/* 顶部导航结构：固定头部、品牌区、主导航和社交入口。 */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    z-index: 30;
    width: 100%;
    height: 68px;
    color: #ffffff;
    background: var(--ghis-navy);
}

.header-inner {
    width: var(--content-width);
    height: 68px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 150px 1fr 92px;
    align-items: center;
    gap: 32px;
}

.brand-mark {
    width: 96px;
    display: flex;
    align-items: center;
    cursor: pointer;
    user-select: none;
}

.brand-logo-img {
    display: block;
    width: 100%;
    max-height: 38px;
    object-fit: contain;
}

.main-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: clamp(24px, 2vw, 42px);
    font-size: 14px;
    line-height: 1;
    font-weight: 700;
}

.nav-item {
    color: rgba(255, 255, 255, .94);
    white-space: nowrap;
    cursor: pointer;
    user-select: none;
}

.nav-item.active,
.nav-item:hover {
    color: var(--ghis-orange);
}

.social-links {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 14px;
}

.social-dot {
    width: 28px;
    height: 28px;
    overflow: hidden;
    border-radius: 50%;
    background: #ffffff;
    cursor: pointer;
    user-select: none;
}

.social-dot img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.mobile-menu-toggle {
    display: none;
}

/* 首页与各内容页首屏偏移：避免 fixed 头部遮挡首屏内容。 */
.site-header + .hero-section,
.site-header + .agenda-hero-section,
.site-header + .roadshow-hero-section,
.site-header + .sponsor-hero-section,
.site-header + .venue-hero-section,
.site-header + .contact-hero-section {
    margin-top: 68px;
}

/* 底部导航结构：统一底部品牌、导航与操作入口布局。 */
.site-footer {
    padding: clamp(52px, 4.6vw, 84px) 0;
    color: #ffffff;
    background: var(--ghis-navy);
}

.footer-inner {
    width: var(--content-width);
    margin: 0 auto;
    display: grid;
    grid-template-columns: minmax(420px, max-content) minmax(520px, 1fr);
    align-items: center;
    gap: clamp(40px, 4vw, 96px);
}

.footer-brand {
    display: grid;
    align-content: center;
    justify-items: start;
}

.footer-cta {
    display: grid;
    justify-items: end;
    align-content: center;
    text-align: right;
}

.footer-logo {
    display: block;
    width: 176px;
    height: auto;
}

.copyright {
    margin-top: 28px;
    font-size: clamp(12px, 0.84vw, 16px);
    line-height: 1.3;
    white-space: nowrap;
}

.footer-nav {
    display: flex;
    flex-wrap: nowrap;
    justify-content: flex-end;
    gap: clamp(14px, 1.2vw, 22px);
    margin-bottom: 48px;
    font-size: clamp(11px, 0.78vw, 14px);
    line-height: 1;
    font-weight: 700;
    white-space: nowrap;
}

.footer-nav span,
.footer-button {
    cursor: pointer;
    user-select: none;
}

.active-footer,
.footer-nav span:hover {
    color: var(--ghis-orange);
}

.join-text,
.footer-line {
    display: block;
    font-size: clamp(14px, 1vw, 19px);
    line-height: 1.25;
    font-weight: 700;
}

.join-text {
    width: min(100%, 430px);
}

.footer-line {
    width: fit-content;
    max-width: 100%;
    margin: 18px 0 24px;
    white-space: nowrap;
}

.footer-button {
    width: 344px;
    margin: 14px 0 0 auto;
    display: grid;
    place-items: center;
    min-height: var(--ghis-shared-button-height);
    border-radius: var(--ghis-shared-button-radius);
    font-size: var(--ghis-shared-button-font);
    line-height: 1;
    font-weight: var(--ghis-shared-button-weight);
    transition:
        transform 0.18s ease,
        background 0.18s ease;
}

.primary-action {
    color: #ffffff;
    background: var(--ghis-orange);
}

.outline-action {
    color: #ffffff;
    border: 1px solid #ffffff;
    background: transparent;
}
.outline-action:hover{
    color: #fff;
}

/* 平板与小屏适配：切换移动端导航按钮与抽屉式主导航。 */
@media (max-width: 1399px) {
    .header-inner {
        grid-template-columns: 140px 1fr 80px;
    }

    .brand-mark {
        width: 92px;
    }

    .main-nav {
        gap: 22px;
        font-size: 13px;
    }
}

@media (max-width: 1199px) {
    .site-header,
    .header-inner {
        height: 64px;
    }

    .header-inner {
        grid-template-columns: 120px 1fr 48px;
        gap: 16px;
    }

    .brand-mark {
        width: 84px;
    }

    .main-nav {
        position: absolute;
        left: 0;
        right: 0;
        top: 64px;
        display: none;
        padding: 16px 20px 18px;
        background: var(--ghis-navy);
        border-top: 1px solid rgba(255, 255, 255, .18);
        box-shadow: 0 10px 24px rgba(1, 18, 150, .18);
    }

    .mobile-nav-open .main-nav {
        display: grid;
        grid-template-columns: 1fr;
        gap: 14px;
    }

    .mobile-menu-toggle {
        justify-self: center;
        display: grid;
        width: 34px;
        height: 28px;
        align-content: center;
        gap: 6px;
        cursor: pointer;
    }

    .mobile-menu-toggle span {
        display: block;
        height: 3px;
        border-radius: 2px;
        background: #ffffff;
    }

    .social-links {
        gap: 0;
    }

    .social-dot + .social-dot {
        display: none;
    }

    .site-header + .hero-section,
    .site-header + .agenda-hero-section,
    .site-header + .roadshow-hero-section,
    .site-header + .sponsor-hero-section,
    .site-header + .venue-hero-section,
    .site-header + .contact-hero-section {
        margin-top: 64px;
    }

    .footer-logo {
        width: min(176px, 52%);
        margin: 0 auto;
    }
    .copyright{
        margin: 0 auto;
        margin-top: 28px;
    }

    .footer-inner {
        grid-template-columns: 1fr;
        gap: 30px;
        padding: 38px 0;
        text-align: center;
    }

    .footer-cta {
        justify-items: center;
        text-align: center;
    }

    .footer-nav {
        justify-content: center;
        margin-bottom: 32px;
    }

    .footer-button {
        width: min(344px, 100%);
        margin-left: auto;
        margin-right: auto;
    }

    .join-text,
    .footer-line {
        width: min(100%, 560px);
    }

    .copyright,
    .footer-line {
        white-space: normal;
    }
}

@media (max-width: 750px) {
    .footer-nav {
        display: grid;
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .footer-button {
        width: min(100%, 380px);
    }
}