:root {
    --bg-color: #ffffff;
    --text-color: #15202b;
    --link-color: #1e6bb8;
    --header-bg: #f4f4f4;
}

[data-theme="dark"] {
    --bg-color: #0d1117;
    --text-color: #c9d1d9;
    --link-color: #58a6ff;
    --header-bg: #161b22;
}

body {
    background-color: var(--bg-color) !important;
    color: var(--text-color) !important;
    transition: background-color 0.3s, color 0.3s;
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
}

a {
    color: var(--link-color) !important;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

header {
    background-color: var(--header-bg) !important;
    border-bottom: 1px solid #30363d;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 20px auto;
}

#theme-toggle {
    position: fixed;
    top: 15px;
    right: 15px;
    z-index: 1000;
    background: var(--bg-color);
    border: 1px solid var(--text-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-color);
}

.wrapper {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

@media (max-width: 768px) {
    body {
        font-size: 18px;
    }

    .wrapper, main, header {
        padding-left: 15px !important;
        padding-right: 15px !important;
        width: auto !important;
        max-width: 100% !important;
    }

    header nav {
        display: flex;
        flex-direction: column;
        gap: 15px;
        padding-bottom: 10px;
    }

    header nav a {
        margin: 0 !important;
        display: block;
        padding: 5px;
    }
}