* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

body {
    --bg-color: white;
    --text-color: rgba(0, 0, 0, 0.8);
}

body.dark-theme {
    --bg-color: #0a0a0a;
    --text-color: rgba(245, 245, 245, 0.8);
}

#theme-toggle {
    position: fixed;
    top: 40px;
    right: 40px;
    width: 50px;
    height: 50px;
    border: 2px solid var(--text-color);
    background: transparent;
    color: var(--text-color);
    cursor: pointer;
    border-radius: 50%;
    transition: all 0.3s ease;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
}

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

#theme-toggle svg {
    width: 20px;
    height: 20px;
}

#theme-toggle .sun {
    display: block;
}

#theme-toggle .moon {
    display: none;
}

body.dark-theme #theme-toggle .sun {
    display: none;
}

body.dark-theme #theme-toggle .moon {
    display: block;
}

main {
    max-width: 900px;
    margin: 0 auto;
    padding: 60px 40px;
}

h1 {
    font-size: 56px;
    font-weight: 100;
    margin-bottom: 32px;
    letter-spacing: -1px;
}

h2 {
    font-size: 32px;
    font-weight: 600;
    margin-top: 80px;
    margin-bottom: 30px;
}

p {
    font-size: 18px;
    font-weight: 400;
    margin-bottom: 20px;
}

@media (max-width: 768px) {
    main {
        padding: 40px 20px;
    }

    #theme-toggle {
        top: 20px;
        right: 20px;
        width: 40px;
        height: 40px;
        font-size: 20px;
    }

    h1 {
        font-size: 48px;
    }

    h2 {
        font-size: 36px;
        margin-top: 60px;
    }

    p {
        font-size: 24px;
    }
}