:root {
  --ink: #141210;
  --ink-soft: #2a2622;
  --paper: #f3efe6;
  --paper-deep: #e8e2d4;
  --mist: #cfc6b4;
  --muted: #6f675c;
  --line: #d6cebf;
  --olive: #3f6212;
  --olive-deep: #2d4a0c;
  --panel: #faf7f0;
  --shadow: rgb(20 18 16 / 18%);
  --font-display: 'Noto Serif SC', 'Songti SC', 'STSong', serif;
  --font-body: 'IBM Plex Sans SC', 'PingFang SC', 'Hiragino Sans GB', sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

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

.site-nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.5rem;
  background: linear-gradient(180deg, rgb(243 239 230 / 92%), rgb(243 239 230 / 0%));
  backdrop-filter: blur(8px);
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.nav-brand img {
  border-radius: 7px;
  box-shadow: 0 1px 0 rgb(20 18 16 / 8%);
}

.nav-links {
  display: flex;
  gap: 1.25rem;
  font-size: 0.92rem;
  color: var(--muted);
}

.nav-links a {
  transition: color 0.2s ease;
}

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

.hero {
  position: relative;
  min-height: 100svh;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  align-items: center;
  gap: 2rem;
  padding: 7rem 6vw 4rem;
  overflow: hidden;
}

.hero-atmosphere {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

.ink-wash {
  position: absolute;
  inset: -10% -5% auto auto;
  width: min(70vw, 780px);
  height: min(70vw, 780px);
  border-radius: 50%;
  background:
    radial-gradient(circle at 40% 40%, rgb(63 98 18 / 14%), transparent 55%),
    radial-gradient(circle at 65% 55%, rgb(20 18 16 / 10%), transparent 60%);
  filter: blur(8px);
  animation: wash-drift 14s ease-in-out infinite alternate;
}

.paper-grain {
  position: absolute;
  inset: 0;
  opacity: 0.35;
  background-image:
    radial-gradient(rgb(20 18 16 / 8%) 0.5px, transparent 0.5px),
    radial-gradient(rgb(20 18 16 / 5%) 0.6px, transparent 0.6px);
  background-size: 3px 3px, 7px 7px;
  background-position: 0 0, 1px 2px;
  mix-blend-mode: multiply;
}

.ruled-lines {
  position: absolute;
  inset: 18% 8% 22% 48%;
  background: repeating-linear-gradient(
    to bottom,
    transparent 0,
    transparent 31px,
    rgb(20 18 16 / 6%) 31px,
    rgb(20 18 16 / 6%) 32px
  );
  mask-image: linear-gradient(90deg, transparent, #000 20%, #000 80%, transparent);
  opacity: 0.55;
}

.hero-copy,
.hero-stage {
  position: relative;
  z-index: 1;
}

.brand-mark {
  margin: 0 0 1.1rem;
  font-family: var(--font-display);
  font-size: clamp(3.8rem, 9vw, 7.2rem);
  font-weight: 700;
  line-height: 0.95;
  letter-spacing: 0.12em;
  color: var(--ink);
  animation: rise 0.9s cubic-bezier(0.22, 1, 0.36, 1) both;
}

.hero h1 {
  margin: 0;
  max-width: 10em;
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 3.2vw, 2.35rem);
  font-weight: 500;
  line-height: 1.35;
  letter-spacing: 0.04em;
  color: var(--ink-soft);
  animation: rise 0.9s cubic-bezier(0.22, 1, 0.36, 1) 0.08s both;
}

.lede {
  margin: 1.25rem 0 0;
  max-width: 28rem;
  font-size: 1.05rem;
  color: var(--muted);
  animation: rise 0.9s cubic-bezier(0.22, 1, 0.36, 1) 0.16s both;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2rem;
  animation: rise 0.9s cubic-bezier(0.22, 1, 0.36, 1) 0.24s both;
}

.meta {
  margin: 1rem 0 0;
  font-size: 0.82rem;
  color: var(--muted);
  letter-spacing: 0.04em;
  animation: rise 0.9s cubic-bezier(0.22, 1, 0.36, 1) 0.3s both;
}

.btn-primary,
.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  min-height: 2.85rem;
  padding: 0.7rem 1.25rem;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 500;
  transition:
    transform 0.2s ease,
    background 0.2s ease,
    color 0.2s ease,
    box-shadow 0.2s ease;
}

.btn-primary {
  background: var(--ink);
  color: var(--paper);
  box-shadow: 0 10px 28px var(--shadow);
}

.btn-primary:hover {
  background: var(--ink-soft);
  transform: translateY(-1px);
}

.btn-ghost {
  border: 1px solid var(--line);
  background: rgb(250 247 240 / 55%);
  color: var(--ink-soft);
}

.btn-ghost:hover {
  background: var(--panel);
  transform: translateY(-1px);
}

.btn-large {
  flex-direction: column;
  align-items: flex-start;
  gap: 0.15rem;
  min-width: min(100%, 18rem);
  min-height: 4.4rem;
  padding: 0.95rem 1.4rem;
  border-radius: 1.1rem;
  font-family: var(--font-display);
  font-size: 1.2rem;
  letter-spacing: 0.06em;
}

.btn-large span {
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 400;
  letter-spacing: 0.02em;
  opacity: 0.72;
}

.hero-stage {
  display: grid;
  place-items: center;
  min-height: 52vh;
  animation: float-in 1.1s cubic-bezier(0.22, 1, 0.36, 1) 0.18s both;
}

.stage-glow {
  position: absolute;
  width: min(72%, 420px);
  aspect-ratio: 1;
  border-radius: 36% 64% 48% 52%;
  background: radial-gradient(circle, rgb(63 98 18 / 22%), transparent 68%);
  filter: blur(18px);
  animation: glow-breathe 7s ease-in-out infinite;
}

.hero-ink {
  position: relative;
  width: min(78%, 460px);
  border-radius: 28%;
  box-shadow:
    0 30px 60px rgb(20 18 16 / 18%),
    0 2px 0 rgb(255 255 255 / 35%) inset;
  transform-origin: center;
  animation: ink-settle 1.2s cubic-bezier(0.22, 1, 0.36, 1) 0.25s both;
}

.features,
.download {
  position: relative;
  padding: 5.5rem 6vw;
}

.features {
  background:
    linear-gradient(180deg, transparent, var(--paper-deep) 12%, var(--paper-deep) 88%, transparent),
    var(--paper);
}

.section-head {
  max-width: 36rem;
  margin-bottom: 2.75rem;
}

.section-head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  font-weight: 700;
  letter-spacing: 0.06em;
}

.section-head p {
  margin: 0.85rem 0 0;
  color: var(--muted);
  font-size: 1.02rem;
}

.feature-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.75rem 2rem;
  border-top: 1px solid var(--line);
}

.feature-list li {
  padding-top: 1.4rem;
  border-top: 1px solid transparent;
}

.feature-list h3 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.feature-list p {
  margin: 0.65rem 0 0;
  color: var(--muted);
  font-size: 0.96rem;
}

.download {
  padding-bottom: 6rem;
}

.download-block {
  max-width: 34rem;
}

.download-note {
  margin: 1rem 0 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.5rem 6vw 2.25rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.88rem;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--ink);
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.08em;
}

.footer-brand img {
  border-radius: 6px;
}

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

@keyframes float-in {
  from {
    opacity: 0;
    transform: translateY(28px) scale(0.96);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes ink-settle {
  from {
    opacity: 0;
    transform: translateY(24px) rotate(-2deg) scale(0.94);
  }
  to {
    opacity: 1;
    transform: translateY(0) rotate(0deg) scale(1);
  }
}

@keyframes wash-drift {
  from {
    transform: translate3d(0, 0, 0) scale(1);
  }
  to {
    transform: translate3d(-3%, 4%, 0) scale(1.06);
  }
}

@keyframes glow-breathe {
  0%,
  100% {
    transform: scale(1);
    opacity: 0.85;
  }
  50% {
    transform: scale(1.08);
    opacity: 1;
  }
}

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    padding-top: 6.5rem;
    min-height: auto;
  }

  .hero-stage {
    order: -1;
    min-height: 38vh;
  }

  .hero-ink {
    width: min(58%, 280px);
  }

  .ruled-lines {
    inset: 8% 6% 55% 6%;
  }

  .feature-list {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 640px) {
  .site-nav {
    padding-inline: 1rem;
  }

  .nav-links {
    gap: 0.9rem;
  }

  .hero,
  .features,
  .download,
  .site-footer {
    padding-inline: 1.15rem;
  }

  .brand-mark {
    letter-spacing: 0.08em;
  }

  .feature-list {
    grid-template-columns: 1fr;
    gap: 1.35rem;
  }

  .cta-row {
    flex-direction: column;
    align-items: stretch;
  }

  .btn-primary,
  .btn-ghost {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }

  html {
    scroll-behavior: auto;
  }
}