/* 深色模式样式 */
body.dark-mode {
    background-color: #121212;
    color: #e0e0e0;
}

body.dark-mode .container {
    background-color: #1e1e1e;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
}

body.dark-mode header {
    background-color: #252525;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

body.dark-mode nav a {
    color: #e0e0e0;
}

body.dark-mode nav a:hover {
    color: #4CAF50;
}

body.dark-mode .card {
    background-color: #252525;
    border: 1px solid #333;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

body.dark-mode .card:hover {
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.4);
}

body.dark-mode h1, body.dark-mode h2, body.dark-mode h3, body.dark-mode h4, body.dark-mode h5, body.dark-mode h6 {
    color: #ffffff;
}

body.dark-mode a {
    color: #81C784;
}

body.dark-mode a:hover {
    color: #4CAF50;
}

body.dark-mode button, body.dark-mode input[type="submit"] {
    background-color: #333;
    color: #e0e0e0;
    border: 1px solid #555;
}

body.dark-mode button:hover, body.dark-mode input[type="submit"]:hover {
    background-color: #444;
}

body.dark-mode input[type="text"], body.dark-mode input[type="email"], body.dark-mode textarea {
    background-color: #333;
    color: #e0e0e0;
    border: 1px solid #555;
}

body.dark-mode input[type="text"]:focus, body.dark-mode input[type="email"]:focus, body.dark-mode textarea:focus {
    border-color: #4CAF50;
    outline: none;
}

body.dark-mode .footer {
    background-color: #252525;
    color: #e0e0e0;
}

/* 深色模式切换按钮 */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
    background: #f1f1f1;
    border: none;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
}

body.dark-mode .theme-toggle {
    background: #333;
    color: #e0e0e0;
}

.theme-toggle:hover {
    transform: scale(1.1);
}

/* 平滑过渡效果 */
body {
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container, header, nav, .card, .footer {
    transition: background-color 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

button, input, textarea {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}