:root {
    --primary-color: #007bff;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --border-color: #dee2e6;
    --border-radius: 8px;
    --text-muted: #6c757d;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--light-color);
    color: var(--dark-color);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 900px;
    background-color: #fff;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

header {
    text-align: center;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1.5rem;
}

header h1 {
    margin: 0;
    font-size: 2.25rem;
}

header p {
    color: var(--text-muted);
    font-size: 1.1rem;
    margin-top: 0.5rem;
}

.supported-formats {
    font-size: 0.9rem !important;
    font-style: italic;
}

.controls {
    display: flex;
    flex-wrap: wrap; /* 允许按钮在小屏幕上换行 */
    gap: 1rem;
    justify-content: center;
    margin-bottom: 2rem;
}

button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--border-radius);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all 0.2s ease-in-out;
    white-space: nowrap;
}

#uploadImageButton, #uploadZipButton {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

#uploadImageButton:hover, #uploadZipButton:hover {
    background-color: #0056b3;
}

#downloadButton {
    background-color: var(--success-color);
    color: white;
    border-color: var(--success-color);
}

#downloadButton:hover {
    background-color: #1e7e34;
}

button:disabled {
    background-color: #6c757d;
    border-color: #6c757d;
    cursor: not-allowed;
    opacity: 0.7;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1.5rem;
}

.result-card {
    background-color: var(--light-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 1rem;
    text-align: center;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: transform 0.2s ease;
}

.result-card:hover {
    transform: translateY(-5px);
}

.result-card p {
    margin: 0 0 0.5rem 0;
    font-weight: 500;
    word-break: break-all;
    font-size: 0.9rem;
    flex-shrink: 0;
}

.thumbnail-container {
    width: 100%;
    padding-top: 100%; /* 1:1 Aspect Ratio */
    position: relative;
    background-color: #e9ecef;
    border-radius: 4px;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 2rem;
}

.thumbnail-container img, .thumbnail-container .spinner {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.status-container {
    margin-top: auto;
}

.status {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: bold;
    width: 100%;
    box-sizing: border-box;
}

.status.success {
    background-color: var(--success-color);
    color: white;
}

.status.error {
    background-color: var(--danger-color);
    color: white;
}

/* 加载动画 */
.spinner {
    border: 4px solid rgba(0, 0, 0, 0.1);
    border-left-color: var(--primary-color);
    border-radius: 50%;
    width: 40px !important;
    height: 40px !important;
    animation: spin 1s linear infinite;
    top: calc(50% - 20px);
    left: calc(50% - 20px);
}

.drag-over {
    border: 2px dashed var(--primary-color) !important;
    background-color: #f0f8ff !important;
}

.result-card.clickable {
    cursor: pointer;
    transition: transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
}

.result-card.clickable:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
}

.progress-container {
    width: 90%;
    max-width: 600px;
    margin: 25px auto;
    text-align: center;
    padding: 20px;
    background-color: #f8f9fa;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

.progress-label {
    margin: 0 0 12px 0;
    font-size: 1em;
    font-weight: 500;
    color: #495057;
}

.progress-bar-background {
    width: 100%;
    height: 22px;
    background-color: #e9ecef;
    border-radius: 11px;
    overflow: hidden;
    border: 1px solid #dee2e6;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.06);
}

.progress-bar-foreground {
    height: 100%;
    width: 0%;
    background-color: #007bff;
    background-image: linear-gradient(45deg, rgba(255, 255, 255, 0.15) 25%, transparent 25%, transparent 50%, rgba(255, 255, 255, 0.15) 50%, rgba(255, 255, 255, 0.15) 75%, transparent 75%, transparent);
    background-size: 40px 40px;
    border-radius: 11px;
    transition: width 0.2s ease-out;
}

.progress-percentage-text {
    display: block;
    margin-top: 12px;
    font-size: 1.1em;
    font-weight: bold;
    color: #007bff;
}

@keyframes progress-bar-stripes {
    from { background-position: 40px 0; }
    to { background-position: 0 0; }
}

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