:root {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --accent-color: #38bdf8;
    --text-main: #f1f5f9;
    --text-dim: #94a3b8;
}

body {
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
}

.container {
    max-width: 800px;
    width: 100%;
}

h1 {
    text-align: center;
    color: var(--accent-color);
    margin-bottom: 5px;
}

.subtitle {
    text-align: center;
    color: var(--text-dim);
    margin-bottom: 30px;
    font-size: 0.9rem;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 16px;
}

.card {
    background: var(--card-bg);
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: transform 0.2s;
}

.card:hover {
    transform: translateY(-2px);
    border-color: var(--accent-color);
}

.card.highlight {
    border-left: 4px solid var(--accent-color);
}

.card h3 {
    margin-top: 0;
    font-size: 0.75rem;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.card p {
    font-size: 1.1rem;
    font-weight: 600;
    margin: 8px 0 0 0;
    word-break: break-all;
}

button {
    display: block;
    margin: 40px auto 20px;
    padding: 12px 30px;
    background-color: var(--accent-color);
    color: #0f172a;
    border: none;
    border-radius: 8px;
    font-weight: bold;
    cursor: pointer;
    font-size: 1rem;
}

button:active {
    transform: scale(0.98);
}

.footer-note {
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-dim);
}

/* スマホ向けの調整 */
@media (max-width: 480px) {
    .info-grid {
        grid-template-columns: 1fr;
    }
}