:root {
    --primary-color: #007AFF;
    --background-color: #F5F5F7;
    --card-background: #FFFFFF;
    --text-primary: #1D1D1F;
    --text-secondary: #86868B;
    --border-radius: 12px;
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.5;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

/* 通用按钮样式 */
.btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
}

.btn:hover {
    background: #0056b3;
}