:root {
    --bg-color: #F0F2F5;
    --text-color: #1a1a1a;
    --gradient-start: #ff9a9e;
    --gradient-end: #fad0c4;
    --toggle-bg: #FFF;
    --toggle-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

body.dark-mode {
    --bg-color: #1a1a1a;
    --text-color: #fff;
    --gradient-start: #ff9a9e;
    --gradient-end: #fad0c4;
    --toggle-bg: #2a2a2a;
    --toggle-shadow: 0 2px 4px rgba(0,0,0,0.4);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    background: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    transition: background 0.3s, color 0.3s;
}

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--toggle-bg);
    border: none;
    color: var(--text-color);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 20px;
    box-shadow: var(--toggle-shadow);
    transition: all 0.3s;
}

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

main {
    text-align: center;
}

h1 {
    font-size: 3rem;
    margin-bottom: 2rem;
    background: linear-gradient(45deg, var(--gradient-start) 0%, var(--gradient-end) 99%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}