/* =================================== AUTOMOTIVE TOPIC PAGE EXCLUSIVE STYLES =================================== */
:root {
    --industrial-blue: #002855;
    --industrial-blue-light: #0b3d77;
    --industrial-light: #f8fafc;
    --text-main: #111827;
    --text-muted: #6b7280;
    --border: #e5e7eb;
    --radius: 12px;
    --shadow: 0 10px 30px rgba(0, 0, 0, .05);
    --shadow-hover: 0 20px 50px rgba(0, 0, 0, .08);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: var(--text-main);
}

section {
    padding: 100px 0;
}

.section-label {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 18px;
    color: var(--industrial-blue);
    font-size: 20px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.section-label:before {
    content: "";
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--industrial-blue);
}

h1, h2 {
    font-weight: 800;
    line-height: 1.15;
    color: var(--text-main);
    letter-spacing: -0.5px;
    margin-bottom: 20px;
}

h1 {
    font-size: 32px;
}

h2 {
    font-size: 24px;
}

h4 {
    font-weight: 700;
}

.section-desc {
    max-width: 1440px;
    font-size: 18px;
    line-height: 1.8;
    color: var(--text-muted);
}

.text-highlight {
    color: var(--industrial-blue);
}

/* =================================== HERO SECTION =================================== */
.topic-hero {
    background: #ffffff;
    padding-top: 120px;
    padding-bottom: 80px;
}

.hero-desc {
    max-width: 680px;
    font-size: 18px;
    line-height: 1.8;
    color: var(--text-muted);
    margin-bottom: 30px;
}

.hero-feature-img {
    width: 100%;
    height: 350px;
    object-fit: cover;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-top: 10px;
    filter: contrast(1.05) saturate(0.9);
}

.inquiry-form-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2.5rem;
    box-shadow: var(--shadow);
}

.inquiry-form-card h3 {
    font-size: 24px;
    font-weight: 800;
    color: var(--text-main);
    margin-bottom: 8px;
}

.form-subtitle {
    font-size: 14px;
    color: var(--text-muted);
    margin-bottom: 25px;
}

.inquiry-form-card .form-control {
    padding: 12px;
    border-radius: 6px;
    border: 1px solid var(--border);
    font-size: 14px;
}

.inquiry-form-card .form-control:focus {
    border-color: var(--industrial-blue);
    box-shadow: 0 0 0 0.2rem rgba(0, 40, 85, 0.1);
}

.file-upload-wrapper.small {
    border: 2px dashed var(--border);
    background: #fff;
    padding: 20px;
    border-radius: 8px;
    text-align: center;
}

.file-upload-wrapper.small .file-label {
    font-size: 13px;
    color: var(--text-muted);
}

.file-upload-wrapper.small .file-label i {
    font-size: 20px;
}

.btn-submit {
    background: var(--industrial-blue);
    color: #fff;
    padding: 14px;
    border: none;
    border-radius: 6px;
    font-weight: 700;
    transition: 0.3s;
}

.btn-submit:hover {
    background: var(--industrial-blue-light);
    color: #fff;
}

/* =================================== PRODUCTS B2B GRID STYLE =================================== */
.topic-products-b2b {
    background: var(--industrial-light);
}

.b2b-product-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    height: 100%;
    transition: 0.3s;
    display: flex;
    flex-direction: column;
}

.b2b-product-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: var(--industrial-blue);
}

.b2b-card-img {
    width: 100%;
    height: 220px;
    object-fit: cover;
    display: block;
}

.b2b-card-body {
    padding: 25px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.b2b-card-body h4 {
    font-size: 18px;
    font-weight: 700;
    color: var(--industrial-blue);
    margin-bottom: 12px;
}

.b2b-card-body p {
    font-size: 14px;
    color: var(--text-muted);
    margin-bottom: 20px;
}

/* 规格列表 */
.b2b-spec-list {
    list-style: none;
    padding: 0;
    margin: auto 0 0 0;
    border-top: 1px solid var(--border);
    padding-top: 15px;
}

.b2b-spec-list li {
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 8px;
    display: flex;
}

.b2b-spec-list li strong {
    color: var(--text-main);
    margin-right: 8px;
    min-width: 100px;
}

/* =================================== CAPABILITIES DEEP DIVE STYLE =================================== */
.topic-capabilities-deep {
    background: #ffffff;
}

.deep-dive-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.deep-dive-header {
    padding: 20px 25px;
    border-bottom: 2px solid var(--industrial-blue);
    background: var(--industrial-light);
}

.deep-dive-header h4 {
    margin: 0;
    font-size: 18px;
    color: var(--industrial-blue);
    font-weight: 700;
}

.deep-dive-body {
    padding: 25px;
    flex: 1;
}

.deep-dive-item {
    margin-bottom: 20px;
}

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

.deep-dive-item h5 {
    font-size: 15px;
    color: var(--text-main);
    font-weight: 700;
    margin-bottom: 8px;
}

.deep-dive-item p {
    font-size: 13px;
    color: var(--text-muted);
    line-height: 1.7;
    margin: 0;
}

.highlight-card {
    border: 2px solid var(--industrial-blue);
}

.highlight-card .deep-dive-header {
    background: var(--industrial-blue);
}

.highlight-card .deep-dive-header h4 {
    color: #fff;
}

/* =================================== PROCESS COMPACT STYLE =================================== */
.topic-process-compact {
    background: var(--industrial-light);
}

.compact-process-flow {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.compact-step {
    display: flex;
    gap: 15px;
    background: #fff;
    padding: 15px;
    border-radius: 8px;
    border: 1px solid var(--border);
}

.step-num {
    width: 40px;
    height: 40px;
    background: var(--industrial-blue);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 16px;
    flex-shrink: 0;
}

.step-info h6 {
    font-size: 14px;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 4px;
}

.step-info p {
    font-size: 12px;
    color: var(--text-muted);
    margin: 0;
    line-height: 1.5;
}

.quality-assurance-box {
    background: #fff;
    padding: 30px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    height: 100%;
    display: flex;
    flex-direction: column;
}

.quality-assurance-box h4 {
    font-size: 20px;
    margin-bottom: 10px;
}

.quality-assurance-box > p {
    font-size: 14px;
    color: var(--text-muted);
    margin-bottom: 25px;
}

.qa-feature {
    display: flex;
    gap: 15px;
    margin-bottom: 25px;
}

.qa-icon {
    font-size: 32px;
    flex-shrink: 0;
}

.qa-content h6 {
    font-size: 15px;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 5px;
}

.qa-content p {
    font-size: 13px;
    color: var(--text-muted);
    margin: 0;
    line-height: 1.6;
}

.qa-certs {
    margin-top: auto;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.cert-tag {
    background: #f8fafc;
    color: var(--industrial-blue);
    padding: 6px 12px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 600;
    border: 1px solid var(--border);
}

/* =================================== FAQ SECTION =================================== */
.topic-faq {
    background: #ffffff;
}

.accordion-item {
    border: 1px solid var(--border);
    border-radius: 8px !important;
    margin-bottom: 15px;
    overflow: hidden;
}

.accordion-button {
    font-weight: 700;
    color: var(--text-main);
    background: #fff;
    box-shadow: none;
}

.accordion-button:not(.collapsed) {
    color: var(--industrial-blue);
    background-color: #fff;
}

.accordion-button::after {
    background-size: 1.2rem;
}

.accordion-body {
    color: var(--text-muted);
    line-height: 1.8;
    font-size: 15px;
}

/* =================================== PROMOTION CTA STYLE =================================== */
.topic-promotion-cta {
    background: var(--industrial-light);
}

.promotion-desc {
    font-size: 18px;
    line-height: 1.8;
    color: var(--text-muted);
    margin-bottom: 30px;
}

.promotion-trust-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 30px;
}

.trust-item {
    display: flex;
    gap: 12px;
    align-items: flex-start;
}

.trust-item .trust-icon {
    font-size: 28px;
    flex-shrink: 0;
}

.trust-item strong {
    display: block;
    margin-bottom: 5px;
    color: var(--text-main);
    font-size: 15px;
}

.trust-item p {
    font-size: 13px;
    color: var(--text-muted);
    margin: 0;
}

.final-cta-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 40px;
    box-shadow: var(--shadow);
    text-align: center;
}

.final-cta-card h3 {
    font-size: 24px;
    font-weight: 800;
    color: var(--text-main);
    margin-bottom: 15px;
}

.final-cta-card > p {
    font-size: 15px;
    color: var(--text-muted);
    margin-bottom: 25px;
}

.cta-contact-info {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-bottom: 20px;
}

.cta-contact-item {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-size: 15px;
    color: var(--text-muted);
}

.cta-contact-item i {
    color: var(--industrial-blue);
    font-size: 18px;
}

.cta-contact-item a {
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s;
}

.cta-contact-item a:hover {
    color: var(--industrial-blue);
}

.btn-cta-primary {
    background: var(--industrial-blue);
    color: #fff;
    padding: 16px;
    border-radius: 6px;
    font-weight: 700;
    font-size: 16px;
    transition: 0.3s;
}

.btn-cta-primary:hover {
    background: var(--industrial-blue-light);
    color: #fff;
    transform: translateY(-2px);
}

.cta-note {
    font-size: 12px;
    color: var(--text-muted);
    margin: 0;
}

/* ===================================
   NEW SECTIONS: TESTING, EXPERTISE & CASES
=================================== */

/* 1. Testing Lab & Expertise Layout */
.topic-testing-lab, .topic-connector-expertise, .topic-project-cases {
    padding: 80px 0;
    background: #fff;
}

/* 列表美化 (Expertise & Projects) */
.topic-testing-lab ul, .topic-connector-expertise ul, .topic-project-cases ul {
    list-style: none;
    padding: 0;
    margin: 20px 0;
}

.topic-testing-lab li, .topic-connector-expertise li, .topic-project-cases li {
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    font-size: 15px;
    color: var(--text-main);
}

.topic-testing-lab li::before, .topic-connector-expertise li::before {
    content: "●";
    color: var(--industrial-blue);
    font-size: 10px;
    margin-right: 15px;
}

/* 表格样式 (Connector Expertise 专用) */
.table {
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    margin-top: 20px;
}

.table th {
    background: var(--industrial-blue);
    color: #fff;
    padding: 12px 20px;
    font-size: 14px;
}

.table td {
    padding: 12px 20px;
    border-bottom: 1px solid var(--border);
    font-size: 14px;
    color: var(--text-muted);
}

/* 案例卡片样式 (Project Cases) */
.topic-project-cases .col-lg-4 {
    transition: 0.3s;
}

.topic-project-cases .col-lg-4:hover {
    transform: translateY(-5px);
}

/* 调整标题与间距 */
.topic-testing-lab h3,
.topic-connector-expertise h3,
.topic-project-cases h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--industrial-blue);
    margin-bottom: 15px;
}

/* =================================== RESPONSIVE =================================== */
@media (max-width: 991px) {
    section {
        padding: 60px 0;
    }

    h1 {
        font-size: 32px;
    }

    h2 {
        font-size: 26px;
    }

    .inquiry-form-card {
        margin-top: 40px;
    }

    .hero-feature-img {
        height: 280px;
    }

    .compact-process-flow {
        grid-template-columns: 1fr;
    }

    .promotion-trust-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .b2b-spec-list li {
        flex-direction: column;
    }

    .b2b-spec-list li strong {
        min-width: auto;
        margin-bottom: 4px;
    }
}