:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --background-color: #f8f9fa;
    --text-color: #333;
    --white: #fff;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Roboto', 'Noto Sans SC', 'Noto Sans JP', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: url('../images/ai_back.avif') no-repeat center center fixed;
    background-size: cover;
    min-height: 100vh;
    background-position: center -100px;
}

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

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: var(--white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo img {
    height: 65px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    margin: 0 15px;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary-color);
}

.language-selector {
    display: flex;
    align-items: center;
}

.lang-select {
    padding: 5px 10px;
    border: 1px solid var(--primary-color);
    border-radius: 4px;
    background-color: var(--white);
    color: var(--text-color);
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s;
    outline: none;
}

.lang-select:hover {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.1);
}

.lang-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.2);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 6px;
    cursor: pointer;
}

.mobile-menu-btn span {
    width: 30px;
    height: 2px;
    background-color: var(--text-color);
    transition: all 0.3s;
}

/* 英雄区样式 */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    text-align: center;
    margin-top: 80px;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 20px;
    color: var(--white);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 40px;
    color: rgba(255, 255, 255, 0.9);
}

.cta-button {
    padding: 15px 40px;
    font-size: 1.2rem;
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 30px;
    cursor: pointer;
    transition: transform 0.3s;
}

.cta-button:hover {
    transform: translateY(-3px);
}

/* 新闻动态样式 */
.news {
    padding: 0;
    background: transparent;
    position: relative;
    overflow: hidden;
    margin-top: -100px;
    z-index: 2;
}

.news-cards {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    justify-content: space-between;
}

.news-card {
    flex: 1 1 calc(33.333% - 20px);
}

@media (max-width: 768px) {
    .news-card {
        flex: 1 1 100%;
    }
}

.news-card.expanded {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 90%;
    max-width: 1000px;
    height: 90vh;
    overflow-y: auto;
    z-index: 1000;
    background: rgba(0, 0, 0, 0.85);
    transition: all 0.3s ease-in-out;
    padding: 40px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.news-card.expanded .news-content {
    display: block;
    opacity: 1;
    margin-top: 20px;
    padding: 0 20px;
    color: #ffffff;
    font-size: 1.3rem;
    line-height: 1.8;
    text-shadow: 0 1px 4px rgba(0, 0, 0, 0.9);
}

.news-card.expanded .news-title {
    color: #ffffff;
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 25px;
    text-shadow: 0 2px 8px rgba(0, 123, 255, 0.8);
}

.news-card.expanded .news-date {
    color: #6ac1ff;
    font-size: 1.2rem;
    font-weight: 500;
    margin-bottom: 20px;
    text-shadow: 0 1px 4px rgba(106, 193, 255, 0.3);
}

.news-card.expanded .news-content {
    color: #ffffff;
    font-size: 1.3rem;
    line-height: 1.8;
    text-shadow: 0 1px 4px rgba(0, 0, 0, 0.3);
}

.news-card .close-btn {
    display: none;
    position: absolute;
    top: 15px;
    right: 15px;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    font-size: 20px;
    cursor: pointer;
    transition: background 0.3s;
}

.news-card.expanded .close-btn {
    display: block;
}

.news-card .close-btn:hover {
    background: rgba(255, 255, 255, 0.3);
}

.overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.1);
    z-index: 999;
}

.overlay.active {
    display: block;
}

.news-card:hover {
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.15);
}

.news-date {
    color: #ffffff; /* ✅ 改为白色 */
    font-size: 0.9rem;
    margin-bottom: 10px;
}

.news-title {
    color: #ffffff;
    font-size: 1.5rem;
    margin-bottom: 15px;
}

.news-description {
    color: rgba(255, 255, 255, 0.9);
}

.news-item.expanded .news-content {
    display: block;
    opacity: 1;
  }

  .news-item.expanded .news-header::after {
    content: "▲";
    margin-left: auto;
    color: #00aaff;
  }
  
  .news-header::after {
    content: "▼";
    margin-left: auto;
    color: #aaa;
  }
  
  .news-content {
    display: none;
    margin-top: 8px;
    color: #ffffff !important; /* 强制白色 */
    opacity: 1 !important;     /* 确保不透明 */
    line-height: 1.6;
  }
  .news-item.expanded .news-content {
    display: block;
  }
      
    .news-content.expanded {
        max-height: 500px;
        margin-top: 15px;
    }
    
    .expand-btn {
        background: none;
        border: 1px solid var(--primary-color);
        color: var(--primary-color);
        padding: 8px 16px;
        border-radius: 4px;
        cursor: pointer;
        margin-top: 15px;
        transition: all 0.3s ease;
    }
    
    .expand-btn:hover {
        background: var(--primary-color);
        color: var(--white);
    }
    
    .hidden {
        display: none;
    }
}

@media (max-width: 768px) {
    .news-cards {
        grid-template-columns: 1fr;
    }
}

/* 关于我们样式 */
.about {
    padding: 100px 0;
    background: rgba(0, 0, 0, 0.5);
    position: relative;
    overflow: hidden;
}

.about::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: none;
    pointer-events: none;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: var(--white);
}

.about-content {
    display: flex;
    align-items: center;
    gap: 50px;
    position: relative;
    z-index: 1;
}

.about-text {
    flex: 1;
    color: var(--white);
}

.about-image {
    flex: 1;
}

.about-image img {
    width: 100%;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

/* 核心技术样式 */
.technology {
    padding: 100px 0;
    background: rgba(0, 0, 0, 0.5);
}

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

.tech-card {
    background: rgba(255, 255, 255, 0.1);
    padding: 30px;
    border-radius: 10px;
    text-align: center;
    transition: transform 0.3s;
    backdrop-filter: blur(5px);
}

.tech-card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.tech-card h3 {
    color: var(--white);
    font-size: 1.5rem;
    margin-bottom: 15px;
}

.tech-card p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 1rem;
    line-height: 1.6;
}

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

.tech-card:hover {
    transform: translateY(-10px);
    background-color: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.3);
}

.tech-card i {
    font-size: 3rem;
    color: var(--white);
    margin-bottom: 20px;
    opacity: 0.9;
}

.tech-card h3 {
    margin-bottom: 15px;
    color: var(--white);
}

/* 案例展示样式 */
.cases {
    padding: 100px 0;
    background-color: rgba(0, 0, 0, 0.5);
}

.case-slider {
    display: flex;
    gap: 30px;
    overflow-x: auto;
    padding: 20px 0;
    scroll-snap-type: x mandatory;
}

.case-card {
    flex: 0 0 350px;
    height: 300px;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    scroll-snap-align: start;
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 30px;
    color: var(--white);
    background-size: cover;
    background-position: center;
}

.case-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to top, rgba(0,0,0,0.8) 0%, rgba(0,0,0,0.4) 50%, rgba(0,0,0,0.1) 100%);
    z-index: 1;
}

.case-card h3, .case-card p {
    position: relative;
    z-index: 2;
    margin: 5px 0;
}

.case-card h3 {
    font-size: 1.5rem;
    color: var(--white);
}

.case-card p {
    font-size: 1rem;
    opacity: 0.9;
}

.case-card audio {
    position: relative;
    z-index: 1;
  }
  
/* 联系我们样式 */
.contact {
    padding: 100px 0;
    background: rgba(10, 25, 47, 0.8);
    backdrop-filter: blur(10px);
}

.contact-content {
    display: flex;
    justify-content: center;
    align-items: center;
    background: rgba(255, 255, 255, 0.05);
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(4px);
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    width: 100%;
    max-width: 1000px;
}

.info-item {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 25px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    transition: transform 0.3s ease, background-color 0.3s ease;
}

.info-item:hover {
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.1);
}

.info-item i {
    font-size: 2rem;
    color: var(--primary-color);
    transition: transform 0.3s ease;
}

.info-item:hover i {
    transform: scale(1.1);
}

.info-item p {
    margin: 0;
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.1rem;
}

@media (max-width: 768px) {
    .contact-info {
        grid-template-columns: 1fr;
    }
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-form input,
.contact-form textarea {
    padding: 15px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    font-size: 1rem;
    color: var(--white);
    transition: all 0.3s ease;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    background: rgba(255, 255, 255, 0.1);
    box-shadow: 0 0 0 2px rgba(0, 123, 255, 0.2);
}

.contact-form textarea {
    height: 150px;
    resize: vertical;
}

.contact-form button {
    padding: 15px;
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 500;
    letter-spacing: 0.5px;
    transition: all 0.3s ease;
}

.contact-form button:hover {
    background-color: #0056b3;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 123, 255, 0.2);
}

/* 页脚样式 */
.footer {
    background-color: #333;
    color: var(--white);
    padding: 50px 0;
}

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

.social-links {
    display: flex;
    gap: 20px;
}

.social-link {
    color: var(--white);
    font-size: 1.5rem;
    transition: color 0.3s;
}

.social-link:hover {
    color: var(--primary-color);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .about-content {
        flex-direction: column;
    }

    .tech-cards {
        grid-template-columns: 1fr;
    }

    .contact-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .case-card {
        flex: 0 0 280px;
    }

    .footer-content {
        flex-direction: column;
        gap: 20px;
        text-align: center;
    }
}

.founder-text {
    font-size: 16px;
    line-height: 1.8;
    color: #fff; /* ✅ 修改为白色 */
  }
  
.founder-message {
    margin-top: 40px;
  }
  
  .founder-title {
    font-size: 22px;
    font-weight: bold;
    margin-bottom: 20px;
    color: #333;
  }
  
  .founder-wrapper {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    align-items: flex-start;
    gap: 30px;
    flex-wrap: nowrap;
  }
  
  .founder-left {
    flex: 1;
  }
  
  .founder-text {
    font-size: 16px;
    line-height: 1.8;
    color: #555;
  }
  
  .founder-right {
    width: 140px;
    text-align: center;
    flex-shrink: 0;
  }
  
  .founder-photo {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 10px;
  }
  
  .founder-signature {
    font-family: 'Segoe Script', cursive;
    font-size: 18px;
    color: #444;
  }
  
  .read-more-link {
    color: #ffffff;
    text-decoration: underline;
    font-weight: bold;
  }
  
  .read-more-link:hover {
    color: #00aaff; /* 悬停时变蓝色（可选） */
  }
  
  .see-more-news a {
    color: #ffffff;
    text-decoration: underline;
    font-weight: bold;
  }
  
  .see-more-news a:hover {
    color: #00aaff; /* 或保持白色 */
  }
  
  .founder-voice {
    margin-top: 20px;
  }
  
  .founder-voice audio {
    width: 100%;
    max-width: 400px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(255,255,255,0.2);
  }
  
  .voice-caption {
    font-size: 0.95rem;
    color: #ccc;
    margin-top: 8px;
    font-style: italic;
  }
  
  .founder-video {
    margin-top: 30px;
    text-align: left;
  }
  
  .founder-video video {
    width: 100%;
    max-width: 140px;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(255, 255, 255, 0.15);
    display: block;
    margin-bottom: 10px;
  }
  
  .video-caption {
    font-size: 0.95rem;
    color: #f0f0f0;  /* ✅ 柔白，清晰可读 */
    font-style: italic;
    line-height: 1.5;
  }
  
  .team {
    padding: 60px 0;
    background-color: #111;
    color: white;
  }
  
  .team-members {
    display: flex;
    flex-wrap: wrap;
    gap: 30px;
    justify-content: center;
  }
  
  .team-member {
    width: 220px;
    background-color: #1e1e1e;
    border-radius: 12px;
    padding: 20px;
    text-align: center;
  }
  
  .team-member img {
    width: 140px;
    height: 140px;
    object-fit: cover;
    border-radius: 50%;
    margin-bottom: 15px;
    background: white;
  }
  
  .member-name {
    font-size: 18px;
    font-weight: bold;
    margin: 5px 0;
  }
  
  .member-role {
    font-size: 14px;
    color: #ffc107;
    margin-bottom: 10px;
  }
  
  .member-desc {
    font-size: 13px;
    line-height: 1.4;
  }
  

/* 移动端菜单展开样式 */
.nav-links.active {
    display: flex !important;
    flex-direction: column;
    position: absolute;
    top: 80px;
    left: 0;
    right: 0;
    background-color: #fff;
    padding: 20px;
    z-index: 999;
}