:root {
    /* Light Mode (Day Luck) */
    --bg-color: oklch(0.97 0.01 25);
    --text-color: oklch(0.15 0.1 25); /* Deep Red-Black */
    --card-bg: oklch(1 0 0);
    --card-shadow: 0 10px 30px oklch(0.4 0.15 25 / 0.15), 0 5px 10px oklch(0.4 0.15 25 / 0.1);
    --primary-color: oklch(0.5 0.2 25); /* Prosperity Red */
    --accent-color: oklch(0.8 0.15 85); /* Golden Wealth */
    --button-text: oklch(0.2 0.1 25);
    --border-color: oklch(0.9 0.05 25);

    /* Sunflower Border (SVG) */
    --flower-border: url("data:image/svg+xml,%3Csvg width='40' height='40' viewBox='0 0 40 40' xmlns='http://www.w3.org/2000/svg'%3E%3Ccircle cx='20' cy='20' r='6' fill='%23630'/%3E%3Cpath d='M20 5l2 8h-4l2-8zM20 35l2-8h-4l2 8zM5 20l8-2v4l-8-2zM35 20l-8-2v4l8-2zM9.5 9.5l7 4-2 3-5-7zM30.5 30.5l-7-4 2-3 5 7zM9.5 30.5l4-7 3 2-7 5zM30.5 9.5l-4 7-3-2 7-5z' fill='%23FFD700'/%3E%3C/svg%3E");
}

[data-theme="dark"] {
    /* Dark Mode (Night Prosperity) - High Contrast */
    --bg-color: oklch(0.08 0.04 25); /* Deepest Black-Red */
    --text-color: oklch(0.99 0.01 25); /* Pure Off-White */
    --card-bg: oklch(0.15 0.08 25); /* Darker Card */
    --card-shadow: 0 25px 60px oklch(0 0 0 / 0.8), 0 15px 30px oklch(0.6 0.3 25 / 0.2);
    --primary-color: oklch(0.65 0.3 25); /* More Vibrant Prosperity Red */
    --accent-color: oklch(0.9 0.25 85); /* Brighter Golden Wealth */
    --button-text: oklch(0.05 0.1 25); /* Darkest text for buttons */
    --border-color: oklch(0.35 0.15 25); /* More defined borders */

    /* Rose Border (SVG) */
    --flower-border: url("data:image/svg+xml,%3Csvg width='40' height='40' viewBox='0 0 40 40' xmlns='http://www.w3.org/2000/svg'%3E%3Ccircle cx='20' cy='20' r='8' fill='%23C00'/%3E%3Ccircle cx='17' cy='17' r='4' fill='%23E33'/%3E%3Ccircle cx='23' cy='23' r='4' fill='%23E33'/%3E%3Cpath d='M20 2v6M20 38v-6M2 20h6M38 20h-6' stroke='%23060' stroke-width='2'/%3E%3C/svg%3E");
}

body {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    font-family: "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
    font-size: 1.25rem; /* Larger font for accessibility */
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.5s ease, color 0.5s ease;
}

/* Traditional Chinese Cloud/Square Pattern */
body::before {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0.04;
    pointer-events: none;
    background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M30 0l30 30-30 30L0 30z' fill='none' stroke='%23000' stroke-width='1'/%3E%3C/svg%3E");
}