/* --- 全局变量与重置 --- */
:root {
--primary: #0b9f6e;         /* 主题色 */
--primary-dark: #087d56;
--text-dark: #2b2b2b;
--text-gray: #555555;
--text-white: #ffffff;
--bg-light: #f9f9f9;
--bg-black: #000000;        /* 纯黑背景 */
--white: #ffffff;
--border-radius: 12px;
--lab-card-radius: 16px;    /* 实验室卡片圆角 */
}

.about-main * {
box-sizing: border-box;
margin: 0;
padding: 0;
}

.about-main {
font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
color: var(--text-dark);
line-height: 1.6;
background-color: var(--white);
-webkit-font-smoothing: antialiased;
}

.about-main img {
max-width: 100%;
height: auto;
display: block;
}

.about-main .container {
width: 90%;
max-width: 1200px;
margin: 0 auto;
padding: 0 20px;
}

.about-main .section {
padding: 40px 0;
}

/* --- 1. Hero 封面区 --- */
.hero-section {
position: relative;
height: 60vh;
min-height: 480px;
display: flex;
align-items: center;
justify-content: center;
color: var(--white);
text-align: center;
overflow: hidden;
}

.hero-bg {
position: absolute;
top: 0;
left: 0;
right: 0;
bottom: 0;
z-index: 0;
}

.hero-bg img {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
object-fit: cover;
z-index: 0;
}

.hero-overlay {
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
background: rgba(0, 0, 0, 0.5);
z-index: 1;
}

.hero-content {
position: relative;
z-index: 2;
}

.hero-content .tag {
display: inline-block;
background-color: var(--primary);
padding: 6px 16px;
border-radius: 20px;
font-size: 1rem;
font-weight: 500;
margin-bottom: 20px;
letter-spacing: 1px;
}

.main-title {
font-size: 2.5rem;
font-weight: 700;
line-height: 1.3;
}

/* --- 2. 简介区域 --- */

article.intro-item {
  font-size: 1.45rem;
}

.intro-item h2 {
font-size: 2rem;
margin-bottom: 24px;
margin-top: 3rem;
position: relative;
padding-left: 16px;
}

.intro-item h2::before {
content: '';
position: absolute;
left: 0;
top: 5px;
bottom: 5px;
width: 4px;
background-color: var(--primary);
border-radius: 2px;
}

.intro-item p {
margin-bottom: 16px;
color: var(--text-dark);
font-size: 1.45rem;
line-height: 2;
text-align: justify;
}

.intro-item ul {
margin: 20px 0 20px 20px;
padding: 0;
list-style: none;
}

.intro-item ul li {
position: relative;
padding-left: 1.4em;
margin-bottom: 8px;
line-height: 1.7;
font-size: 1.45rem;
color: var(--text-dark);
}

.intro-item ul li::before {
content: '';
position: absolute;
left: 0;
top: 0.9em;
width: 6px;
height: 6px;
border-radius: 50%;
background-color: var(--primary);
transform: translateY(-50%);
}

/* --- 3. [新] 全链路产品体系 (System Section) --- */
.system-section {
background-color: var(--white);
position: relative;
}

.section-header {
text-align: center;
max-width: 800px;
margin: 0 auto 60px;
}

.section-header h2 {
font-size: 2.2rem;
margin-bottom: 20px;
font-weight: 800;
}

.section-desc {
font-size: 1.25rem;
color: var(--text-gray);
line-height: 1.8;
}

.section-desc strong {
color: var(--primary);
}

.system-grid {
display: grid;
grid-template-columns: repeat(3, 1fr);
gap: 30px;
margin-bottom: 50px;
margin-top: 40px;
}

.system-card {
background: #fff;
border: 1px solid #eee;
border-radius: var(--border-radius);
padding: 35px 30px;
transition: all 0.3s ease;
position: relative;
overflow: hidden;
background: linear-gradient(145deg, #ffffff, #fcfcfc);
}

.system-card:hover {
transform: translateY(-8px);
box-shadow: 0 15px 30px rgba(11, 159, 110, 0.1);
border-color: var(--primary);
}

.card-icon {
font-size: 2rem;
font-weight: 900;
color: #e0e0e0;
margin-bottom: 20px;
font-family: 'Arial', sans-serif;
transition: color 0.3s;
}

.system-card:hover .card-icon {
color: var(--primary);
}

.system-card h3 {
font-size: 1.75rem;
margin-bottom: 15px;
display: flex;
align-items: center;
gap: 10px;
}

.card-tag {
font-size: 0.8rem;
background-color: rgba(11, 159, 110, 0.1);
color: var(--primary);
padding: 4px 10px;
border-radius: 20px;
font-weight: normal;
}

.system-card p {
color: var(--text-gray);
font-size: 1.25rem;
line-height: 1.6;
}

.video-play-btn {
display: inline-flex;
align-items: center;
gap: 8px;
margin-top: 16px;
padding: 8px 14px;
border-radius: 999px;
border: 1px solid rgba(11, 159, 110, 0.35);
color: var(--primary);
font-size: 0.9rem;
font-weight: 600;
text-decoration: none;
transition: all 0.2s ease;
}

.video-play-btn::before {
content: '';
display: inline-block;
width: 0;
height: 0;
border-top: 5px solid transparent;
border-bottom: 5px solid transparent;
border-left: 8px solid currentColor;
}

.video-play-btn:hover {
background-color: rgba(11, 159, 110, 0.08);
border-color: var(--primary);
transform: translateY(-1px);
}

/* 核心卡片高亮样式 */
.active-card {
border-color: var(--primary);
background: rgba(11, 159, 110, 0.03);
}

.active-card .card-icon {
color: var(--primary);
}

/* --- 4. [深色] 核心团队与能力展示 (Lab Section) --- */
.lab-section {
background-color: var(--bg-black);
color: var(--text-white);
padding: 100px 0;
overflow: hidden;
}

.lab-intro-wrapper {
display: flex;
align-items: center;
justify-content: space-between;
gap: 60px;
margin-bottom: 60px;
}

.lab-content {
  text-align: center;
}

.lab-title {
font-size: 3rem;
font-weight: 800;
line-height: 1.2;
margin-bottom: 30px;
letter-spacing: -1px;
}

.lab-desc {
font-size: 1.25rem;
line-height: 1.8;
color: rgba(255, 255, 255, 0.9);
text-align: justify;
}

.lab-desc strong {
color: var(--text-white);
font-weight: bold;
border-bottom: 2px solid var(--primary);
}

.lab-features-grid {
display: grid;
grid-template-columns: repeat(3, 1fr);
gap: 30px;
}

.feature-card {
border-radius: var(--lab-card-radius);
overflow: hidden;
transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card img {
width: 100%;
height: auto;
border-radius: var(--lab-card-radius);
border: 1px solid rgba(255,255,255,0.15);
}

.feature-card:hover {
transform: translateY(-10px);
box-shadow: 0 10px 20px rgba(11, 159, 110, 0.25);
border-color: var(--primary);
}

/* --- 5. 数据统计 --- */
.stats-section {
background-color: var(--white);
}

.stats-grid {
display: grid;
grid-template-columns: repeat(4, 1fr);
gap: 20px;
text-align: center;
}

.stat-num {
font-size: 1.8rem;
font-weight: 800;
color: #d90a2c;
font-family: Impact, 'Arial Black', sans-serif;
line-height: 1;
margin-bottom: 10px;
}

.stat-desc {
font-size: 1.55rem;
color: var(--text-dark);
font-weight: 500;
}

.stat-divider {
border: 0;
height: 1px;
background-color: #e6e6e6;
margin: 12px auto;
width: 60%;
}

/* --- 6. 荣誉历程 --- */
.timeline-section {
background-color: var(--bg-light);
}

.timeline-layout {
display: flex;
gap: 60px;
}

.timeline-header {
flex: 1;
}

.timeline-header h2 {
font-size: 2.5rem;
line-height: 1.3;
}

.color-primary {
color: var(--primary);
}

.timeline-list {
flex: 2;
}

.timeline-list ul {
list-style: none;
border-left: 2px solid #ddd;
padding-left: 30px;
}

.timeline-list li {
margin-bottom: 25px;
position: relative;
padding-bottom: 10px;
border-bottom: 1px dashed #eee;
}

.timeline-list li::before {
content: '';
position: absolute;
left: -37px;
top: 6px;
width: 12px;
height: 12px;
background: var(--white);
border: 3px solid var(--primary);
border-radius: 50%;
}

.timeline-list strong {
color: var(--primary);
margin-right: 10px;
font-weight: 700;
}

/* --- 7. 新闻网格 --- */
.news-grid {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
gap: 30px;
}

.news-card {
transition: transform 0.3s;
}

.news-card:hover {
transform: translateY(-5px);
}

.news-card .img-box {
border-radius: var(--border-radius);
overflow: hidden;
margin-bottom: 15px;
box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}

.news-card h4 {
font-size: 1.1rem;
font-weight: 600;
line-height: 1.4;
color: var(--text-dark);
}

/* --- 8. CTA 底部 --- */
.cta-section {
padding: 100px 0;
text-align: center;
background: linear-gradient(rgba(0,0,0,0.7), rgba(0,0,0,0.7)), url('https://chatexcel.com/blog/wp-content/uploads/2025/02/getintouch-bg.jpg');
background-size: cover;
background-position: center;
color: var(--white);
}

.cta-content h2 {
font-size: 2.2rem;
margin-bottom: 10px;
}

.cta-subtitle {
font-size: 1.4rem;
font-weight: 300;
margin-bottom: 40px;
opacity: 0.9;
}

.btn-cta {
display: inline-block;
background-color: transparent;
border: 2px solid var(--white);
color: var(--white);
padding: 14px 45px;
font-size: 1.2rem;
text-decoration: none;
border-radius: 50px;
transition: all 0.3s ease;
font-weight: 500;
}

.btn-cta:hover {
background-color: var(--primary);
border-color: var(--primary);
transform: scale(1.05);
}

/* --- 响应式适配 --- */
@media (max-width: 992px) {
.intro-grid {
    grid-template-columns: 1fr;
    gap: 40px;
}
.system-grid {
    grid-template-columns: repeat(2, 1fr);
}
.lab-intro-wrapper {
    flex-direction: column;
    text-align: center;
    gap: 40px;
}
.lab-content { flex: 0 0 100%; }
.lab-title { font-size: 2.2rem; }
.lab-desc { text-align: left; }
.lab-features-grid {
    grid-template-columns: 1fr;
    gap: 20px;
}
.stats-grid {
    grid-template-columns: repeat(2, 1fr);
}
}

@media (max-width: 768px) {
.hero-section { height: auto; padding: 100px 0; }
.main-title { font-size: 1.8rem; }

.system-grid {
    grid-template-columns: 1fr;
}
.section-header h2 {
    font-size: 1.8rem;
}

.timeline-layout {
    flex-direction: column;
    gap: 30px;
}

.cta-content h2 {
    font-size: 1.6rem;
}

.section {
    padding: 50px 0;
}
}