/* 基本样式回退 - 确保即使CDN资源加载失败，页面也能有基本样式 */

/* 基础样式 */
* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: #4E5969;
    line-height: 1.6;
    background-color: #fff;
}

/* 文本颜色 */
.text-primary { color: #165DFF; }
.text-dark { color: #1D2129; }
.text-gray-600 { color: #4E5969; }
.text-white { color: white; }

/* 字体粗细 */
.font-medium { font-weight: 500; }
.font-bold { font-weight: 700; }

/* 字体大小 */
.text-xl { font-size: 1.25rem; }
.text-3xl { font-size: 1.875rem; }
.text-4xl { font-size: 2.25rem; }

/* 响应式字体大小 */
@media (min-width: 768px) {
    .md\:text-4xl { font-size: 2.25rem; }
}

/* 背景颜色 */
.bg-light { background-color: #F2F3F5; }
.bg-white { background-color: white; }

/* 布局 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

.row {
    display: flex;
    flex-wrap: wrap;
    margin: 0 -15px;
}

/* 响应式网格 */
.col-lg-3, .col-lg-4, .col-lg-6, .col-lg-12,
.col-md-6,
.col-12 {
    position: relative;
    width: 100%;
    padding: 0 15px;
}

/* 中等屏幕以上 (>=768px) */
@media (min-width: 768px) {
    .col-md-6 {
        flex: 0 0 50%;
        max-width: 50%;
    }
}

/* 大屏幕以上 (>=992px) */
@media (min-width: 992px) {
    .col-lg-3 {
        flex: 0 0 25%;
        max-width: 25%;
    }
    .col-lg-4 {
        flex: 0 0 33.3333%;
        max-width: 33.3333%;
    }
    .col-lg-6 {
        flex: 0 0 50%;
        max-width: 50%;
    }
    .col-lg-12 {
        flex: 0 0 100%;
        max-width: 100%;
    }
}

/* 文本对齐 */
.text-center { text-align: center; }

/* 外边距 */
.m-0 { margin: 0; }
.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 1rem; }
.mt-4 { margin-top: 1.5rem; }
.mt-5 { margin-top: 3rem; }
.mt-12 { margin-top: 3rem; }
.mb-1 { margin-bottom: 0.25rem; }
.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 1.5rem; }
.mb-5 { margin-bottom: 3rem; }
.mb-6 { margin-bottom: 1.5rem; }
.mb-8 { margin-bottom: 2rem; }
.mb-12 { margin-bottom: 3rem; }

/* 左右边距 */
.mx-auto { margin-left: auto; margin-right: auto; }

/* 内边距 */
.p-0 { padding: 0; }
.p-6 { padding: 1.5rem; }

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 8px 16px;
    border: 1px solid transparent;
    border-radius: 4px;
    font-size: 1rem;
    line-height: 1.5;
    text-align: center;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: #165DFF;
    border-color: #165DFF;
    color: white;
}

.btn-primary:hover {
    background-color: #0E4BDC;
    border-color: #0E4BDC;
}

.btn-outline-white {
    background-color: transparent;
    border-color: white;
    color: white;
}

.btn-outline-white:hover {
    background-color: white;
    color: #165DFF;
}

/* 卡片样式 */
.card {
    background-color: #fff;
    border-radius: 0.25rem;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    margin-bottom: 1rem;
}

.card-body {
    padding: 1.25rem;
}

.card-hover {
    transition: all 0.3s ease;
}

.card-hover:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

/* 阴影类 */
.shadow-sm { box-shadow: 0 1px 3px rgba(0,0,0,0.1); }
.shadow { box-shadow: 0 4px 6px rgba(0,0,0,0.1); }
.shadow-lg { box-shadow: 0 10px 15px rgba(0,0,0,0.1); }

/* 圆角类 */
.rounded { border-radius: 0.25rem; }
.rounded-lg { border-radius: 0.5rem; }
.rounded-xl { border-radius: 0.75rem; }
.rounded-2xl { border-radius: 1rem; }
.rounded-pill { border-radius: 50rem; }

/* 尺寸类 */
.w-14 { width: 3.5rem; }
.h-14 { height: 3.5rem; }
.w-full { width: 100%; }
.h-full { height: 100%; }
.h-48 { height: 12rem; }

/* Flex布局 */
.flex { display: flex; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }

/* 溢出控制 */
.overflow-hidden { overflow: hidden; }

/* 导航样式 */
.navbar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    padding: 0.5rem 1rem;
}

.navbar-brand {
    display: inline-block;
    padding-top: 0.3125rem;
    padding-bottom: 0.3125rem;
    margin-right: 1rem;
    font-size: 1.25rem;
    line-height: inherit;
    white-space: nowrap;
    text-decoration: none;
}

.navbar-nav {
    display: flex;
    flex-direction: column;
    padding-left: 0;
    margin-bottom: 0;
    list-style: none;
}

.nav-link {
    display: block;
    padding: 0.5rem 1rem;
    text-decoration: none;
}

/* 表单样式 */
.form-control {
    display: block;
    width: 100%;
    padding: 0.375rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    color: #495057;
    background-color: #fff;
    background-clip: padding-box;
    border: 1px solid #ced4da;
    border-radius: 0.25rem;
    transition: border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

.form-label {
    display: inline-block;
    margin-bottom: 0.5rem;
}

/* 间距 */
.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 1rem; }
.mt-4 { margin-top: 1.5rem; }
.mt-5 { margin-top: 3rem; }
.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 1.5rem; }
.mb-5 { margin-bottom: 3rem; }

/* 文本样式 */
.text-center { text-align: center; }
.text-white { color: white; }
.font-bold { font-weight: bold; }
.display-4 { font-size: 3rem; }
.lead { font-size: 1.25rem; }

/* 渐变背景 */
.bg-gradient-blue {
    background: linear-gradient(135deg, #165DFF 0%, #36CFFB 100%);
}

/* 半透明背景 */
.bg-primary\/10 { background-color: rgba(22, 93, 255, 0.1); }

/* 最大宽度 */
.max-w-2xl { max-width: 42rem; }

/* 最大宽度响应式 */
@media (min-width: 768px) {
    .md\:flex { display: flex; }
}