/* 品牌首页专属样式(mobile-first;PC 在断点内增强为多栏/全幅) */

/* ============ 导航 ============ */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 16px 0; transition: background .3s var(--rb-ease), box-shadow .3s var(--rb-ease), padding .3s var(--rb-ease);
}
.nav.scrolled { background: rgba(255,255,255,0.92); backdrop-filter: saturate(180%) blur(12px); box-shadow: 0 1px 0 var(--rb-line); padding: 10px 0; }
.nav-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.nav-logo img { height: 56px; width: auto; }
.nav-links { display: none; gap: 28px; font-size: 14px; color: var(--rb-ink); }
.nav-links a { position: relative; padding: 4px 0; transition: color .2s; }
.nav-links a:hover { color: var(--rb-red); }
.nav-cta { display: none; padding: 10px 24px; font-size: 14px; }
.nav-toggle { display: inline-flex; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 6px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--rb-ink); transition: transform .3s, opacity .3s; }
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
.nav-mobile {
  display: none; flex-direction: column; gap: 4px;
  position: fixed; top: 64px; left: 0; right: 0;
  background: #fff; padding: 16px 20px 24px; box-shadow: var(--rb-shadow);
}
.nav-mobile.open { display: flex; }
.nav-mobile a { padding: 12px 4px; border-bottom: 1px solid var(--rb-line); font-size: 15px; }
.nav-mobile .btn { margin-top: 12px; }
@media (min-width: 900px) {
  .nav-links { display: flex; }
  .nav-cta { display: inline-flex; }
  .nav-toggle { display: none; }
}

/* ============ Hero ============ */
.hero { position: relative; padding: 120px 0 64px; overflow: hidden; }
.hero-grid { display: grid; gap: 32px; align-items: center; }
.hero-eyebrow { font-family: var(--rb-font-serif); letter-spacing: 3px; color: var(--rb-red); font-size: 12px; text-transform: uppercase; }
.hero-title {
  font-family: var(--rb-font-serif); font-weight: 700; line-height: 1.15;
  font-size: clamp(2.4rem, 8vw, 4.2rem); margin-top: 14px; color: var(--rb-ink);
}
.hero-title em { font-style: normal; color: var(--rb-red); }
.hero-sub { font-size: clamp(1rem, 2.2vw, 1.18rem); color: #666; margin-top: 20px; max-width: 34ch; line-height: 1.8; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 32px; }
.hero-visual { position: relative; display: flex; justify-content: center; align-items: center; }
.hero-product-img { max-width: 100%; height: auto; max-height: 440px; border-radius: 16px; box-shadow: var(--rb-shadow); }
.hero-blob {
  position: absolute; inset: -8% -8% auto auto; width: 70%; aspect-ratio: 1; border-radius: 50%;
  background: radial-gradient(circle, rgba(var(--rb-red-rgb),0.10), transparent 70%); z-index: -1;
}
@media (min-width: 900px) {
  .hero { padding: 168px 0 100px; }
  .hero-grid { grid-template-columns: 1.05fr 0.95fr; gap: 56px; }
  .hero-product-img { max-height: 600px; }
}

/* ============ 通用 section 头 ============ */
.sec-head { max-width: 720px; }

/* ============ 品牌故事 ============ */
.story { background: #fff; }
.story-quote {
  font-family: var(--rb-font-serif); font-size: clamp(1.4rem, 3.2vw, 2.1rem);
  line-height: 1.5; color: var(--rb-ink); font-style: italic; max-width: 30ch; margin-top: 14px;
}
.story-text { margin-top: 32px; color: #555; font-size: 1.02rem; line-height: 1.95; max-width: 64ch; }
.story-text p + p { margin-top: 18px; }

/* ============ 科研数据墙 ============ */
.stats { background: var(--rb-cream); }
.stats-grid { display: grid; gap: 28px 24px; margin-top: 44px; }
@media (min-width: 560px) { .stats-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 900px) { .stats-grid { grid-template-columns: repeat(3, 1fr); } }
.stat { padding-left: 18px; border-left: 2px solid var(--rb-line); }
.stat-num { font-family: var(--rb-font-serif); font-size: clamp(3rem, 7vw, 4.6rem); font-weight: 700; color: var(--rb-red); line-height: 1; }
.stat-num span { font-size: 0.42em; color: var(--rb-gold); margin-left: 2px; }
.stat-lab { margin-top: 12px; font-size: 0.92rem; color: #666; line-height: 1.5; }
.stats-note { margin-top: 40px; font-size: 0.9rem; color: #999; max-width: 70ch; }

/* ============ 核心科学 ============ */
.science { background: #fff; }
.science-grid { display: grid; gap: 16px; margin-top: 40px; }
@media (min-width: 640px) { .science-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .science-grid { grid-template-columns: repeat(3, 1fr); gap: 20px; } }
.ing-card .ing-patent { display: inline-block; font-size: 11px; color: var(--rb-gold); letter-spacing: 1px; margin-bottom: 10px; }
.tech-bar {
  margin-top: 40px; display: flex; flex-wrap: wrap; gap: 12px 24px; align-items: center;
  padding: 22px 26px; background: var(--rb-cream); border-radius: var(--rb-radius); border: 1px solid var(--rb-line);
}
.tech-label { font-weight: 700; color: var(--rb-red); font-size: 0.96rem; padding-right: 22px; border-right: 1px solid var(--rb-line); }
.tech-item { font-size: 0.88rem; color: #666; }

/* ============ 产品 ============ */
.product { background: var(--rb-cream); }
.product-grid { display: grid; gap: 36px; align-items: center; margin-top: 40px; }
@media (min-width: 900px) { .product-grid { grid-template-columns: 0.9fr 1.1fr; gap: 64px; } }
.product-visual img { width: 100%; max-height: 560px; object-fit: contain; border-radius: 16px; box-shadow: var(--rb-shadow); }
.product-info { padding: 4px 0; }
.product-name { font-family: var(--rb-font-serif); font-size: clamp(1.5rem, 3vw, 2rem); font-weight: 700; line-height: 1.3; }
.product-pos { color: var(--rb-gold); margin-top: 10px; font-size: 0.86rem; letter-spacing: 0.5px; }
.product-desc { color: #666; margin-top: 20px; line-height: 1.9; }
.product-claims { margin-top: 26px; display: flex; flex-direction: column; gap: 14px; }
.product-claims li { list-style: none; font-size: 0.96rem; color: #555; line-height: 1.6; }
.product-cta { margin-top: 32px; }
.product-note { margin-top: 14px; font-size: 0.78rem; color: #aaa; }

/* ============ AI 肌龄检测入口 ============ */
.detect { background: #fff; text-align: center; }
.detect-steps { display: grid; gap: 20px; margin: 48px auto 0; max-width: 960px; }
@media (min-width: 768px) { .detect-steps { grid-template-columns: repeat(3, 1fr); } }
.detect-step { background: var(--rb-cream); border-radius: var(--rb-radius); padding: 32px 24px; }
.detect-step .step-num { margin: 0 auto 16px; }
.detect-step h3 { font-size: 1.1rem; margin-bottom: 8px; }
.detect-step p { color: #777; font-size: 0.9rem; }
.detect-cta { margin-top: 48px; }

/* ============ Footer ============ */
.footer { background: var(--rb-ink); color: #bbb; padding: 56px 0 28px; }
.footer-inner { display: grid; gap: 32px; }
@media (min-width: 768px) { .footer-inner { grid-template-columns: 1.4fr 1fr; } }
.footer-logo { height: 56px; width: auto; margin-bottom: 14px; filter: brightness(0) invert(1); }
.footer-tag { color: #999; font-size: 0.9rem; letter-spacing: 1px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 16px 28px; font-size: 0.92rem; }
.footer-links a:hover { color: #fff; }
.footer-disclaim { margin-top: 36px; padding-top: 24px; border-top: 1px solid #444; font-size: 0.78rem; color: #777; line-height: 1.7; }

/* ============ Hero 轮播 ============ */
.hero-text { text-align: left; }
.carousel { position: relative; width: 100%; max-width: 440px; margin: 0 auto; }
.carousel-track { position: relative; border-radius: 18px; overflow: hidden; box-shadow: var(--rb-shadow); aspect-ratio: 3/4; background: var(--rb-soft); }
.carousel-slide { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; opacity: 0.16; transform: scale(1.12); filter: blur(14px); transition: opacity .9s var(--rb-ease), transform 1.5s var(--rb-ease), filter 1.2s var(--rb-ease); }
.carousel-slide.is-active { opacity: 1; transform: scale(1); filter: blur(0); }
.carousel-dots { display: flex; justify-content: center; gap: 8px; margin-top: 18px; }
.carousel-dots .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--rb-line); cursor: pointer; transition: all .3s; border: none; padding: 0; }
.carousel-dots .dot.is-active { background: var(--rb-red); width: 26px; border-radius: 4px; }

/* ============ 临床实证 ============ */
.clinical { background: #fff; }
.clinical-stats { display: grid; gap: 20px; margin-top: 40px; }
@media (min-width: 560px) { .clinical-stats { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .clinical-stats { grid-template-columns: repeat(4, 1fr); } }
.cl-stat { text-align: center; padding: 28px 12px; background: var(--rb-cream); border-radius: var(--rb-radius); }
.cl-num { font-family: var(--rb-font-serif); font-size: clamp(2.1rem, 5vw, 3.1rem); font-weight: 700; color: var(--rb-red); line-height: 1; }
.cl-num span { font-size: 0.5em; }
.cl-lab { margin-top: 12px; font-size: 0.9rem; color: #666; }
.clinical-imgs { display: grid; gap: 22px; margin-top: 44px; }
@media (min-width: 768px) { .clinical-imgs { grid-template-columns: 1fr 1fr; } }
.clinical-imgs figure { margin: 0; }
.clinical-imgs img { width: 100%; border-radius: var(--rb-radius); box-shadow: var(--rb-shadow-sm); }
.clinical-imgs figcaption { margin-top: 10px; font-size: 0.85rem; color: #999; text-align: center; }
.clinical-note { margin-top: 28px; font-size: 0.78rem; color: #aaa; }

/* ============ 品牌影片(视频)============ */
.video-sec { background: var(--rb-cream); text-align: center; }
.video-wrap { max-width: 820px; margin: 40px auto 0; }
.video-wrap video { width: 100%; border-radius: var(--rb-radius); box-shadow: var(--rb-shadow); background: #000; aspect-ratio: 16/9; object-fit: cover; display: block; }
.video-hint { margin-top: 16px; font-size: 0.85rem; color: #999; }
.video-hint code { background: #fff; padding: 2px 6px; border-radius: 4px; font-size: 0.8em; color: var(--rb-red); }