:root {
    --primary-color: #3498db;
    --secondary-color: #2ecc71;
    --background-color: #f0f2f5;
    --text-color: #333;
    --container-bg: #fff;
    --shadow: rgba(0, 0, 0, 0.1);
    --input-bg: #fff;
    --input-border: #ddd;
    --divider: #eee;
    --nav-bg: #fff;
}

body.dark-mode {
    --background-color: #1a1a1a;
    --text-color: #f0f2f5;
    --container-bg: #2d2d2d;
    --shadow: rgba(0, 0, 0, 0.5);
    --input-bg: #3d3d3d;
    --input-border: #555;
    --divider: #444;
    --nav-bg: #222;
}

body {
    font-family: 'Helvetica Neue', 'Apple SD Gothic Neo', 'Malgun Gothic', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
    background-image: linear-gradient(to right top, #d16ba5, #c777b9, #ba83ca, #aa8fd8, #9a9ae1, #8aa7ec, #79b3f4, #69bff8, #52cffe, #41dfff, #46eefa, #5ffbf1);
    background-attachment: fixed;
}

body.dark-mode {
    background-image: linear-gradient(to right top, #051937, #004d7a, #008793, #00bf72, #a8eb12);
}

/* Navigation */
header {
    background-color: var(--nav-bg);
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    text-decoration: none;
    color: var(--primary-color);
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    margin-left: 1.5rem;
    font-weight: 500;
}

/* Main Content */
.main-content {
    padding: 2rem 1rem;
    display: flex;
    justify-content: center;
}

.container {
    background-color: var(--container-bg);
    padding: 3rem 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px var(--shadow);
    text-align: center;
    width: 100%;
    max-width: 600px;
    transition: background-color 0.3s, box-shadow 0.3s;
    position: relative;
}

.subtitle {
    font-size: 1.1rem;
    color: #777;
    margin-bottom: 2rem;
}

h1 { color: var(--primary-color); margin-bottom: 0.5rem; }
h2 { color: var(--text-color); margin-bottom: 1.5rem; font-size: 1.4rem; }

/* Info Section */
.info-section {
    text-align: left;
    margin-top: 2rem;
}

.info-section ul {
    padding-left: 1.2rem;
}

.info-section li {
    margin-bottom: 0.5rem;
}

/* Lotto Numbers */
.numbers {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 2.5rem;
    flex-wrap: wrap;
}

.number {
    background-color: var(--secondary-color);
    color: #fff;
    width: 55px;
    height: 55px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.6rem;
    font-weight: bold;
    box-shadow: 0 4px 10px var(--shadow);
}

.generate-btn {
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    padding: 1.2rem 2.5rem;
    font-size: 1.3rem;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 6px 20px var(--shadow);
    width: 100%;
}

.generate-btn:hover { transform: translateY(-3px); box-shadow: 0 8px 25px var(--shadow); }

/* Form */
.form-group { margin-bottom: 1.2rem; }
.form-group input, .form-group textarea {
    width: 100%; padding: 1rem; border: 1px solid var(--input-border);
    border-radius: 10px; background-color: var(--input-bg); color: var(--text-color);
}

/* Footer */
footer {
    background-color: var(--nav-bg);
    padding: 3rem 1rem;
    text-align: center;
    margin-top: 4rem;
}

.footer-links { margin-top: 1rem; }
.footer-links a { color: var(--primary-color); text-decoration: none; margin: 0 1rem; }

/* Theme Toggle */
.theme-toggle { position: absolute; top: 1.5rem; right: 1.5rem; }
#theme-toggle-btn { background: none; border: none; font-size: 1.8rem; cursor: pointer; }

@media (max-width: 600px) {
    .container { padding: 2rem 1.5rem; }
    .number { width: 45px; height: 45px; font-size: 1.3rem; }
}