:root {
    --bg-color: #f7f7f7;
    --bg-image: linear-gradient(to top, #f3e7e9 0%, #e3eeff 99%, #e3eeff 100%);
    --container-bg: white;
    --text-color: #333;
    --nav-bg: rgba(255, 255, 255, 0.9);
    --shadow-color: rgba(0, 0, 0, 0.1);
    --btn-shadow: rgba(0, 0, 0, 0.2);
    --accent-color: #007bff;
}

[data-theme="dark"] {
    --bg-color: #121212;
    --bg-image: none;
    --container-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --nav-bg: rgba(30, 30, 30, 0.9);
    --shadow-color: rgba(0, 0, 0, 0.5);
    --btn-shadow: rgba(0, 0, 0, 0.4);
    --accent-color: #3793ff;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    background-color: var(--bg-color);
    background-image: var(--bg-image);
    color: var(--text-color);
    transition: background 0.3s, color 0.3s;
    padding-top: 80px;
}

/* Header & Nav */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: var(--nav-bg);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px var(--shadow-color);
    z-index: 1000;
}

.nav-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 1.5rem;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
}

.nav-menu a:hover {
    color: var(--accent-color);
}

#theme-toggle-btn {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    background-color: var(--text-color);
    color: var(--container-bg);
}

/* Main Content */
main {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2rem;
}

.container {
    background-color: var(--container-bg);
    padding: 3rem;
    border-radius: 20px;
    box-shadow: 0 10px 30px var(--shadow-color);
    margin-bottom: 3rem;
    text-align: center;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.description-text {
    max-width: 600px;
    margin: 0 auto 2rem;
    opacity: 0.9;
}

/* Animal Test */
#upload-btn {
    background-color: #ff6b6b;
    color: white;
}

#image-preview {
    max-width: 100%;
    max-height: 400px;
    border-radius: 15px;
    margin: 2rem 0;
    box-shadow: 0 4px 15px var(--shadow-color);
}

#label-container {
    margin-top: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

#label-container div {
    padding: 1rem;
    border-radius: 10px;
    font-size: 1.2rem;
    font-weight: bold;
    background-color: var(--bg-color);
}

/* Lotto */
.numbers-container {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 0;
    flex-wrap: wrap;
}

.number {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: white;
    box-shadow: 0 4px 10px var(--btn-shadow);
}

.button-container {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

/* Text Section & Grid */
.text-section {
    text-align: left;
}

.info-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-top: 2rem;
}

.info-item h3 {
    margin-bottom: 0.5rem;
    color: var(--accent-color);
}

/* Form */
.form-group {
    margin-bottom: 1rem;
}

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

#submit-btn {
    width: 100%;
    background-color: var(--text-color);
    color: var(--container-bg);
}

/* Footer */
footer {
    background-color: var(--container-bg);
    padding: 3rem 2rem;
    margin-top: 4rem;
    border-top: 1px solid var(--shadow-color);
}

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

.footer-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.footer-links a {
    text-decoration: none;
    color: var(--text-color);
    font-size: 0.9rem;
}

/* Shared UI Components */
button {
    padding: 0.8rem 2rem;
    font-size: 1rem;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    font-weight: 600;
    transition: transform 0.2s, opacity 0.3s;
}

button:hover {
    transform: translateY(-2px);
    opacity: 0.9;
}

#generate-btn { background-color: #007bff; color: white; }
#open-new-tab-btn { background-color: #28a745; color: white; }

/* Responsive */
@media (max-width: 768px) {
    .nav-menu { display: none; }
    .info-grid { grid-template-columns: 1fr; }
    .footer-container { flex-direction: column; gap: 1.5rem; text-align: center; }
    .container { padding: 1.5rem; }
}