:root {
    --primary-color: #4a6bff;
    --secondary-color: #f5f7ff;
    --text-color: #333;
    --light-gray: #f0f2f5;
    --medium-gray: #e0e3e7;
    --dark-gray: #6c757d;
    --white: #ffffff;
    --error-color: #ff4757;
    --success-color: #2ed573;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--light-gray);
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

header h1 i {
    margin-right: 0.5rem;
}

header p {
    color: var(--dark-gray);
    font-size: 1.1rem;
}

.generator-container {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    background: var(--white);
    border-radius: 10px;
    padding: 2rem;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.input-section {
    flex: 1;
    min-width: 300px;
}

.output-section {
    flex: 1;
    min-width: 300px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.input-group {
    margin-bottom: 2rem;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.input-group label i {
    margin-right: 0.5rem;
    color: var(--primary-color);
}

.input-group input[type="url"] {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 1px solid var(--medium-gray);
    border-radius: 5px;
    font-size: 1rem;
    margin-bottom: 1rem;
    transition: border-color 0.3s;
}

.input-group input[type="url"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(74, 107, 255, 0.2);
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: 5px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s;
    width: 100%;
}

.btn-primary:hover {
    background-color: #3a5bef;
}

.btn-primary i {
    margin-right: 0.5rem;
}

.customization-section {
    background-color: var(--secondary-color);
    padding: 1.5rem;
    border-radius: 8px;
}

.customization-section h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.customization-section h3 i {
    margin-right: 0.5rem;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.option-group {
    margin-bottom: 1rem;
}

.option-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.option-group input[type="range"] {
    width: 100%;
    margin-bottom: 0.5rem;
}

.option-group input[type="color"] {
    width: 100%;
    height: 40px;
    cursor: pointer;
    border: 1px solid var(--medium-gray);
    border-radius: 5px;
}

.option-group select {
    width: 100%;
    padding: 0.5rem;
    border: 1px solid var(--medium-gray);
    border-radius: 5px;
    font-size: 1rem;
}

.qr-container {
    width: 100%;
    max-width: 300px;
    aspect-ratio: 1/1;
    background-color: var(--white);
    border: 1px solid var(--medium-gray);
    border-radius: 8px;
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 1.5rem;
    overflow: hidden;
}

.placeholder {
    text-align: center;
    color: var(--dark-gray);
}

.placeholder i {
    font-size: 3rem;
    color: var(--medium-gray);
    margin-bottom: 1rem;
}

.placeholder p {
    font-size: 0.9rem;
}

.download-options {
    display: flex;
    gap: 0.8rem;
    flex-wrap: wrap;
    justify-content: center;
}

.btn-secondary {
    background-color: var(--white);
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
    padding: 0.6rem 1.2rem;
    border-radius: 5px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: white;
}

.btn-secondary i {
    margin-right: 0.3rem;
}

.btn-secondary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    background-color: var(--white);
    color: var(--dark-gray);
    border-color: var(--dark-gray);
}

footer {
    text-align: center;
    margin-top: 2rem;
    color: var(--dark-gray);
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .generator-container {
        flex-direction: column;
    }
    
    .options-grid {
        grid-template-columns: 1fr;
    }
}