:root {
    --primary-color: #4F46E5;
    --primary-hover: #4338CA;
    --bg-color: #F9FAFB;
    --card-bg: #FFFFFF;
    --text-color: #1F2937;
    --text-muted: #6B7280;
    --border-color: #E5E7EB;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    width: 100%;
    max-width: 900px;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, #4F46E5 0%, #7C3AED 100%);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

header p {
    color: var(--text-muted);
}

.settings-panel {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 1rem;
    padding: 1.5rem 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
}

.settings-panel h3 {
    margin-top: 0;
    margin-bottom: 1rem;
    font-size: 1.125rem;
    color: var(--text-color);
}

.settings-content {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    align-items: flex-end;
}

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

.setting-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-color);
}

.setting-group select {
    padding: 0.6rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    font-family: inherit;
    font-size: 0.875rem;
    color: var(--text-color);
    background-color: white;
    cursor: pointer;
    min-width: 220px;
}

.setting-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(79, 70, 229, 0.2);
}

.setting-toggles {
    display: flex;
    gap: 1.5rem;
    padding-bottom: 0.3rem; /* align with select field visually */
}

.setting-group.checkbox-group {
    flex-direction: row;
    align-items: center;
    gap: 0.5rem;
}

.setting-group.checkbox-group input[type="checkbox"] {
    width: 1.125rem;
    height: 1.125rem;
    cursor: pointer;
    accent-color: var(--primary-color);
}

.setting-group.checkbox-group label {
    cursor: pointer;
    font-weight: 400;
}

.upload-area {
    background: var(--card-bg);
    border: 2px dashed var(--border-color);
    border-radius: 1rem;
    padding: 4rem 2rem;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
}

.upload-area:hover,
.upload-area.dragover {
    border-color: var(--primary-color);
    background-color: #EEF2FF;
}

.upload-icon {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.upload-btn {
    background-color: var(--primary-color);
    color: white;
    padding: 0.75rem 2rem;
    border: none;
    border-radius: 0.5rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.2s;
    margin-top: 1rem;
}

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

.preview-area {
    background: var(--card-bg);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.image-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.image-box {
    position: relative;
    background-color: #F3F4F6;
    /* Fallback for transparency */
    background-image: linear-gradient(45deg, #E5E7EB 25%, transparent 25%),
        linear-gradient(-45deg, #E5E7EB 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, #E5E7EB 75%),
        linear-gradient(-45deg, transparent 75%, #E5E7EB 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;
    border-radius: 0.5rem;
    overflow: hidden;
    min-height: 300px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.image-box h3 {
    position: absolute;
    top: 0;
    left: 0;
    background: rgba(0, 0, 0, 0.5);
    color: white;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    border-bottom-right-radius: 0.5rem;
    margin: 0;
    z-index: 10;
}

.image-box img {
    max-width: 100%;
    max-height: 400px;
    object-fit: contain;
}

.loading-overlay {
    position: absolute;
    inset: 0;
    background: rgba(255, 255, 255, 0.8);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 20;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #E5E7EB;
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

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

.download-btn {
    background-color: var(--primary-color);
    color: white;
    padding: 0.75rem 2rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 500;
    transition: background-color 0.2s;
    cursor: pointer;
}

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

.secondary-btn {
    background-color: white;
    color: var(--text-color);
    border: 1px solid var(--border-color);
    padding: 0.75rem 2rem;
    border-radius: 0.5rem;
    cursor: pointer;
    font-family: inherit;
    font-weight: 500;
    transition: background-color 0.2s;
}

.secondary-btn:hover {
    background-color: #F9FAFB;
}

.hidden {
    display: none !important;
}

/* Tab Styles */
.tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-top: 1.5rem;
}

.tab-btn {
    background-color: transparent;
    color: var(--text-color);
    border: 2px solid var(--border-color);
    padding: 0.5rem 1.5rem;
    border-radius: 2rem;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    font-family: inherit;
}

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

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

.tab-content {
    opacity: 0;
    visibility: hidden;
    height: 0;
    overflow: hidden;
    transition: opacity 0.3s ease;
}

.tab-content.active {
    opacity: 1;
    visibility: visible;
    height: auto;
    overflow: visible;
}

/* Compression Stats */
.file-size-badge {
    position: absolute;
    bottom: 0;
    right: 0;
    background: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 0.5rem;
    font-size: 0.8rem;
    border-top-left-radius: 0.5rem;
    z-index: 10;
}
.file-size-badge.success {
    background: rgba(16, 185, 129, 0.9);
}

.compression-stats {
    text-align: center;
    font-size: 1.25rem;
    font-weight: 600;
    color: #10B981;
    margin-bottom: 2rem;
}

input[type="range"] {
    width: 100%;
    accent-color: var(--primary-color);
    margin-top: 0.5rem;
}

/* Resize Width Control */
.resize-group {
    width: 100%;
    margin-top: 0.25rem;
}

.resize-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.resize-header input[type="checkbox"] {
    width: 1.125rem;
    height: 1.125rem;
    cursor: pointer;
    accent-color: var(--primary-color);
}

.resize-header label {
    cursor: pointer;
    font-weight: 500;
    font-size: 0.875rem;
}

.resize-input-wrapper {
    display: flex;
    align-items: center;
    gap: 0;
    margin-top: 0.5rem;
    max-width: 160px;
    transition: opacity 0.2s;
}

.resize-input-wrapper.disabled {
    opacity: 0.45;
    pointer-events: none;
}

.resize-input-wrapper input[type="number"] {
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border-color);
    border-right: none;
    border-radius: 0.5rem 0 0 0.5rem;
    font-family: inherit;
    font-size: 0.875rem;
    color: var(--text-color);
    background-color: white;
    -moz-appearance: textfield;
}

.resize-input-wrapper input[type="number"]::-webkit-outer-spin-button,
.resize-input-wrapper input[type="number"]::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.resize-input-wrapper input[type="number"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(79, 70, 229, 0.2);
}

.resize-unit {
    padding: 0.5rem 0.75rem;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-left: none;
    border-radius: 0 0.5rem 0.5rem 0;
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 500;
    white-space: nowrap;
}

/* Batch Area Styles */
.upload-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 1rem;
}

.upload-buttons .upload-btn {
    margin-top: 0;
}

.upload-btn.folder-btn {
    background-color: var(--text-color);
}
.upload-btn.folder-btn:hover {
    background-color: #000;
}

.batch-area {
    background: var(--card-bg);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.batch-content {
    text-align: center;
    margin-bottom: 2rem;
}

.progress-container {
    width: 100%;
    height: 12px;
    background-color: #E5E7EB;
    border-radius: 6px;
    overflow: hidden;
    margin: 1.5rem 0;
}

.progress-bar {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--primary-color), #7C3AED);
    transition: width 0.3s ease;
}

.batch-status {
    color: var(--text-muted);
    font-weight: 500;
    margin-bottom: 1rem;
}

.batch-file-list {
    list-style: none;
    padding: 0;
    margin: 0;
    max-height: 200px;
    overflow-y: auto;
    text-align: left;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
}

.batch-file-list li {
    padding: 0.5rem 1rem;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.875rem;
    display: flex;
    justify-content: space-between;
}
.batch-file-list li:last-child {
    border-bottom: none;
}
.batch-file-list li .success {
    color: #10B981;
    font-weight: 500;
}
.batch-file-list li .error {
    color: #EF4444;
    font-weight: 500;
}

@media (max-width: 768px) {
    .image-container {
        grid-template-columns: 1fr;
    }
}