:root {
    --dc-red: #C40233;
    --dc-green: #00A651;
    --dc-blue: #0055A4;
    --dc-yellow: #FFD700;
    --dc-white: #FFFFFF;
    --dc-black: #111111;
    --dc-light-blue: #00BFFF;
    --dc-brown: #5D4037;
    
    --background-color: #121212;
    --text-color: #F5F5F5;
    --card-background: #1E1E1E;
}

body {
    font-family: 'Noto Sans KR', sans-serif;
    background-color: var(--background-color);
    background-image: radial-gradient(var(--card-background) 0.5px, transparent 0.5px);
    background-size: 30px 30px;
    color: var(--text-color);
    margin: 0;
    padding: 0;
    text-align: center;
}

header {
    background-color: var(--dc-brown);
    padding: 2em;
    border-bottom: 5px solid var(--dc-red);
    box-shadow: 0 4px 10px rgba(0,0,0,0.5);
    position: relative;
}

header::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 0;
    width: 100%;
    height: 10px;
    background: repeating-linear-gradient(
        90deg,
        var(--dc-green),
        var(--dc-green) 20px,
        var(--dc-blue) 20px,
        var(--dc-blue) 40px,
        var(--dc-yellow) 40px,
        var(--dc-yellow) 60px
    );
}

h1 {
    margin: 0;
    font-size: 2.8em;
    font-weight: 900;
    letter-spacing: 2px;
    color: var(--dc-yellow);
    text-shadow: 3px 3px 0px var(--dc-red), 5px 5px 0px var(--dc-black);
    text-transform: uppercase;
}

main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4em 2em;
}

#pattern-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 3em;
    margin-bottom: 4em;
}

.pattern-card {
    background-color: var(--card-background);
    border: 8px solid var(--dc-brown);
    border-radius: 4px;
    padding: 0;
    overflow: hidden;
    box-shadow: 0 15px 35px rgba(0,0,0,0.4);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
}

.pattern-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; height: 5px;
    background: var(--dc-red);
    z-index: 10;
}

.pattern-card:hover {
    transform: translateY(-15px) rotate(1deg);
    box-shadow: 0 25px 50px rgba(0,0,0,0.6);
    border-color: var(--dc-red);
}

.pattern-card svg {
    width: 100%;
    height: 100%;
    display: block;
    background: var(--dc-black);
}

#generate-btn {
    background-color: var(--dc-red);
    color: var(--dc-white);
    border: 3px solid var(--dc-yellow);
    padding: 1.2em 3em;
    font-size: 1.3em;
    font-weight: bold;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 8px 20px rgba(196, 2, 51, 0.4);
    text-transform: uppercase;
    letter-spacing: 1px;
}

#generate-btn:hover {
    background-color: var(--dc-green);
    transform: scale(1.1);
    box-shadow: 0 12px 25px rgba(0, 166, 81, 0.5);
}