/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --background: #f8fafc;
    --surface: #ffffff;
    --border-color: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --radius: 12px;
    --radius-sm: 8px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--background);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    text-align: center;
    padding: 40px 20px;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

/* Main Content */
main {
    flex: 1;
    background: var(--surface);
    border-radius: var(--radius);
    padding: 30px;
    box-shadow: var(--shadow-md);
}

/* Tab Navigation */
.tab-container {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    border-bottom: 2px solid var(--border-color);
}

.tab-btn {
    background: none;
    border: none;
    padding: 12px 24px;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.3s;
    border-bottom: 3px solid transparent;
    margin-bottom: -2px;
}

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

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

/* Tab Content */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* Upload Area */
.upload-section {
    margin-bottom: 30px;
}

.upload-area {
    border: 3px dashed var(--border-color);
    border-radius: var(--radius);
    padding: 60px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    background: var(--background);
}

.upload-area:hover,
.upload-area.dragover {
    border-color: var(--primary-color);
    background: #eff6ff;
}

.upload-icon {
    width: 64px;
    height: 64px;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.upload-area h3 {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.upload-area p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Controls Section */
.controls-section {
    display: grid;
    gap: 25px;
    margin-bottom: 30px;
}

.control-group {
    background: var(--background);
    padding: 20px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
}

.control-group h3 {
    font-size: 1.1rem;
    margin-bottom: 15px;
    color: var(--text-primary);
}

.control-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.control-group input[type="range"] {
    width: 100%;
    height: 8px;
    border-radius: 5px;
    background: var(--border-color);
    outline: none;
    -webkit-appearance: none;
}

.control-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
}

.control-group input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
}

.control-group input[type="number"] {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 1rem;
}

.control-group select {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    background: var(--surface);
    cursor: pointer;
}

.control-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    margin-right: 8px;
    cursor: pointer;
}

.help-text {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 5px;
}

/* Resize Options */
.resize-options {
    margin-top: 15px;
    padding-top: 15px;
    border-top: 1px solid var(--border-color);
}

.resize-options.disabled {
    opacity: 0.5;
    pointer-events: none;
}

.input-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 15px;
}

/* Preview Section */
.preview-section {
    margin-top: 30px;
    padding-top: 30px;
    border-top: 2px solid var(--border-color);
}

.preview-section h3 {
    font-size: 1.3rem;
    margin-bottom: 20px;
}

.preview-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 25px;
}

.preview-item {
    position: relative;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    overflow: hidden;
    background: var(--background);
}

.preview-item img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
}

.preview-info {
    padding: 12px;
    background: var(--surface);
}

.preview-info .filename {
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 5px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.preview-info .filesize {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.remove-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    background: var(--danger-color);
    color: white;
    border: none;
    border-radius: 50%;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 18px;
    box-shadow: var(--shadow-md);
    transition: all 0.3s;
}

.remove-btn:hover {
    background: #dc2626;
    transform: scale(1.1);
}

/* Buttons */
.action-buttons {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: var(--shadow-sm);
}

.btn svg {
    width: 20px;
    height: 20px;
}

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

.btn-primary:hover {
    background: var(--primary-hover);
    box-shadow: var(--shadow-md);
}

.btn-primary:disabled {
    background: var(--secondary-color);
    cursor: not-allowed;
}

.btn-secondary {
    background: var(--surface);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

/* Results Section */
.results-section {
    margin-top: 30px;
    padding-top: 30px;
    border-top: 2px solid var(--border-color);
}

.results-section h3 {
    font-size: 1.3rem;
    margin-bottom: 20px;
}

.results-container {
    display: grid;
    gap: 20px;
    margin-bottom: 25px;
}

.result-item {
    display: grid;
    grid-template-columns: 100px 1fr auto;
    gap: 20px;
    padding: 20px;
    background: var(--background);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    align-items: center;
}

.result-item img {
    width: 100px;
    height: 100px;
    object-fit: cover;
    border-radius: var(--radius-sm);
}

.result-info h4 {
    font-size: 1rem;
    margin-bottom: 8px;
}

.result-stats {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.stat {
    display: flex;
    flex-direction: column;
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.stat-value {
    font-weight: 600;
    color: var(--text-primary);
}

.savings {
    color: var(--success-color);
    font-weight: 600;
}

.download-btn {
    padding: 10px 20px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s;
}

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

/* Footer */
footer {
    text-align: center;
    padding: 30px 20px;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Utility Classes */
.hidden {
    display: none !important;
}

/* Loading Spinner */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    main {
        padding: 20px;
    }

    .tab-btn {
        padding: 10px 16px;
        font-size: 0.9rem;
    }

    .upload-area {
        padding: 40px 15px;
    }

    .upload-icon {
        width: 48px;
        height: 48px;
    }

    .upload-area h3 {
        font-size: 1.1rem;
    }

    .preview-container {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
        gap: 15px;
    }

    .preview-item img {
        height: 150px;
    }

    .result-item {
        grid-template-columns: 80px 1fr;
        gap: 15px;
    }

    .result-item img {
        width: 80px;
        height: 80px;
    }

    .result-item .download-btn {
        grid-column: 1 / -1;
        width: 100%;
    }

    .result-stats {
        gap: 10px;
    }

    .input-row {
        grid-template-columns: 1fr;
    }

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

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

@media (max-width: 480px) {
    .container {
        padding: 10px;
    }

    header {
        padding: 20px 10px;
    }

    header h1 {
        font-size: 1.5rem;
    }

    main {
        padding: 15px;
    }

    .preview-container {
        grid-template-columns: 1fr;
    }
}

/* Squarespace Compatibility */
.sqs-block-content {
    background: transparent !important;
}

/* Print Styles */
@media print {
    .upload-section,
    .controls-section,
    .action-buttons,
    footer {
        display: none;
    }
}