/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 500px;
    margin: 0 auto;
    padding: 20px;
}

/* 卡片样式 */
.card {
    background: white;
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.card h1 {
    font-size: 24px;
    margin-bottom: 20px;
    color: #2c3e50;
    text-align: center;
}

.card p {
    margin-bottom: 25px;
    text-align: center;
    color: #7f8c8d;
}

/* 表单样式 */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #2c3e50;
}

.form-group input {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.form-group input:focus {
    border-color: #3498db;
    outline: none;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

/* 按钮样式 */
.btn {
    width: 100%;
    padding: 12px;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.btn:hover {
    background-color: #2980b9;
}

/* 提示信息 */
.alert {
    padding: 12px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 14px;
}

.alert.error {
    background-color: #fdecea;
    color: #d32f2f;
    border-left: 4px solid #d32f2f;
}

.alert.success {
    background-color: #e8f5e9;
    color: #388e3c;
    border-left: 4px solid #388e3c;
}

/* 底部链接 */
.footer-links {
    margin-top: 20px;
    text-align: center;
}

.footer-links a {
    color: #3498db;
    text-decoration: none;
    font-size: 14px;
}

.footer-links a:hover {
    text-decoration: underline;
}

/* 响应式设计 */
@media (max-width: 600px) {
    .container {
        padding: 10px;
    }
    
    .card {
        padding: 20px;
    }
}

.dropdown-container {
    margin: 25px 0;
    border-radius: 12px;
    overflow: hidden;
}

/* 下拉栏标题 */
.dropdown-header {
    background: rgba(255, 255, 255, 0.6);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 16px 20px;
    border-radius: 12px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.dropdown-header:hover {
    background: rgba(255, 255, 255, 0.8);
}

.dropdown-header.active {
    border-bottom-left-radius: 0;
    border-bottom-right-radius: 0;
}

.dropdown-title {
    font-weight: 600;
    color: var(--primary);
    font-size: 15px;
}

.dropdown-icon {
    transition: transform 0.3s ease;
    color: var(--primary-light);
}

.dropdown-header.active .dropdown-icon {
    transform: rotate(180deg);
}

/* 下拉内容 */
.dropdown-content {
    background: rgba(255, 255, 255, 0.5);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-top: none;
    border-bottom-left-radius: 12px;
    border-bottom-right-radius: 12px;
    padding: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.dropdown-content.active {
    padding: 20px;
    max-height: 500px;
}

/* 说明内容样式 */
.instructions {
    font-size: 14px;
    line-height: 1.7;
    color: var(--text-light);
}

.instructions ul {
    padding-left: 20px;
    margin: 15px 0;
}

.instructions li {
    margin-bottom: 8px;
    position: relative;
}

.instructions li:before {
    content: "•";
    color: var(--primary);
    font-weight: bold;
    display: inline-block;
    width: 1em;
    margin-left: -1em;
}

.instructions strong {
    color: var(--text);
    font-weight: 600;
}

.note {
    background: rgba(67, 97, 238, 0.08);
    border-left: 3px solid var(--primary);
    padding: 12px;
    border-radius: 0 8px 8px 0;
    margin: 15px 0;
    font-size: 13px;
}