:root {
    --bg-color: #f0f2f5;
    --card-color: #ffffff;
    --text-color: #333;
    --heading-color: #1c1e21;
    --subtle-text-color: #65676b;
    --border-color: #e0e0e0;
    --accent-color: #007bff;
}

body.dark-mode {
    --bg-color: #18191a;
    --card-color: #242526;
    --text-color: #e4e6eb;
    --heading-color: #e4e6eb;
    --subtle-text-color: #b0b3b8;
    --border-color: #3a3b3c;
    --accent-color: #4dabf7;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    transition: background-color 0.3s, color 0.3s;
}

.about-container {
    position: relative;
    max-width: 500px;
    background-color: var(--card-color);
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    text-align: center;
    padding: 40px;
    border: 1px solid var(--border-color);
    transition: background-color 0.3s, border-color 0.3s;
}

#theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    color: var(--subtle-text-color);
    transition: color 0.3s, transform 0.3s;
}

#theme-toggle:hover {
    color: var(--accent-color);
    transform: scale(1.1);
}

.profile-picture {
    width: 130px;
    height: 130px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--bg-color);
    margin-bottom: 20px;
    transition: border-color 0.3s;
}

h1 {
    font-size: 2em;
    margin: 0;
    color: var(--heading-color);
    transition: color 0.3s;
}

h2 {
    font-size: 1.1em;
    color: var(--subtle-text-color);
    font-weight: 500;
    margin: 5px 0 15px;
    transition: color 0.3s;
}

.bio {
    font-size: 1em;
    line-height: 1.6;
    margin-bottom: 25px;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 15px;
}

.social-links a {
    text-decoration: none;
    color: var(--subtle-text-color);
    font-size: 1.5em;
    transition: color 0.3s ease, transform 0.3s ease;
}

.social-links a:hover {
    color: var(--accent-color);
    transform: scale(1.1);
}