/* 全局样式 */
:root {
    --primary-color: #3498db;
    --primary-dark: #2980b9;
    --text-color: #333;
    --bg-color: #ffffff;
    --button-bg: #3498db;
    --button-text: white;
    --button-hover: #2980b9;
    --button-active: #1f618d;
    --button-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --button-shadow-hover: 0 6px 10px rgba(0, 0, 0, 0.15);
}

/* 深色模式 */
@media (prefers-color-scheme: dark) {
    :root {
        --primary-color: #3498db;
        --primary-dark: #2980b9;
        --text-color: #f1f1f1;
        --bg-color: #1a1a1a;
        --button-bg: #3498db;
        --button-text: white;
        --button-hover: #2980b9;
        --button-active: #1f618d;
        --button-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
        --button-shadow-hover: 0 6px 10px rgba(0, 0, 0, 0.4);
    }
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* 标题样式 */
h1 {
    color: #2c3e50;
    margin-bottom: 20px;
    text-align: center;
    font-size: 2.5rem;
    background: linear-gradient(to right, #3498db, #2980b9);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

h2 {
    color: #666666;
    margin: 25px 0 15px;
    font-size: 1.5rem;
    text-align: center;
}

h3 {
    color: #34495e;
    margin: 20px 0 10px;
    font-size: 1.2rem;
}

/* 段落样式 */
p {
    margin-bottom: 20px;
    text-align: justify;
}

/* 分隔线样式 */
hr {
    border: none;
    border-top: 1px solid #ddd;
    margin: 30px 0;
}

/* 按钮样式 */
a {
    display: inline-block;
    background-color: var(--button-bg);
    color: var(--button-text);
    padding: 10px 16px;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
    transition: all 0.3s ease;
    margin-top: 10px;
    border: none;
    cursor: pointer;
    box-shadow: var(--button-shadow);
    position: relative;
    overflow: hidden;
}

a:hover {
    background-color: var(--button-hover);
    transform: translateY(-3px);
    box-shadow: var(--button-shadow-hover);
}

a:active {
    transform: translateY(1px);
    background-color: var(--button-active);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

a::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.6s ease, height 0.6s ease;
}

a:hover::after {
    width: 200px;
    height: 200px;
}

/* 按钮组样式 */
.button-group {
    display: flex;
    gap: 10px;
    margin-top: 15px;
    flex-wrap: wrap;
}

@media (max-width: 600px) {
    .button-group {
        flex-direction: column;
        width: 100%;
    }
}

/* 响应式设计 */
@media (max-width: 600px) {
    body {
        padding: 15px;
    }

    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.3rem;
    }

    a {
        padding: 8px 14px;
        width: 100%;
        text-align: center;
    }
}