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

/* 音乐播放器 */
.music-player {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 1000;
}

.play-btn {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background-color: #fff;
    border: 1px solid #eee;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: transform 0.2s;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.play-btn:hover {
    transform: scale(1.05);
}

.play-icon {
    width: 0;
    height: 0;
    border-left: 12px solid #333;
    border-top: 8px solid transparent;
    border-bottom: 8px solid transparent;
    margin-left: 2px;
}

.play-icon.pause {
    width: 12px;
    height: 16px;
    border-left: 4px solid #333;
    border-right: 4px solid #333;
    background: none;
}

:root {
    --bgcolor: #F7FEFB;
    --primary-color: #007acc;
    --text-color: #333;
    --border-color: #e0e0e0;
    --shadow-light: 0 2px 10px rgba(0,0,0,0.08);
    --shadow-medium: 0 4px 12px rgba(0,0,0,0.12);
}

body {
    background-color: var(--bgcolor);
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
}

h2 {
    margin-bottom: 15px;
    font-weight: 600;
    font-size: 1.8rem;
}

p {
    margin-bottom: 15px;
    max-width: 600px;
}

.main-nav {
    background-color: white;
    box-shadow: var(--shadow-light);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 15px 20px;
    transition: all 0.3s ease;
}

.main-nav p {
    font-size: 20px;
    font-weight: bold;
    display: flex;
    justify-content: center;
    align-items: center;
}

.nav-links {
    margin-top: 15px;
    display: none;
    text-decoration: none;
    transition: color 0.3s;
    list-style-type: none;
    text-align: center;
}

.nav-links.show {
    display: block;
    z-index: 100;
    animation: fadeIn 0.3s ease;
}

.nav-links li {
    display: inline-block;
    margin: 0 10px;
    padding: 5px 0;
}

.nav-links li:last-child {
    margin-right: 0;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

a {
    text-decoration: none;
    color: inherit;
    font-size: 16px;
    transition: color 0.2s ease;
    position: relative;
}

a:hover {
    color: var(--primary-color);
}

a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}

a:hover::after {
    width: 100%;
}

.main-header,
.about,
.tools,
.links {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 8% 5%;
    margin: 0;
    background-color: white;
    text-align: center;
    position: relative;
}

.header-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    object-fit: cover;
    display: block;
    margin: 20px auto;
    border: 3px solid white;
    box-shadow: var(--shadow-light);
    transition: transform 0.3s ease;
}

.header-avatar:hover {
    transform: scale(1.05);
}

.scroll-down {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 24px;
    color: var(--primary-color);
    animation: bounce 1.8s infinite;
    cursor: pointer;
}

@keyframes bounce {
    0%, 20% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-8px); }
    60% { transform: translateX(-50%) translateY(0); }
    80% { transform: translateX(-50%) translateY(4px); }
    100% { transform: translateX(-50%) translateY(0); }
}

.Btn {
    margin-top: 15px;
    width: 100%;
    max-width: 250px;
    background-color: white;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-shadow: var(--shadow-light);
    color: var(--text-color);
    font-size: 16px;
    padding: 12px 24px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    justify-content: center;
    align-items: center;
}

.Btn:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-medium);
    border-color: var(--primary-color);
}

.Btn:active {
    transform: translateY(-1px);
}

.Btn.clicked {
    background-color: #f8f8f8;
    border-color: #d0d0d0;
    cursor: default;
    transform: translateY(0);
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.card {
    background: white;
    border-radius: 10px;
    padding: 25px;
    margin: 15px 0;
    box-shadow: var(--shadow-light);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
    width: 100%;
    max-width: 400px;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

footer {
    padding: 40px 0;
    text-align: center;
    background-color: #51D0FA;
    color: white;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .main-nav {
        padding: 12px 15px;
    }
    
    .nav-links li {
        display: block;
        margin: 8px 0;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .Btn {
        width: 90%;
        max-width: none;
    }
    
    .main-header,
    .about,
    .tools,
    .links {
        padding: 15% 5%;
    }
}

@media (max-width: 480px) {
    .header-avatar {
        width: 70px;
        height: 70px;
    }
    
    .scroll-down {
        bottom: 20px;
        font-size: 20px;
    }
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
    width: 30px;
    height: 24px;
}

.hamburger {
    display: block;
    height: 3px;
    background-color: #333;
    position: relative;
    margin-top: 35px;
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: #333;
}

.hamburger::before {
    top: -8px;
}

.hamburger::after {
    bottom: -8px;
}

/* 移动端显示汉堡菜单 */
@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }
}