:root {
    --primary-color: #4a90e2;
    --primary-hover: #357abd;
    --background-color: #f5f7fa;
    --card-background: #ffffff;
    --text-color: #333333;
    --secondary-text: #666666;
    --border-color: #e1e4e8;
}

body {
    font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    min-height: 100vh;
}

.container {
    width: 100%;
    max-width: 800px;
    margin: 40px 20px;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 40px;
}

header h1 {
    font-size: 2.2rem;
    color: var(--primary-color);
    margin-bottom: 10px;
}

header p {
    color: var(--secondary-text);
    font-size: 1.1rem;
}

.upload-section {
    background: var(--card-background);
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    text-align: center;
}

.file-drop-area {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    max-width: 100%;
    padding: 40px 20px;
    border: 2px dashed var(--border-color);
    border-radius: 12px;
    transition: 0.2s;
    background-color: #fafafa;
    cursor: pointer;
    box-sizing: border-box;
}

.file-drop-area:hover, .file-drop-area.dragover {
    border-color: var(--primary-color);
    background-color: rgba(74, 144, 226, 0.05);
}

.file-msg {
    font-size: 1.1rem;
    color: var(--secondary-text);
    pointer-events: none;
}

.file-input {
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 100%;
    cursor: pointer;
    opacity: 0;
}

.preview-container {
    margin-top: 20px;
    position: relative;
    display: inline-block;
}

.preview-container img {
    max-width: 100%;
    max-height: 400px;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.remove-btn {
    position: absolute;
    top: -10px;
    right: -10px;
    background: #ff5b5b;
    color: white;
    border: none;
    border-radius: 50%;
    width: 24px;
    height: 24px;
    cursor: pointer;
    font-weight: bold;
    line-height: 24px;
    padding: 0;
}

.primary-btn {
    margin-top: 25px;
    padding: 12px 40px;
    font-size: 1.1rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 30px;
    cursor: pointer;
    transition: background-color 0.3s;
    box-shadow: 0 4px 6px rgba(74, 144, 226, 0.2);
}

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

.primary-btn:disabled {
    background-color: #a0c4e8;
    cursor: not-allowed;
    box-shadow: none;
}

.result-section {
    margin-top: 30px;
    background: var(--card-background);
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.hidden {
    display: none;
}

.loading {
    text-align: center;
    color: var(--secondary-text);
    padding: 20px;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #f3f3f3;
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    margin: 0 auto 15px;
    animation: spin 1s linear infinite;
}

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

.report-content {
    line-height: 1.8;
    font-size: 1.05rem;
    color: #2c3e50;
}

.report-content h3 {
    color: var(--primary-color);
    margin-top: 20px;
}

.report-content ul, .report-content ol {
    padding-left: 20px;
}