:root {
    --primary: #333;
    --accent: #0077cc;
    --background: #f9f9f9;
    --font: 'Segoe UI', sans-serif;
}

html,
body {
    height: 100%;
}

body {
    margin: 0;
    font-family: var(--font);
    background: var(--background);
    color: var(--primary);
    padding-top: 60px;
}

header {
    position: fixed;
    top: 0;
    width: 100%;
    background: white;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 20px;
}

header h1 {
    font-size: 1.2rem;
    margin: 0;
}

nav {
    margin-right: 30px;
}

nav select {
    padding: 5px;
    font-size: 1rem;
}

main {
    max-width: 800px;
    margin: auto;
    padding: 20px;
}

footer {
    width: 100%;
    text-align: center;
    padding: 20px;
    background-color: #fff;
    color: #666;
    font-size: 0.9rem;
    border-top: 1px solid #eee;
    box-sizing: border-box;
}

article {
    margin-bottom: 60px;
}

article img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 20px 0;
    display: block;
}

hr {
    border: none;
    border-top: 1px solid #ccc;
    margin: 40px 0;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.about-title {
    font-size: 1.6rem;
    color: var(--accent);
    margin-bottom: 5px;
}

.article-title {
    font-size: 1.6rem;
    color: var(--accent);
    margin-bottom: 5px;
}

.article-date {
    font-size: 0.9rem;
    color: gray;
    margin-bottom: 15px;
}

.back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    font-size: 18px;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

@media (max-width: 600px) {
    .article-title {
        font-size: 1.3rem;
    }

    nav select#articleMenu {
        width: 50%;
        font-size: 1rem;
        padding: 8px;
        margin-top: 10px;
    }

    nav {
        width: 100%;
        margin: 0;
    }

    header {
        flex-direction: column;
        align-items: flex-start;
        gap: 5px;
    }
}