body {
    font-family: 'Source Serif Pro', 'Merriweather', 'Noto Serif', 'Georgia', 'Times New Roman', Times, serif;
    background: #fff;
    color: #222;
    margin: 0;
    padding: 0;
    font-size: 15px;
    font-weight: 400;
    letter-spacing: 0.01em;
    transition: background 0.4s, color 0.4s, border-color 0.4s;
}

main {
    max-width: 600px;
    margin: 40px auto 0 auto;
    padding: 0 20px;
    background: #fff;
    font-size: 1em;
    transition: background 0.4s, color 0.4s, border-color 0.4s;
}

h2 {
    font-size: 2.2em;
    margin-top: 0.5em;
    margin-bottom: 0.7em;
    font-weight: 500;
    letter-spacing: 0.01em;
    transition: background 0.4s, color 0.4s, border-color 0.4s;
}

p, ul {
    font-size: 1em;
    line-height: 1.7;
    font-weight: 400;
}

ul {
    margin-left: 1.5em;
    padding-left: 1em;
}

li {
    margin-bottom: 0.5em;
}

footer {
    margin-top: 40px;
    padding: 20px 0;
    text-align: center;
    font-size: 1em;
    color: #888;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.footer-bar {
    width: 100%;
    max-width: 600px;
    border-top: 3px solid #bbb;
    margin-bottom: 16px;
}

footer > div {
    max-width: 600px;
    width: 100%;
}

body.dark-mode {
    background: #181a1b;
    color: #e0e0e0;
}

body.dark-mode main {
    background: #181a1b;
}

body.dark-mode h2 {
    color: #fff;
}

body.dark-mode a {
    color: #8ab4f8;
    border-bottom: 1px dotted #8ab4f8;
}

body.dark-mode footer {
    color: #aaa;
}

body.dark-mode footer a {
    color: #8ab4f8;
}

body.dark-mode footer a:hover {
    color: #a3c9fa;
}

#mode-toggle {
    position: fixed;
    top: 18px;
    right: 18px;
    left: auto;
    z-index: 1000;
    font-size: 1.3em;
    background: none;
    color: #333;
    border: none;
    border-radius: 0;
    width: auto;
    height: auto;
    cursor: pointer;
    box-shadow: none;
    padding: 0;
    transition: color 0.2s;
}

#mode-toggle:hover {
    color: #174080;
    background: none;
    border: none;
}

body.dark-mode #mode-toggle {
    color: #e0e0e0;
    background: none;
    border: none;
}

body.dark-mode #mode-toggle:hover {
    color: #a3c9fa;
    background: none;
    border: none;
}

body, main, h2, a, footer {
    transition: background 0.2s, color 0.2s, border-color 0.2s;
}

a {
    color: #4a90e2;
    text-decoration: none;
    border-bottom: 1px dotted #2a5db0;
    transition: border-bottom 0.2s, color 0.2s;
}

footer a {
    color: #4a90e2;
    margin: 0 10px;
    text-decoration: none;
    border-bottom: none;
}

/* Responsive styles for mobile */
@media (max-width: 600px) {
    html {
        font-size: 17px;
    }
    main, footer > div, .footer-bar {
        max-width: 98vw;
        padding-left: 2vw;
        padding-right: 2vw;
    }
    .footer-bar {
        margin-bottom: 12px;
    }
}