/* 重置与基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 
        /* 系统中文字体 */
        "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", 
        /* 系统西文字体 */
        -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial,
        /* 通用后备字体 */
        "Noto Sans CJK SC", sans-serif;
    line-height: 1.6;
    color: #333;
    /* 字体渲染优化 */
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

a {
    color: #0073aa;
    text-decoration: none;
}

a:hover {
    color: #005a87;
}

/* 响应式容器 */
.container {
    width: 100%;
    padding: 0 15px;
    margin: 0 auto;
}

@media (min-width: 576px) {
    .container {
        max-width: 540px;
    }
}

@media (min-width: 768px) {
    .container {
        max-width: 720px;
    }
}

@media (min-width: 992px) {
    .container {
        max-width: 960px;
    }
}

@media (min-width: 1200px) {
    .container {
        max-width: 1140px;
    }
}

/* 卡片 */
.card {
    border: 1px solid #e1e5e9;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.card:hover {
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.card-img-top {
    width: 100%;
    height: 200px;
    object-fit: cover;
    /* 懒加载效果 */
    opacity: 0;
    transition: opacity 0.3s ease;
}

.card-img-top.loaded {
    opacity: 1;
}

/* WebP 支持 */
.webp .card-img-top {
    /* 如果支持WebP，优先使用WebP格式 */
}

/* 图片加载状态 */
.image-loading {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: loading 2s infinite;
}

@keyframes loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.card-body {
    padding: 1.25rem;
}

.card-title {
    margin-bottom: 0.75rem;
    color: #111;
}

.card-text {
    color: #555;
    margin-bottom: 1rem;
}

/* 按钮 */
.btn {
    display: inline-block;
    font-weight: 400;
    text-align: center;
    white-space: nowrap;
    vertical-align: middle;
    cursor: pointer;
    border: 1px solid transparent;
    padding: 0.375rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    border-radius: 4px;
    transition: all 0.15s ease;
}

.btn-primary {
    color: #fff;
    background-color: #0073aa;
    border-color: #0073aa;
}

.btn-primary:hover {
    background-color: #005a87;
    border-color: #005a87;
}

.btn-outline-primary {
    color: #0073aa;
    background-color: transparent;
    border-color: #0073aa;
}

.btn-outline-primary:hover {
    color: #fff;
    background-color: #0073aa;
    border-color: #0073aa;
}

/* 表单 */
.form-control {
    display: block;
    width: 100%;
    padding: 0.375rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    color: #495057;
    background-color: #fff;
    border: 1px solid #ced4da;
    border-radius: 4px;
    transition: border-color 0.15s ease;
}

.form-control:focus {
    border-color: #0073aa;
    outline: 0;
    box-shadow: 0 0 0 0.2rem rgba(0, 115, 170, 0.25);
}

.form-group {
    margin-bottom: 1rem;
}

label {
    display: inline-block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

textarea.form-control {
    min-height: 120px;
    resize: vertical;
}

/* 导航 */
.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
}

.navbar-nav .nav-link {
    padding: 0.5rem 1rem;
}

.navbar-toggler {
    border: 1px solid #0073aa;
}

/* 页脚 */
.footer {
    background-color: #f8f9fa;
    padding: 3rem 0;
    margin-top: 3rem;
    border-top: 1px solid #e1e5e9;
}

/* 响应式实用工具 */
.text-md-center {
    text-align: center;
}

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

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

.d-md-none {
    display: none;
}

@media (min-width: 768px) {
    .text-md-center {
        text-align: center;
    }
    .text-md-start {
        text-align: left;
    }
    .text-md-end {
        text-align: right;
    }
    .d-md-none {
        display: block;
    }
}

/* 移动端优化 */
.hero {
    padding: 2rem 1rem;
    text-align: center;
}

.hero h1 {
    font-size: 2rem;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero .lead {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

.hero .btn {
    margin-top: 1rem;
    width: 100%;
    max-width: 200px;
}

/* 表单移动端优化 */
.submit-form-container {
    padding: 1rem;
}

.form-control {
    font-size: 16px; /* 防止iOS缩放 */
    padding: 0.75rem;
}

.btn-block {
    width: 100%;
    padding: 0.75rem;
    font-size: 1.1rem;
}

/* 卡片移动端优化 */
.card {
    margin-bottom: 1.5rem;
    border-radius: 12px;
}

.card-body {
    padding: 1rem;
}

/* 导航移动端优化 */
.navbar-brand {
    font-size: 1.3rem;
}

.navbar-toggler {
    padding: 0.25rem 0.5rem;
    border: none;
}

/* 图片移动端优化 */
.card-img-top {
    height: 180px;
}

.post-thumbnail {
    width: 100%;
    height: auto;
    border-radius: 8px;
    margin-bottom: 1rem;
}

/* 文字大小优化 */
body {
    font-size: 14px;
    line-height: 1.5;
}

h1 { font-size: 1.8rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.3rem; }
h4 { font-size: 1.1rem; }
h5 { font-size: 1rem; }

/* 间距优化 */
.container {
    padding-left: 1rem;
    padding-right: 1rem;
}

.py-5 {
    padding-top: 2rem !important;
    padding-bottom: 2rem !important;
}

/* 触摸优化 */
.btn, .form-control, .navbar-toggler {
    min-height: 44px; /* iOS推荐的最小触摸区域 */
}

a {
    min-height: 44px;
    display: inline-block;
    line-height: 44px;
    vertical-align: top;
}

/* 小屏幕特殊优化 */
@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.75rem;
    }
    
    .card-img-top {
        height: 160px;
    }
    
    .container {
        padding-left: 0.75rem;
        padding-right: 0.75rem;
    }
    
    .form-control {
        font-size: 16px;
    }
}

/* 平板端 */
@media (min-width: 768px) {
    .hero {
        padding: 4rem 1rem;
    }
    
    .hero h1 {
        font-size: 2.8rem;
    }
    
    .hero .btn {
        width: auto;
        margin-top: 1.5rem;
    }
    
    .card-img-top {
        height: 200px;
    }
    
    body {
        font-size: 15px;
    }
    
    .submit-form-container {
        padding: 1.5rem;
    }
    
    .text-md-center {
        text-align: center;
    }
    .text-md-start {
        text-align: left;
    }
    .text-md-end {
        text-align: right;
    }
    .d-md-none {
        display: block;
    }
}

/* 桌面端 */
@media (min-width: 992px) {
    .hero {
        padding: 5rem 1rem;
    }
    
    .hero h1 {
        font-size: 3.2rem;
    }
    
    .card-img-top {
        height: 220px;
    }
    
    body {
        font-size: 16px;
    }
    
    .submit-form-container {
        padding: 2rem;
        max-width: 600px;
        margin: 0 auto;
    }
    
    .py-5 {
        padding-top: 3rem !important;
        padding-bottom: 3rem !important;
    }
}

/* 大屏幕 */
@media (min-width: 1200px) {
    .hero h1 {
        font-size: 3.5rem;
    }
    
    .container {
        max-width: 1140px;
    }
    
    .card-img-top {
        height: 240px;
    }
}

/* 联系表单样式 */
.contact-form-container {
    padding: 2rem 0;
}

.contact-form-wrapper {
    background: #fff;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

.contact-info {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 12px;
    height: fit-content;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid #e9ecef;
}

.contact-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.contact-item i {
    font-size: 1.2rem;
    color: #0073aa;
    margin-right: 1rem;
    margin-top: 0.2rem;
    width: 20px;
    text-align: center;
}

.contact-item div {
    flex: 1;
}

.contact-item strong {
    color: #333;
    margin-bottom: 0.5rem;
    display: block;
}

.contact-item p {
    margin: 0;
    color: #666;
    line-height: 1.4;
}

.contact-social {
    border-top: 1px solid #e9ecef;
    padding-top: 1.5rem;
}

.social-links {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.contact-status {
    min-height: 60px;
}

.contact-status.alert {
    border-radius: 8px;
    padding: 1rem;
    margin-top: 1rem;
}

/* 表单验证样式 */
.was-validated .form-control:valid {
    border-color: #198754;
}

.was-validated .form-control:invalid {
    border-color: #dc3545;
}

.invalid-feedback {
    display: block;
    color: #dc3545;
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

/* 移动端联系表单优化 */
@media (max-width: 768px) {
    .contact-form-wrapper,
    .contact-info {
        padding: 1.5rem;
        margin-bottom: 1.5rem;
    }
    
    .contact-item {
        margin-bottom: 1rem;
        padding-bottom: 1rem;
    }
    
    .social-links {
        justify-content: center;
    }
    
    .contact-form-container {
        padding: 1rem 0;
    }
}

/* 首页联系区域 */
.contact-cta {
    border: 2px solid #e9ecef;
    transition: all 0.3s ease;
}

.contact-cta:hover {
    border-color: #0073aa;
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(0, 115, 170, 0.1);
}

.contact-cta h3 {
    color: #333;
    margin-bottom: 1rem;
}

.contact-cta p {
    color: #666;
    font-size: 1.1rem;
}