*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

:root {
    --black: #0a0a0a;
    --gray-950: #111111;
    --gray-900: #1a1a1a;
    --gray-800: #222222;
    --gray-700: #333333;
    --gray-600: #555555;
    --gray-500: #777777;
    --gray-400: #999999;
    --gray-300: #bbbbbb;
    --gray-200: #dddddd;
    --gray-100: #f0f0f0;
    --gray-50: #f8f8f8;
    --white: #ffffff;
    --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    --max-w: 1200px;
    --nav-h: 72px;
}

body {
    font-family: var(--font);
    background: var(--black);
    color: var(--gray-200);
    -webkit-font-smoothing: antialiased;
}

/* Light theme when Chinese language is active */
html[lang="zh-CN"] {
    --black: #f8f9fa;
    --gray-950: #f0f1f3;
    --gray-900: #e8eaed;
    --gray-800: #d1d4d9;
    --gray-700: #b0b3b9;
    --gray-600: #8e9199;
    --gray-500: #5f6369;
    --gray-400: #3c4043;
    --gray-300: #282a2d;
    --gray-200: #1c1d1f;
    --gray-100: #111111;
    --gray-50: #0a0a0a;
    --white: #000000;
}
html[lang="zh-CN"] nav { background: rgba(255,255,255,.9); border-bottom-color: rgba(0,0,0,.06); }
html[lang="zh-CN"] .nav-links a { color: var(--gray-500); }
html[lang="zh-CN"] .nav-links a:hover,
html[lang="zh-CN"] .nav-links a.active { color: var(--gray-200); }
html[lang="zh-CN"] .nav-cta { background: var(--gray-200); color: var(--gray-900) !important; }
html[lang="zh-CN"] .btn-primary { background: var(--gray-200); color: var(--gray-900) !important; }
html[lang="zh-CN"] .btn-primary:hover { background: var(--gray-400); }
html[lang="zh-CN"] .btn-secondary { border-color: var(--gray-700); color: var(--gray-500) !important; }
html[lang="zh-CN"] .btn-secondary:hover { border-color: var(--gray-500); color: var(--gray-200) !important; }
html[lang="zh-CN"] .lang-switch { border-color: var(--gray-700); }
html[lang="zh-CN"] .lang-switch:hover { border-color: var(--gray-500); }
html[lang="zh-CN"] input,
html[lang="zh-CN"] textarea { background: var(--gray-100) !important; border-color: var(--gray-700) !important; color: var(--gray-400) !important; }
html[lang="zh-CN"] input:focus,
html[lang="zh-CN"] textarea:focus { border-color: var(--gray-500) !important; }
html[lang="zh-CN"] footer { border-top-color: rgba(0,0,0,.06); }
html[lang="zh-CN"] .footer-bottom { border-top-color: rgba(0,0,0,.06); }
html[lang="zh-CN"] .product-card,
html[lang="zh-CN"] .cat-card,
html[lang="zh-CN"] .service-card,
html[lang="zh-CN"] .hl-card,
html[lang="zh-CN"] .value-card,
html[lang="zh-CN"] .about-stat,
html[lang="zh-CN"] .faq-item,
html[lang="zh-CN"] .contact-form,
html[lang="zh-CN"] .p-card { border-color: rgba(0,0,0,.08) !important; }
html[lang="zh-CN"] .product-card:hover,
html[lang="zh-CN"] .cat-card:hover,
html[lang="zh-CN"] .service-card:hover,
html[lang="zh-CN"] .value-card:hover,
html[lang="zh-CN"] .p-card:hover { border-color: rgba(0,0,0,.15) !important; }
html[lang="zh-CN"] .compare-bar { border-top-color: rgba(0,0,0,.1); }
html[lang="zh-CN"] .compare-modal { border-color: rgba(0,0,0,.1); }
html[lang="zh-CN"] .page-header { background: var(--gray-950); }
html[lang="zh-CN"] .trust-bar { border-bottom-color: rgba(0,0,0,.06); }
html[lang="zh-CN"] .breadcrumb { background: var(--gray-950); }
html[lang="zh-CN"] .hero-device { background: radial-gradient(ellipse at center, #e8e8e8 0%, #f0f0f0 50%, #f8f8f8 100%) !important; border-color: rgba(0,0,0,.08) !important; }
html[lang="zh-CN"] .hero-device .charge-ring { border-color: var(--gray-700); border-top-color: var(--gray-400); }
html[lang="zh-CN"] .hero-device .badge,
html[lang="zh-CN"] .hero-device .icon-stack i,
html[lang="zh-CN"] .hero-device .charge-ring i { color: var(--gray-500); }
html[lang="zh-CN"] .adapter-visual { background: radial-gradient(ellipse at center, #e8e8e8 0%, #f0f0f0 50%, #f8f8f8 100%) !important; border-color: rgba(0,0,0,.08) !important; }
html[lang="zh-CN"] .pillow-visual { background: radial-gradient(ellipse at center, #e8e8e8 0%, #f0f0f0 50%, #f8f8f8 100%) !important; border-color: rgba(0,0,0,.08) !important; }
html[lang="zh-CN"] .product-visual { background: radial-gradient(ellipse at center, #e8e8e8 0%, #f0f0f0 50%, #f8f8f8 100%) !important; border-color: rgba(0,0,0,.08) !important; }
html[lang="zh-CN"] .p-card .thumb { background: radial-gradient(ellipse at center, #e8e8e8 0%, #f0f0f0 50%, #f8f8f8 100%) !important; }
html[lang="zh-CN"] .p-card .thumb i { color: var(--gray-500); }
html[lang="zh-CN"] .adapter-visual i,
html[lang="zh-CN"] .pillow-visual i,
html[lang="zh-CN"] .product-visual i { color: var(--gray-500); }
html[lang="zh-CN"] .hero::before { background: radial-gradient(circle, rgba(0,0,0,.03) 0%, transparent 70%); }
html[lang="zh-CN"] .cta { border-top-color: rgba(0,0,0,.04) !important; border-bottom-color: rgba(0,0,0,.04) !important; }
html[lang="zh-CN"] .hero-text h1 .highlight { color: var(--gray-500); }
html[lang="zh-CN"] .product-card .tag { background: rgba(0,0,0,.06); color: var(--gray-500); }
html[lang="zh-CN"] .compare-check label { border-color: var(--gray-600); }
html[lang="zh-CN"] .filter-btn { border-color: var(--gray-700); color: var(--gray-500); }
html[lang="zh-CN"] .filter-btn:hover { border-color: var(--gray-500); color: var(--gray-200); }
html[lang="zh-CN"] .filter-btn.active { background: var(--gray-200); color: var(--gray-900); border-color: var(--gray-200); }
html[lang="zh-CN"] .logo-bubbles .b { background: var(--c, rgba(0,0,0,.15)) !important; box-shadow: 0 0 6px var(--c, rgba(0,0,0,.1)) !important; }
html[lang="zh-CN"] .price { color: var(--gray-100) !important; }
html[lang="zh-CN"] .price span { color: var(--gray-500) !important; }
html[lang="zh-CN"] .rating i { color: var(--gray-500) !important; }
html[lang="zh-CN"] .rating { color: var(--gray-500) !important; }

a { color: var(--gray-300); text-decoration: none; transition: color .2s; }
a:hover { color: var(--white); }

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

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

/* Nav */
nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 100;
    height: var(--nav-h);
    background: rgba(10,10,10,.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255,255,255,.04);
}
nav .container {
    display: flex; align-items: center; justify-content: space-between;
    height: 100%;
}
.logo-wrap {
    position: relative; display: inline-flex; align-items: center;
}
.logo {
    font-size: 22px; font-weight: 800; color: var(--white);
    letter-spacing: -.5px; position: relative; z-index: 1;
}
.logo span { color: var(--gray-500); }

/* ─── Logo Bubbles ─── */
.logo-bubbles { position: absolute; inset: 0; pointer-events: none; overflow: visible; z-index: 0; }
.logo-bubbles .b {
    position: absolute;
    border-radius: 50%;
    background: var(--c, rgba(255,255,255,.5));
    animation: bubbleRise var(--d, 3s) ease-out infinite;
    animation-delay: var(--dd, 0s);
    opacity: 0;
    width: var(--s, 8px);
    height: var(--s, 8px);
    bottom: 0;
    left: var(--x, 50%);
    box-shadow: 0 0 6px var(--c, rgba(255,255,255,.3));
}
@keyframes bubbleRise {
    0%   { opacity: 0; transform: translateY(0) scale(1); }
    20%  { opacity: .6; }
    80%  { opacity: .3; }
    100% { opacity: 0; transform: translateY(calc(var(--h, -40px))) scale(.3); }
}
.nav-links { display: flex; gap: 24px; align-items: center; }
.nav-links a {
    font-size: 13px; font-weight: 500; color: var(--gray-400);
    letter-spacing: .3px; white-space: nowrap;
}
.nav-links a:hover { color: var(--white); }
.nav-links a.active { color: var(--white); }

.lang-switch {
    display: flex; align-items: center; gap: 4px;
    background: none; border: 1px solid var(--gray-700);
    border-radius: 100px; padding: 4px 12px;
    font-family: var(--font); font-size: 12px; font-weight: 500;
    color: var(--gray-400); cursor: pointer;
    transition: all .2s; white-space: nowrap;
    letter-spacing: .3px;
}
.lang-switch:hover { border-color: var(--gray-500); color: var(--white); }
.lang-switch .sep { color: var(--gray-600); margin: 0 2px; }
.lang-switch .active { color: var(--white); }

.mobile-toggle {
    display: none; background: none; border: none;
    color: var(--white); font-size: 24px; cursor: pointer;
}

/* Page Header */
.page-header {
    padding: 140px 0 60px;
    background: linear-gradient(165deg, var(--black) 0%, var(--gray-950) 40%, var(--gray-900) 100%);
    text-align: center;
}
.page-header h1 {
    font-size: clamp(32px, 4vw, 48px);
    font-weight: 800; color: var(--white);
    margin-bottom: 12px;
}
.page-header p {
    font-size: 17px; color: var(--gray-500);
    max-width: 600px; margin: 0 auto;
}

/* Content section */
.content-section { padding: 80px 0; }
.content-section.dark { background: var(--gray-950); }

.section-label {
    font-size: 12px; font-weight: 600; letter-spacing: 2px; text-transform: uppercase;
    color: var(--gray-500); margin-bottom: 12px;
}
.section-title {
    font-size: clamp(26px, 3vw, 38px);
    font-weight: 700; color: var(--white);
    margin-bottom: 16px; letter-spacing: -.5px;
}
.section-desc {
    font-size: 16px; color: var(--gray-500);
    max-width: 600px; line-height: 1.7;
}

/* Buttons */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 28px; border-radius: 100px;
    font-weight: 600; font-size: 14px;
    transition: all .25s; cursor: pointer; border: none; font-family: var(--font);
}
.btn-primary {
    background: var(--white); color: var(--black) !important;
}
.btn-primary:hover { background: var(--gray-300); transform: translateY(-2px); }
.btn-secondary {
    border: 1px solid var(--gray-700); color: var(--gray-300) !important;
    background: transparent;
}
.btn-secondary:hover { border-color: var(--gray-500); color: var(--white) !important; }

/* Footer */
footer {
    padding: 60px 0 32px;
    background: var(--black);
    border-top: 1px solid rgba(255,255,255,.04);
}
footer .container {
    display: flex; justify-content: space-between; align-items: center;
    flex-wrap: wrap; gap: 24px;
}
footer .social { display: flex; gap: 12px; }
footer .social a {
    width: 36px; height: 36px; border-radius: 50%;
    border: 1px solid var(--gray-700);
    display: flex; align-items: center; justify-content: center;
    color: var(--gray-500); font-size: 14px;
    transition: all .2s;
}
footer .social a:hover { border-color: var(--gray-400); color: var(--white); }
.footer-bottom {
    margin-top: 32px; padding-top: 24px;
    border-top: 1px solid rgba(255,255,255,.04);
    text-align: center; font-size: 13px; color: var(--gray-700);
}

/* Breadcrumb */
.breadcrumb {
    padding: 88px 0 0;
    background: var(--gray-950);
    font-size: 13px; color: var(--gray-600);
}
.breadcrumb .container { padding-top: 16px; padding-bottom: 16px; }
.breadcrumb a { color: var(--gray-500); }
.breadcrumb a:hover { color: var(--white); }
.breadcrumb span { color: var(--gray-400); }

/* Back link */
.back-link {
    display: inline-flex; align-items: center; gap: 6px;
    font-size: 14px; color: var(--gray-500); margin-bottom: 24px;
}
.back-link:hover { color: var(--white); }

/* Animations */
.reveal {
    opacity: 0; transform: translateY(30px);
    transition: opacity .7s ease, transform .7s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* Responsive */
@media (max-width: 900px) {
    .nav-links { display: none; }
    .mobile-toggle { display: block; }
    .nav-links.open {
        display: flex; flex-direction: column;
        position: absolute; top: var(--nav-h); left: 0; right: 0;
        background: rgba(10,10,10,.98);
        padding: 24px; gap: 16px;
        border-bottom: 1px solid rgba(255,255,255,.06);
    }
    .nav-links.open a { font-size: 15px; }
}