/* ==========================================================================
   MegaDatatech 全站导航栏重设计 (Premium Nav)
   全站加载, .nav-* 前缀类作用域, 与原站 .header 体系完全区隔
   品牌色: 黑 #131313 / 亮红 #F02F2C / 深红 #B11A17
   ========================================================================== */

.nav {
    --nav-red: #F02F2C;
    --nav-red-deep: #B11A17;
    --nav-black: #131313;
    --nav-text: #2b2c2e;
    --nav-muted: #9a9b9d;
    --nav-line: #ececea;
    --nav-ease: cubic-bezier(.22, .61, .36, 1);

    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, .98);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--nav-line);
    transition: box-shadow .35s var(--nav-ease), background .35s var(--nav-ease);
}
/* 滚动收缩态: 投影浮出 */
body.nav-scrolled .nav {
    box-shadow: 0 10px 30px rgba(19, 19, 19, .08);
}

.nav-inner {
    /* 通铺整个浏览器宽度: 不限最大宽度, logo 贴左 / 菜单与操作贴右 */
    max-width: none;
    margin: 0;
    padding: 22px 44px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
    transition: padding .35s var(--nav-ease);
}
body.nav-scrolled .nav-inner { padding-top: 13px; padding-bottom: 13px; }

.nav-logo { flex: none; display: block; }
.nav-logo img {
    display: block;
    height: 46px;
    width: auto;
    transition: height .35s var(--nav-ease);
}
body.nav-scrolled .nav-logo img { height: 40px; }

/* ---------- 主菜单(桌面) ---------- */
.nav-menu { display: block; }
.nav-menu ul {
    display: flex;
    align-items: center;
    gap: clamp(20px, 2.4vw, 38px);
    list-style: none;
    margin: 0;
    padding: 0;
}
.nav-menu a {
    position: relative;
    display: inline-block;
    padding: 8px 2px;
    font-size: 15px;
    font-weight: 500;
    letter-spacing: .09em;
    color: var(--nav-text);
    text-decoration: none;
    transition: color .3s;
}
/* 下划线: 从中心展开 */
.nav-menu a::after {
    content: "";
    position: absolute;
    left: 50%;
    bottom: 0;
    width: 0;
    height: 2px;
    border-radius: 2px;
    background: linear-gradient(90deg, var(--nav-red), var(--nav-red-deep));
    transform: translateX(-50%);
    transition: width .32s var(--nav-ease);
}
.nav-menu a:hover { color: var(--nav-black); }
.nav-menu a:hover::after { width: 100%; }
.nav-menu a.is-active { color: var(--nav-red-deep); font-weight: 600; }
.nav-menu a.is-active::after { width: 100%; }

/* ---------- 右侧: 语言对 + CTA + 汉堡 ---------- */
.nav-side {
    display: flex;
    align-items: center;
    gap: 26px;
    flex: none;
}
.nav-lang { display: flex; align-items: center; }
.nav-lang a {
    font-size: 13px;
    font-weight: 600;
    letter-spacing: .06em;
    color: var(--nav-muted);
    text-decoration: none;
    padding: 4px 2px;
    transition: color .3s;
}
.nav-lang a:hover { color: var(--nav-black); }
.nav-lang a.is-cur { color: var(--nav-red); }
.nav-lang a:not(:first-child)::before {
    content: "/";
    color: #d8d8d6;
    margin-right: 8px;
    font-weight: 400;
}

.nav-cta {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 26px;
    border-radius: 100px;
    font-size: 14px;
    font-weight: 600;
    letter-spacing: .05em;
    color: #fff;
    text-decoration: none;
    background: linear-gradient(96deg, var(--nav-red) 0%, var(--nav-red-deep) 100%);
    box-shadow: 0 10px 24px rgba(240, 47, 44, .28);
    transition: transform .35s var(--nav-ease), box-shadow .35s var(--nav-ease);
    white-space: nowrap;
}
.nav-cta svg { width: 14px; height: 14px; }
.nav-cta:hover {
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 14px 30px rgba(240, 47, 44, .4);
}

/* 汉堡(移动) */
.nav-burger {
    display: none;
    width: 44px;
    height: 44px;
    border: none;
    background: transparent;
    cursor: pointer;
    padding: 10px 8px;
    flex-direction: column;
    justify-content: center;
    gap: 7px;
    align-items: flex-end;
}
.nav-burger span {
    display: block;
    height: 2px;
    border-radius: 2px;
    background: var(--nav-black);
    transition: transform .35s var(--nav-ease), width .35s var(--nav-ease), background .3s;
}
.nav-burger span:nth-child(1) { width: 26px; }
.nav-burger span:nth-child(2) { width: 18px; }
.nav-burger:hover span { width: 26px; }
.nav-burger.is-open span { width: 26px !important; background: var(--nav-red); }
.nav-burger.is-open span:nth-child(1) { transform: translateY(4.5px) rotate(45deg); }
.nav-burger.is-open span:nth-child(2) { transform: translateY(-4.5px) rotate(-45deg); }

/* ==========================================================================
   移动端抽屉
   ========================================================================== */
.nav-overlay {
    position: fixed;
    inset: 0;
    z-index: 150;
    background: rgba(19, 19, 19, .44);
    opacity: 0;
    pointer-events: none;
    transition: opacity .4s var(--nav-ease);
}
.nav-overlay.is-show { opacity: 1; pointer-events: auto; }

.nav-drawer {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 200;
    width: min(400px, 88vw);
    background: #fff;
    display: flex;
    flex-direction: column;
    transform: translateX(102%);
    transition: transform .45s var(--nav-ease);
    box-shadow: -20px 0 60px rgba(19, 19, 19, .18);
    visibility: hidden;
}
.nav-drawer.is-open { transform: translateX(0); visibility: visible; }

.nav-drawer-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 22px 26px 18px;
    border-bottom: 1px solid var(--nav-line);
}
.nav-drawer-close {
    width: 40px;
    height: 40px;
    border: 1px solid var(--nav-line);
    border-radius: 50%;
    background: #fff;
    color: var(--nav-black);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all .3s;
}
.nav-drawer-close:hover {
    background: var(--nav-black);
    border-color: var(--nav-black);
    color: #fff;
    transform: rotate(90deg);
}
.nav-drawer-close svg { width: 14px; height: 14px; }

.nav-drawer-menu { flex: 1; overflow-y: auto; padding: 18px 26px; }
.nav-drawer-menu ul { list-style: none; margin: 0; padding: 0; }
.nav-drawer-menu li {
    opacity: 0;
    transform: translateX(26px);
    transition: opacity .45s var(--nav-ease), transform .45s var(--nav-ease);
}
.nav-drawer.is-open li { opacity: 1; transform: none; }
.nav-drawer.is-open li:nth-child(1) { transition-delay: .10s; }
.nav-drawer.is-open li:nth-child(2) { transition-delay: .16s; }
.nav-drawer.is-open li:nth-child(3) { transition-delay: .22s; }
.nav-drawer.is-open li:nth-child(4) { transition-delay: .28s; }
.nav-drawer.is-open li:nth-child(5) { transition-delay: .34s; }
.nav-drawer.is-open li:nth-child(6) { transition-delay: .40s; }
.nav-drawer-menu a {
    display: flex;
    align-items: baseline;
    gap: 16px;
    padding: 17px 4px;
    border-bottom: 1px solid var(--nav-line);
    font-size: 19px;
    font-weight: 600;
    letter-spacing: .04em;
    color: var(--nav-black);
    text-decoration: none;
    transition: color .3s, padding-left .3s;
}
.nav-drawer-menu a:hover,
.nav-drawer-menu a.is-active { color: var(--nav-red-deep); padding-left: 10px; }
.nav-drawer-menu a.is-active .nav-drawer-no { background: var(--nav-red); color: #fff; border-color: var(--nav-red); }
.nav-drawer-no {
    flex: none;
    font: 700 11px/1 'Roboto', sans-serif;
    letter-spacing: .08em;
    color: var(--nav-muted);
    border: 1px solid var(--nav-line);
    border-radius: 6px;
    padding: 5px 7px;
    transition: all .3s;
}

.nav-drawer-foot {
    padding: 22px 26px 30px;
    border-top: 1px solid var(--nav-line);
    background: linear-gradient(180deg, #fff, #faf9f8);
}
.nav-drawer-foot .nav-cta { width: 100%; justify-content: center; margin-bottom: 16px; }
.nav-drawer-contact { display: flex; flex-direction: column; gap: 7px; }
.nav-drawer-contact a {
    font-size: 13px;
    color: var(--nav-muted);
    text-decoration: none;
    letter-spacing: .02em;
    transition: color .3s;
}
.nav-drawer-contact a:hover { color: var(--nav-red-deep); }

body.nav-lock { overflow: hidden; }

/* ==========================================================================
   首页沉浸态(迁移自 home-premium.css): 深色玻璃 -> 滚动后白底
   ========================================================================== */
body.hp-home .nav {
    position: fixed;
    left: 0;
    right: 0;
    background: rgba(19, 19, 19, .58);
    border-bottom-color: rgba(255, 255, 255, .08);
}
body.hp-home:not(.nav-scrolled) .nav .nav-menu a { color: rgba(255, 255, 255, .92); }
body.hp-home:not(.nav-scrolled) .nav .nav-menu a:hover { color: #fff; }
body.hp-home:not(.nav-scrolled) .nav .nav-lang a { color: rgba(255, 255, 255, .6); }
body.hp-home:not(.nav-scrolled) .nav .nav-lang a:hover { color: #fff; }
body.hp-home:not(.nav-scrolled) .nav .nav-lang a.is-cur { color: #ff6a52; }
body.hp-home:not(.nav-scrolled) .nav .nav-lang a:not(:first-child)::before { color: rgba(255, 255, 255, .3); }
body.hp-home:not(.nav-scrolled) .nav .nav-burger span { background: #fff; }
/* 沉浸态下 logo 轻微光晕, 保证黑字可读 */
body.hp-home:not(.nav-scrolled) .nav-logo img {
    filter: drop-shadow(0 1px 10px rgba(255, 255, 255, .38));
}
body.hp-home.nav-scrolled .nav {
    background: rgba(255, 255, 255, .97);
    border-bottom-color: var(--nav-line);
}

/* ==========================================================================
   响应式
   ========================================================================== */
@media (max-width: 1200px) {
    .nav-menu ul { gap: 22px; }
    .nav-side { gap: 18px; }
}
@media (max-width: 1023px) {
    .nav-menu, .nav-cta { display: none; }
    .nav-burger { display: flex; }
    .nav-inner { padding: 14px 20px; }
    .nav-logo img { height: 38px; }
    body.nav-scrolled .nav-inner { padding-top: 14px; padding-bottom: 14px; }
    body.nav-scrolled .nav-logo img { height: 38px; }
}
@media (max-width: 425px) {
    .nav-lang { display: none; }
    .nav-inner { padding: 12px 16px; }
}