/* ============================================================
   tech-upgrade.css  —  Impeccable refinement layer for the
   walkie-talkie landing page. Linked AFTER tech.css so it
   overrides the shared design system without touching the
   legacy ASP pages. ASCII-only comments (page is GBK).
   ============================================================ */

/* ---------- 1. Fluid typography & rhythm ---------- */
:root {
  --u-display: "SF Pro Display", "PingFang SC", "Microsoft YaHei", -apple-system, system-ui, sans-serif;
  --sp-section: clamp(64px, 7vw, 112px);
  --sp-section-head: clamp(36px, 4.5vw, 56px);
  --ease-out: cubic-bezier(.2, .7, .2, 1);
}

body { letter-spacing: 0.01em; }

/* Headings get a tighter, more confident rhythm */
.section-head { margin-bottom: var(--sp-section-head); }
.section-head h2 {
  font-size: clamp(1.7rem, 1.05rem + 2.4vw, 2.6rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
}
.section-head p {
  font-size: clamp(0.95rem, 0.9rem + 0.3vw, 1.05rem);
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}
.section-tag {
  font-size: 12.5px;
  letter-spacing: 0.08em;
  padding: 7px 18px 7px 14px;
}

/* Section vertical breathing room */
.section { padding: var(--sp-section) 0; }
.section-head[style*="margin-top"] { margin-top: clamp(48px, 6vw, 72px) !important; }

/* ---------- 2. Hero: keep tech feel, tame the neon ---------- */
.hero h1 {
  font-size: clamp(2.25rem, 1.3rem + 3.6vw, 3.4rem);
  line-height: 1.12;
  letter-spacing: -0.025em;
}
.hero h1 .hl { letter-spacing: -0.02em; }

.hero-desc {
  font-size: clamp(0.95rem, 0.88rem + 0.45vw, 1.1rem);
  line-height: 1.75;
  opacity: 0.92;
  max-width: 540px;
}

/* Soften the glowing orbs so the hero reads as "premium" not "gamer" */
.hero-orb.o1 {
  background: radial-gradient(circle, rgba(0, 102, 255, 0.18), transparent 70%);
  filter: blur(90px);
}
.hero-orb.o2 {
  background: radial-gradient(circle, rgba(0, 212, 255, 0.12), transparent 70%);
  filter: blur(100px);
}
.hero-device-glow { opacity: 0.45; }

/* Subtle bottom vignette so the CTA area stays legible */
.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 220px;
  background: linear-gradient(180deg, transparent, rgba(6, 12, 26, 0.55));
  z-index: 1;
  pointer-events: none;
}

.hero-stat .n { font-size: clamp(1.6rem, 1.2rem + 1.4vw, 2rem); letter-spacing: -0.02em; }
.hero-stat .l { letter-spacing: 0.02em; }

/* ---------- 3. Elevated cards ---------- */
.cat-card,
.product-card,
.adv-card,
.card-dark,
.solution-card,
.grid-4 .card {
  transition: transform .35s var(--ease-out),
              box-shadow .35s var(--ease-out),
              border-color .35s var(--ease-out);
  will-change: transform;
}
.cat-card:hover,
.product-card:hover,
.adv-card:hover,
.card-dark:hover,
.solution-card:hover,
.grid-4 .card:hover {
  transform: translateY(-6px);
  box-shadow: 0 24px 50px rgba(11, 17, 32, 0.12);
  border-color: rgba(0, 102, 255, 0.35);
}

/* Product / category image zoom already exists — make it smoother */
.product-img-wrap,
.cat-img { overflow: hidden; }
.product-card .product-img-wrap img,
.cat-card .cat-img {
  transition: transform .6s var(--ease-out);
}
.product-card:hover .product-img-wrap img,
.cat-card:hover .cat-img { transform: scale(1.07); }

/* Solution cards: keep the overlay, lift the whole tile */
.solution-card { border-radius: var(--r-lg); overflow: hidden; }
.solution-card:hover .sc-overlay { background: linear-gradient(180deg, rgba(6,12,26,0.1), rgba(6,12,26,0.78)); }
.solution-card .sc-content { transition: transform .35s var(--ease-out); }
.solution-card:hover .sc-content { transform: translateY(-4px); }

/* Advantage cards: tidy list spacing + hover accent */
.adv-card { border-radius: var(--r-lg); }
.adv-card ul { padding-left: 2px; }
.adv-card li { position: relative; padding-left: 16px; color: var(--t-muted); }
.adv-card li::before {
  content: "";
  position: absolute; left: 0; top: 12px;
  width: 5px; height: 5px; border-radius: 50%;
  background: var(--c-primary);
}
.adv-card:hover .adv-icon { transform: scale(1.08); }
.adv-icon { transition: transform .35s var(--ease-out); }

/* ---------- 4. Buttons & links ---------- */
.btn { letter-spacing: 0.01em; }
.btn-primary {
  background: var(--g-brand);
  box-shadow: 0 6px 22px rgba(0, 102, 255, 0.32);
}
.btn-primary:hover { box-shadow: 0 12px 34px rgba(0, 102, 255, 0.42); }
.btn-outline { font-weight: 600; }

/* Accessibility: visible, consistent focus ring everywhere */
a:focus-visible,
button:focus-visible,
.btn:focus-visible,
.mbn-item:focus-visible {
  outline: 2px solid var(--c-primary);
  outline-offset: 3px;
  border-radius: 4px;
}

/* Card "read more" link underline sweep */
.card-link {
  position: relative;
  font-weight: 600;
  color: var(--c-primary);
}
.card-link::after {
  content: "";
  position: absolute; left: 0; bottom: -2px;
  width: 100%; height: 1.5px;
  background: var(--c-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .3s var(--ease-out);
}
.card-link:hover::after { transform: scaleX(1); }

/* ---------- 5. Header polish ---------- */
.site-header.scrolled {
  border-bottom: 1px solid rgba(11, 17, 32, 0.06);
}
.site-header.on-hero .main-nav > ul > li > a {
  text-shadow: 0 1px 12px rgba(0, 0, 0, 0.25);
}

/* ---------- 6. Mobile bottom nav ---------- */
.mobile-bottom-nav .mbn-track {
  padding-bottom: var(--mobile-safe-bottom);
}
.mbn-item.active { color: var(--c-primary); }
.mbn-item.active .mbn-icon { color: var(--c-primary); }
.mbn-cta {
  background: var(--g-brand);
  box-shadow: 0 6px 18px rgba(0, 102, 255, 0.4);
}

/* ---------- 7. Scroll reveal (no markup edits; JS adds .reveal) ---------- */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity .7s var(--ease-out), transform .7s var(--ease-out);
}
.reveal.is-visible { opacity: 1; transform: none; }

/* ---------- 8. Responsive typography keeps scaling down ---------- */
@media (max-width: 1024px) {
  .hero h1 { font-size: clamp(2rem, 1.2rem + 3vw, 2.8rem); }
}
@media (max-width: 640px) {
  .hero h1 { font-size: 1.85rem; letter-spacing: -0.02em; }
  .section-head h2 { font-size: 1.55rem; }
  .hero-stats { gap: 24px; }
}
@media (max-width: 380px) {
  .hero h1 { font-size: 1.6rem; }
}

/* ---------- 9. Respect reduced-motion ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
  .hero-orb, .hero-device-glow { animation: none; }
}