:root {
    --color-bg: #fafafa;
    --color-surface: #ffffff;
    --color-text: #1c1c1e;
    --color-text-secondary: #6e6e73;
    --color-accent: #ff8c42;
    --color-border: #e5e5e7;
    --max-width: 720px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #1c1c1e;
        --color-surface: #2c2c2e;
        --color-text: #ffffff;
        --color-text-secondary: #98989d;
        --color-border: #38383a;
    }
}

* {
    box-sizing: border-box;
}

html {
    -webkit-text-size-adjust: 100%;
}

body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", Meiryo, sans-serif;
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

header {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 48px 24px 24px;
    border-bottom: 1px solid var(--color-border);
}

header h1 {
    margin: 0 0 8px;
    font-size: 32px;
    font-weight: 700;
    letter-spacing: -0.02em;
}

header .tagline {
    margin: 0;
    color: var(--color-text-secondary);
    font-size: 17px;
}

header a {
    color: var(--color-accent);
    text-decoration: none;
    font-size: 15px;
}

header a:hover {
    text-decoration: underline;
}

main {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 32px 24px 48px;
}

main h2 {
    margin: 40px 0 12px;
    font-size: 20px;
    font-weight: 600;
    letter-spacing: -0.01em;
}

main h2:first-of-type {
    margin-top: 24px;
}

main p {
    margin: 0 0 16px;
    font-size: 16px;
}

main p.meta {
    color: var(--color-text-secondary);
    font-size: 14px;
    margin-bottom: 32px;
}

main ul {
    margin: 0 0 16px;
    padding-left: 24px;
}

main ul li {
    margin-bottom: 8px;
}

main a {
    color: var(--color-accent);
    text-decoration: none;
}

main a:hover {
    text-decoration: underline;
}

main section {
    margin-bottom: 32px;
}

footer {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 24px;
    border-top: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    font-size: 14px;
    text-align: center;
}

@media (max-width: 480px) {
    header {
        padding: 32px 20px 20px;
    }

    header h1 {
        font-size: 26px;
    }

    main {
        padding: 24px 20px 32px;
    }

    main h2 {
        font-size: 18px;
    }
}

header .nav {
    margin: 12px 0 0;
    color: var(--color-text-secondary);
}

main .summary {
    margin: 0 0 24px;
    padding: 16px 20px;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
}

main .summary ul {
    margin: 0;
    padding-left: 20px;
}

main .summary li:last-child {
    margin-bottom: 0;
}