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

:root {
    --primary-color: #4299e1;
    --primary-hover: #3182ce;
    --success-color: #48bb78;
    --bg-color: #f7fafc;
    --text-color: #2d3748;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    max-width: 800px;
    width: 100%;
    background: white;
    border-radius: 20px;
    box-shadow: var(--shadow);
    padding: 30px;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

h1 {
    color: var(--text-color);
    font-size: 2.5em;
    margin-bottom: 10px;
}

.subtitle {
    color: #718096;
    font-size: 1.1em;
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    padding: 40px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #f8fafc;
}

.upload-area:hover, .upload-area.dragover {
    border-color: var(--primary-color);
    background: #ebf8ff;
}

.upload-icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.upload-text {
    font-size: 1.2em;
    color: var(--text-color);
    margin-bottom: 10px;
}

.upload-hint {
    color: #a0aec0;
    font-size: 0.9em;
    margin-bottom: 20px;
}

.upload-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 8px;
    font-size: 1em;
    cursor: pointer;
    transition: background 0.3s ease;
}

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

.preview-area {
    margin-top: 30px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    overflow: hidden;
}

.preview-header {
    background: #f8fafc;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
}

.preview-header span {
    font-weight: 600;
    color: var(--text-color);
}

.new-upload {
    background: transparent;
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: 6px;
    cursor: pointer;
    color: var(--text-color);
    transition: all 0.3s ease;
}

.new-upload:hover {
    background: var(--bg-color);
    border-color: var(--primary-color);
}

.preview-content {
    padding: 20px;
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 20px;
}

.image-preview {
    width: 200px;
    height: 200px;
    border-radius: 8px;
    overflow: hidden;
    background: #f8fafc;
}

.image-preview img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.result-info {
    flex: 1;
}

.url-container, .markdown-info, .html-info {
    margin-bottom: 15px;
}

.url-container label, .markdown-info label, .html-info label {
    display: block;
    margin-bottom: 5px;
    color: #718096;
    font-size: 0.9em;
    font-weight: 500;
}

.url-box {
    display: flex;
    gap: 10px;
}

.url-box input {
    flex: 1;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.9em;
    color: var(--text-color);
    background: #f8fafc;
}

.url-box input:read-only {
    cursor: default;
}

.copy-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9em;
    transition: background 0.3s ease;
    white-space: nowrap;
}

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

.copy-btn.success {
    background: var(--success-color);
}

.loading {
    text-align: center;
    padding: 40px;
}

.spinner {
    border: 4px solid var(--border-color);
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

footer {
    text-align: center;
    margin-top: 30px;
    color: #a0aec0;
    font-size: 0.9em;
}

@media (max-width: 768px) {
    .container {
        padding: 20px;
    }

    h1 {
        font-size: 2em;
    }

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

    .image-preview {
        width: 100%;
        height: 250px;
        margin-bottom: 15px;
    }
}