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

html {
    scroll-behavior: smooth;
}

body {
    font-family: "Microsoft YaHei", "微软雅黑", Arial, sans-serif;
    color: #333;
    line-height: 1.6;
    background-color: #fff;
    margin: 0;
    padding: 0;
    overflow-x: hidden;
}

* {
    font-family: "Microsoft YaHei", "微软雅黑", Arial, sans-serif;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏样式 */
/* 占位符样式，避免布局跳动和黑屏 */
#header-placeholder {
    height: 70px; /* 固定占位高度，避免 header 注入/状态切换导致页面上下跳动（闪烁） */
    background-color: #fff;
    width: 100%;
    position: relative;
    /* 不要设置 z-index：否则会创建 stacking context，导致 fixed 的 .header 无法盖住首页 hero 的背景层 */
    display: block;
    visibility: visible;
    margin: 0;
    padding: 0;
}

#header-placeholder:empty {
    background-color: #fff;
}

/* 当header加载后，placeholder应该让位 */
#header-placeholder .header {
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    right: 0 !important;
    z-index: 1000 !important;
    margin: 0 !important;
    padding: 0 !important;
}

/* 当 header 加载后：保持占位高度不变（否则会产生 layout shift） */
#header-placeholder.has-header {
    height: 70px;
    overflow: visible;
    padding: 0;
    margin: 0;
}

#footer-placeholder {
    min-height: 200px;
    background-color: #fff;
    width: 100%;
    display: block;
    visibility: visible;
}

#footer-placeholder:empty {
    background-color: #fff;
}

.header {
    background-color: rgba(255, 255, 255, 0.98) !important;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    right: 0 !important;
    width: 100% !important;
    z-index: 1000 !important;
    height: 70px;
    overflow: visible;
    margin: 0;
    padding: 0;
    border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
    gap: 30px;
    position: relative;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
}

.nav {
    flex: 1;
    display: flex;
    justify-content: center;
    overflow: visible;
    max-width: 1200px;
}

.logo {
    flex-shrink: 0;
}

.logo a {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    transition: transform 0.2s ease;
    padding: 5px;
    margin-left: -5px;
}

.logo a:hover {
    transform: scale(1.02);
}

.logo-img {
    height: 42px;
    width: auto;
    min-width: 120px;
    max-width: 150px;
    object-fit: contain;
    display: block;
    background-color: transparent;
}

.logo-text {
    font-size: 22px;
    font-weight: 700;
    background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: all 0.3s ease;
    letter-spacing: 0.5px;
}

.logo a:hover .logo-text {
    background: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 8px;
    margin: 0;
    padding: 0;
    flex-wrap: nowrap;
    align-items: center;
    justify-content: center;
}

.nav-list > li {
    white-space: nowrap;
    flex-shrink: 0;
    position: relative;
}

.nav-list > li > a {
    color: #333;
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    padding: 10px 16px;
    display: block;
    white-space: nowrap;
    line-height: 1.4;
    border-radius: 6px;
    position: relative;
}

.nav-list > li > a:hover {
    color: #2563eb;
    background-color: rgba(37, 99, 235, 0.06);
}

/* 下拉菜单样式 */
.nav-item-dropdown {
    position: relative;
}

.nav-item-dropdown > a {
    position: relative;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-item-dropdown > a::after {
    content: '';
    position: absolute;
    bottom: 6px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #2563eb, #60a5fa);
    transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border-radius: 2px;
}

.nav-item-dropdown:hover > a {
    color: #2563eb;
    background-color: rgba(37, 99, 235, 0.06);
}

.nav-item-dropdown:hover > a::after {
    width: calc(100% - 32px);
}

.dropdown-menu {
    position: absolute;
    top: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%) translateY(-8px) scale(0.96);
    background-color: #fff;
    min-width: 220px;
    max-width: 280px;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15), 0 4px 12px rgba(37, 99, 235, 0.08);
    opacity: 0;
    visibility: hidden;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    list-style: none;
    padding: 8px 0;
    margin: 0;
    z-index: 1001;
    border-radius: 10px;
    pointer-events: none;
    border: 1px solid rgba(0, 0, 0, 0.08);
    overflow: hidden;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

/* 创建连接区域，消除间隙 */
.nav-item-dropdown::after {
    content: '';
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    height: 10px;
    background: transparent;
    z-index: 1000;
}

.dropdown-menu::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #2563eb, #60a5fa, #2563eb);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.4s ease;
}

.nav-item-dropdown:hover .dropdown-menu,
.nav-item-dropdown .dropdown-menu:hover {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0) scale(1);
    pointer-events: auto;
}

.nav-item-dropdown:hover .dropdown-menu::before,
.nav-item-dropdown .dropdown-menu:hover::before {
    transform: scaleX(1);
}

.dropdown-menu li {
    margin: 0;
    padding: 0;
    position: relative;
    opacity: 0;
    transform: translateY(-4px);
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-item-dropdown:hover .dropdown-menu li {
    opacity: 1;
    transform: translateY(0);
}

.nav-item-dropdown:hover .dropdown-menu li:nth-child(1) {
    transition-delay: 0.03s;
}

.nav-item-dropdown:hover .dropdown-menu li:nth-child(2) {
    transition-delay: 0.06s;
}

.nav-item-dropdown:hover .dropdown-menu li:nth-child(3) {
    transition-delay: 0.09s;
}

.nav-item-dropdown:hover .dropdown-menu li:nth-child(4) {
    transition-delay: 0.12s;
}

.nav-item-dropdown:hover .dropdown-menu li:nth-child(5) {
    transition-delay: 0.15s;
}

.nav-item-dropdown:hover .dropdown-menu li:nth-child(6) {
    transition-delay: 0.18s;
}

.dropdown-menu a {
    display: flex;
    align-items: center;
    padding: 11px 20px;
    color: #4b5563;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    white-space: nowrap;
    position: relative;
    letter-spacing: 0.1px;
    border-radius: 6px;
    margin: 2px 8px;
}

.dropdown-menu a::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 0;
    background: linear-gradient(180deg, #2563eb, #60a5fa);
    border-radius: 0 2px 2px 0;
    transition: height 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.dropdown-menu a::after {
    content: '→';
    position: absolute;
    right: 16px;
    opacity: 0;
    transform: translateX(-8px);
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    color: #2563eb;
    font-weight: 600;
    font-size: 12px;
}

.dropdown-menu a:hover {
    background-color: rgba(37, 99, 235, 0.08);
    color: #2563eb;
    padding-left: 24px;
    transform: translateX(2px);
}

.dropdown-menu a:hover::before {
    height: 60%;
}

.dropdown-menu a:hover::after {
    opacity: 1;
    transform: translateX(0);
}

/* 3级菜单样式 */
.nav-item-dropdown-sub {
    position: relative;
}

.nav-item-dropdown-sub > a::after {
    content: '▶';
    position: absolute;
    right: 16px;
    font-size: 10px;
    color: #9ca3af;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-item-dropdown-sub:hover > a {
    background-color: rgba(37, 99, 235, 0.08);
    color: #2563eb;
}

.nav-item-dropdown-sub:hover > a::after {
    transform: rotate(90deg);
    color: #2563eb;
}

.dropdown-menu-sub {
    position: absolute;
    left: calc(100% + 4px);
    top: -8px;
    background-color: #fff;
    min-width: 220px;
    max-width: 280px;
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15), 0 4px 12px rgba(37, 99, 235, 0.08);
    opacity: 0;
    visibility: hidden;
    transform: translateX(-8px) scale(0.96);
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    list-style: none;
    padding: 8px 0;
    margin: 0;
    z-index: 1002;
    border-radius: 10px;
    pointer-events: none;
    border: 1px solid rgba(0, 0, 0, 0.08);
    overflow: hidden;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.dropdown-menu-sub::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, #2563eb, #60a5fa, #2563eb);
    transform: scaleX(0);
    transform-origin: center;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-item-dropdown-sub:hover .dropdown-menu-sub,
.nav-item-dropdown-sub .dropdown-menu-sub:hover {
    opacity: 1;
    visibility: visible;
    transform: translateX(0) scale(1);
    pointer-events: auto;
}

.nav-item-dropdown-sub:hover .dropdown-menu-sub::before,
.nav-item-dropdown-sub .dropdown-menu-sub:hover::before {
    transform: scaleX(1);
}

.dropdown-menu-sub li {
    margin: 0;
    padding: 0;
    position: relative;
    opacity: 0;
    transform: translateY(-4px);
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-item-dropdown-sub:hover .dropdown-menu-sub li {
    opacity: 1;
    transform: translateY(0);
}

.nav-item-dropdown-sub:hover .dropdown-menu-sub li:nth-child(1) {
    transition-delay: 0.03s;
}

.nav-item-dropdown-sub:hover .dropdown-menu-sub li:nth-child(2) {
    transition-delay: 0.06s;
}

.nav-item-dropdown-sub:hover .dropdown-menu-sub li:nth-child(3) {
    transition-delay: 0.09s;
}

.dropdown-menu-sub a {
    display: flex;
    align-items: center;
    padding: 11px 20px;
    color: #4b5563;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    white-space: nowrap;
    position: relative;
    letter-spacing: 0.1px;
    border-radius: 6px;
    margin: 2px 8px;
}

.dropdown-menu-sub a::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 0;
    background: linear-gradient(180deg, #2563eb, #60a5fa);
    border-radius: 0 2px 2px 0;
    transition: height 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.dropdown-menu-sub a::after {
    content: '→';
    position: absolute;
    right: 16px;
    opacity: 0;
    transform: translateX(-8px);
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    color: #2563eb;
    font-weight: 600;
    font-size: 12px;
}

.dropdown-menu-sub a:hover {
    background-color: rgba(37, 99, 235, 0.08);
    color: #2563eb;
    padding-left: 24px;
    transform: translateX(2px);
}

.dropdown-menu-sub a:hover::before {
    height: 60%;
}

.dropdown-menu-sub a:hover::after {
    opacity: 1;
    transform: translateX(0);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 6px;
    transition: background-color 0.2s ease;
}

.mobile-menu-toggle:hover {
    background-color: rgba(37, 99, 235, 0.08);
}

.mobile-menu-toggle span {
    width: 24px;
    height: 2.5px;
    background-color: #333;
    border-radius: 2px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.mobile-menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translateY(8px);
}

.mobile-menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translateY(-8px);
}

/* 主横幅 */
.hero {
    position: relative;
    width: 100%;
    height: 600px;
    margin: 0;
    padding: 0;
    margin-top: 0; /* 顶部间距由 #header-placeholder 统一承担，避免重复偏移造成跳动 */
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #333;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #f0f7ff 0%, #e0f2fe 50%, #dbeafe 100%);
    z-index: 0;
}

.hero-animation {
    position: absolute;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 50%, rgba(147, 197, 253, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(96, 165, 250, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(59, 130, 246, 0.2) 0%, transparent 50%);
    animation: backgroundMove 20s ease-in-out infinite;
    z-index: 1;
}

@keyframes backgroundMove {
    0%, 100% {
        transform: translate(0, 0) scale(1);
        opacity: 1;
    }
    33% {
        transform: translate(30px, -30px) scale(1.1);
        opacity: 0.8;
    }
    66% {
        transform: translate(-20px, 20px) scale(0.9);
        opacity: 0.9;
    }
}

.hero::before {
    content: '';
    position: absolute;
    width: 200%;
    height: 200%;
    background: 
        repeating-linear-gradient(
            45deg,
            transparent,
            transparent 50px,
            rgba(147, 197, 253, 0.05) 50px,
            rgba(147, 197, 253, 0.05) 100px
        );
    animation: patternMove 30s linear infinite;
    z-index: 1;
}

@keyframes patternMove {
    0% {
        transform: translate(0, 0);
    }
    100% {
        transform: translate(50px, 50px);
    }
}

/* Logo动效 */
.hero-logo {
    position: absolute;
    width: 200px;
    height: 200px;
    background-image: url('../images/赫莱科logo-3.png');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    opacity: 0.08;
    z-index: 1;
    pointer-events: none;
}

.hero-logo-1 {
    top: 15%;
    left: 5%;
    animation: logoFloat1 25s ease-in-out infinite;
}

.hero-logo-2 {
    top: 50%;
    right: 8%;
    animation: logoFloat2 30s ease-in-out infinite;
    animation-delay: -10s;
}

.hero-logo-3 {
    bottom: 20%;
    left: 50%;
    transform: translateX(-50%);
    animation: logoFloat3 28s ease-in-out infinite;
    animation-delay: -15s;
}

@keyframes logoFloat1 {
    0%, 100% {
        transform: translate(0, 0) rotate(0deg) scale(1);
        opacity: 0.08;
    }
    25% {
        transform: translate(40px, -30px) rotate(90deg) scale(1.1);
        opacity: 0.12;
    }
    50% {
        transform: translate(20px, 40px) rotate(180deg) scale(0.9);
        opacity: 0.1;
    }
    75% {
        transform: translate(-30px, 20px) rotate(270deg) scale(1.05);
        opacity: 0.11;
    }
}

@keyframes logoFloat2 {
    0%, 100% {
        transform: translate(0, 0) rotate(0deg) scale(1);
        opacity: 0.08;
    }
    33% {
        transform: translate(-50px, 30px) rotate(-120deg) scale(1.15);
        opacity: 0.12;
    }
    66% {
        transform: translate(30px, -40px) rotate(-240deg) scale(0.85);
        opacity: 0.09;
    }
}

@keyframes logoFloat3 {
    0%, 100% {
        transform: translate(-50%, 0) rotate(0deg) scale(1);
        opacity: 0.08;
    }
    20% {
        transform: translate(-50%, -50px) rotate(72deg) scale(1.2);
        opacity: 0.12;
    }
    40% {
        transform: translate(-30%, 30px) rotate(144deg) scale(0.8);
        opacity: 0.09;
    }
    60% {
        transform: translate(-70%, 20px) rotate(216deg) scale(1.1);
        opacity: 0.11;
    }
    80% {
        transform: translate(-50%, -30px) rotate(288deg) scale(0.95);
        opacity: 0.1;
    }
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    padding: 0 20px;
}

.hero-title {
    font-size: 56px;
    font-weight: 700;
    margin-bottom: 24px;
    letter-spacing: 1px;
    line-height: 1.2;
    background: linear-gradient(135deg, #1e40af 0%, #3b82f6 50%, #60a5fa 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 2px 10px rgba(30, 64, 175, 0.1);
    animation: titleFadeIn 1s ease-out;
}

@keyframes titleFadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-subtitle {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 40px;
    color: #1e3a8a;
    line-height: 1.5;
    animation: subtitleFadeIn 1s ease-out 0.2s both;
}

@keyframes subtitleFadeIn {
    from {
        opacity: 0;
        transform: translateY(15px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.btn-primary {
    display: inline-block;
    padding: 16px 48px;
    background: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
    color: #fff;
    text-decoration: none;
    border-radius: 50px;
    font-size: 18px;
    font-weight: 600;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
    position: relative;
    overflow: hidden;
    animation: buttonFadeIn 1s ease-out 0.4s both;
}

@keyframes buttonFadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn-primary:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #1d4ed8 0%, #2563eb 100%);
    transform: translateY(-4px) scale(1.05);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
}

.btn-primary:active {
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

/* 页面标题 */
.page-header {
    background: linear-gradient(135deg, #1e3a8a 0%, #3b82f6 100%);
    color: #fff;
    padding: 80px 0;
    text-align: center;
    margin-bottom: 0;
    margin-top: 0; /* 顶部间距由 #header-placeholder 统一承担，避免重复偏移造成跳动 */
}

.page-header-content {
    max-width: 800px;
    margin: 0 auto;
}

.page-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    letter-spacing: 1px;
    line-height: 1.2;
}

.page-subtitle {
    font-size: 20px;
    font-weight: 500;
    opacity: 0.95;
    line-height: 1.5;
}

/* 页面内容 */
.page-content {
    padding: 80px 0;
    background-color: #f5f5f5;
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.research-card {
    background-color: #fff;
    padding: 40px 30px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    text-align: center;
    position: relative;
    overflow: hidden;
    border: 1px solid #f1f5f9;
}

.research-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #2563eb, #60a5fa);
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.research-card:hover::before {
    transform: scaleX(1);
}

.research-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 40px rgba(37, 99, 235, 0.2);
    border-color: #dbeafe;
}

.research-icon {
    font-size: 56px;
    margin-bottom: 24px;
    display: block;
    transition: transform 0.3s ease;
}

.research-card:hover .research-icon {
    transform: scale(1.1) rotate(5deg);
}

.research-title {
    font-size: 24px;
    font-weight: 700;
    color: #1e3a8a;
    margin-bottom: 16px;
    letter-spacing: 0.5px;
    line-height: 1.4;
    transition: color 0.3s ease;
}

.research-card:hover .research-title {
    color: #2563eb;
}

.research-desc {
    font-size: 16px;
    line-height: 1.7;
    color: #4b5563;
    font-weight: 500;
    letter-spacing: 0.2px;
    margin: 0;
}

/* 关于我们页面现代化样式 */
.about-section-modern {
    padding: 100px 0;
    background-color: #fff;
}

.about-section-modern:nth-child(even) {
    background-color: #f8fafc;
}

.about-modern-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
}

.about-modern-text {
    padding-right: 40px;
}

.about-modern-title {
    font-size: 42px;
    font-weight: 700;
    color: #1e3a8a;
    margin-bottom: 30px;
    letter-spacing: 0.5px;
    line-height: 1.3;
    position: relative;
    padding-bottom: 20px;
}

.about-modern-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, #2563eb, #60a5fa);
    border-radius: 2px;
}

.about-modern-description {
    font-size: 18px;
    line-height: 1.9;
    color: #4b5563;
    font-weight: 500;
}

.about-modern-description p {
    margin-bottom: 20px;
}

.about-modern-description p:last-child {
    margin-bottom: 0;
}

.about-modern-image {
    position: relative;
}

.image-placeholder {
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    border-radius: 20px;
    padding: 80px 40px;
    text-align: center;
    box-shadow: 0 10px 40px rgba(37, 99, 235, 0.1);
    transition: transform 0.3s ease;
}

.image-placeholder:hover {
    transform: translateY(-5px);
}

.placeholder-icon {
    font-size: 80px;
    margin-bottom: 20px;
}

.image-placeholder p {
    font-size: 18px;
    color: #1e3a8a;
    font-weight: 600;
}

.section-title-modern {
    text-align: center;
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 60px;
    color: #1e3a8a;
    letter-spacing: 1px;
    line-height: 1.3;
    position: relative;
    display: inline-block;
    width: 100%;
}

.section-title-modern::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, #2563eb, #60a5fa);
    border-radius: 2px;
}

/* 核心团队卡片 */
.team-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    max-width: 1200px;
    margin: 0 auto;
}

.team-card {
    background: #fff;
    padding: 50px 40px;
    border-radius: 20px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
    text-align: center;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid #f1f5f9;
    position: relative;
    overflow: hidden;
}

.team-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #2563eb, #60a5fa);
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.team-card:hover::before {
    transform: scaleX(1);
}

.team-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 50px rgba(37, 99, 235, 0.2);
    border-color: #dbeafe;
}

.team-icon {
    font-size: 64px;
    margin-bottom: 24px;
    display: block;
    transition: transform 0.3s ease;
}

.team-card:hover .team-icon {
    transform: scale(1.1) rotate(5deg);
}

.team-name {
    font-size: 24px;
    font-weight: 700;
    color: #1e3a8a;
    margin-bottom: 16px;
    letter-spacing: 0.5px;
}

.team-desc {
    font-size: 16px;
    line-height: 1.7;
    color: #4b5563;
    font-weight: 500;
    margin: 0;
}

/* 发展历程时间线 */
.timeline-section {
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
}

.timeline {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    padding: 40px 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, #2563eb, #60a5fa);
    transform: translateX(-50%);
}

.timeline-item {
    display: flex;
    align-items: center;
    margin-bottom: 60px;
    position: relative;
}

.timeline-item:nth-child(odd) {
    flex-direction: row;
}

.timeline-item:nth-child(even) {
    flex-direction: row-reverse;
}

.timeline-year {
    width: 120px;
    height: 120px;
    background: linear-gradient(135deg, #2563eb, #60a5fa);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 700;
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.3);
    position: relative;
    z-index: 2;
    flex-shrink: 0;
    transition: transform 0.3s ease;
}

.timeline-item:hover .timeline-year {
    transform: scale(1.1);
}

.timeline-content {
    flex: 1;
    background: #fff;
    padding: 30px 40px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    margin: 0 40px;
    border: 1px solid #f1f5f9;
    transition: all 0.3s ease;
}

.timeline-item:hover .timeline-content {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(37, 99, 235, 0.15);
    border-color: #dbeafe;
}

.timeline-content h3 {
    font-size: 22px;
    font-weight: 700;
    color: #1e3a8a;
    margin-bottom: 12px;
    letter-spacing: 0.5px;
}

.timeline-content p {
    font-size: 16px;
    line-height: 1.7;
    color: #4b5563;
    font-weight: 500;
    margin: 0;
}

/* 联系我们页面样式 */
.contact-section-modern {
    padding: 100px 0;
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
}

.contact-modern-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin-bottom: 80px;
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.contact-info-card {
    background: #fff;
    padding: 50px 40px;
    border-radius: 20px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
    text-align: center;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid #f1f5f9;
    position: relative;
    overflow: hidden;
}

.contact-info-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #2563eb, #60a5fa);
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.contact-info-card:hover::before {
    transform: scaleX(1);
}

.contact-info-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 50px rgba(37, 99, 235, 0.2);
    border-color: #dbeafe;
}

.contact-icon {
    font-size: 64px;
    margin-bottom: 24px;
    display: block;
    transition: transform 0.3s ease;
}

.contact-info-card:hover .contact-icon {
    transform: scale(1.1) rotate(5deg);
}

.contact-card-title {
    font-size: 22px;
    font-weight: 700;
    color: #1e3a8a;
    margin-bottom: 16px;
    letter-spacing: 0.5px;
}

.contact-card-content {
    font-size: 20px;
    font-weight: 600;
    color: #2563eb;
    margin-bottom: 8px;
}

.contact-card-desc {
    font-size: 14px;
    color: #6b7280;
    margin: 0;
}

/* 联系表单 */
.contact-form-section {
    max-width: 800px;
    margin: 0 auto;
    background: #fff;
    padding: 60px 50px;
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
    border: 1px solid #f1f5f9;
}

.contact-form {
    margin-top: 40px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 30px;
}

.form-group {
    margin-bottom: 30px;
}

.form-group label {
    display: block;
    font-size: 16px;
    font-weight: 600;
    color: #1e3a8a;
    margin-bottom: 10px;
    letter-spacing: 0.3px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 18px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 16px;
    font-family: "Microsoft YaHei", "微软雅黑", Arial, sans-serif;
    color: #333;
    transition: all 0.3s ease;
    background-color: #fff;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

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

.btn-submit {
    width: 100%;
    padding: 16px 48px;
    background: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
    color: #fff;
    border: none;
    border-radius: 50px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
    font-family: "Microsoft YaHei", "微软雅黑", Arial, sans-serif;
}

.btn-submit:hover {
    background: linear-gradient(135deg, #1d4ed8 0%, #2563eb 100%);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
}

.btn-submit:active {
    transform: translateY(0);
}

/* 服务项目 */
.services {
    padding: 80px 0;
    background-color: #f5f5f5;
    margin-top: 0;
    width: 100%;
}

.services > .container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
}

.services .section-title {
    margin-bottom: 60px;
}

.section-title {
    text-align: center;
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 60px;
    color: #1e3a8a;
    letter-spacing: 1px;
    line-height: 1.3;
    position: relative;
    display: inline-block;
    width: 100%;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, #2563eb, #60a5fa);
    border-radius: 2px;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    width: 100%;
    margin: 0;
    padding: 0;
}

.service-card {
    background-color: #fff;
    padding: 40px 30px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(37, 99, 235, 0.1), transparent);
    transition: left 0.5s;
}

.service-card:hover::before {
    left: 100%;
}

.service-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 12px 30px rgba(37, 99, 235, 0.2);
    z-index: 10;
}

.service-card:active {
    transform: translateY(-4px) scale(0.98);
    transition: all 0.1s ease;
}

/* 点击波纹效果 */
.ripple {
    position: absolute;
    border-radius: 50%;
    background: rgba(37, 99, 235, 0.3);
    transform: scale(0);
    animation: ripple-animation 0.6s ease-out;
    pointer-events: none;
}

@keyframes ripple-animation {
    to {
        transform: scale(4);
        opacity: 0;
    }
}

.service-icon {
    font-size: 48px;
    margin-bottom: 20px;
    text-align: center;
}

.service-title {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 24px;
    color: #1e3a8a;
    text-align: center;
    letter-spacing: 0.5px;
    line-height: 1.4;
    transition: color 0.3s ease;
}

.service-card:hover .service-title {
    color: #2563eb;
}

.service-list {
    list-style: none;
    padding: 0;
}

.service-list li {
    padding: 14px 0;
    color: #374151;
    border-bottom: 1px solid #e5e7eb;
    position: relative;
    padding-left: 32px;
    font-size: 16px;
    font-weight: 600;
    line-height: 1.7;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    letter-spacing: 0.3px;
}

.service-list li:hover {
    color: #2563eb;
    transform: translateX(8px);
    padding-left: 35px;
    background: linear-gradient(90deg, rgba(37, 99, 235, 0.05) 0%, transparent 100%);
    border-left: 3px solid #2563eb;
    margin-left: -3px;
}

.service-list li:last-child {
    border-bottom: none;
}

.service-list li::before {
    content: "→";
    color: #2563eb;
    font-weight: 700;
    position: absolute;
    left: 0;
    font-size: 18px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    opacity: 0.7;
}

.service-list li:hover::before {
    transform: translateX(5px);
    opacity: 1;
    color: #1d4ed8;
}

.service-list a {
    color: inherit;
    text-decoration: none;
    display: block;
    width: 100%;
    transition: all 0.3s ease;
}

.service-list a:hover {
    color: #2563eb;
}

.service-desc {
    color: #374151;
    text-align: center;
    margin-top: 10px;
    font-size: 16px;
    font-weight: 600;
    line-height: 1.7;
    letter-spacing: 0.3px;
    padding: 12px 20px;
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.03) 0%, rgba(96, 165, 250, 0.03) 100%);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.service-card:hover .service-desc {
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.08) 0%, rgba(96, 165, 250, 0.08) 100%);
    color: #2563eb;
    transform: translateY(-2px);
}

/* 关于我们 */
.about {
    padding: 100px 0;
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
    position: relative;
    overflow: hidden;
}

.about::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, #e5e7eb, transparent);
}

.about-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    position: relative;
    z-index: 1;
}

.about-section {
    background: #fff;
    padding: 40px 35px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    border: 1px solid #f1f5f9;
}

.about-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #2563eb, #60a5fa);
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.about-section:hover::before {
    transform: scaleX(1);
}

.about-section:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 40px rgba(37, 99, 235, 0.15);
    border-color: #dbeafe;
}

.about-section:last-child {
    margin-bottom: 0;
}

.about-section h3 {
    font-size: 26px;
    font-weight: 700;
    color: #1e3a8a;
    margin-bottom: 24px;
    text-align: center;
    letter-spacing: 0.5px;
    position: relative;
    padding-bottom: 16px;
}

.about-section h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background: linear-gradient(90deg, #2563eb, #60a5fa);
    border-radius: 2px;
}

.about-text {
    font-size: 16px;
    line-height: 1.8;
    color: #4b5563;
    text-align: left;
    font-weight: 500;
    letter-spacing: 0.2px;
}

/* 联系我们 */
.contact {
    padding: 80px 0;
    background-color: #f5f5f5;
}

.contact-content {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.contact-info p {
    font-size: 18px;
    color: #666;
    margin-bottom: 20px;
}

.contact-details {
    margin-top: 30px;
}

.contact-details p {
    font-size: 16px;
    color: #333;
    margin-bottom: 10px;
}

/* 页脚 */
.footer {
    background-color: #fff !important;
    border-top: 1px solid #e0e0e0;
    padding: 40px 0;
    margin-top: 80px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.footer-copyright {
    text-align: center;
    width: 100%;
    margin-top: 20px;
}

.footer-links a {
    color: #666;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

/* 页脚导航 */
.footer-nav {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid #e0e0e0;
}

.footer-nav-column h4 {
    font-size: 16px;
    font-weight: 700;
    color: #333;
    margin-bottom: 15px;
}

.footer-nav-column h4 a {
    color: #333;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-nav-column h4 a:hover {
    color: #2563eb;
}

.footer-nav-column ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-nav-column ul li {
    margin-bottom: 10px;
}

.footer-nav-column a {
    color: #666;
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s;
}

.footer-nav-column a:hover {
    color: #2563eb;
}

.footer-links a:hover {
    color: #2563eb;
}


.footer-copyright p {
    font-size: 12px;
    color: #999;
    margin-bottom: 5px;
}

/* 响应式设计 */
@media (max-width: 1200px) {
    .nav-list {
        gap: 12px;
    }
    
    .nav-list > li > a {
        font-size: 12px;
        font-weight: 600;
        padding: 5px 4px;
    }
}

@media (max-width: 1024px) {
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
}

@media (max-width: 768px) {
    .nav {
        display: none;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        background-color: #fff;
        box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    }

    .nav.active {
        display: block;
    }

    .nav-list {
        flex-direction: column;
        padding: 20px;
        gap: 0;
    }

    .nav-list li {
        padding: 15px 0;
        border-bottom: 1px solid #f0f0f0;
    }

    .nav-list > li > a {
        font-size: 16px;
        font-weight: 600;
        padding: 10px 0;
    }

    .nav-item-dropdown {
        position: static;
    }

    .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        background-color: #f5f5f5;
        margin-left: 20px;
        margin-top: 10px;
        display: none;
    }

    .nav-item-dropdown.active .dropdown-menu {
        display: block;
    }

    .nav-item-dropdown-sub {
        position: relative;
    }

    .dropdown-menu-sub {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        background-color: #e5e7eb;
        margin-left: 20px;
        margin-top: 10px;
        display: none;
        border: none;
        padding: 8px 0;
    }

    .nav-item-dropdown-sub.active .dropdown-menu-sub {
        display: block;
    }

    .nav-item-dropdown-sub > a::after {
        content: '▼';
        position: absolute;
        right: 20px;
        font-size: 12px;
        color: #9ca3af;
        transition: transform 0.3s ease;
    }

    .nav-item-dropdown-sub.active > a::after {
        transform: rotate(180deg);
        color: #2563eb;
    }

    .mobile-menu-toggle {
        display: flex;
    }
    
    .logo-img {
        height: 35px;
    }
    
    .logo-text {
        font-size: 20px;
    }
    
    .hero {
        height: 500px;
    }
    
    .hero-logo {
        width: 150px;
        height: 150px;
    }
    
    .hero-title {
        font-size: 32px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

    .services-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .section-title {
        font-size: 32px;
        font-weight: 700;
    }
    
    .section-title::after {
        width: 60px;
        height: 3px;
    }

    .footer-nav {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }

    .footer-nav-column h4 {
        font-size: 14px;
    }

    .footer-nav-column a {
        font-size: 12px;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    .footer-copyright {
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero {
        height: 400px;
    }
    
    .hero-logo {
        width: 120px;
        height: 120px;
        opacity: 0.06;
    }

    .hero-title {
        font-size: 28px;
        font-weight: 700;
    }
    
    .hero-subtitle {
        font-size: 16px;
        font-weight: 600;
    }
    
    .btn-primary {
        padding: 14px 36px;
        font-size: 16px;
    }

    .services {
        padding: 60px 0;
    }
    
    .page-header {
        padding: 60px 0;
    }
    
    .page-title {
        font-size: 36px;
    }
    
    .page-subtitle {
        font-size: 18px;
    }
    
    .page-content {
        padding: 60px 0;
    }
    
    .research-grid {
        grid-template-columns: 1fr;
        gap: 25px;
    }
    
    .research-card {
        padding: 30px 25px;
    }
    
    .research-title {
        font-size: 22px;
    }
    
    .research-desc {
        font-size: 15px;
    }
    
    .about-modern-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .about-modern-text {
        padding-right: 0;
    }
    
    .about-modern-title {
        font-size: 32px;
    }
    
    .team-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .timeline::before {
        left: 30px;
    }
    
    .timeline-item {
        flex-direction: row !important;
        padding-left: 80px;
    }
    
    .timeline-year {
        width: 60px;
        height: 60px;
        font-size: 18px;
        position: absolute;
        left: 0;
    }
    
    .timeline-content {
        margin: 0;
    }
    
    .contact-modern-grid {
        grid-template-columns: 1fr;
        gap: 25px;
    }
    
    .contact-form-section {
        padding: 40px 30px;
    }
    
    .form-row {
        grid-template-columns: 1fr;
        gap: 0;
    }

    .about {
        padding: 60px 0;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .about-section {
        padding: 30px 25px;
    }
    
    .about-section h3 {
        font-size: 22px;
    }
    
    .about-text {
        text-align: center;
        font-size: 15px;
    }

    .contact {
        padding: 60px 0;
    }

    .footer-nav {
        grid-template-columns: 1fr;
        gap: 15px;
    }
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.service-card {
    animation: fadeIn 0.6s ease-out;
}

.service-card:nth-child(1) { animation-delay: 0.1s; }
.service-card:nth-child(2) { animation-delay: 0.2s; }
.service-card:nth-child(3) { animation-delay: 0.3s; }
.service-card:nth-child(4) { animation-delay: 0.4s; }
.service-card:nth-child(5) { animation-delay: 0.5s; }
.service-card:nth-child(6) { animation-delay: 0.6s; }

/* 早期药代动力学研究页面样式 */
.pk-content-section {
    padding: 60px 0 100px;
    background-color: #f8fafc;
    min-height: calc(100vh - 60px);
}

.pk-container {
    display: flex;
    gap: 40px;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
}

/* 左侧导航栏 */
.pk-sidebar {
    width: 280px;
    flex-shrink: 0;
    position: sticky;
    top: 80px;
    height: fit-content;
    max-height: calc(100vh - 100px);
    overflow-y: auto;
}

.pk-nav {
    background-color: #fff;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    padding: 20px 0;
    border: 1px solid #e2e8f0;
}

.pk-nav-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.pk-nav-item {
    margin: 0;
}

.pk-nav-link {
    display: block;
    padding: 16px 24px;
    color: #475569;
    font-size: 16px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    border-left: 3px solid transparent;
    position: relative;
}

.pk-nav-link:hover {
    color: #2563eb;
    background-color: #eff6ff;
    border-left-color: #2563eb;
}

.pk-nav-link.active {
    color: #2563eb;
    background-color: #eff6ff;
    border-left-color: #2563eb;
}

.pk-nav-link.active::after {
    content: '';
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    width: 6px;
    height: 6px;
    background-color: #2563eb;
    border-radius: 50%;
}

.pk-nav-sublist {
    list-style: none;
    margin: 0;
    padding: 0;
    background-color: #f8fafc;
    display: none;
}

.pk-nav-link.active + .pk-nav-sublist,
.pk-nav-item:hover .pk-nav-sublist {
    display: block;
}

.pk-nav-sublist li {
    margin: 0;
}

.pk-nav-sublist a {
    display: block;
    padding: 12px 24px 12px 48px;
    color: #64748b;
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
    position: relative;
}

.pk-nav-sublist a::before {
    content: '•';
    position: absolute;
    left: 32px;
    color: #cbd5e1;
    transition: color 0.3s ease;
}

.pk-nav-sublist a:hover,
.pk-nav-sublist a.active {
    color: #2563eb;
    background-color: #e0e7ff;
    padding-left: 52px;
}

.pk-nav-sublist a.active::before {
    color: #2563eb;
}

/* 右侧内容区域 */
.pk-main-content {
    flex: 1;
    background-color: #fff;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    padding: 50px 60px;
    border: 1px solid #e2e8f0;
}

.pk-content-block {
    margin-bottom: 60px;
}

.pk-content-block:last-child {
    margin-bottom: 0;
}

.pk-block-title {
    font-size: 36px;
    font-weight: 700;
    color: #1e3a8a;
    margin-bottom: 20px;
    padding-bottom: 20px;
    border-bottom: 3px solid #2563eb;
    letter-spacing: 0.5px;
}

.pk-block-intro {
    font-size: 18px;
    line-height: 1.8;
    color: #475569;
    margin-bottom: 40px;
    font-weight: 500;
}

.pk-item {
    margin-bottom: 40px;
    padding: 30px;
    background-color: #f8fafc;
    border-radius: 10px;
    border-left: 4px solid #dbeafe;
    transition: all 0.3s ease;
}

.pk-item:hover {
    background-color: #f1f5f9;
    border-left-color: #2563eb;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.1);
}

.pk-item:last-child {
    margin-bottom: 0;
}

.pk-item-title {
    font-size: 24px;
    font-weight: 700;
    color: #1e3a8a;
    margin-bottom: 16px;
    letter-spacing: 0.3px;
}

.pk-item-content {
    font-size: 16px;
    line-height: 1.8;
    color: #475569;
}

.pk-item-content p {
    margin-bottom: 16px;
    font-weight: 500;
}

.pk-feature-list {
    list-style: none;
    padding: 0;
    margin: 20px 0 0;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.pk-feature-list li {
    padding: 12px 16px;
    background-color: #fff;
    border-radius: 8px;
    color: #334155;
    font-weight: 500;
    position: relative;
    padding-left: 36px;
    transition: all 0.3s ease;
}

.pk-feature-list li::before {
    content: '✓';
    position: absolute;
    left: 12px;
    color: #2563eb;
    font-weight: 700;
}

.pk-feature-list li:hover {
    background-color: #eff6ff;
    transform: translateX(4px);
}

/* 模型表格样式 */
.model-table-container {
    margin-top: 30px;
    overflow-x: auto;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.model-table {
    width: 100%;
    border-collapse: collapse;
    background-color: #fff;
    font-size: 15px;
    font-family: "微软雅黑", "Microsoft YaHei", sans-serif;
}

.model-table thead {
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    color: #fff;
}

.model-table th {
    padding: 16px 20px;
    text-align: left;
    font-weight: 600;
    font-size: 16px;
    letter-spacing: 0.5px;
    border: none;
}

.model-table tbody tr {
    border-bottom: 1px solid #e2e8f0;
    transition: background-color 0.2s ease;
}

.model-table tbody tr:hover {
    background-color: #f8fafc;
}

.model-table tbody tr:last-child {
    border-bottom: none;
}

.model-table td {
    padding: 14px 20px;
    color: #334155;
    vertical-align: top;
    line-height: 1.6;
    font-size: 15px;
    font-weight: 400;
}

.model-table td:first-child {
    font-weight: 400;
    color: #334155;
    background-color: #f1f5f9;
    min-width: 150px;
}

.model-table td:nth-child(2) {
    font-weight: 400;
    color: #334155;
    background-color: #f1f5f9;
    min-width: 180px;
}

.model-table td:nth-child(2) {
    font-weight: 400;
    color: #334155;
    background-color: #f1f5f9;
    min-width: 180px;
}

.model-table td:nth-child(3) {
    font-weight: 400;
    color: #334155;
    background-color: #f1f5f9;
    min-width: 300px;
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .pk-container {
        flex-direction: column;
        padding: 0 20px;
    }

    .pk-sidebar {
        width: 100%;
        position: relative;
        top: 0;
        max-height: none;
    }

    .pk-main-content {
        padding: 40px 30px;
    }

    .pk-feature-list {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .pk-content-section {
        padding: 40px 0 60px;
    }

    .pk-main-content {
        padding: 30px 20px;
    }

    .pk-block-title {
        font-size: 28px;
    }

    .pk-item-title {
        font-size: 20px;
    }

    .pk-item {
        padding: 20px;
    }

    .model-table-container {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }

    .model-table {
        font-size: 14px;
        min-width: 600px;
    }

    .model-table th,
    .model-table td {
        padding: 12px 15px;
        font-size: 14px;
    }

    .model-table td:first-child {
        min-width: 120px;
    }

    .model-table td:nth-child(2) {
        min-width: 150px;
    }

    .model-table td:nth-child(3) {
        min-width: 250px;
    }
}

/* SEND转化页面样式 */
.send-kpi-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 25px;
    margin: 40px 0;
}

.send-kpi-item {
    text-align: center;
    padding: 30px 20px;
    background: linear-gradient(135deg, #2563eb 0%, #1e3a8a 100%);
    border-radius: 12px;
    color: #fff;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.send-kpi-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.3);
}

.send-kpi-number {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 10px;
    line-height: 1.2;
}

.send-kpi-label {
    font-size: 16px;
    font-weight: 500;
    opacity: 0.95;
}

.send-process-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    margin: 30px 0;
}

.send-process-card {
    background: #fff;
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    position: relative;
    border: 2px solid transparent;
}

.send-process-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.15);
    border-color: #2563eb;
}

.send-process-number {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #2563eb 0%, #1e3a8a 100%);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 20px;
}

.send-process-title {
    font-size: 20px;
    font-weight: 600;
    color: #1e3a8a;
    margin-bottom: 15px;
    line-height: 1.4;
}

.send-process-desc {
    font-size: 15px;
    line-height: 1.8;
    color: #475569;
    margin: 0;
}

.send-study-type-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin: 30px 0;
}

.send-study-type-card {
    background: #fff;
    border-radius: 10px;
    padding: 25px 20px;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    text-align: center;
    border: 1px solid #e2e8f0;
}

.send-study-type-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.15);
    border-color: #2563eb;
}

.send-study-type-chinese {
    font-size: 18px;
    font-weight: 600;
    color: #1e3a8a;
    margin-bottom: 10px;
    line-height: 1.4;
}

.send-study-type-english {
    font-size: 14px;
    color: #64748b;
    line-height: 1.5;
}

.send-glossary {
    margin-top: 40px;
}

.send-glossary-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.send-glossary-item {
    font-size: 15px;
    line-height: 1.8;
    color: #334155;
    padding: 15px;
    background: #fff;
    border-radius: 8px;
    border-left: 3px solid #2563eb;
}

.send-glossary-item strong {
    color: #1e3a8a;
    font-weight: 600;
}

/* SEND转化页面响应式设计 */
@media (max-width: 1200px) {
    .send-process-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .send-study-type-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .send-glossary-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .send-kpi-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
    }
    
    .send-kpi-item {
        padding: 20px 15px;
    }
    
    .send-kpi-number {
        font-size: 28px;
    }
    
    .send-kpi-label {
        font-size: 14px;
    }
    
    .send-process-grid {
        grid-template-columns: 1fr;
    }
    
    .send-study-type-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
    }
    
    .send-glossary-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .send-kpi-grid {
        grid-template-columns: 1fr;
    }
    
    .send-study-type-grid {
        grid-template-columns: 1fr;
    }
}