:root {
    --ios-background: #F0F0F0;
    --card-background: #FFFFFF;
    --primary-text: #000000;
    --ios-blue: #007AFF;
    --ios-blue-tapped: #0056B3;
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.iphone-frame.dark-mode {
    --card-background: #1C1C1E;
    --primary-text: #FFFFFF;
}

body {
    margin: 0;
    font-family: var(--font-family);
    background-color: var(--ios-background);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.iphone-frame {
    background-color: var(--card-background);
    width: 375px;
    height: 812px; /* iPhone X/XS/11 Pro dimensions */
    border-radius: 44px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.15), 0 0 0 8px #333;
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.notch {
    background: #333;
    width: 210px;
    height: 30px;
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    border-bottom-left-radius: 20px;
    border-bottom-right-radius: 20px;
    z-index: 2;
}

.main-container {
    padding: 60px 20px 40px; /* Padding to account for notch and home bar area */
    text-align: center;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    height: 100%;
}

.theme-switcher {
    position: absolute;
    top: 40px;
    right: 20px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
}

.title {
    font-size: 2.2rem; /* 34pt in iOS */
    font-weight: 700;
    color: var(--primary-text);
    margin: 0 0 2rem;
}

.numbers-container {
    position: relative;
    width: 100%;
    flex-grow: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    animation: rotate 20s linear infinite;
}

@keyframes rotate {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

.number-ball {
    position: absolute;
    width: 45px;
    height: 45px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.2rem;
    font-weight: 600;
    color: #FFFFFF;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    animation: counter-rotate 20s linear infinite;
}

@keyframes counter-rotate {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(-360deg);
    }
}

.generate-button {
    background-color: var(--ios-blue);
    color: #FFFFFF;
    border: none;
    border-radius: 12px; /* iOS style rounded corners */
    width: 100%;
    padding: 1rem 0;
    font-size: 1.1rem; /* 17pt in iOS */
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s ease;
    margin-top: auto; /* Pushes button to the bottom */
}

.generate-button:hover, .generate-button:focus {
    background-color: var(--ios-blue-tapped);
    outline: none;
}