/* ========================================================
   上海万斯供应链管理有限公司 (Vance Supply Chain) 官方样式表
   风格定位：沉稳、纯粹、专业的中日国际物流商务风格
   布局基准：全局基线严格对齐，彻底消除中日切换时的位置位移
   ======================================================== */

:root {
    --primary-color: #152A4A;
    --primary-hover: #0E1E36;
    --secondary-color: #1E6091;
    --accent-color: #2B7BBB;
    --text-main: #2D3748;
    --text-muted: #5A6A80;
    --bg-light: #F7F9FC;
    --bg-white: #FFFFFF;
    --border-color: #E2E8F0;
    /* 采用完全统一的现代系统字族，中日英文字形统一，绝不发生字体切换抖动 */
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Microsoft YaHei UI", "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Yu Gothic UI", Meiryo, sans-serif;
    --container-width: 1200px;
}

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    /* 核心锁定：强制纵向滚动条始终占位，彻底杜绝任何页面横向跳动 (17px shift) */
    overflow-y: scroll;
    scrollbar-gutter: stable;
}

body {
    font-family: var(--font-family);
    color: var(--text-main);
    line-height: 1.6;
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    letter-spacing: normal;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.2s ease, background-color 0.2s ease;
}

ul {
    list-style: none;
}

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

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

.section-padding {
    padding: 70px 0;
}

.section-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 36px;
    text-align: center;
    letter-spacing: 0.5px;
    line-height: 1.3;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    border-radius: 4px;
    font-weight: 600;
    font-size: 15px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
    border: 1px solid transparent;
    white-space: nowrap;
    font-family: inherit;
    line-height: 1.3;
}

.btn-primary {
    background-color: var(--primary-color);
    color: var(--bg-white);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    color: var(--bg-white);
}

.btn-outline {
    background-color: rgba(255, 255, 255, 0.92);
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-outline:hover {
    background-color: var(--primary-color);
    color: var(--bg-white);
}

.btn-large {
    padding: 14px 36px;
    font-size: 16px;
    background-color: #2B7BBB;
    color: #FFFFFF;
    border: none;
}

.btn-large:hover {
    background-color: #1E6091;
    color: #FFFFFF;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: var(--bg-white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.06);
    z-index: 1000;
    height: 76px;
    display: flex;
    align-items: center;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}

.logo-mark {
    font-size: 26px;
    font-weight: 900;
    color: var(--bg-white);
    background-color: var(--primary-color);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    letter-spacing: -1px;
    flex-shrink: 0;
    line-height: 1;
}

.logo-text {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.logo-text strong {
    font-size: 17px;
    color: var(--primary-color);
    line-height: 1.25;
    font-weight: 700;
    letter-spacing: 0.5px;
    white-space: nowrap;
    font-family: inherit;
}

.logo-text span {
    font-size: 11px;
    color: var(--text-muted);
    font-weight: 500;
    white-space: nowrap;
    line-height: 1.2;
    font-family: inherit;
}

.nav {
    display: flex;
    align-items: center;
}

.nav-list {
    display: flex;
    gap: 26px;
    align-items: center;
}

.nav-list a {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-main);
    padding: 6px 0;
    position: relative;
    white-space: nowrap;
}

.nav-list a:hover {
    color: var(--secondary-color);
}

.nav-list a.nav-link-highlight {
    color: var(--secondary-color);
    font-weight: 600;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}

.lang-switch {
    display: inline-flex;
    align-items: center;
    gap: 2px;
    font-size: 13px;
    user-select: none;
    border: 1px solid var(--border-color);
    padding: 3px 5px;
    border-radius: 4px;
    background-color: #FAFCFE;
}

.lang-switch .lang-btn {
    display: inline-block;
    padding: 2px 7px;
    border-radius: 3px;
    cursor: pointer;
    font-weight: 500;
    color: var(--text-muted);
    transition: all 0.2s ease;
}

.lang-switch .lang-btn:hover {
    color: var(--secondary-color);
}

.lang-switch .lang-btn.active {
    background-color: var(--primary-color);
    color: #FFFFFF;
    font-weight: 700;
    cursor: default;
}

.lang-switch .lang-divider {
    color: var(--border-color);
    font-size: 12px;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    flex-direction: column;
    gap: 5px;
    padding: 6px;
}

.mobile-menu-btn span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--primary-color);
    transition: 0.3s;
}

/* Hero Section */
.hero {
    margin-top: 76px;
    min-height: 520px;
    background-color: #E6EDF5;
    background-image: linear-gradient(rgba(21, 42, 74, 0.45), rgba(21, 42, 74, 0.55)), url('assets/hero_bg.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    display: flex;
    align-items: center;
}

.hero-container {
    width: 100%;
}

.hero-content {
    max-width: 650px;
    padding: 40px 0;
}

.hero-content h1 {
    font-size: 44px;
    color: #FFFFFF;
    line-height: 1.25;
    margin-bottom: 18px;
    font-weight: 800;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
}

.hero-subtitle {
    font-size: 18px;
    color: #E2E8F0;
    margin-bottom: 32px;
    line-height: 1.6;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
}

.hero-actions {
    display: flex;
    gap: 16px;
    align-items: center;
    flex-wrap: wrap;
}

/* Features Bar */
.features {
    background-color: var(--bg-white);
    padding: 45px 0;
    border-bottom: 1px solid var(--border-color);
}

.features-container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 28px;
    text-align: center;
}

.feature-item {
    padding: 0 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.feature-icon {
    width: 52px;
    height: 52px;
    margin: 0 auto 16px;
    color: var(--secondary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.feature-icon svg {
    width: 100%;
    height: 100%;
}

.feature-item h3 {
    font-size: 17px;
    margin-bottom: 8px;
    color: var(--primary-color);
    font-weight: 700;
    line-height: 1.3;
    white-space: nowrap;
}

.feature-item p {
    font-size: 13.5px;
    color: var(--text-muted);
    line-height: 1.55;
}

/* Services */
.services {
    background-color: var(--bg-light);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 22px;
}

.service-card {
    background: var(--bg-white);
    border-radius: 6px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.04);
    border: 1px solid var(--border-color);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
    display: flex;
    flex-direction: column;
}

.service-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
}

.service-image {
    width: 100%;
    height: 180px;
    object-fit: cover;
    display: block;
    background-color: #D1D9E6;
}

.service-content {
    padding: 20px 18px;
    text-align: center;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.service-content h3 {
    font-size: 16.5px;
    margin-bottom: 8px;
    color: var(--primary-color);
    font-weight: 700;
    line-height: 1.3;
    white-space: nowrap;
}

.service-content p {
    font-size: 13px;
    color: var(--text-muted);
    line-height: 1.55;
}

/* EC System Banner */
.ec-system {
    background-color: var(--primary-color);
    color: var(--bg-white);
    text-align: center;
    padding: 85px 0;
    background-image: linear-gradient(rgba(21, 42, 74, 0.82), rgba(21, 42, 74, 0.88)), url('assets/ec_system_bg.jpg');
    background-size: cover;
    background-position: center;
    position: relative;
}

.ec-content {
    position: relative;
    z-index: 1;
    max-width: 680px;
    margin: 0 auto;
}

.ec-content h2 {
    font-size: 32px;
    margin-bottom: 14px;
    font-weight: 700;
    letter-spacing: 0.5px;
    line-height: 1.3;
}

.ec-content p {
    font-size: 16px;
    margin-bottom: 28px;
    opacity: 0.92;
    line-height: 1.6;
}

/* Blog */
.blog {
    background-color: var(--bg-white);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 30px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 14px;
}

.section-header .section-title {
    margin-bottom: 0;
    text-align: left;
}

.view-all {
    font-size: 14px;
    color: var(--secondary-color);
    font-weight: 500;
}

.view-all:hover {
    text-decoration: underline;
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 26px;
}

.blog-card {
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 22px;
    background: var(--bg-white);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
    display: flex;
    flex-direction: column;
}

.blog-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.06);
}

.blog-date {
    font-size: 12px;
    color: #8C9BAE;
    font-weight: 600;
    display: block;
    margin-bottom: 8px;
}

.blog-content h3 {
    font-size: 16px;
    color: var(--primary-color);
    margin-bottom: 8px;
    font-weight: 600;
    line-height: 1.4;
}

.blog-content p {
    font-size: 13.5px;
    color: var(--text-muted);
    line-height: 1.55;
}

/* Contact */
.bg-light {
    background-color: var(--bg-light);
}

.contact-container {
    display: flex;
    gap: 50px;
    align-items: flex-start;
}

.contact-left {
    flex: 1;
}

.contact-left h2 {
    font-size: 26px;
    color: var(--primary-color);
    margin-bottom: 14px;
    font-weight: 700;
}

.contact-direct-info {
    margin-top: 24px;
    background: var(--bg-white);
    border-radius: 6px;
    padding: 22px;
    border: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 12px;
    font-size: 14.5px;
}

.contact-direct-info p {
    display: flex;
    gap: 8px;
}

.contact-direct-info strong {
    color: var(--primary-color);
    white-space: nowrap;
    min-width: 80px;
}

.contact-right {
    flex: 1.25;
    background: var(--bg-white);
    padding: 34px;
    border-radius: 6px;
    box-shadow: 0 4px 18px rgba(0, 0, 0, 0.04);
    border: 1px solid var(--border-color);
}

.form-row {
    display: flex;
    gap: 16px;
    margin-bottom: 16px;
}

.form-group {
    flex: 1;
}

.form-group-full {
    width: 100%;
    margin-bottom: 16px;
}

input, textarea {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-family: inherit;
    font-size: 14px;
    transition: border-color 0.25s;
    background-color: #FAFCFE;
}

input:focus, textarea:focus {
    outline: none;
    border-color: var(--secondary-color);
    background-color: #FFFFFF;
}

.btn-submit {
    width: 100%;
    padding: 13px;
}

.form-message {
    margin-top: 14px;
    font-size: 14px;
    text-align: center;
}

.form-message.success, .form-feedback.success { color: #166534; font-weight: 600; }
.form-message.error, .form-feedback.error { color: #DC2626; font-weight: 600; }

/* Footer */
.footer {
    background-color: var(--primary-color);
    color: var(--bg-white);
    padding: 55px 0 20px;
}

.footer-container {
    display: flex;
    justify-content: space-between;
    margin-bottom: 35px;
    gap: 40px;
}

.footer-info {
    max-width: 440px;
}

.logo-white {
    margin-bottom: 18px;
}

.logo-white .logo-mark {
    background-color: #FFFFFF;
    color: var(--primary-color);
}

.logo-white .logo-text strong {
    color: #FFFFFF;
}

.logo-white .logo-text span {
    color: #94A3B8;
}

.footer-info p {
    font-size: 13.5px;
    color: #CBD5E1;
    margin-bottom: 8px;
    line-height: 1.5;
}

.footer-links-group {
    display: flex;
    gap: 70px;
}

.footer-links h4 {
    font-size: 15.5px;
    margin-bottom: 16px;
    font-weight: 600;
    color: #FFFFFF;
}

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

.footer-links a {
    font-size: 13.5px;
    color: #94A3B8;
}

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

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.12);
    padding-top: 20px;
}

.footer-bottom .container {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: #94A3B8;
    flex-wrap: wrap;
    gap: 10px;
}

.footer-bottom a:hover {
    color: #FFFFFF;
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 992px) {
    .features-container {
        grid-template-columns: repeat(2, 1fr);
    }
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .contact-container {
        flex-direction: column;
    }
    .footer-container {
        flex-direction: column;
        gap: 30px;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }

    .section-padding {
        padding: 48px 0;
    }

    .section-title {
        font-size: 23px;
        margin-bottom: 26px;
    }

    /* Header & Navigation on Mobile */
    .header {
        height: 60px;
    }

    html {
        scrollbar-gutter: auto;
    }

    .container {
        width: 100%;
        max-width: 100%;
        padding: 0 12px;
        box-sizing: border-box;
    }

    .header-container {
        display: flex;
        justify-content: space-between;
        align-items: center;
        width: 100%;
        gap: 6px;
    }

    .logo {
        display: flex;
        align-items: center;
        gap: 6px;
        flex-shrink: 1;
        min-width: 0;
    }

    .logo-mark {
        width: 28px;
        height: 28px;
        font-size: 16px;
        border-radius: 4px;
        flex-shrink: 0;
    }

    .logo-text {
        min-width: 0;
    }

    .logo-text strong {
        font-size: 13px;
        letter-spacing: 0;
        white-space: nowrap;
    }

    .logo-text span {
        display: none;
    }

    .header-actions {
        gap: 6px;
        flex-shrink: 0;
        display: flex;
        align-items: center;
    }

    .lang-switch {
        padding: 2px 4px;
        font-size: 11px;
        gap: 2px;
    }

    .lang-switch .lang-btn {
        padding: 1px 3px;
    }

    .nav {
        display: none;
    }

    .nav.mobile-active {
        display: block;
        position: absolute;
        top: 60px;
        left: 0;
        width: 100%;
        background: #FFFFFF;
        box-shadow: 0 10px 20px -3px rgba(0, 0, 0, 0.12);
        padding: 12px 20px 20px;
        border-bottom: 1px solid #E2E8F0;
        z-index: 999;
    }

    .nav.mobile-active .nav-list {
        display: flex;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
    }

    .nav.mobile-active .nav-list li {
        width: 100%;
        border-bottom: 1px solid #F1F5F9;
    }

    .nav.mobile-active .nav-list a {
        display: block;
        padding: 12px 6px;
        font-size: 15px;
        color: var(--text-main);
    }

    .nav.mobile-active .nav-list a.nav-link-highlight {
        margin-top: 8px;
        padding: 10px 14px;
        text-align: center;
        background-color: #2B7BBB;
        color: #FFFFFF;
        border-radius: 4px;
        border: none;
    }

    .mobile-menu-btn {
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 4px;
        width: 32px;
        height: 32px;
        padding: 4px;
        background: none;
        border: none;
        cursor: pointer;
        flex-shrink: 0;
    }

    .mobile-menu-btn span {
        display: block;
        width: 18px;
        height: 2px;
        background-color: var(--primary-color);
        transition: 0.3s;
    }

    /* Hero Section on Mobile */
    .hero {
        margin-top: 60px;
        min-height: 420px;
    }

    .hero-content {
        padding: 28px 0;
    }

    .hero-content h1 {
        font-size: 28px;
        line-height: 1.3;
        margin-bottom: 14px;
    }

    .hero-subtitle {
        font-size: 15px;
        margin-bottom: 24px;
        line-height: 1.5;
    }

    .hero-actions {
        flex-direction: column;
        width: 100%;
        gap: 12px;
    }

    .hero-actions .btn {
        width: 100%;
        padding: 13px 20px;
        font-size: 15px;
    }

    /* Features on Mobile */
    .features {
        padding: 36px 0;
    }

    .features-container {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    /* Services on Mobile */
    .services-grid {
        grid-template-columns: 1fr;
        gap: 18px;
    }

    .service-image {
        height: 160px;
    }

    /* EC System Banner on Mobile */
    .ec-system {
        padding: 55px 0;
    }

    .ec-content h2 {
        font-size: 24px;
        margin-bottom: 12px;
    }

    .ec-content p {
        font-size: 14px;
        margin-bottom: 22px;
    }

    .ec-content .btn {
        width: 100%;
        max-width: 280px;
    }

    /* Blog on Mobile */
    .blog-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .blog-card {
        padding: 18px;
    }

    /* Contact on Mobile */
    .contact-container {
        gap: 26px;
        align-items: stretch;
    }

    .contact-left,
    .contact-right {
        width: 100%;
        box-sizing: border-box;
    }

    .contact-direct-info {
        padding: 18px 16px;
        font-size: 14px;
    }

    .contact-direct-info p {
        flex-direction: column;
        gap: 2px;
    }

    .contact-direct-info strong {
        min-width: auto;
    }

    .contact-right {
        padding: 24px 18px;
    }

    .form-row {
        flex-direction: column;
        gap: 14px;
    }

    /* Footer on Mobile */
    .footer {
        padding: 42px 0 20px;
    }

    .footer-container {
        gap: 28px;
    }

    .footer-links-group {
        display: flex;
        flex-direction: row;
        justify-content: flex-start;
        gap: 40px;
    }

    .footer-bottom .container {
        flex-direction: column;
        text-align: center;
        gap: 8px;
    }
}