/* 星澜宸海科技 — 品牌站样式 PRD v1.1 */
:root {
  --bg-deep: #0a1628;
  --bg-elevated: rgba(15, 28, 52, 0.72);
  --brand: #4a3aff;
  --accent: #00f5ff;
  --text: #ffffff;
  --text-muted: #e0e0e0;
  --text-dim: #9ca3af;
  --border-glass: rgba(255, 255, 255, 0.12);
  --shadow-glow: 0 0 40px rgba(74, 58, 255, 0.25);
  --radius-lg: 20px;
  --radius-md: 14px;
  --space-section: clamp(4rem, 8vw, 7.5rem);
  --font-sans: "Inter", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --header-h: 72px;
  --grad-brand: linear-gradient(135deg, #4a3aff 0%, #00f5ff 100%);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .reveal {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
  .hero__mesh {
    animation: none !important;
  }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.65;
  color: var(--text-muted);
  background: var(--bg-deep);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
}

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

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

.skip-link:focus {
  left: 16px;
  top: 16px;
  width: auto;
  height: auto;
  padding: 10px 16px;
  background: var(--brand);
  color: #fff;
  z-index: 10000;
  border-radius: 8px;
}

.container {
  width: min(1120px, 100% - 32px);
  margin-inline: auto;
}

/* Header */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 1000;
  height: var(--header-h);
  display: flex;
  align-items: center;
  background: rgba(10, 22, 40, 0.75);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-glass);
  transition: box-shadow 0.3s ease;
}

.site-header.is-scrolled {
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
}

.site-header__inner {
  width: min(1120px, 100% - 32px);
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
}

.logo__mark {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.logo__mark svg {
  display: block;
  width: 100%;
  height: 100%;
  border-radius: 12px;
}

.logo__text small {
  display: none;
}

.site-header .logo__text small {
  display: inline;
  font-size: 18px;
  font-weight: 700;
  background: linear-gradient(90deg, #00f5ff, #a78bfa, #00f5ff);
  background-size: 200% auto;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  border-left: 1px solid rgba(0, 245, 255, 0.3);
  padding-left: 12px;
  margin-left: 10px;
  letter-spacing: 0.08em;
  animation: nav-sub-shine 3s linear infinite;
}

.site-header .logo__text small:empty {
  display: none;
}

@keyframes nav-sub-shine {
  0%   { background-position: 0% center; }
  100% { background-position: 200% center; }
}

.site-footer .logo__text small {
  display: block;
  font-size: 11px;
  font-weight: 500;
  color: var(--text-dim);
  letter-spacing: 0.04em;
  margin-top: 2px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 4px;
}

@media (max-width: 900px) {
  .nav__links {
    position: fixed;
    inset: var(--header-h) 0 0 0;
    flex-direction: column;
    align-items: stretch;
    padding: 24px;
    gap: 0;
    background: rgba(10, 22, 40, 0.96);
    border-bottom: 1px solid var(--border-glass);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.25s ease;
  }

  .nav__links.is-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav__links .nav__cta {
    margin-top: 16px;
    margin-left: 0;
    padding-top: 8px;
    border-top: 1px solid var(--border-glass);
  }

  .nav__links .nav__cta .btn {
    width: 100%;
  }

  .nav__links a {
    padding: 14px 12px;
    border-radius: 10px;
  }
}

@media (min-width: 901px) {
  .nav__toggle {
    display: none;
  }
}

.nav__links a {
  padding: 8px 14px;
  border-radius: 10px;
  font-size: 15px;
  color: var(--text-dim);
  transition: color 0.2s, background 0.2s;
}

.nav__links a:hover,
.nav__links a[aria-current="page"] {
  color: var(--text);
  background: rgba(255, 255, 255, 0.06);
}

.nav__cta {
  margin-left: 8px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 15px;
  border: none;
  cursor: pointer;
  transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.25s, background 0.25s;
}

.btn:active {
  transform: scale(0.98);
}

.btn--primary {
  background: var(--grad-brand);
  color: #0a1628;
  box-shadow: 0 8px 28px rgba(74, 58, 255, 0.35);
}

.btn--primary:hover {
  box-shadow: 0 12px 36px rgba(0, 245, 255, 0.25), var(--shadow-glow);
  transform: translateY(-2px);
}

.btn--ghost {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text);
  border: 1px solid var(--border-glass);
}

.btn--ghost:hover {
  border-color: rgba(0, 245, 255, 0.45);
  color: var(--accent);
}

.nav__toggle {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  border: 1px solid var(--border-glass);
  background: rgba(255, 255, 255, 0.05);
  color: var(--text);
  cursor: pointer;
  display: grid;
  place-items: center;
}

.nav__toggle-icon {
  width: 20px;
  height: 14px;
  position: relative;
}

.nav__toggle-icon span {
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.25s, top 0.25s, opacity 0.2s;
}

.nav__toggle-icon span:nth-child(1) {
  top: 0;
}

.nav__toggle-icon span:nth-child(2) {
  top: 6px;
}

.nav__toggle-icon span:nth-child(3) {
  top: 12px;
}

.nav__toggle[aria-expanded="true"] .nav__toggle-icon span:nth-child(1) {
  top: 6px;
  transform: rotate(45deg);
}

.nav__toggle[aria-expanded="true"] .nav__toggle-icon span:nth-child(2) {
  opacity: 0;
}

.nav__toggle[aria-expanded="true"] .nav__toggle-icon span:nth-child(3) {
  top: 6px;
  transform: rotate(-45deg);
}

/* Main offset for fixed header */
main {
  padding-top: var(--header-h);
}

/* Hero */
.hero {
  position: relative;
  min-height: calc(100vh - var(--header-h));
  display: flex;
  align-items: center;
  padding-block: clamp(3rem, 10vw, 6rem);
  overflow: hidden;
}

.hero__mesh {
  position: absolute;
  inset: -20%;
  background:
    radial-gradient(ellipse 80% 50% at 20% 40%, rgba(74, 58, 255, 0.45), transparent 55%),
    radial-gradient(ellipse 60% 40% at 80% 20%, rgba(0, 245, 255, 0.2), transparent 50%),
    radial-gradient(ellipse 50% 60% at 60% 90%, rgba(74, 58, 255, 0.25), transparent 45%);
  animation: mesh-move 12s ease-in-out infinite alternate;
  pointer-events: none;
}

@media (prefers-reduced-motion: reduce) {
  .hero__mesh {
    animation: none;
  }
}

@keyframes mesh-move {
  0% {
    transform: translate(0, 0) scale(1);
  }
  100% {
    transform: translate(-3%, 2%) scale(1.05);
  }
}

.hero__grid {
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, black 20%, transparent 70%);
  pointer-events: none;
}

.hero__particles {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.35;
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: 720px;
}

.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 999px;
  border: 1px solid var(--border-glass);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-dim);
  font-size: 13px;
  margin-bottom: 1.25rem;
}

.hero__eyebrow::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 12px var(--accent);
}

.hero h1 {
  margin: 0 0 1.25rem;
  font-size: clamp(2.5rem, 6vw, 4.25rem);
  line-height: 1.08;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text);
}

.text-gradient {
  background: var(--grad-brand);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero__lead {
  margin: 0 0 2rem;
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: var(--text-muted);
  max-width: 540px;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* Sections */
.section {
  padding-block: var(--space-section);
}

.section__head {
  max-width: 640px;
  margin-bottom: clamp(2rem, 5vw, 3rem);
}

.section__head h2 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.75rem, 3.5vw, 2.5rem);
  color: var(--text);
  letter-spacing: -0.02em;
}

.section__head p {
  margin: 0;
  color: var(--text-dim);
}

.section__label {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}

/* Trust strip */
.trust-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
}

.trust-strip__item {
  padding: 16px 18px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-glass);
  background: rgba(255, 255, 255, 0.03);
  font-size: 14px;
  color: var(--text-muted);
}

.trust-strip__item strong {
  display: block;
  color: var(--text);
  font-size: 15px;
  margin-bottom: 4px;
}

/* Glass cards & Bento */
.glass {
  background: var(--bg-elevated);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-glass);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 3vw, 28px);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), border-color 0.3s, box-shadow 0.3s;
}

.glass:hover {
  transform: translateY(-4px);
  border-color: rgba(0, 245, 255, 0.35);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.35);
}

.bento {
  display: grid;
  gap: 16px;
}

@media (min-width: 640px) {
  .bento--founder {
    grid-template-columns: repeat(2, 1fr);
  }

  .bento--founder .bento__item--wide {
    grid-column: span 2;
  }
}

@media (min-width: 900px) {
  .bento--founder {
    grid-template-columns: repeat(4, 1fr);
  }

  .bento--founder .bento__item--wide {
    grid-column: span 2;
  }

  .bento--biz {
    grid-template-columns: 1fr 1.15fr 1fr;
    align-items: stretch;
  }

  .bento--biz .bento__item--focus {
    transform: scale(1.02);
    z-index: 1;
  }
}

@media (max-width: 899px) {
  .bento--biz .bento__item--focus {
    transform: none;
  }
}

.bento__icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: rgba(74, 58, 255, 0.25);
  color: var(--accent);
  font-size: 20px;
  margin-bottom: 14px;
}

.bento h3 {
  margin: 0 0 8px;
  font-size: 1.1rem;
  color: var(--text);
}

.bento p {
  margin: 0;
  font-size: 15px;
  color: var(--text-dim);
}

.tag {
  display: inline-block;
  margin-top: 12px;
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(0, 245, 255, 0.1);
  color: var(--accent);
}

/* Tech pipeline */
.pipeline {
  display: grid;
  gap: 20px;
}

@media (min-width: 768px) {
  .pipeline {
    grid-template-columns: 1.2fr 1fr;
    align-items: start;
  }
}

.pipeline__flow {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.flow-step {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-glass);
  background: rgba(255, 255, 255, 0.03);
}

.flow-step__num {
  flex-shrink: 0;
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: var(--grad-brand);
  color: #0a1628;
  font-weight: 800;
  font-size: 13px;
  display: grid;
  place-items: center;
}

.flow-step h4 {
  margin: 0 0 4px;
  font-size: 15px;
  color: var(--text);
}

.flow-step p {
  margin: 0;
  font-size: 14px;
  color: var(--text-dim);
}

.checklist {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.checklist li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  font-size: 15px;
  color: var(--text-muted);
}

.checklist li::before {
  content: "✓";
  color: var(--accent);
  font-weight: 700;
  flex-shrink: 0;
}

/* Business model grid */
.quad-grid {
  display: grid;
  gap: 16px;
}

@media (min-width: 640px) {
  .quad-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.quad-card {
  padding: 24px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-glass);
  background: rgba(255, 255, 255, 0.03);
  transition: border-color 0.25s, transform 0.25s;
}

.quad-card:hover {
  border-color: rgba(74, 58, 255, 0.5);
  transform: translateY(-3px);
}

.quad-card h3 {
  margin: 0 0 10px;
  font-size: 1.05rem;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 10px;
}

.quad-card h3 span {
  width: 26px;
  height: 26px;
  border-radius: 8px;
  background: rgba(74, 58, 255, 0.35);
  color: var(--accent);
  font-size: 13px;
  font-weight: 800;
  display: grid;
  place-items: center;
}

/* Timeline */
.timeline {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 0;
}

@media (min-width: 900px) {
  .timeline {
    flex-direction: row;
    justify-content: space-between;
    gap: 24px;
  }

  .timeline::before {
    content: "";
    position: absolute;
    top: 22px;
    left: 8%;
    right: 8%;
    height: 2px;
    background: linear-gradient(90deg, rgba(74, 58, 255, 0.3), rgba(0, 245, 255, 0.5), rgba(74, 58, 255, 0.3));
    z-index: 0;
  }
}

.timeline__phase {
  flex: 1;
  position: relative;
  z-index: 1;
  padding: 20px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-glass);
  background: rgba(255, 255, 255, 0.03);
  margin-bottom: 12px;
}

@media (min-width: 900px) {
  .timeline__phase {
    margin-bottom: 0;
    padding-top: 56px;
  }
}

.timeline__dot {
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--bg-deep);
  border: 2px solid var(--text-dim);
  margin-bottom: 12px;
}

.timeline__phase.is-active .timeline__dot {
  border-color: var(--accent);
  background: var(--accent);
  box-shadow: 0 0 16px var(--accent);
}

.timeline__year {
  font-size: 13px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 0.06em;
  margin-bottom: 6px;
}

.timeline__phase h3 {
  margin: 0 0 10px;
  color: var(--text);
  font-size: 1.1rem;
}

.timeline__phase ul {
  margin: 0;
  padding-left: 1.1rem;
  color: var(--text-dim);
  font-size: 14px;
}

/* CTA band */
.cta-band {
  padding: clamp(2.5rem, 6vw, 4rem);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-glass);
  background: linear-gradient(135deg, rgba(74, 58, 255, 0.2), rgba(0, 245, 255, 0.08));
  text-align: center;
}

.cta-band h2 {
  margin: 0 0 12px;
  color: var(--text);
  font-size: clamp(1.5rem, 3vw, 2rem);
}

.cta-band p {
  margin: 0 0 1.5rem;
  color: var(--text-dim);
}

/* Footer */
.site-footer {
  padding: 48px 0 32px;
  border-top: 1px solid var(--border-glass);
  background: rgba(5, 12, 24, 0.9);
}

.site-footer__grid {
  display: grid;
  gap: 32px;
}

@media (min-width: 768px) {
  .site-footer__grid {
    grid-template-columns: 1.2fr 1fr 1fr;
  }
}

.site-footer h4 {
  margin: 0 0 14px;
  color: var(--text);
  font-size: 14px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.site-footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.site-footer li {
  margin-bottom: 10px;
  font-size: 14px;
  color: var(--text-dim);
}

.site-footer a:hover {
  color: var(--accent);
}

.footer__legal {
  margin-top: 40px;
  padding-top: 24px;
  border-top: 1px solid var(--border-glass);
  font-size: 13px;
  color: var(--text-dim);
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  justify-content: space-between;
}

/* Prose (inner pages) */
.prose {
  max-width: 720px;
}

.prose h1 {
  font-size: clamp(2rem, 4vw, 2.75rem);
  color: var(--text);
  margin: 0 0 1rem;
  letter-spacing: -0.02em;
}

.prose h2 {
  margin: 2.5rem 0 1rem;
  font-size: 1.35rem;
  color: var(--text);
}

.prose p,
.prose li {
  color: var(--text-muted);
}

.prose ul {
  padding-left: 1.2rem;
}

.page-hero {
  padding: clamp(2rem, 5vw, 3.5rem) 0;
  border-bottom: 1px solid var(--border-glass);
}

.page-hero p {
  margin: 0;
  max-width: 640px;
  color: var(--text-dim);
  font-size: 1.05rem;
}

/* Form */
.form-grid {
  display: grid;
  gap: 16px;
}

@media (min-width: 640px) {
  .form-grid--2 {
    grid-template-columns: 1fr 1fr;
  }
}

.field label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-dim);
  margin-bottom: 6px;
}

.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid var(--border-glass);
  background: rgba(255, 255, 255, 0.05);
  color: var(--text);
  font: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: none;
  border-color: rgba(0, 245, 255, 0.55);
  box-shadow: 0 0 0 3px rgba(0, 245, 255, 0.1);
}

.field input::placeholder,
.field textarea::placeholder {
  color: #6b7280;
}

.field select {
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%239ca3af' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  background-size: 16px;
  padding-right: 40px;
  cursor: pointer;
}

.field select option {
  background: #0f1c34;
  color: var(--text);
}

.field textarea {
  min-height: 120px;
  resize: vertical;
}

.honeypot {
  position: absolute;
  left: -9999px;
  height: 0;
  overflow: hidden;
}

.form-msg {
  margin-top: 16px;
  padding: 14px 16px;
  border-radius: 12px;
  font-size: 14px;
  display: none;
}

.form-msg.is-visible {
  display: block;
}

.form-msg--success {
  background: rgba(0, 245, 255, 0.12);
  border: 1px solid rgba(0, 245, 255, 0.35);
  color: var(--text-muted);
}

.form-msg--error {
  background: rgba(239, 68, 68, 0.12);
  border: 1px solid rgba(239, 68, 68, 0.35);
}

.contact-layout {
  display: grid;
  gap: 32px;
}

@media (min-width: 900px) {
  .contact-layout {
    grid-template-columns: 1fr 1.1fr;
    align-items: start;
  }
}

.map-embed {
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-glass);
  min-height: 280px;
  background: rgba(255, 255, 255, 0.03);
}

.map-embed iframe {
  width: 100%;
  height: 280px;
  border: 0;
}

.map-fallback {
  padding: 24px;
  text-align: center;
  color: var(--text-dim);
}

.map-fallback a {
  color: var(--accent);
  text-decoration: underline;
}

/* Reveal on scroll */
.reveal {
  opacity: 0;
  transform: translateY(36px);
  transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Cursor glow (desktop) */
.cursor-glow {
  position: fixed;
  width: 420px;
  height: 420px;
  border-radius: 50%;
  pointer-events: none;
  z-index: 999;
  background: radial-gradient(circle, rgba(0, 245, 255, 0.12) 0%, transparent 70%);
  transform: translate(-50%, -50%);
  opacity: 0;
  transition: opacity 0.3s;
  mix-blend-mode: screen;
}

body.has-cursor-glow .cursor-glow {
  opacity: 1;
}

/* Utility */
.mt-0 {
  margin-top: 0;
}

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

.mx-auto {
  margin-inline: auto;
}

.mb-lg {
  margin-bottom: var(--space-section);
}

/* ── 语言切换器 ── */
.lang-switcher {
  display: flex;
  align-items: center;
  gap: 3px;
  margin-left: 8px;
}

.lang-btn {
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--border-glass);
  background: transparent;
  color: var(--text-dim);
  font: 500 12px/1 var(--font-sans);
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
}

.lang-btn:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.06);
}

.lang-btn.is-active {
  background: rgba(0, 245, 255, 0.12);
  border-color: rgba(0, 245, 255, 0.45);
  color: var(--accent);
}

@media (max-width: 900px) {
  .lang-switcher {
    margin: 16px 0 0;
    padding-top: 12px;
    border-top: 1px solid var(--border-glass);
    justify-content: center;
    gap: 8px;
  }
  .lang-btn {
    padding: 7px 16px;
    font-size: 13px;
  }
}

/* ── Logo 光晕脉冲 ── */
@media (prefers-reduced-motion: no-preference) {
  .logo__mark svg {
    animation: logo-glow 3s ease-in-out infinite;
  }
}

@keyframes logo-glow {
  0%, 100% { filter: drop-shadow(0 0 4px rgba(0, 245, 255, 0.3)); }
  50% { filter: drop-shadow(0 0 14px rgba(0, 245, 255, 0.9)) drop-shadow(0 0 28px rgba(74, 58, 255, 0.5)); }
}

/* ── Hero 标题故障闪烁 ── */
@media (prefers-reduced-motion: no-preference) {
  .hero h1 {
    animation: hero-glitch 10s ease-in-out infinite;
  }
}

@keyframes hero-glitch {
  0%, 88%, 100% { transform: none; filter: none; }
  89% { transform: skewX(-1.5deg) translateX(-3px); filter: hue-rotate(40deg) brightness(1.2); }
  90% { transform: skewX(1deg) translateX(3px); filter: hue-rotate(-40deg); }
  91% { transform: translateX(-1px); filter: none; }
  92% { transform: none; }
}

/* ── Hero 扫描线 ── */
@media (prefers-reduced-motion: no-preference) {
  .hero::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 0;
    height: 80px;
    background: linear-gradient(180deg, transparent 0%, rgba(0, 245, 255, 0.05) 50%, transparent 100%);
    animation: scan-line 10s ease-in-out infinite 1.5s;
    pointer-events: none;
    z-index: 0;
  }
}

@keyframes scan-line {
  0% { transform: translateY(-100px); opacity: 0; }
  5% { opacity: 1; }
  90% { opacity: 0.5; }
  100% { transform: translateY(110vh); opacity: 0; }
}

/* ── 按钮点击涟漪 ── */
.btn {
  position: relative;
  overflow: hidden;
}

.btn-ripple {
  position: absolute;
  width: 8px;
  height: 8px;
  background: rgba(255, 255, 255, 0.4);
  border-radius: 50%;
  transform: translate(-50%, -50%) scale(0);
  animation: btn-ripple 0.55s ease-out forwards;
  pointer-events: none;
}

@keyframes btn-ripple {
  to { transform: translate(-50%, -50%) scale(50); opacity: 0; }
}

/* ── 语言切换淡入淡出 ── */
body.lang-fading [data-i18n],
body.lang-fading [data-i18n-html] {
  opacity: 0;
  transition: opacity 0.15s ease;
}