:root {
  --ink: #031512;
  --ink-2: #0a2a24;
  --panel: #0e3530;
  --mist: #d7ebe4;
  --fog: #9bb8ae;
  --paper: #f2f7f4;
  --accent: #d4f06a;
  --accent-ink: #13240a;
  --line: rgba(215, 235, 228, 0.14);
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --font-brand: "Syne", "Pretendard Variable", sans-serif;
  --font-body: "Pretendard Variable", "Apple SD Gothic Neo", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--mist);
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.55;
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(212, 240, 106, 0.12), transparent 55%),
    radial-gradient(900px 500px at -10% 30%, rgba(60, 140, 120, 0.22), transparent 50%),
    linear-gradient(165deg, var(--ink) 0%, var(--ink-2) 48%, #071f1c 100%);
  min-height: 100vh;
}

a {
  color: inherit;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.92em;
  color: var(--accent);
}

.topbar {
  position: fixed;
  inset: 0 0 auto;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem clamp(1.25rem, 4vw, 3rem);
  background: linear-gradient(to bottom, rgba(3, 21, 18, 0.88), rgba(3, 21, 18, 0));
  backdrop-filter: blur(0px);
}

.topbar-brand {
  font-family: var(--font-brand);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.02em;
  text-decoration: none;
}

.topbar-nav {
  display: flex;
  gap: 1.25rem;
  font-size: 0.92rem;
}

.topbar-nav a {
  text-decoration: none;
  color: var(--fog);
  transition: color 0.25s var(--ease);
}

.topbar-nav a:hover {
  color: var(--accent);
}

.brand {
  margin: 0;
  font-family: var(--font-brand);
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: none;
}

/* —— Hero: one composition —— */
.hero {
  position: relative;
  min-height: 100svh;
  display: grid;
  align-items: end;
  overflow: hidden;
}

.hero-media {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  background:
    radial-gradient(ellipse 80% 60% at 70% 35%, rgba(212, 240, 106, 0.16), transparent 55%),
    radial-gradient(ellipse 50% 45% at 15% 80%, rgba(47, 120, 108, 0.35), transparent 60%),
    linear-gradient(155deg, #02110e 0%, #0a2a24 45%, #061a17 100%);
}

.hero-field {
  position: absolute;
  inset: -10%;
  background-image:
    linear-gradient(rgba(215, 235, 228, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(215, 235, 228, 0.06) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 75% 65% at 65% 40%, #000 20%, transparent 75%);
  animation: field-drift 22s linear infinite;
}

.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(2px);
}

.hero-orb-a {
  width: min(48vw, 28rem);
  height: min(48vw, 28rem);
  right: -6%;
  top: 12%;
  background: radial-gradient(circle at 35% 35%, rgba(212, 240, 106, 0.45), rgba(212, 240, 106, 0) 68%);
  animation: orb-float 14s var(--ease) infinite alternate;
}

.hero-orb-b {
  width: min(36vw, 20rem);
  height: min(36vw, 20rem);
  left: 8%;
  bottom: 8%;
  background: radial-gradient(circle at 50% 50%, rgba(90, 170, 150, 0.35), rgba(90, 170, 150, 0) 70%);
  animation: orb-float 18s var(--ease) infinite alternate-reverse;
}

.hero-veil {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(2, 17, 14, 0.88) 0%, rgba(2, 17, 14, 0.45) 55%, rgba(2, 17, 14, 0.2) 100%),
    linear-gradient(0deg, rgba(2, 17, 14, 0.92) 0%, transparent 42%);
}

.hero-copy {
  position: relative;
  z-index: 1;
  width: min(40rem, 100%);
  padding: clamp(5.5rem, 14vh, 8rem) clamp(1.25rem, 4vw, 3rem) clamp(2.5rem, 8vh, 4.5rem);
}

.hero-copy .brand {
  font-size: clamp(2.4rem, 7vw, 4.4rem);
  line-height: 0.95;
  color: #fff;
  opacity: 0;
  animation: rise 0.9s var(--ease) 0.1s forwards;
}

.headline {
  margin: 1rem 0 0;
  font-size: clamp(1.7rem, 4.2vw, 2.55rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--paper);
  opacity: 0;
  animation: rise 0.9s var(--ease) 0.28s forwards;
}

.lede {
  margin: 1rem 0 0;
  max-width: 32rem;
  color: var(--fog);
  font-size: 1.05rem;
  opacity: 0;
  animation: rise 0.9s var(--ease) 0.42s forwards;
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.75rem;
  opacity: 0;
  animation: rise 0.9s var(--ease) 0.55s forwards;
}

.meta {
  margin: 1rem 0 0;
  font-size: 0.88rem;
  color: color-mix(in srgb, var(--fog) 80%, transparent);
  opacity: 0;
  animation: rise 0.9s var(--ease) 0.68s forwards;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.85rem;
  padding: 0.7rem 1.2rem;
  border-radius: 0.35rem;
  font-weight: 700;
  font-size: 0.98rem;
  text-decoration: none;
  transition:
    transform 0.25s var(--ease),
    background 0.25s var(--ease),
    color 0.25s var(--ease),
    border-color 0.25s var(--ease);
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--accent);
  color: var(--accent-ink);
}

.btn-primary:hover {
  background: #e4f98a;
}

.btn-ghost {
  border: 1px solid var(--line);
  color: var(--mist);
  background: rgba(14, 53, 48, 0.35);
}

.btn-ghost:hover {
  border-color: color-mix(in srgb, var(--accent) 45%, transparent);
  color: var(--accent);
}

/* —— Sections —— */
.section {
  padding: clamp(4rem, 10vh, 6.5rem) clamp(1.25rem, 4vw, 3rem);
  max-width: 68rem;
  margin: 0 auto;
}

.section-kicker {
  margin: 0;
  font-family: var(--font-brand);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
}

.section h2 {
  margin: 0.55rem 0 0;
  font-size: clamp(1.55rem, 3.2vw, 2.15rem);
  line-height: 1.3;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.section-lede {
  margin: 0.9rem 0 0;
  max-width: 36rem;
  color: var(--fog);
}

.feature-list {
  list-style: none;
  margin: 2.5rem 0 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.feature-list li {
  display: grid;
  grid-template-columns: 4.5rem 1fr;
  gap: 1rem;
  padding: 1.35rem 0;
  border-bottom: 1px solid var(--line);
  opacity: 0;
  transform: translateY(12px);
  transition:
    opacity 0.7s var(--ease),
    transform 0.7s var(--ease);
}

.feature-list li.is-in {
  opacity: 1;
  transform: none;
}

.feature-index {
  font-family: var(--font-brand);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--accent);
}

.feature-list h3 {
  margin: 0;
  font-size: 1.12rem;
  color: var(--paper);
}

.feature-list p {
  margin: 0.35rem 0 0;
  color: var(--fog);
}

.download,
.notes,
.howto {
  border-top: 1px solid var(--line);
}

.platform-list {
  list-style: none;
  margin: 2rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
}

.platform-list li {
  opacity: 0;
  transform: translateY(10px);
  transition:
    opacity 0.65s var(--ease),
    transform 0.65s var(--ease);
}

.platform-list li.is-in {
  opacity: 1;
  transform: none;
}

.platform-link {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1.1rem 1.15rem;
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 0.4rem;
  background: color-mix(in srgb, var(--panel) 65%, transparent);
  transition:
    border-color 0.25s var(--ease),
    background 0.25s var(--ease),
    transform 0.25s var(--ease);
}

.platform-link:hover {
  border-color: color-mix(in srgb, var(--accent) 50%, transparent);
  background: color-mix(in srgb, var(--panel) 90%, transparent);
  transform: translateY(-2px);
}

.platform-name {
  font-family: var(--font-brand);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--paper);
}

.platform-meta {
  font-size: 0.88rem;
  color: var(--fog);
}

.changelog {
  margin-top: 2rem;
  display: grid;
  gap: 1.25rem;
}

.changelog-entry {
  padding: 1.25rem 0;
  border-top: 1px solid var(--line);
  opacity: 0;
  transform: translateY(10px);
  transition:
    opacity 0.65s var(--ease),
    transform 0.65s var(--ease);
}

.changelog-entry.is-in {
  opacity: 1;
  transform: none;
}

.changelog-entry:first-child {
  border-top: none;
  padding-top: 0;
}

.changelog-entry header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.65rem 1rem;
  margin-bottom: 0.65rem;
}

.changelog-entry h3 {
  margin: 0;
  font-family: var(--font-brand);
  font-size: 1.2rem;
  color: var(--paper);
}

.changelog-entry time {
  font-size: 0.88rem;
  color: var(--fog);
}

.changelog-summary {
  margin: 0 0 0.75rem;
  color: var(--fog);
}

.changelog-entry h4 {
  margin: 0.85rem 0 0.35rem;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

.changelog-entry ul {
  margin: 0;
  padding-left: 1.15rem;
  color: var(--fog);
}

.changelog-entry li {
  margin: 0.2rem 0;
}

.changelog-fallback {
  color: var(--fog);
}

.steps {
  list-style: none;
  margin: 2.25rem 0 0;
  padding: 0;
  counter-reset: step;
  display: grid;
  gap: 1rem;
}

.steps li {
  counter-increment: step;
  display: grid;
  gap: 0.25rem;
  padding: 1.15rem 1.15rem 1.15rem 4rem;
  position: relative;
  background: color-mix(in srgb, var(--panel) 70%, transparent);
  border: 1px solid var(--line);
  border-radius: 0.4rem;
  opacity: 0;
  transform: translateY(12px);
  transition:
    opacity 0.7s var(--ease),
    transform 0.7s var(--ease);
}

.steps li.is-in {
  opacity: 1;
  transform: none;
}

.steps li::before {
  content: counter(step);
  position: absolute;
  left: 1.1rem;
  top: 1.15rem;
  width: 1.7rem;
  height: 1.7rem;
  display: grid;
  place-items: center;
  border-radius: 999px;
  background: var(--accent);
  color: var(--accent-ink);
  font-family: var(--font-brand);
  font-weight: 700;
  font-size: 0.85rem;
}

.steps strong {
  color: var(--paper);
  font-size: 1.05rem;
}

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

.footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
  padding: 2rem clamp(1.25rem, 4vw, 3rem) 2.75rem;
  border-top: 1px solid var(--line);
  color: var(--fog);
  font-size: 0.9rem;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.footer-brand .brand {
  font-size: 1.15rem;
  color: var(--paper);
}

.footer a {
  color: var(--accent);
  text-decoration: none;
}

.footer a:hover {
  text-decoration: underline;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

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

@keyframes orb-float {
  from {
    transform: translate3d(0, 0, 0) scale(1);
  }
  to {
    transform: translate3d(-3%, 4%, 0) scale(1.08);
  }
}

@media (max-width: 720px) {
  .topbar-nav {
    display: none;
  }

  .hero-copy .brand {
    font-size: clamp(2.1rem, 11vw, 3rem);
  }

  .feature-list li {
    grid-template-columns: 3rem 1fr;
  }

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

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .hero-field,
  .hero-orb,
  .hero-copy .brand,
  .headline,
  .lede,
  .cta-row,
  .meta,
  .feature-list li,
  .steps li,
  .platform-list li,
  .changelog-entry {
    animation: none !important;
    transition: none !important;
    opacity: 1 !important;
    transform: none !important;
  }
}