/* ============================================
   卓越健康与长寿中心 - Wellness & Longevity Center
   Design System & Styles
   ============================================ */

/* --- CSS Variables / Design Tokens --- */
:root {
    /* Colors */
    --color-bg: #F5F3EF;
    --color-bg-warm: #FAF9F6;
    --color-dark: #2C4A3E;
    --color-dark-light: #3A5A4E;
    --color-gold: #C9A961;
    --color-gold-light: #D4BA7A;
    --color-text: #2C2C2C;
    --color-text-secondary: #6B6B6B;
    --color-text-light: #999;
    --color-white: #FFFFFF;
    --color-border: #E0DDD8;
    --color-border-light: rgba(0, 0, 0, 0.08);

    /* Typography */
    --font-cn: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    --font-cn-serif: 'Noto Serif SC', 'STSong', 'SimSun', serif;
    --font-en: 'Inter', 'Helvetica Neue', Arial, sans-serif;
    --font-en-serif: 'Playfair Display', 'Georgia', serif;

    /* Spacing */
    --section-padding: 100px 0;
    --container-max: 1100px;
    --container-padding: 0 24px;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.6s ease;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-pill: 100px;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-cn);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.7;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

ul {
    list-style: none;
}

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

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

/* --- Navigation --- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 20px 0;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(44, 74, 62, 0.95);
    backdrop-filter: blur(12px);
    padding: 14px 0;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--container-padding);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 28px;
}

.nav-brand {
    display: flex;
    flex-direction: column;
    gap: 2px;
    flex: 0 0 auto;
    min-height: 44px;
    justify-content: center;
}

.brand-cn {
    font-family: var(--font-cn);
    font-size: 16px;
    font-weight: 500;
    color: var(--color-white);
    letter-spacing: 0.05em;
}

.brand-en {
    font-family: var(--font-en);
    font-size: 10px;
    font-weight: 400;
    color: var(--color-gold);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    white-space: nowrap;
}

.nav-links {
    display: flex;
    flex: 1 1 auto;
    justify-content: flex-end;
    gap: clamp(18px, 2.5vw, 34px);
    align-items: center;
    min-width: 0;
}

.nav-link {
    display: flex;
    align-items: center;
    font-family: var(--font-cn);
    font-size: 14px;
    font-weight: 400;
    color: rgba(255, 255, 255, 0.85);
    letter-spacing: 0.05em;
    line-height: 1.2;
    min-height: 44px;
    white-space: nowrap;
    position: relative;
    padding: 4px 0;
    transition: color var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--color-gold);
    transition: width var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-gold);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* Language Toggle Button */
.lang-toggle {
    display: flex;
    align-items: center;
    flex: 0 0 auto;
    gap: 2px;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: var(--radius-pill);
    padding: 6px 12px;
    cursor: pointer;
    transition: all var(--transition-base);
    font-family: var(--font-en);
    font-size: 12px;
    font-weight: 500;
    letter-spacing: 0.05em;
}

.lang-toggle:hover {
    border-color: var(--color-gold);
    background: rgba(201, 169, 97, 0.1);
}

.lang-zh,
.lang-en {
    color: rgba(255, 255, 255, 0.7);
    transition: color var(--transition-fast);
}

.lang-divider {
    color: rgba(255, 255, 255, 0.3);
    margin: 0 2px;
}

/* Active state for current language */
body.lang-zh .lang-zh,
body.lang-en .lang-en {
    color: var(--color-gold);
}

body.lang-en .nav-container {
    gap: 24px;
}

body.lang-en .nav-brand {
    min-width: 220px;
}

body.lang-en .brand-cn {
    display: none;
}

body.lang-en .brand-en {
    font-size: 11px;
    letter-spacing: 0.16em;
}

body.lang-en .nav-links {
    gap: clamp(18px, 2.1vw, 28px);
}

body.lang-en .nav-link {
    font-family: var(--font-en);
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 0.01em;
}

/* Mobile Nav Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    min-width: 44px;
    min-height: 44px;
    padding: 10px;
    align-items: center;
    justify-content: center;
    position: relative;
    z-index: 1002;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 1.5px;
    background: var(--color-white);
    transition: all var(--transition-base);
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(4px, 5px);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(4px, -5px);
}

/* --- Hero Section --- */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    background:
        linear-gradient(135deg, #2C4A3E 0%, #1a3329 40%, #0f1f18 100%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(ellipse at 20% 50%, rgba(201, 169, 97, 0.08) 0%, transparent 60%),
        radial-gradient(ellipse at 80% 20%, rgba(255, 255, 255, 0.03) 0%, transparent 50%);
    z-index: 1;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 200px;
    background: linear-gradient(to top, var(--color-bg), transparent);
    z-index: 2;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(15, 20, 18, 0.3);
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 3;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 60px;
    width: 100%;
}

.hero-tag {
    display: inline-block;
    font-family: var(--font-en);
    font-size: 11px;
    font-weight: 500;
    color: var(--color-gold);
    letter-spacing: 0.25em;
    text-transform: uppercase;
    margin-bottom: 28px;
    opacity: 0;
    animation: fadeInUp 0.8s ease 0.3s forwards;
}

.hero-title {
    font-family: var(--font-cn-serif);
    font-size: clamp(36px, 5vw, 56px);
    font-weight: 500;
    color: var(--color-white);
    line-height: 1.25;
    margin-bottom: 24px;
    opacity: 0;
    animation: fadeInUp 0.8s ease 0.5s forwards;
}

.hero-title-en {
    font-family: var(--font-en-serif);
    font-size: clamp(18px, 2.5vw, 28px);
    font-weight: 400;
    font-style: italic;
    color: rgba(255, 255, 255, 0.7);
    letter-spacing: 0.02em;
    display: block;
    margin-top: 8px;
}

.hero-desc {
    font-family: var(--font-cn);
    font-size: 18px;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 8px;
    opacity: 0;
    animation: fadeInUp 0.8s ease 0.7s forwards;
}

.hero-desc-en {
    font-family: var(--font-en);
    font-size: 14px;
    color: rgba(255, 255, 255, 0.5);
    line-height: 1.8;
    margin-bottom: 40px;
    opacity: 0;
    animation: fadeInUp 0.8s ease 0.8s forwards;
}

.hero-cta {
    display: flex;
    gap: 24px;
    opacity: 0;
    animation: fadeInUp 0.8s ease 0.9s forwards;
}

.cta-btn {
    font-family: var(--font-cn);
    font-size: 14px;
    font-weight: 400;
    letter-spacing: 0.08em;
    padding: 14px 32px;
    border-radius: var(--radius-pill);
    transition: all var(--transition-base);
    cursor: pointer;
}

.cta-primary {
    background: var(--color-gold);
    color: var(--color-dark);
}

.cta-primary:hover {
    background: var(--color-gold-light);
    transform: translateY(-1px);
}

.cta-secondary {
    background: transparent;
    color: var(--color-white);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.cta-secondary:hover {
    border-color: var(--color-gold);
    color: var(--color-gold);
}

/* --- Section Common --- */
.section {
    padding: var(--section-padding);
}

.section-dark {
    background: var(--color-dark);
    color: var(--color-white);
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-tag {
    display: inline-block;
    font-family: var(--font-en);
    font-size: 11px;
    font-weight: 500;
    color: var(--color-gold);
    letter-spacing: 0.25em;
    text-transform: uppercase;
    margin-bottom: 16px;
}

.section-title {
    font-family: var(--font-cn-serif);
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 500;
    color: var(--color-text);
    line-height: 1.3;
    margin-bottom: 8px;
}

.section-dark .section-title {
    color: var(--color-white);
}

.section-subtitle {
    font-family: var(--font-en-serif);
    font-size: 16px;
    font-weight: 400;
    font-style: italic;
    color: var(--color-text-secondary);
}

.section-dark .section-subtitle {
    color: rgba(255, 255, 255, 0.5);
}

.section-intro {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px;
    font-size: 15px;
    line-height: 1.9;
    color: var(--color-text-secondary);
}

.section-dark .section-intro {
    color: rgba(255, 255, 255, 0.6);
}

/* --- About Section --- */
.about-grid {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 60px;
    align-items: start;
}

.about-lead {
    font-size: 17px;
    line-height: 1.9;
    color: var(--color-text);
    margin-bottom: 20px;
}

.about-body {
    font-size: 15px;
    line-height: 1.9;
    color: var(--color-text-secondary);
    margin-bottom: 36px;
}

.about-highlights {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.highlight-item {
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding-left: 20px;
    border-left: 2px solid var(--color-gold);
}

.highlight-label {
    font-family: var(--font-cn);
    font-size: 15px;
    font-weight: 500;
    color: var(--color-text);
}

.highlight-desc {
    font-size: 14px;
    line-height: 1.7;
    color: var(--color-text-secondary);
}

.advantages-title {
    font-family: var(--font-cn-serif);
    font-size: 20px;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: 24px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--color-border);
}

.advantage-card {
    display: flex;
    gap: 16px;
    align-items: flex-start;
    padding: 18px 0;
    border-bottom: 1px solid var(--color-border-light);
}

.advantage-num {
    font-family: var(--font-en);
    font-size: 13px;
    font-weight: 500;
    color: var(--color-gold);
    min-width: 28px;
    padding-top: 2px;
}

.advantage-label {
    display: block;
    font-size: 15px;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: 4px;
}

.advantage-desc {
    display: block;
    font-size: 13px;
    line-height: 1.6;
    color: var(--color-text-secondary);
}

.about-audience {
    margin-top: 32px;
}

.audience-list li {
    font-size: 14px;
    line-height: 1.8;
    color: var(--color-text-secondary);
    padding-left: 16px;
    position: relative;
    margin-bottom: 6px;
}

.audience-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--color-gold);
}

/* --- Detection Section --- */
.detection-card {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: 40px;
    margin-bottom: 24px;
    transition: all var(--transition-base);
}

.detection-card:hover {
    background: rgba(255, 255, 255, 0.09);
    border-color: rgba(201, 169, 97, 0.3);
}

.detection-card-header {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 16px;
}

.detection-num {
    font-family: var(--font-en);
    font-size: 14px;
    font-weight: 500;
    color: var(--color-gold);
}

.detection-title {
    font-family: var(--font-cn-serif);
    font-size: 22px;
    font-weight: 500;
    color: var(--color-white);
}

.detection-price {
    font-family: var(--font-en);
    font-size: 14px;
    color: var(--color-gold);
    margin-left: 12px;
}

.detection-slogan {
    font-family: var(--font-cn);
    font-size: 16px;
    color: var(--color-gold-light);
    margin-bottom: 16px;
    font-style: italic;
}

.detection-body {
    font-size: 14px;
    line-height: 1.9;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 20px;
}

.detection-features {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.feature-tag {
    display: inline-block;
    font-size: 12px;
    color: var(--color-gold);
    border: 1px solid rgba(201, 169, 97, 0.3);
    padding: 4px 14px;
    border-radius: var(--radius-pill);
}

.detection-modules {
    margin-bottom: 16px;
}

.detection-modules h4 {
    font-family: var(--font-cn);
    font-size: 13px;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.5);
    letter-spacing: 0.1em;
    margin-bottom: 12px;
}

.module-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.module-tag {
    display: inline-block;
    font-size: 12px;
    color: rgba(255, 255, 255, 0.7);
    background: rgba(255, 255, 255, 0.08);
    padding: 5px 14px;
    border-radius: var(--radius-pill);
}

.detection-audience,
.iv-audience,
.tech-audience {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.45);
    line-height: 1.7;
    padding-top: 16px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.audience-label {
    color: var(--color-gold);
    font-weight: 500;
}

/* --- IV / Medication Section --- */
.iv-card {
    background: var(--color-bg-warm);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 40px;
    margin-bottom: 24px;
    transition: all var(--transition-base);
}

.iv-card:hover {
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.06);
    transform: translateY(-2px);
}

.iv-card-premium {
    border-left: 3px solid var(--color-gold);
}

.iv-card-header {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 12px;
}

.iv-num {
    font-family: var(--font-en);
    font-size: 14px;
    font-weight: 500;
    color: var(--color-gold);
}

.iv-title {
    font-family: var(--font-cn-serif);
    font-size: 22px;
    font-weight: 500;
    color: var(--color-text);
}

.iv-price {
    font-family: var(--font-en);
    font-size: 14px;
    color: var(--color-gold);
    margin-left: 12px;
}

.iv-slogan {
    font-size: 15px;
    color: var(--color-text-secondary);
    margin-bottom: 24px;
    font-style: italic;
}

.iv-ingredients {
    margin-bottom: 20px;
}

.iv-ingredients h4 {
    font-family: var(--font-cn);
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text-light);
    letter-spacing: 0.1em;
    margin-bottom: 14px;
}

.ingredient-list {
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.ingredient {
    display: flex;
    flex-direction: column;
    gap: 3px;
    padding-left: 16px;
    border-left: 2px solid var(--color-border);
}

.ingredient-name {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text);
}

.ingredient-desc {
    font-size: 13px;
    line-height: 1.6;
    color: var(--color-text-secondary);
}

.iv-audience {
    color: var(--color-text-light);
    border-top-color: var(--color-border);
}

.iv-audience .audience-label {
    color: var(--color-gold);
}

/* Oxygen Synergy */
.oxygen-synergy {
    display: flex;
    gap: 20px;
    align-items: flex-start;
    background: var(--color-dark);
    border-radius: var(--radius-md);
    padding: 32px 36px;
    margin-top: 40px;
}

.synergy-icon {
    color: var(--color-gold);
    flex-shrink: 0;
    margin-top: 2px;
}

.synergy-content h4 {
    font-family: var(--font-cn);
    font-size: 16px;
    font-weight: 500;
    color: var(--color-white);
    margin-bottom: 8px;
}

.synergy-content p {
    font-size: 14px;
    line-height: 1.7;
    color: rgba(255, 255, 255, 0.6);
}

/* --- Technology Section --- */
.tech-card {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: 40px;
    margin-bottom: 24px;
    transition: all var(--transition-base);
}

.tech-card:hover {
    background: rgba(255, 255, 255, 0.09);
    border-color: rgba(201, 169, 97, 0.3);
}

.tech-card-header {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 12px;
}

.tech-num {
    font-family: var(--font-en);
    font-size: 14px;
    font-weight: 500;
    color: var(--color-gold);
}

.tech-title {
    font-family: var(--font-cn-serif);
    font-size: 22px;
    font-weight: 500;
    color: var(--color-white);
}

.tech-title-en {
    display: block;
    font-family: var(--font-en);
    font-size: 13px;
    font-weight: 400;
    color: rgba(255, 255, 255, 0.4);
    letter-spacing: 0.05em;
    margin-top: 2px;
}

.tech-price {
    font-family: var(--font-en);
    font-size: 14px;
    color: var(--color-gold);
    margin-left: 12px;
}

.tech-slogan {
    font-size: 16px;
    color: var(--color-gold-light);
    margin-bottom: 16px;
    font-style: italic;
}

.tech-body {
    font-size: 14px;
    line-height: 1.9;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 24px;
}

.tech-features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-bottom: 20px;
}

.tech-feature {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.tech-feature-title {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-gold);
}

.tech-feature-desc {
    font-size: 13px;
    line-height: 1.5;
    color: rgba(255, 255, 255, 0.5);
}

/* Combo Card */
.combo-card {
    background: linear-gradient(135deg, rgba(201, 169, 97, 0.15), rgba(201, 169, 97, 0.05));
    border: 1px solid rgba(201, 169, 97, 0.3);
    border-radius: var(--radius-md);
    padding: 36px 40px;
    margin-bottom: 24px;
}

.combo-header {
    margin-bottom: 24px;
}

.combo-badge {
    display: inline-block;
    font-family: var(--font-cn);
    font-size: 11px;
    font-weight: 500;
    color: var(--color-dark);
    background: var(--color-gold);
    padding: 4px 14px;
    border-radius: var(--radius-pill);
    margin-bottom: 14px;
    letter-spacing: 0.1em;
}

.combo-title {
    font-family: var(--font-cn-serif);
    font-size: 20px;
    font-weight: 500;
    color: var(--color-white);
    margin-bottom: 6px;
}

.combo-slogan {
    font-size: 15px;
    color: var(--color-gold-light);
    font-style: italic;
}

.combo-pricing {
    display: flex;
    gap: 24px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.combo-price-item {
    display: flex;
    gap: 8px;
    font-family: var(--font-en);
    font-size: 14px;
    color: rgba(255, 255, 255, 0.6);
}

.combo-price-item span:last-child {
    color: var(--color-white);
    font-weight: 500;
}

.combo-total {
    border-left: 1px solid rgba(201, 169, 97, 0.3);
    padding-left: 24px;
}

.combo-total span:last-child {
    color: var(--color-gold);
    font-size: 18px;
}

.combo-desc {
    font-size: 14px;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.6);
}

/* --- TPE / Reconstruction Section --- */
.tpe-hero {
    text-align: center;
    margin-bottom: 50px;
}

.tpe-main-title {
    font-family: var(--font-cn-serif);
    font-size: clamp(26px, 3.5vw, 36px);
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: 12px;
}

.tpe-main-slogan {
    font-family: var(--font-cn);
    font-size: 18px;
    color: var(--color-gold);
    font-style: italic;
}

.tpe-content {
    max-width: 800px;
    margin: 0 auto;
}

.tpe-body {
    font-size: 15px;
    line-height: 1.9;
    color: var(--color-text-secondary);
    margin-bottom: 40px;
}

.tpe-benefits {
    margin-bottom: 40px;
}

.tpe-benefits h4 {
    font-family: var(--font-cn);
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text-light);
    letter-spacing: 0.1em;
    margin-bottom: 18px;
}

.tpe-benefit-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.tpe-benefit {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 20px;
    background: var(--color-bg-warm);
    border-radius: var(--radius-sm);
    font-size: 14px;
    color: var(--color-text);
}

.benefit-icon {
    color: var(--color-gold);
    flex-shrink: 0;
}

.tpe-process {
    margin-bottom: 40px;
}

.tpe-process h4 {
    font-family: var(--font-cn);
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text-light);
    letter-spacing: 0.1em;
    margin-bottom: 18px;
}

.process-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.process-item {
    text-align: center;
    padding: 24px 16px;
    background: var(--color-dark);
    border-radius: var(--radius-sm);
}

.process-num {
    display: block;
    font-family: var(--font-cn);
    font-size: 18px;
    font-weight: 500;
    color: var(--color-gold);
    margin-bottom: 6px;
}

.process-label {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.6);
}

.tpe-research {
    margin-bottom: 40px;
}

.tpe-research h4 {
    font-family: var(--font-cn);
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text-light);
    letter-spacing: 0.1em;
    margin-bottom: 18px;
}

.research-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.research-item {
    padding: 20px 24px;
    background: var(--color-bg-warm);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--color-gold);
}

.research-source {
    display: block;
    font-family: var(--font-en);
    font-size: 12px;
    font-weight: 500;
    color: var(--color-gold);
    letter-spacing: 0.05em;
    margin-bottom: 8px;
}

.research-item p {
    font-size: 14px;
    line-height: 1.7;
    color: var(--color-text-secondary);
}

.research-item strong {
    color: var(--color-text);
}

.tpe-audience-box {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.audience-box-item {
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding: 18px 24px;
    border-radius: var(--radius-sm);
    background: var(--color-bg-warm);
    font-size: 14px;
    color: var(--color-text-secondary);
}

.audience-box-item.audience-exclude {
    background: rgba(201, 169, 97, 0.08);
    border: 1px solid rgba(201, 169, 97, 0.2);
}

.audience-box-label {
    font-size: 13px;
    font-weight: 500;
    color: var(--color-text);
}

.audience-exclude .audience-box-label {
    color: #b8860b;
}

/* --- Environment Gallery Section --- */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(3, 200px);
    gap: 16px;
    margin-top: 40px;
}

.gallery-item {
    position: relative;
    overflow: hidden;
    border-radius: var(--radius-md);
    cursor: pointer;
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.gallery-item:hover img {
    transform: scale(1.05);
}

.gallery-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 20px 16px 16px;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.7), transparent);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.gallery-item:hover .gallery-overlay {
    opacity: 1;
}

.gallery-caption {
    font-family: var(--font-cn);
    font-size: 14px;
    font-weight: 500;
    color: var(--color-white);
    letter-spacing: 0.05em;
}

/* Gallery item size variations for staggered layout */
.gallery-item-large {
    grid-column: span 2;
    grid-row: span 2;
}

.gallery-item-tall {
    grid-row: span 2;
}

.gallery-item-wide {
    grid-column: span 2;
}

/* --- Footer --- */
.footer {
    background: #1a1a1a;
    color: var(--color-white);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 60px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-title {
    font-family: var(--font-cn-serif);
    font-size: 22px;
    font-weight: 500;
    color: var(--color-white);
    margin-bottom: 4px;
}

.footer-title-en {
    font-family: var(--font-en);
    font-size: 12px;
    color: var(--color-gold);
    letter-spacing: 0.15em;
    margin-bottom: 12px;
}

.footer-tagline {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.4);
}

.footer-info {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.footer-info-item {
    display: flex;
    gap: 14px;
    align-items: flex-start;
    color: rgba(255, 255, 255, 0.6);
}

.footer-info-item svg {
    flex-shrink: 0;
    margin-top: 3px;
    color: var(--color-gold);
}

.footer-info-item p {
    font-size: 14px;
    line-height: 1.6;
}

.footer-info-en {
    font-size: 12px !important;
    color: rgba(255, 255, 255, 0.3) !important;
}

.footer-qrcode-inline {
    display: flex;
    flex-direction: column;
    gap: 12px;
    padding-top: 2px;
}

.footer-qrcode {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 20px 0;
    gap: 12px;
}

.footer-qrcode-text {
    font-family: var(--font-cn);
    font-size: 14px;
    color: rgba(255, 255, 255, 0.7);
    letter-spacing: 0.05em;
}

.footer-qrcode-img {
    width: 120px;
    height: 120px;
    border-radius: var(--radius-sm);
    background: var(--color-white);
    padding: 8px;
}

.footer-bottom {
    padding-top: 24px;
    text-align: center;
}

.footer-bottom p {
    font-size: 12px;
    color: rgba(255, 255, 255, 0.25);
    letter-spacing: 0.05em;
}

/* --- Fade In Animation --- */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* --- Responsive Design --- */

/* Tablet */
@media (max-width: 1024px) {
    :root {
        --section-padding: 80px 0;
    }

    .nav-container {
        gap: 20px;
    }

    .nav-links {
        gap: 18px;
    }

    .nav-link {
        font-size: 13px;
    }

    body.lang-en .nav-brand {
        min-width: 188px;
    }

    body.lang-en .brand-en {
        font-size: 10px;
        letter-spacing: 0.12em;
    }

    body.lang-en .nav-links {
        gap: 16px;
    }

    body.lang-en .nav-link {
        font-size: 12px;
    }

    .about-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .tpe-benefit-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .process-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .tech-features {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .gallery-grid {
        grid-template-columns: repeat(2, 1fr);
        grid-template-rows: auto;
    }

    .gallery-item-large,
    .gallery-item-tall,
    .gallery-item-wide {
        grid-column: span 1;
        grid-row: span 1;
    }

    .gallery-item {
        aspect-ratio: 4/3;
    }
}

/* Mobile */
@media (max-width: 768px) {
    :root {
        --section-padding: 60px 0;
    }

    .nav-toggle {
        display: flex;
    }

    body.lang-en .nav-brand {
        min-width: 0;
    }

    .lang-toggle {
        position: absolute;
        top: 20px;
        right: 70px;
        min-height: 44px;
        min-width: 72px;
        justify-content: center;
        padding: 8px 12px;
        font-size: 11px;
    }

    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 100vw;
        height: 100vh;
        background: rgba(44, 74, 62, 0.98);
        backdrop-filter: blur(12px);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 28px;
        transition: right var(--transition-base);
        box-shadow: -5px 0 30px rgba(0, 0, 0, 0.2);
        z-index: 1001;
    }

    .nav-links.open {
        right: 0;
    }

    .nav-link {
        font-size: 16px;
        min-height: 44px;
        display: flex;
        align-items: center;
    }

    .hero-content {
        padding: 0 24px;
    }

    .hero-cta {
        flex-direction: column;
        gap: 12px;
    }

    .cta-btn {
        text-align: center;
    }

    .detection-card,
    .iv-card,
    .tech-card {
        padding: 28px 20px;
    }

    .detection-card-header,
    .iv-card-header,
    .tech-card-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .detection-price,
    .iv-price,
    .tech-price {
        margin-left: 0;
    }

    .tpe-benefit-grid {
        grid-template-columns: 1fr;
    }

    .process-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .combo-pricing {
        flex-direction: column;
        gap: 8px;
    }

    .combo-total {
        border-left: none;
        padding-left: 0;
        border-top: 1px solid rgba(201, 169, 97, 0.3);
        padding-top: 12px;
    }

    .oxygen-synergy {
        flex-direction: column;
        gap: 12px;
        padding: 24px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .gallery-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .gallery-item {
        aspect-ratio: 16/10;
    }
}

/* Small Mobile */
@media (max-width: 480px) {
    .nav-container {
        padding: 0 18px;
    }

    .brand-cn {
        font-size: 15px;
        max-width: 190px;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
    }

    .brand-en {
        font-size: 9px;
        max-width: 190px;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        letter-spacing: 0.14em;
    }

    body.lang-en .brand-en {
        font-size: 8.5px;
        max-width: 210px;
        letter-spacing: 0.08em;
    }

    .lang-toggle {
        right: 62px;
        min-width: 64px;
        padding: 8px 10px;
    }

    .hero-title {
        font-size: 28px;
    }

    .hero-title-en {
        font-size: 16px;
    }

    .section-title {
        font-size: 24px;
    }

    .detection-title,
    .iv-title,
    .tech-title {
        font-size: 18px;
    }

    .process-grid {
        grid-template-columns: 1fr 1fr;
        gap: 10px;
    }

    .process-item {
        padding: 18px 12px;
    }
}