:root {
    --page-bg-solid: #f0f2f5;
    --page-bg: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --text-color: #1f2633;
    --panel-bg: rgba(255, 255, 255, 0.14);
    --panel-border: rgba(255, 255, 255, 0.25);
    --panel-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    --title-color: #ffffff;
    --title-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    --button-bg: #ffffff;
    --button-text: #4a5ad6;
    --toggle-bg: rgba(255, 255, 255, 0.85);
    --toggle-text: #2f2f45;
    --toggle-border: rgba(255, 255, 255, 0.6);
    --toggle-shadow: 0 6px 14px rgba(0, 0, 0, 0.12);
}

:root[data-theme="dark"] {
    --page-bg-solid: #0d0f1b;
    --page-bg: radial-gradient(circle at 20% 20%, #1b2a4a 0%, #0d0f1b 55%, #0a0b12 100%);
    --text-color: #e8ebff;
    --panel-bg: rgba(20, 23, 38, 0.72);
    --panel-border: rgba(98, 109, 174, 0.45);
    --panel-shadow: 0 12px 40px rgba(0, 0, 0, 0.5);
    --title-color: #f5f6ff;
    --title-shadow: 0 6px 18px rgba(9, 11, 21, 0.6);
    --button-bg: #1f2338;
    --button-text: #dbe2ff;
    --toggle-bg: rgba(27, 31, 52, 0.9);
    --toggle-text: #e3e7ff;
    --toggle-border: rgba(120, 136, 210, 0.6);
    --toggle-shadow: 0 8px 16px rgba(0, 0, 0, 0.45);
}

body {
    font-family: 'Montserrat', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: var(--page-bg-solid);
    background-image: var(--page-bg);
    color: var(--text-color);
    margin: 0;
    transition: background 0.6s ease, color 0.6s ease;
}