:root {
    --bg-color: #0d1117;
    --card-bg: #161b22;
    --text-main: #c9d1d9;
    --text-sub: #8b949e;
    --border-color: #30363d;
    --accent-blue: #58a6ff;
}

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

body {
    font-family: 'Noto Sans KR', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 40px 20px;
}

.container {
    width: 100%;
    max-width: 1100px;
    text-align: center;
}

header {
    margin-bottom: 50px;
}

.logo-icon {
    font-size: 2.5rem;
    color: var(--accent-blue);
    margin-bottom: 15px;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-sub);
    font-weight: 300;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    text-align: left;
}

.nav-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 25px;
    text-decoration: none;
    color: var(--text-main);
    transition: transform 0.2s ease, border-color 0.2s ease;
    display: flex;
    flex-direction: column;
}

.nav-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-blue);
}

.card-header {
    display: flex;
    align-items: center;
    margin-bottom: 20px;
}

.card-icon {
    font-size: 1.5rem;
    color: var(--text-sub);
    width: 40px;
    height: 40px;
    display: grid;
    place-items: center;
    border-radius: 8px;
    background-color: rgba(139, 148, 158, 0.1);
    margin-right: 15px;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 700;
}

.card-desc {
    font-size: 0.95rem;
    color: var(--text-sub);
    flex-grow: 1;
}

footer {
    margin-top: 60px;
    font-size: 0.9rem;
    color: var(--text-sub);
}

footer a {
    color: var(--text-sub);
    text-decoration: none;
    transition: color 0.2s;
}

footer a:hover {
    color: var(--accent-blue);
}