:root {
  --ink: #0b0f0d;
  --ink-2: #121815;
  --ink-3: #1a211c;
  --fog: #9aa89c;
  --paper: #e8efe6;
  --paper-dim: #c5d0c3;
  --mark: #d6f25c;
  --mark-deep: #a8c93a;
  --line: rgba(232, 239, 230, 0.1);
  --line-strong: rgba(232, 239, 230, 0.18);
  --glow: rgba(214, 242, 92, 0.18);
  --font-display: "Syne", sans-serif;
  --font-body: "Public Sans", sans-serif;
  --font-mono: "IBM Plex Mono", monospace;
  --max: 1120px;
  --radius: 14px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--paper);
  background: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a {
  color: inherit;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}

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

.grain {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 50;
  opacity: 0.045;
  mix-blend-mode: soft-light;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

.wrap {
  width: min(100% - 2.5rem, var(--max));
  margin-inline: auto;
}

/* ——— Nav ——— */
.nav {
  position: relative;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.35rem 0 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.7rem;
  text-decoration: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.03em;
}

.brand img {
  width: 28px;
  height: 28px;
  border-radius: 50%;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  font-size: 0.9rem;
  color: var(--fog);
}

.nav-links a {
  text-decoration: none;
  transition: color 160ms ease;
}

.nav-links a:hover {
  color: var(--paper);
}

.lang-switch {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-left: 0.15rem;
  padding-left: 1rem;
  border-left: 1px solid var(--line-strong);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.02em;
}

.lang-switch a[aria-current="page"] {
  color: var(--mark);
  pointer-events: none;
}

.lang-switch span {
  color: var(--line-strong);
}

html[lang^="zh"] body {
  font-family: "Noto Sans SC", var(--font-body), "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", sans-serif;
}

html[lang^="zh"] .hero h1,
html[lang^="zh"] .section h2,
html[lang^="zh"] .steps h3,
html[lang^="zh"] .legal h1,
html[lang^="zh"] .legal h2 {
  font-family: "Noto Sans SC", var(--font-display), "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", sans-serif;
  letter-spacing: -0.02em;
  font-weight: 700;
}

html[lang^="zh"] .hero h1 {
  max-width: 16em;
}

html[lang^="zh"] .section h2 {
  max-width: 14em;
}

html[lang^="zh"] .hero-lead,
html[lang^="zh"] .section-lead {
  max-width: 36em;
}

/* ——— Hero ——— */
.hero {
  position: relative;
  min-height: 100svh;
  overflow: hidden;
  isolation: isolate;
}

.hero-stage {
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(ellipse 80% 55% at 70% 35%, rgba(214, 242, 92, 0.12), transparent 60%),
    radial-gradient(ellipse 50% 40% at 15% 80%, rgba(154, 168, 156, 0.08), transparent 55%),
    linear-gradient(180deg, #0b0f0d 0%, #101612 55%, #0b0f0d 100%);
}

.hero-grid {
  position: absolute;
  inset: -10% -5%;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 70% 60% at 65% 40%, #000 20%, transparent 75%);
  animation: drift 28s linear infinite;
}

@keyframes drift {
  from { transform: translate3d(0, 0, 0); }
  to { transform: translate3d(-56px, -56px, 0); }
}

.hero-tree {
  position: absolute;
  right: max(-2rem, calc(50% - 36rem));
  top: 12%;
  width: min(48vw, 520px);
  height: 70%;
  font-family: var(--font-mono);
  font-size: clamp(11px, 1.1vw, 13px);
  line-height: 1.7;
  color: rgba(232, 239, 230, 0.28);
  white-space: pre;
  user-select: none;
  mask-image: linear-gradient(180deg, transparent, #000 18%, #000 72%, transparent);
  animation: fade-in 1.2s ease both 0.15s;
}

.hero-cursor {
  position: absolute;
  width: 18px;
  height: 18px;
  border: 2px solid var(--mark);
  border-radius: 50%;
  box-shadow: 0 0 0 6px var(--glow);
  right: max(8%, calc(50% - 10rem));
  top: 42%;
  animation: tap 2.8s ease-in-out infinite;
}

.hero-cursor::after {
  content: "";
  position: absolute;
  left: 12px;
  top: 12px;
  width: 14px;
  height: 18px;
  background: var(--mark);
  clip-path: polygon(0 0, 100% 70%, 55% 70%, 75% 100%, 55% 100%, 35% 70%, 0 70%);
  opacity: 0.9;
}

@keyframes tap {
  0%, 100% { transform: translate(0, 0) scale(1); opacity: 0.85; }
  45% { transform: translate(-28px, 36px) scale(0.92); opacity: 1; }
  55% { transform: translate(-28px, 36px) scale(0.88); }
}

.hero-content {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  justify-content: center;
  min-height: 100svh;
  padding: 6rem 0 5rem;
  max-width: 38rem;
  animation: rise 0.9s cubic-bezier(0.22, 1, 0.36, 1) both;
}

@keyframes rise {
  from { opacity: 0; transform: translateY(18px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

.hero-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.85rem;
  margin: 0 0 1.5rem;
  font-family: var(--font-display);
  font-size: clamp(2.6rem, 7vw, 4.4rem);
  font-weight: 800;
  letter-spacing: -0.055em;
  line-height: 0.95;
}

.hero-brand img {
  width: clamp(2.4rem, 6vw, 3.5rem);
  height: clamp(2.4rem, 6vw, 3.5rem);
  border-radius: 50%;
  box-shadow: 0 0 0 1px var(--line-strong), 0 0 40px var(--glow);
}

.hero h1 {
  margin: 0 0 1rem;
  max-width: 14ch;
  font-family: var(--font-display);
  font-size: clamp(1.65rem, 3.6vw, 2.35rem);
  font-weight: 650;
  letter-spacing: -0.035em;
  line-height: 1.15;
}

.hero-lead {
  margin: 0 0 2rem;
  max-width: 34ch;
  color: var(--paper-dim);
  font-size: 1.05rem;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  min-height: 2.85rem;
  padding: 0.7rem 1.15rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: transform 160ms ease, background 160ms ease, border-color 160ms ease, color 160ms ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--mark);
  color: #12160f;
}

.btn-primary:hover {
  background: #e4ff78;
}

.btn-ghost {
  border-color: var(--line-strong);
  color: var(--paper);
  background: rgba(18, 24, 21, 0.55);
  backdrop-filter: blur(8px);
}

.btn-ghost:hover {
  border-color: rgba(214, 242, 92, 0.45);
  color: var(--mark);
}

.hero-meta {
  margin-top: 1.35rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--fog);
  letter-spacing: 0.02em;
}

/* ——— Sections ——— */
.section {
  position: relative;
  padding: 5.5rem 0;
  border-top: 1px solid var(--line);
}

.section-label {
  margin: 0 0 0.85rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mark-deep);
}

.section h2 {
  margin: 0 0 0.85rem;
  max-width: 18ch;
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.2vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1.1;
}

.section-lead {
  margin: 0 0 2.5rem;
  max-width: 42ch;
  color: var(--fog);
}

.feature-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.feature-list li {
  display: grid;
  grid-template-columns: 7rem 1fr;
  gap: 1.25rem;
  padding: 1.35rem 1.4rem;
  background: var(--ink-2);
}

.feature-list code {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--mark);
}

.feature-list p {
  margin: 0;
  color: var(--paper-dim);
  font-size: 0.98rem;
}

.steps {
  display: grid;
  gap: 1.25rem;
  counter-reset: step;
}

.steps li {
  position: relative;
  list-style: none;
  padding: 1.35rem 1.35rem 1.35rem 4.25rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(135deg, rgba(214, 242, 92, 0.04), transparent 45%), var(--ink-2);
  animation: rise 0.7s ease both;
}

.steps li:nth-child(2) { animation-delay: 0.08s; }
.steps li:nth-child(3) { animation-delay: 0.16s; }
.steps li:nth-child(4) { animation-delay: 0.24s; }
.steps li:nth-child(5) { animation-delay: 0.32s; }
.steps li:nth-child(6) { animation-delay: 0.4s; }

.steps a {
  color: var(--mark);
}

.steps kbd {
  display: inline-block;
  padding: 0.1em 0.4em;
  border: 1px solid var(--line-strong);
  border-radius: 6px;
  background: var(--ink-3);
  font-family: var(--font-mono);
  font-size: 0.85em;
}

.install-note {
  margin: 1.5rem 0 0;
  color: var(--fog);
  font-size: 0.92rem;
}

.install-note a {
  color: var(--mark);
}

.steps li::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 1.2rem;
  top: 1.4rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--mark);
}

.steps h3 {
  margin: 0 0 0.35rem;
  font-family: var(--font-display);
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}

.steps p {
  margin: 0;
  color: var(--fog);
  font-size: 0.95rem;
}

.privacy-box,
.note-box {
  padding: 1.4rem 1.5rem;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--ink-3);
}

.privacy-box p,
.note-box p {
  margin: 0;
  color: var(--paper-dim);
}

.privacy-box a {
  color: var(--mark);
}

/* ——— Footer ——— */
.footer {
  padding: 2.5rem 0 3rem;
  border-top: 1px solid var(--line);
  color: var(--fog);
  font-size: 0.88rem;
}

.footer-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 1.75rem;
  align-items: center;
  justify-content: space-between;
}

.footer nav {
  display: flex;
  gap: 1.1rem;
}

.footer a {
  text-decoration: none;
}

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

/* ——— Privacy page ——— */
.legal {
  padding: 4.5rem 0 5rem;
  max-width: 42rem;
}

.legal h1 {
  margin: 0 0 0.5rem;
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 2.8rem);
  letter-spacing: -0.04em;
}

.legal .updated {
  margin: 0 0 2.5rem;
  color: var(--fog);
  font-family: var(--font-mono);
  font-size: 0.78rem;
}

.legal h2 {
  margin: 2.25rem 0 0.7rem;
  font-family: var(--font-display);
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.legal p,
.legal li {
  color: var(--paper-dim);
}

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

.legal li + li {
  margin-top: 0.4rem;
}

@media (max-width: 720px) {
  .hero-tree,
  .hero-cursor {
    display: none;
  }

  .hero-content {
    padding-top: 5rem;
    max-width: none;
  }

  .feature-list li {
    grid-template-columns: 1fr;
    gap: 0.4rem;
  }

  .nav-links .hide-sm {
    display: none;
  }
}