/* ── Design Tokens ── */
:root {
  --color-bg: #f6f4fa;
  --color-bg-hero: #e8e4f4;
  --color-bg-features: #ffffff;
  --color-bg-alt: #eeebf5;
  --color-surface: #ffffff;
  --color-text: #1e1a2e;
  --color-text-secondary: #5c5670;
  --color-text-muted: #8a8498;
  --color-accent: #676ee5;
  --color-accent-light: #817ef8;
  --color-accent-hover: #5558c8;
  --color-accent-subtle: rgba(103, 110, 229, 0.12);
  --color-accent-glow: rgba(103, 110, 229, 0.28);
  --color-border: rgba(50, 30, 80, 0.08);
  --color-border-strong: rgba(50, 30, 80, 0.14);
  --font-ui: TsangerJinKai02, STKaiti, KaiTi, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  /* 字号阶梯（仓耳今楷视觉偏小，整体略放大） */
  --text-xs: 0.9375rem;   /* 15px */
  --text-sm: 1rem;        /* 16px */
  --text-base: 1.125rem;  /* 18px */
  --text-md: 1.25rem;     /* 20px */
  --text-lg: 1.5rem;      /* 24px */
  --text-xl: 1.875rem;    /* 30px */
  --text-2xl: 2.25rem;    /* 36px */
  --text-3xl: 3rem;       /* 48px */
  --text-hero: clamp(2.75rem, 6vw, 4.25rem);

  --leading-tight: 1.25;
  --leading-snug: 1.45;
  --leading-normal: 1.7;
  --leading-relaxed: 1.85;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --shadow-sm: 0 2px 12px rgba(50, 30, 80, 0.06);
  --shadow-md: 0 8px 32px rgba(50, 30, 80, 0.1);
  --shadow-lg: 0 20px 60px rgba(50, 30, 80, 0.14);
  --header-h: 76px;
  --container: 1320px;
  --transition: 0.2s ease;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  font-family: var(--font-ui);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  letter-spacing: 0.04em;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.font-letter {
  letter-spacing: 0.04em;
  line-height: var(--leading-normal);
}

img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
code {
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
  font-size: 0.875em;
  background: var(--color-accent-subtle);
  padding: 0.15em 0.45em;
  border-radius: 4px;
}

.container {
  width: min(100% - 2rem, var(--container));
  margin-inline: auto;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  z-index: 9999;
  padding: 0.5rem 1rem;
  background: var(--color-accent);
  color: #fff;
  border-radius: var(--radius-sm);
}
.skip-link:focus { top: 1rem; }

/* ── Header ── */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  height: var(--header-h);
  background: rgba(246, 244, 250, 0.82);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), box-shadow var(--transition);
}
.site-header.is-scrolled {
  border-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  gap: 1.5rem;
}

.nav__brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: var(--text-md);
  letter-spacing: 0.06em;
}
.nav__brand img { border-radius: 10px; width: 40px; height: 40px; }

.nav__end {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav__menu {
  display: flex;
  align-items: center;
  gap: 2.25rem;
}
.nav__menu a {
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--color-text-secondary);
  transition: color var(--transition);
}
.nav__menu a:hover,
.nav__menu a:focus-visible { color: var(--color-accent); }

/* ── Nav GitHub Icon ── */
.nav-github {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  color: var(--color-text-secondary);
  transition: color 0.3s ease, transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.nav-github:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

.nav-github__ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 1.5px dashed rgba(103, 110, 229, 0.22);
  animation: nav-github-ring-spin 12s linear infinite;
  transition: border-color 0.3s ease;
}

.nav-github__glow {
  position: absolute;
  inset: -6px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--color-accent-glow) 0%, transparent 68%);
  opacity: 0;
  transform: scale(0.75);
  animation: nav-github-glow-pulse 3.2s ease-in-out infinite;
  pointer-events: none;
}

.nav-github__icon {
  position: relative;
  z-index: 1;
  transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.nav-github:hover,
.nav-github:focus-visible {
  color: var(--color-accent);
  transform: translateY(-2px);
}

.nav-github:hover .nav-github__icon,
.nav-github:focus-visible .nav-github__icon {
  transform: rotate(-15deg) scale(1.14);
}

.nav-github:hover .nav-github__ring,
.nav-github:focus-visible .nav-github__ring {
  border-color: rgba(103, 110, 229, 0.55);
  animation-duration: 2.5s;
}

.nav-github:hover .nav-github__glow,
.nav-github:focus-visible .nav-github__glow {
  animation: nav-github-glow-burst 0.65s ease forwards;
}

@keyframes nav-github-ring-spin {
  to { transform: rotate(360deg); }
}

@keyframes nav-github-glow-pulse {
  0%, 100% { opacity: 0; transform: scale(0.75); }
  50% { opacity: 0.45; transform: scale(1.1); }
}

@keyframes nav-github-glow-burst {
  0% { opacity: 0.7; transform: scale(0.85); }
  100% { opacity: 0; transform: scale(1.65); }
}

@media (prefers-reduced-motion: reduce) {
  .nav-github__ring { animation: none; }
  .nav-github__glow { animation: none; }
  .nav-github:hover .nav-github__glow,
  .nav-github:focus-visible .nav-github__glow { animation: none; opacity: 0.35; }
}

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  background: none;
  border: none;
  cursor: pointer;
}
.nav__toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 1px;
  transition: transform var(--transition), opacity var(--transition);
}
.nav__toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav__toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.9rem 1.75rem;
  font-family: inherit;
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.06em;
  border-radius: 999px;
  border: none;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
}
.btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}
.btn--primary {
  background: linear-gradient(135deg, var(--color-accent-light), var(--color-accent));
  color: #fff;
  box-shadow: 0 4px 20px var(--color-accent-glow);
}
.btn--primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 28px var(--color-accent-glow);
}
.btn--ghost {
  background: transparent;
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border-strong);
}
.btn--ghost:hover {
  background: var(--color-surface);
  color: var(--color-text);
}
.btn--outline {
  background: transparent;
  color: var(--color-accent);
  border: 1.5px solid var(--color-accent);
}
.btn--outline:hover { background: var(--color-accent-subtle); }
.btn--sm { padding: 0.65rem 1.25rem; font-size: var(--text-xs); }

/* ── Hero ── */
.hero {
  position: relative;
  padding: calc(var(--header-h) + 5rem) 0 3.5rem;
  overflow: hidden;
  background: linear-gradient(165deg, #ebe7f6 0%, var(--color-bg-hero) 45%, #e2ddf0 100%);
}

.hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 6rem;
  background: linear-gradient(to bottom, transparent, var(--color-bg-features));
  pointer-events: none;
  z-index: 1;
}

.hero__bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}
.hero__orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.55;
}
.hero__orb--1 {
  width: 520px;
  height: 520px;
  top: -120px;
  right: -80px;
  background: radial-gradient(circle, #c4b8ff 0%, transparent 70%);
}
.hero__orb--2 {
  width: 400px;
  height: 400px;
  bottom: -60px;
  left: -100px;
  background: radial-gradient(circle, #e8d4ff 0%, transparent 70%);
}
.hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(103, 110, 229, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(103, 110, 229, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(to bottom, black 0%, black 55%, transparent 100%);
}

.hero__inner {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
  gap: 3rem;
  align-items: center;
}

.hero__content {
  max-width: 36rem;
}

.hero__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.hero__tag {
  display: inline-block;
  padding: 0.35rem 0.85rem;
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-text-secondary);
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid rgba(103, 110, 229, 0.12);
  border-radius: 999px;
  backdrop-filter: blur(6px);
}

.hero__tag--accent {
  color: var(--color-accent);
  background: var(--color-accent-subtle);
  border-color: rgba(103, 110, 229, 0.2);
}

.hero__title {
  font-family: var(--font-ui);
  font-size: var(--text-hero);
  font-weight: 700;
  line-height: var(--leading-tight);
  letter-spacing: 0.08em;
  margin-bottom: 1.25rem;
}
.hero__title em {
  font-style: normal;
  background: linear-gradient(135deg, var(--color-accent-light), #9d89fc);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero__desc {
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
  color: var(--color-text-secondary);
  max-width: 30rem;
  margin-bottom: 1.75rem;
}

.hero__highlights {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem 1.75rem;
  margin-bottom: 2rem;
}
.hero__highlights li {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--color-text-secondary);
}
.hero__highlights svg {
  flex-shrink: 0;
  color: var(--color-accent);
  opacity: 0.85;
}

.hero__actions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.25rem;
}

.hero__link {
  display: inline-flex;
  align-items: center;
  gap: 0.2rem;
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--color-text-secondary);
  transition: color var(--transition), gap 0.25s ease;
}
.hero__link::after {
  content: "→";
  transition: transform 0.25s ease;
}
.hero__link:hover,
.hero__link:focus-visible {
  color: var(--color-accent);
}
.hero__link:hover::after,
.hero__link:focus-visible::after {
  transform: translateX(3px);
}

/* ── Hero 轮播图 ── */
.hero__preview {
  position: relative;
  width: 100%;
  min-width: 0;
}

.hero-carousel {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.9rem;
}

.hero-carousel__viewport {
  position: relative;
  width: 100%;
  line-height: 0;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  overflow: hidden;
}

.hero-carousel__slide {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  margin: 0;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.5s ease, visibility 0.5s ease;
  pointer-events: none;
}
.hero-carousel__slide.is-active {
  position: relative;
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  z-index: 1;
}

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

.hero-carousel__caption {
  position: absolute;
  right: 1rem;
  top: 1rem;
  left: auto;
  bottom: auto;
  padding: 0.55rem 1.15rem;
  font-size: var(--text-xs);
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: 0.06em;
  color: var(--color-text-secondary);
  background: rgba(232, 228, 244, 0.72);
  background: color-mix(in srgb, var(--color-bg-hero) 72%, transparent);
  border: 1px solid rgba(235, 231, 246, 0.85);
  border: 1px solid color-mix(in srgb, #ebe7f6 80%, transparent);
  border-radius: 999px;
  box-shadow: 0 4px 16px rgba(50, 30, 80, 0.08);
  backdrop-filter: blur(14px) saturate(160%);
  -webkit-backdrop-filter: blur(14px) saturate(160%);
}

.hero-carousel__dots {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.35rem 0.6rem;
}

.hero-carousel__dot {
  width: 0.5rem;
  height: 0.5rem;
  padding: 0;
  border: none;
  border-radius: 50%;
  background: #d5cee8;
  cursor: pointer;
  transition: background 0.2s, transform 0.2s;
}
.hero-carousel__dot.is-active {
  background: var(--color-accent);
  transform: scale(1.15);
}
.hero-carousel__dot:hover {
  background: var(--color-accent-light);
}

.hero-carousel__empty {
  display: grid;
  place-items: center;
  min-height: 12rem;
  padding: 2rem;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  letter-spacing: 0.06em;
}

.section-divider {
  position: relative;
  z-index: 2;
  margin-top: -1rem;
  margin-bottom: 0;
  line-height: 0;
  background: var(--color-bg-hero);
}

.section-divider svg {
  display: block;
  width: 100%;
  height: 3rem;
}

/* ── Sections ── */
.section {
  padding: 6.5rem 0;
}

#features {
  padding-top: 6.5rem;
  background: var(--color-bg-features);
  border-top: 1px solid rgba(103, 110, 229, 0.08);
  box-shadow: 0 -12px 40px rgba(50, 30, 80, 0.04);
}

#features .section__header {
  margin-bottom: 3rem;
}

.section--alt {
  background: var(--color-bg-alt);
}
.section--cta {
  background: linear-gradient(160deg, #eeebf5 0%, #e4dff5 50%, #f6f4fa 100%);
}

.section__header {
  text-align: center;
  max-width: 40rem;
  margin: 0 auto 4rem;
}
.section__eyebrow {
  display: inline-block;
  margin-bottom: 1rem;
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--color-accent);
}
.section__title {
  font-family: var(--font-ui);
  font-size: clamp(var(--text-2xl), 4vw, var(--text-3xl));
  font-weight: 700;
  line-height: var(--leading-tight);
  letter-spacing: 0.1em;
  margin-bottom: 1.25rem;
}
.section__header .section__title::after {
  content: "";
  display: block;
  width: 4rem;
  height: 3px;
  margin: 1.25rem auto 0;
  background: linear-gradient(90deg, transparent, var(--color-accent-light), transparent);
  border-radius: 2px;
  opacity: 0.55;
}

.security__content .section__title,
.download-cta__content .section__title {
  font-size: clamp(var(--text-xl), 3.5vw, var(--text-2xl));
  letter-spacing: 0.08em;
  text-align: left;
}

.download-cta__content .section__title {
  text-align: center;
}
.section__desc {
  font-size: var(--text-md);
  line-height: var(--leading-relaxed);
  color: var(--color-text-secondary);
  letter-spacing: 0.04em;
}

/* ── Features ── */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}

.opensource-cta {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 2.5rem;
}

.feature-card {
  padding: 2rem 1.85rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(103, 110, 229, 0.18);
}
.feature-card__icon {
  display: grid;
  place-items: center;
  width: 56px;
  height: 56px;
  margin-bottom: 1.5rem;
  background: var(--color-accent-subtle);
  color: var(--color-accent);
  border-radius: var(--radius-md);
}
.feature-card h3 {
  font-size: var(--text-lg);
  font-weight: 700;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
}
.feature-card p {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
  letter-spacing: 0.04em;
}
.feature-card--accent {
  border-color: rgba(103, 110, 229, 0.22);
  background: linear-gradient(160deg, #ffffff 0%, #f3f1fc 100%);
}
.feature-card--accent .feature-card__icon {
  background: rgba(103, 110, 229, 0.18);
}

/* ── Products ── */
.products-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.product-card {
  padding: 2.25rem 2rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
}
.product-card__badge {
  display: inline-block;
  margin-bottom: 1.15rem;
  padding: 0.35rem 0.9rem;
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  border-radius: 999px;
}
.product-card--desktop .product-card__badge {
  color: var(--color-accent);
  background: var(--color-accent-subtle);
}
.product-card--extension .product-card__badge {
  color: #2d6a4f;
  background: rgba(45, 106, 79, 0.12);
}
.product-card h3 {
  font-family: var(--font-ui);
  font-size: var(--text-xl);
  font-weight: 700;
  letter-spacing: 0.08em;
  margin-bottom: 0.85rem;
}
.product-card > p {
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  color: var(--color-text-secondary);
  margin-bottom: 1.35rem;
}
.product-card__list {
  margin-bottom: 1.65rem;
}
.product-card__list li {
  position: relative;
  padding-left: 1.35rem;
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  color: var(--color-text-secondary);
  margin-bottom: 0.55rem;
}
.product-card__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 6px;
  height: 6px;
  background: var(--color-accent-light);
  border-radius: 50%;
}
.product-card__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  align-items: center;
}
.product-card__note {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
}

/* ── Security ── */
.security-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
  margin-bottom: 4rem;
}

.security-card {
  padding: 1.5rem 1.35rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.security-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-sm);
  border-color: rgba(103, 110, 229, 0.2);
}
.security-card__icon {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  margin-bottom: 1rem;
  color: var(--color-accent);
  background: var(--color-accent-subtle);
  border-radius: var(--radius-sm);
}
.security-card h3 {
  font-size: var(--text-base);
  font-weight: 700;
  letter-spacing: 0.06em;
  margin-bottom: 0.55rem;
}
.security-card p {
  font-size: var(--text-xs);
  line-height: var(--leading-relaxed);
  color: var(--color-text-secondary);
  letter-spacing: 0.03em;
}

.security-flow {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3rem;
  align-items: start;
  padding: 2.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
}
.security-flow__title {
  font-size: var(--text-xl);
  font-weight: 700;
  letter-spacing: 0.08em;
  margin-bottom: 1.5rem;
}

.security {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}
.security__steps {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}
.security__steps li {
  display: flex;
  gap: 1.25rem;
  align-items: flex-start;
}
.security__step-num {
  flex-shrink: 0;
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--color-accent);
  background: var(--color-accent-subtle);
  padding: 0.4rem 0.7rem;
  border-radius: var(--radius-sm);
}
.security__steps strong {
  display: block;
  font-size: var(--text-md);
  font-weight: 700;
  letter-spacing: 0.06em;
  margin-bottom: 0.35rem;
}
.security__steps p {
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  color: var(--color-text-secondary);
}

.security-diagram {
  position: relative;
  padding: 2.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
}
.security-diagram__node {
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-md);
  text-align: center;
}
.security-diagram__node span {
  display: block;
  font-weight: 700;
  font-size: var(--text-md);
  letter-spacing: 0.06em;
}
.security-diagram__node small {
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
}
.security-diagram__node--client {
  background: var(--color-accent-subtle);
  border: 1px solid rgba(103, 110, 229, 0.2);
  margin-bottom: 1rem;
}
.security-diagram__node--server {
  background: #f0edf5;
  border: 1px solid var(--color-border);
}
.security-diagram__arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem;
  margin-bottom: 1rem;
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-accent);
}
.security-diagram__arrow::before,
.security-diagram__arrow::after {
  content: "";
  flex: 1;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-accent-light), transparent);
}
.security-diagram__arrow span { padding: 0 0.75rem; }
.security-diagram__bridge {
  margin-top: 1.25rem;
  padding: 0.85rem 1rem;
  text-align: center;
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.06em;
  color: #2d6a4f;
  background: rgba(45, 106, 79, 0.1);
  border: 1px dashed rgba(45, 106, 79, 0.28);
  border-radius: var(--radius-md);
}
.security-diagram__bridge span {
  display: block;
  font-weight: 700;
  font-size: var(--text-sm);
  margin-bottom: 0.2rem;
}
.security-diagram__bridge small {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
}
.security-diagram__shield {
  position: absolute;
  top: 50%;
  right: -20px;
  transform: translateY(-50%);
  color: var(--color-accent);
  background: var(--color-surface);
  border-radius: 50%;
  padding: 0.5rem;
  box-shadow: var(--shadow-sm);
}

/* ── Download CTA ── */
.download-cta {
  text-align: center;
}
.download-cta__content {
  max-width: 36rem;
  margin: 0 auto 3rem;
}
.download-cta__cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  max-width: 1100px;
  margin: 0 auto 1.75rem;
}
.download-card {
  display: flex;
  align-items: center;
  gap: 1.15rem;
  padding: 1.75rem 1.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  text-align: left;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.download-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-accent-light);
}
.download-card svg:first-child { color: var(--color-text); flex-shrink: 0; }
.download-card strong {
  display: block;
  font-size: var(--text-md);
  font-weight: 700;
  letter-spacing: 0.06em;
}
.download-card span {
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
}
.download-card__arrow {
  margin-left: auto;
  color: var(--color-accent);
  flex-shrink: 0;
  transition: transform var(--transition);
}
.download-card:hover .download-card__arrow { transform: translateY(3px); }
.download-cta__hint {
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
}

.download-card--extension svg:first-child {
  color: var(--color-accent);
}

.extension-install {
  max-width: 42rem;
  margin: 0 auto 1.75rem;
  padding: 1.75rem 1.85rem;
  text-align: left;
  background: var(--color-surface);
  border: 1px solid rgba(103, 110, 229, 0.16);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.extension-install__header h3 {
  font-size: var(--text-lg);
  font-weight: 700;
  letter-spacing: 0.06em;
  margin-bottom: 0.5rem;
}

.extension-install__header p {
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  color: var(--color-text-secondary);
}

.extension-install__steps {
  margin: 1.25rem 0 1.5rem;
  padding-left: 1.35rem;
  list-style: decimal;
}

.extension-install__steps li {
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  color: var(--color-text-secondary);
  margin-bottom: 0.65rem;
  padding-left: 0.35rem;
}

.extension-install__steps strong {
  color: var(--color-text);
  font-weight: 700;
}

.extension-install__version {
  margin-top: 0.85rem;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
}

/* ── Footer ── */
.site-footer {
  padding: 3.5rem 0;
  background: var(--color-text);
  color: rgba(255, 255, 255, 0.75);
}
.site-footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  text-align: center;
}
.site-footer__brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}
.site-footer__brand img {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: block;
  flex-shrink: 0;
}
.site-footer__brand > div {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 0.25rem;
  text-align: left;
}
.site-footer__brand strong {
  display: block;
  color: #fff;
  font-size: var(--text-md);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.06em;
}
.site-footer__brand span {
  font-size: var(--text-xs);
  line-height: 1.4;
  letter-spacing: 0.04em;
}
.site-footer__links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1.75rem;
}
.site-footer__links a {
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  transition: color var(--transition);
}
.site-footer__links a:hover { color: #fff; }
.site-footer__copy {
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
}
.site-footer__copy a {
  color: var(--color-accent-light);
  transition: color var(--transition);
}
.site-footer__copy a:hover { color: #fff; }

/* ── Scroll Reveal Animation ── */
.reveal {
  opacity: 0;
  transform: translate3d(0, 36px, 0);
  transition:
    opacity 0.8s cubic-bezier(0.22, 1, 0.36, 1),
    transform 0.8s cubic-bezier(0.22, 1, 0.36, 1);
  transition-delay: var(--reveal-delay, 0ms);
  will-change: opacity, transform;
}
.reveal--left {
  transform: translate3d(-48px, 0, 0);
}
.reveal--right {
  transform: translate3d(48px, 0, 0);
}
.reveal--scale {
  transform: translate3d(0, 28px, 0) scale(0.96);
}
.reveal.is-visible {
  opacity: 1;
  transform: translate3d(0, 0, 0) scale(1);
}

/* ── Hero 首屏入场 ── */
.hero-entrance {
  opacity: 0;
  transform: translate3d(0, 28px, 0);
  animation: heroEnter 0.9s cubic-bezier(0.22, 1, 0.36, 1) forwards;
  animation-delay: var(--hero-delay, 0ms);
}
.hero-entrance--float {
  transform: translate3d(0, 28px, 0) scale(0.98);
  animation-name: heroEnterFloat;
}
@keyframes heroEnter {
  to {
    opacity: 1;
    transform: translate3d(0, 0, 0);
  }
}
@keyframes heroEnterFloat {
  to {
    opacity: 1;
    transform: translate3d(0, 0, 0) scale(1);
  }
}

@media (prefers-reduced-motion: reduce) {
  .reveal,
  .hero-entrance {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
    animation: none !important;
  }
}

/* ── Responsive ── */
@media (max-width: 1100px) {
  .security-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 960px) {
  .hero__inner,
  .security-flow,
  .features-grid,
  .products-grid,
  .security-grid {
    grid-template-columns: 1fr;
  }
  .security-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero__preview { max-width: 100%; width: 100%; margin: 0 auto; }
  .security-diagram__shield { display: none; }
  .download-cta__cards { grid-template-columns: 1fr; max-width: 680px; }
}

@media (max-width: 960px) and (min-width: 641px) {
  .download-cta__cards {
    grid-template-columns: repeat(2, 1fr);
    max-width: 680px;
  }
  .download-card--extension {
    grid-column: 1 / -1;
    max-width: 20rem;
    margin: 0 auto;
    width: 100%;
  }
}

@media (max-width: 768px) {
  :root {
    --text-hero: clamp(2.25rem, 9vw, 3rem);
    --text-base: 1.0625rem;
    --text-md: 1.125rem;
  }

  .hero { padding-top: calc(var(--header-h) + 3rem); }
  .hero__highlights { gap: 0.85rem 1.25rem; }
  .section__title { letter-spacing: 0.06em; }

  .nav__toggle { display: flex; }
  .nav__end { gap: 0.25rem; }
  .nav__menu {
    position: fixed;
    inset: var(--header-h) 0 auto;
    flex-direction: column;
    gap: 0;
    padding: 1rem;
    background: rgba(246, 244, 250, 0.98);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition), opacity var(--transition);
  }
  .nav__menu.is-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .nav__menu a {
    display: block;
    padding: 0.85rem 0;
    border-bottom: 1px solid var(--color-border);
    width: 100%;
    text-align: center;
  }
  .nav__menu a:last-child { border-bottom: none; }
  .features-grid { grid-template-columns: 1fr; }
  .security-grid { grid-template-columns: 1fr; }
  .security-flow { padding: 1.5rem; }
  .hero { padding-bottom: 2.5rem; }
  .section-divider { margin-top: -0.5rem; margin-bottom: 0; }
  .section-divider svg { height: 2rem; }
  #features { padding-top: 4rem; }
  .section { padding: 4rem 0; }
}