0.65rem;
    }
}