:root {
    --primary: #4361ee;
    --primary-light: #4895ef;
    --secondary: #3f37c9;
    --dark: #1a1a2e;
    --light: #f8f9fa;
    --gray: #adb5bd;
    --light-gray: #e9ecef;
    --white: #ffffff;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
    background: linear-gradient(135deg, #f5f7fa 0%, #dfe7ff 100%);
    min-height: 100vh;
    padding: 2rem 1rem;
    color: var(--dark);
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: var(--white);
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: var(--white);
    padding: 2rem;
    text-align: center;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.logo i {
    font-size: 2.5rem;
}

.logo h1 {
    font-size: 2.2rem;
    font-weight: 700;
}

.tagline {
    font-weight: 300;
    opacity: 0.9;
}

main {
    padding: 2rem;
}

.upload-area {
    border: 2px dashed var(--gray);
    border-radius: 12px;
    padding: 3rem 2rem;
    text-align: center;
    transition: all 0.3s ease;
    margin-bottom: 2rem;
    background-color: var(--light);
    cursor: pointer;
    position: relative;
}

.upload-area:hover {
    border-color: var(--primary);
    background-color: rgba(67, 97, 238, 0.05);
}

.upload-area.active {
    border-color: var(--primary);
    background-color: rgba(67, 97, 238, 0.1);
}

.upload-content i {
    font-size: 3rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.upload-content h3 {
    margin-bottom: 0.5rem;
    color: var(--dark);
}

.upload-content p {
    color: var(--gray);
    margin-bottom: 1.5rem;
}

#fileInput {
    display: none;
}

.btn-browse {
    background-color: var(--primary);
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: 8px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

.options-panel {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
    background-color: var(--light-gray);
    padding: 1.5rem;
    border-radius: 12px;
}

.option-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.option-group label {
    font-weight: 500;
    color: var(--dark);
    display: flex;
    justify-content: space-between;
}

.option-group select, .option-group input {
    padding: 0.7rem;
    border: 1px solid var(--gray);
    border-radius: 8px;
    background-color: var(--white);
}

.option-group input[type="range"] {
    padding: 0;
}

.preview-container {
    display: none;
    margin-bottom: 2rem;
}

.preview-container h3 {
    margin-bottom: 1rem;
    color: var(--dark);
    display: flex;
    align-items: center;
}

.preview-container h3 small {
    font-weight: normal;
    margin-left: 0.5rem;
    color: var(--gray);
}

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

.image-item {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    background: var(--light-gray);
    min-height: 200px;
    display: flex;
    flex-direction: column;
}

.image-preview-container {
    flex-grow: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--light-gray);
}

.image-item img {
    max-width: 100%;
    max-height: 180px;
    display: block;
}

.image-info {
    background: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 0.5rem;
    font-size: 0.9rem;
    display: flex;
    justify-content: space-between;
}

.download-btn {
    position: absolute;
    top: 5px;
    right: 5px;
    background-color: rgba(46, 204, 113, 0.9);
    color: white;
    border: none;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.image-item:hover .download-btn {
    opacity: 1;
}

.action-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.btn-primary, .btn-secondary {
    padding: 0.9rem 1.8rem;
    border-radius: 8px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-primary {
    background-color: var(--primary);
    color: white;
    border: none;
}

.btn-primary:hover {
    background-color: var(--secondary);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(67, 97, 238, 0.2);
}

.btn-primary:disabled {
    background-color: var(--gray);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn-secondary {
    background-color: var(--light-gray);
    color: var(--dark);
    border: 1px solid var(--gray);
}

.btn-secondary:hover {
    background-color: #d6d9e0;
    transform: translateY(-2px);
}

footer {
    text-align: center;
    padding: 1.5rem;
    background-color: var(--light-gray);
    color: var(--dark);
}

.copyright {
    margin-top: 0.5rem;
    font-size: 0.9rem;
    color: var(--gray);
}

/* Loading states */
.loading-placeholder {
    width: 100%;
    height: 180px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--light-gray);
    color: var(--gray);
}

.spinner {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        border-radius: 0;
    }

    header {
        padding: 1.5rem;
    }

    .logo {
        flex-direction: column;
        gap: 0.5rem;
    }

    .logo i {
        font-size: 2rem;
    }

    .logo h1 {
        font-size: 1.8rem;
    }

    main {
        padding: 1.5rem;
    }

    .upload-area {
        padding: 2rem 1rem;
    }

    .options-panel {
        grid-template-columns: 1fr;
    }

    .action-buttons {
        flex-direction: column;
    }

    .btn-primary, .btn-secondary {
        width: 100%;
        justify-content: center;
    }
}