:root {
    --primary-color: #4a6bff;
    --secondary-color: #f8f9fa;
    --text-color: #333;
    --light-text: #777;
    --border-color: #ddd;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Poppins', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: #f5f7ff;
    padding: 20px;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    background-color: white;
    border-radius: 10px;
    box-shadow: var(--shadow);
    overflow: hidden;
    padding-bottom: 20px;
}

header {
    text-align: center;
    padding: 30px 20px;
    background: linear-gradient(135deg, var(--primary-color), #6a5acd);
    color: white;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

.converter-box {
    padding: 20px;
}

.drop-area {
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    margin-bottom: 20px;
}

.drop-area:hover {
    border-color: var(--primary-color);
    background-color: rgba(74, 107, 255, 0.05);
}

.drop-area i {
    font-size: 48px;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.drop-area h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.drop-area p {
    color: var(--light-text);
    margin-bottom: 15px;
}

.btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    transition: var(--transition);
    display: inline-block;
}

.btn:hover {
    background-color: #3a5bef;
    transform: translateY(-2px);
}

.options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.option-group {
    margin-bottom: 15px;
}

.option-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: 500;
}

.option-group input, .option-group select {
    width: 100%;
    padding: 8px 10px;
    border: 1px solid var(--border-color);
    border-radius: 5px;
    font-family: inherit;
}

.preview {
    margin-bottom: 20px;
}

.preview h3 {
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.thumbnail-container {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.thumbnail {
    width: 100px;
    height: 100px;
    object-fit: cover;
    border-radius: 5px;
    border: 1px solid var(--border-color);
    position: relative;
}

.thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    background-color: #f5f5f5;
}

.remove-btn {
    position: absolute;
    top: -8px;
    right: -8px;
    background-color: #ff4a4a;
    color: white;
    border: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 10px;
}

.convert-btn {
    width: 100%;
    padding: 12px;
    font-size: 1.1rem;
}

.convert-btn:disabled {
    background-color: #ccc;
    cursor: not-allowed;
    transform: none;
}

.features {
    padding: 20px;
    margin-top: 30px;
}

.features h2 {
    text-align: center;
    margin-bottom: 30px;
    font-size: 1.8rem;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 25px;
}

.feature {
    text-align: center;
    padding: 20px;
    border-radius: 8px;
    transition: var(--transition);
}

.feature:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

.feature i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.feature h3 {
    margin-bottom: 10px;
    font-size: 1.2rem;
}

.feature p {
    color: var(--light-text);
    font-size: 0.9rem;
}

footer {
    text-align: center;
    margin-top: 30px;
    color: var(--light-text);
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }
    
    .options {
        grid-template-columns: 1fr;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
}