/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Microsoft YaHei", Arial, sans-serif;
    font-size: 14px;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

a {
    color: #007bff;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

img {
    max-width: 100%;
    height: auto;
}

.clear {
    clear: both;
}

.clearfix:after {
    content: "";
    display: table;
    clear: both;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 8px 16px;
    margin-bottom: 0;
    font-size: 14px;
    font-weight: normal;
    line-height: 1.42857143;
    text-align: center;
    white-space: nowrap;
    vertical-align: middle;
    cursor: pointer;
    border: 1px solid transparent;
    border-radius: 4px;
    text-decoration: none;
    transition: all 0.3s;
}

.btn-primary {
    color: #fff;
    background-color: #007bff;
    border-color: #007bff;
}

.btn-primary:hover {
    color: #fff;
    background-color: #0056b3;
    border-color: #004085;
}

.btn-secondary {
    color: #fff;
    background-color: #6c757d;
    border-color: #6c757d;
}

.btn-secondary:hover {
    color: #fff;
    background-color: #545b62;
    border-color: #4e555b;
}

/* 表单样式 */
.form-group {
    margin-bottom: 15px;
}

.form-control {
    display: block;
    width: 100%;
    padding: 8px 12px;
    font-size: 14px;
    line-height: 1.42857143;
    color: #555;
    background-color: #fff;
    background-image: none;
    border: 1px solid #ccc;
    border-radius: 4px;
    transition: border-color ease-in-out .15s, box-shadow ease-in-out .15s;
}

.form-control:focus {
    border-color: #66afe9;
    outline: 0;
    box-shadow: inset 0 1px 1px rgba(0,0,0,.075), 0 0 8px rgba(102, 175, 233, .6);
}

/* 消息提示样式 */
.alert {
    padding: 15px;
    margin-bottom: 20px;
    border: 1px solid transparent;
    border-radius: 4px;
}

.alert-success {
    color: #3c763d;
    background-color: #dff0d8;
    border-color: #d6e9c6;
}

.alert-danger {
    color: #a94442;
    background-color: #f2dede;
    border-color: #ebccd1;
}

.alert-warning {
    color: #8a6d3b;
    background-color: #fcf8e3;
    border-color: #faebcc;
}

.alert-info {
    color: #31708f;
    background-color: #d9edf7;
    border-color: #bce8f1;
}

/* 工具类 */
.text-center {
    text-align: center;
}

.text-left {
    text-align: left;
}

.text-right {
    text-align: right;
}

.pull-left {
    float: left;
}

.pull-right {
    float: right;
}

.hidden {
    display: none;
}

.visible {
    display: block;
}

/* 响应式工具类 */
@media (max-width: 768px) {
    .hidden-xs {
        display: none !important;
    }
}

@media (min-width: 769px) and (max-width: 991px) {
    .hidden-sm {
        display: none !important;
    }
}

@media (min-width: 992px) and (max-width: 1199px) {
    .hidden-md {
        display: none !important;
    }
}

@media (min-width: 1200px) {
    .hidden-lg {
        display: none !important;
    }
}