/* Base styles - Core layout and typography */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Arial', sans-serif;
    background-image: url('istockphoto-157622968-612x612.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px;
}

.container {
    text-align: center;
    width: 100%;
    max-width: 1200px;
}

.title {
    color: white;
    font-size: 3.5rem;
    margin-bottom: 3rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    padding: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

/* Page index navigation */
.page-index {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.index-item {
    background: rgba(255, 255, 255, 0.9);
    padding: 12px 20px;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 500;
    color: #333;
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.index-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.3);
    border-color: #3498db;
}

/* Instruction container */
.instruction-container {
    margin-bottom: 2rem;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.spinning-letters {
    font-size: 2.5rem;
    font-weight: bold;
    color: white;
    text-shadow: 3px 3px 6px rgba(0,0,0,0.5);
    letter-spacing: 3px;
    text-transform: uppercase;
    animation: letterSpin 2s ease-out;
}

@keyframes letterSpin {
    0% {
        transform: rotateX(0deg) scale(0.5);
        opacity: 0;
        letter-spacing: -10px;
    }
    50% {
        transform: rotateX(180deg) scale(1.2);
        opacity: 0.8;
        letter-spacing: 8px;
    }
    100% {
        transform: rotateX(360deg) scale(1);
        opacity: 1;
        letter-spacing: 3px;
    }
}

/* Utility classes */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); }
}

@keyframes highlight {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}