:root {
    --primary-color: #4a69bd;
    --secondary-color: #6a89cc;
    --accent-color: #1e3799;
    --light-color: #f5f6fa;
    --dark-color: #2c3e50;
    --error-color: #e74c3c;
    --success-color: #2ecc71;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
    --bg-color: #f9f9f9;
    --container-bg: white;
    --text-color: #2c3e50;
    --border-color: #ddd;
}

.dark-mode {
    --primary-color: #6a89cc;
    --secondary-color: #4a69bd;
    --accent-color: #3498db;
    --light-color: #2c3e50;
    --dark-color: #f5f6fa;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    --bg-color: #1a1a2e;
    --container-bg: #16213e;
    --text-color: #f5f6fa;
    --border-color: #4a69bd;
}

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

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

.container {
    max-width: 900px;
    margin: 2rem auto;
    padding: 2rem;
    background-color: var(--container-bg);
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

h1, h2 {
    text-align: center;
    color: var(--primary-color);
    transition: var(--transition);
}

h1 {
    margin-bottom: 2rem;
    position: relative;
    padding-bottom: 0.5rem;
}

h1::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 3px;
    background-color: var(--secondary-color);
    border-radius: 3px;
}

.tabs {
    display: flex;
    justify-content: center;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.tab-btn {
    padding: 0.75rem 1.5rem;
    background-color: transparent;
    border: none;
    border-bottom: 3px solid transparent;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    color: #777;
    transition: var(--transition);
}

.tab-btn:hover {
    color: var(--primary-color);
}

.tab-btn.active {
    color: var(--primary-color);
    border-bottom: 3px solid var(--primary-color);
}

.tab-pane {
    display: none;
    padding: 1.5rem 0;
}

.tab-pane.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-color);
}

.qr-options {
    display: flex;
    gap: 20px;
    margin-bottom: 1.5rem;
    align-items: center;
}

.option-group {
    display: flex;
    flex-direction: column;
    flex: 1;
}

.option-group label {
    margin-bottom: 0.5rem;
}

.option-group input[type="color"] {
    height: 40px;
    padding: 0;
    border: none;
    cursor: pointer;
    background: none;
}

.option-group select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
    transition: var(--transition);
    background-color: var(--container-bg);
    color: var(--text-color);
}

.option-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(74, 105, 189, 0.2);
}

input, textarea, select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-size: 1rem;
    transition: var(--transition);
    background-color: var(--container-bg);
    color: var(--text-color);
}

textarea {
    min-height: 120px;
    resize: vertical;
}

input:focus, textarea:focus, select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(74, 105, 189, 0.2);
}

.button-group {
    display: flex;
    gap: 10px;
    margin-top: 1rem;
}

.generate-btn {
    flex: 1;
    padding: 0.75rem;
    background-color: var(--success-color);
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.generate-btn:hover {
    background-color: #27ae60;
    transform: translateY(-2px);
}

.reset-btn {
    flex: 1;
    padding: 0.75rem;
    background-color: #e74c3c;
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.reset-btn:hover {
    background-color: #c0392b;
}

.results-container {
    margin-top: 2rem;
    border-top: 1px dashed var(--border-color);
    padding-top: 2rem;
}

#qr-results {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    justify-content: center;
    margin-top: 1.5rem;
}

.qr-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    max-width: 200px;
    background-color: var(--container-bg);
    border-radius: 8px;
    padding: 1rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.qr-item canvas {
    width: 160px;
    height: 160px;
    background-color: white;
    border-radius: 4px;
}

.qr-info {
    width: 100%;
    text-align: center;
    margin-top: 1rem;
    word-break: break-all;
    font-size: 0.875rem;
    color: var(--text-color);
}

.download-btn {
    margin-top: 0.75rem;
    padding: 0.5rem 1rem;
    background-color: var(--secondary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.875rem;
    transition: var(--transition);
}

.download-btn:hover {
    background-color: var(--accent-color);
}

footer {
    text-align: center;
    margin-top: 2rem;
    padding: 1rem;
    color: #777;
    font-size: 0.875rem;
}

.message {
    display: none;
    padding: 0.75rem;
    border-radius: 5px;
    margin-bottom: 1.5rem;
    text-align: center;
    font-weight: 500;
}

.message.success {
    background-color: var(--success-color);
    color: white;
}

.message.error {
    background-color: var(--error-color);
    color: white;
}

.message.warning {
    background-color: #f39c12;
    color: white;
}

.file-input {
    padding: 1rem;
    border: 2px dashed var(--border-color);
    border-radius: 5px;
    width: 100%;
    cursor: pointer;
    transition: var(--transition);
}

.file-input:hover {
    border-color: var(--primary-color);
}

.file-upload-info {
    margin-top: 0.75rem;
    font-size: 0.85rem;
    color: #777;
}

.file-upload-info p {
    margin: 0.25rem 0;
}

.results-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.clear-btn {
    padding: 0.5rem 1rem;
    background-color: var(--accent-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.875rem;
    transition: var(--transition);
    font-weight: 600;
}

.clear-btn:hover {
    background-color: var(--primary-color);
    transform: translateY(-2px);
}

.qr-canvas-container {
    display: flex;
    justify-content: center;
    width: 100%;
}

.gallery-container {
    width: 100%;
    max-width: 100%;
    overflow-x: auto;
    white-space: nowrap;
    padding: 10px 0;
    scroll-behavior: smooth;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: thin;
    scrollbar-color: var(--primary-color) #f1f1f1;
}

.gallery-container::-webkit-scrollbar {
    height: 8px;
}

.gallery-container::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

.gallery-container::-webkit-scrollbar-thumb {
    background-color: var(--primary-color);
    border-radius: 4px;
}

.gallery-image {
    display: inline-block;
    height: 200px;
    margin-right: 10px;
    border-radius: 5px;
    box-shadow: var(--shadow);
}

.gallery-page {
    max-width: 800px;
    margin: 20px auto;
    padding: 20px;
    background-color: var(--container-bg);
    border-radius: 10px;
    box-shadow: var(--shadow);
}

.gallery-page h1 {
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    text-align: center;
}

.gallery-controls {
    display: flex;
    justify-content: center;
    margin-top: 10px;
    gap: 10px;
}

.gallery-btn {
    padding: 8px 15px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.875rem;
    transition: var(--transition);
}

.gallery-btn:hover {
    background-color: var(--accent-color);
}

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 100;
}

.theme-toggle button {
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.theme-toggle button:hover {
    transform: translateY(-2px);
    background-color: var(--accent-color);
}

.moon-icon, .sun-icon {
    transition: var(--transition);
}

.dark-mode .sun-icon, .moon-icon {
    display: none;
}

.dark-mode .moon-icon, .sun-icon {
    display: block;
}

.year-label {
    position: fixed;
    top: 20px;
    left: 20px;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
    z-index: 100;
    transition: var(--transition);
}

@media (max-width: 768px) {
    .container {
        margin: 1rem;
        padding: 1.5rem;
    }
    
    .tabs {
        flex-direction: column;
        align-items: center;
    }
    
    .tab-btn {
        width: 100%;
        text-align: center;
        margin-bottom: 0.5rem;
    }
}