:root {
    --bg: #0d1117;
    --bg-card: #161b22;
    --fg: #e6edf3;
    --fg-muted: #8b949e;
    --accent: #58a6ff;
    --border: #30363d;
}

* { box-sizing: border-box; }

html, body {
    margin: 0;
    padding: 0;
    background: var(--bg);
    color: var(--fg);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans KR",
                 "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
    line-height: 1.7;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    width: 100%;
    max-width: 720px;
    padding: 48px 24px;
    text-align: center;
}

.hero h1 {
    margin: 0 0 12px;
    font-size: clamp(2.5rem, 8vw, 4rem);
    letter-spacing: 0.03em;
    color: var(--accent);
}

.tagline {
    margin: 0 0 32px;
    color: var(--fg-muted);
    font-size: clamp(1.1rem, 3vw, 1.4rem);
}

.intro {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 32px;
    margin-bottom: 32px;
}

.intro p {
    margin: 0;
    color: var(--fg);
}

footer {
    color: var(--fg-muted);
    font-size: 0.9rem;
}

@media (max-width: 560px) {
    .container { padding: 32px 16px; }
    .intro { padding: 24px 20px; }
}