:root {
  color-scheme: dark;
  --ink: #071020;
  --ink-soft: #0d1930;
  --panel: rgba(16, 29, 52, 0.86);
  --panel-strong: #132440;
  --line: rgba(166, 196, 235, 0.19);
  --text: #f5f8fc;
  --muted: #b8c7db;
  --cyan: #62d5ff;
  --violet: #9a8cff;
  --coral: #ff7a72;
  --green: #6ee7b7;
  --shadow: 0 28px 90px rgba(0, 0, 0, 0.28);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  background:
    radial-gradient(circle at 82% 8%, rgba(154, 140, 255, 0.19), transparent 32rem),
    radial-gradient(circle at 10% 28%, rgba(98, 213, 255, 0.14), transparent 28rem),
    var(--ink);
  color: var(--text);
  font-size: 16px;
  line-height: 1.65;
}

a { color: inherit; }

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 100;
  transform: translateY(-180%);
  padding: 10px 14px;
  border-radius: 10px;
  background: white;
  color: #071020;
}

.skip-link:focus { transform: translateY(0); }

.shell {
  width: min(1160px, calc(100% - 40px));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(166, 196, 235, 0.12);
  background: rgba(7, 16, 32, 0.88);
  backdrop-filter: blur(18px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  letter-spacing: 0.01em;
  font-size: 1.08rem;
  font-weight: 700;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border: 1px solid rgba(98, 213, 255, 0.45);
  border-radius: 12px;
  background: linear-gradient(145deg, rgba(98, 213, 255, 0.16), rgba(154, 140, 255, 0.2));
  color: var(--cyan);
  font-family: "Yu Gothic UI", "Noto Sans JP", sans-serif;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 26px;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
}

.nav-links a:hover,
.nav-links a:focus-visible { color: var(--text); }

.button,
.button-secondary {
  display: inline-flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 9px;
  padding: 12px 20px;
  border-radius: 12px;
  text-decoration: none;
  font-weight: 650;
}

.button {
  border: 1px solid transparent;
  background: linear-gradient(110deg, var(--cyan), #a7e9ff);
  color: #06111f;
  box-shadow: 0 12px 34px rgba(98, 213, 255, 0.2);
}

.button-secondary {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.035);
  color: var(--text);
}

.button.disabled {
  cursor: not-allowed;
  border-color: var(--line);
  background: rgba(184, 199, 219, 0.1);
  box-shadow: none;
  color: var(--muted);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(360px, 0.92fr);
  align-items: center;
  gap: 70px;
  min-height: 690px;
  padding-block: 92px 82px;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--cyan);
  font-size: 0.86rem;
  font-weight: 700;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

h1, h2, h3 { margin-top: 0; line-height: 1.12; }

h1 {
  max-width: 760px;
  margin-bottom: 24px;
  font-size: clamp(2.65rem, 6vw, 5.2rem);
  letter-spacing: -0.055em;
}

h1 span { color: var(--cyan); }

.hero-copy > p:not(.eyebrow) {
  max-width: 650px;
  margin: 0 0 30px;
  color: var(--muted);
  font-size: clamp(1.06rem, 2vw, 1.24rem);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 22px;
}

.microcopy {
  color: #8fa5c1;
  font-size: 0.9rem;
}

.app-window {
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(166, 196, 235, 0.23);
  border-radius: 22px;
  background: #101a2c;
  box-shadow: var(--shadow);
  transform: rotate(1.2deg);
}

.app-window::after {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  box-shadow: inset 0 1px rgba(255, 255, 255, 0.07);
  content: "";
  pointer-events: none;
}

.window-bar {
  display: flex;
  align-items: center;
  gap: 7px;
  height: 46px;
  padding: 0 16px;
  border-bottom: 1px solid var(--line);
  background: #0c1627;
}

.dot { width: 10px; height: 10px; border-radius: 50%; background: #34435a; }
.dot:first-child { background: var(--coral); }
.dot:nth-child(2) { background: #ffd166; }
.dot:nth-child(3) { background: var(--green); }

.window-body { padding: 28px; }

.mode-row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 26px;
  color: var(--muted);
  font-size: 0.88rem;
}

.mode-pill {
  padding: 6px 10px;
  border: 1px solid rgba(98, 213, 255, 0.28);
  border-radius: 999px;
  color: var(--cyan);
}

.input-demo {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: rgba(7, 16, 32, 0.75);
}

.input-label { margin-bottom: 8px; color: #8fa5c1; font-size: 0.77rem; letter-spacing: 0.08em; text-transform: uppercase; }
.romaji-line { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; color: #aab8ca; }
.conversion { margin: 8px 0; color: var(--cyan); font-size: 1.75rem; font-family: "Yu Gothic UI", "Noto Sans JP", sans-serif; }
.candidate { display: inline-flex; gap: 10px; padding: 8px 10px; border-radius: 8px; background: rgba(154, 140, 255, 0.15); color: #e8e3ff; }
.candidate small { color: #b8addf; }

.send-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 24px;
  color: var(--muted);
  font-size: 0.88rem;
}

.send-button { padding: 10px 14px; border-radius: 9px; background: var(--cyan); color: #06111f; font-weight: 700; }

.section { padding-block: 92px; }
.section-heading { max-width: 720px; margin-bottom: 44px; }
.section-heading h2 { margin-bottom: 16px; font-size: clamp(2rem, 4vw, 3.25rem); letter-spacing: -0.035em; }
.section-heading p { margin: 0; color: var(--muted); font-size: 1.08rem; }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.feature-card {
  min-height: 240px;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: linear-gradient(145deg, rgba(19, 36, 64, 0.82), rgba(11, 23, 42, 0.82));
}

.feature-number { display: inline-block; margin-bottom: 40px; color: var(--cyan); font-family: ui-monospace, monospace; font-size: 0.86rem; }
.feature-card h3 { margin-bottom: 12px; font-size: 1.25rem; }
.feature-card p { margin: 0; color: var(--muted); }

.showcase {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  align-items: center;
  gap: 62px;
  padding: 44px;
  border: 1px solid var(--line);
  border-radius: 26px;
  background: linear-gradient(125deg, rgba(154, 140, 255, 0.12), rgba(98, 213, 255, 0.07));
}

.showcase h2 { font-size: clamp(2rem, 4vw, 3rem); letter-spacing: -0.035em; }
.showcase p { color: var(--muted); }
.showcase ul { padding-left: 1.15rem; color: var(--muted); }
.showcase li + li { margin-top: 8px; }

.screenshots { display: grid; gap: 14px; }
.screenshot-frame { overflow: hidden; border: 1px solid var(--line); border-radius: 14px; background: #292929; box-shadow: 0 18px 55px rgba(0, 0, 0, 0.24); }
.screenshot-frame img { display: block; width: 100%; height: auto; }
.screenshot-frame:nth-child(2) { width: 88%; margin-left: auto; }

.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; counter-reset: steps; }
.step { position: relative; padding-top: 62px; border-top: 1px solid var(--line); counter-increment: steps; }
.step::before { position: absolute; top: 17px; left: 0; color: var(--cyan); content: "0" counter(steps); font-family: ui-monospace, monospace; }
.step h3 { margin-bottom: 10px; }
.step p { margin: 0; color: var(--muted); }

.download-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 34px;
  padding: 44px;
  border: 1px solid rgba(98, 213, 255, 0.26);
  border-radius: 24px;
  background: linear-gradient(105deg, rgba(98, 213, 255, 0.12), rgba(154, 140, 255, 0.12));
}
.download-panel h2 { margin-bottom: 12px; font-size: clamp(2rem, 4vw, 3rem); }
.download-panel p { max-width: 720px; margin: 0; color: var(--muted); }
.release-state { display: block; margin-top: 10px; color: #ffd79b; font-size: 0.9rem; }

.site-footer { padding: 54px 0 34px; border-top: 1px solid var(--line); }
.footer-grid { display: grid; grid-template-columns: 1fr auto; gap: 30px; }
.footer-copy { max-width: 560px; color: var(--muted); }
.footer-links { display: grid; grid-template-columns: repeat(2, auto); gap: 10px 22px; align-content: start; }
.footer-links a { color: var(--muted); text-decoration: none; }
.footer-links a:hover, .footer-links a:focus-visible { color: var(--cyan); }
.footer-bottom { margin-top: 34px; color: #7f93ae; font-size: 0.88rem; }

:focus-visible { outline: 3px solid rgba(98, 213, 255, 0.62); outline-offset: 3px; }

@media (max-width: 900px) {
  .nav-links a:not(.button) { display: none; }
  .hero { grid-template-columns: 1fr; min-height: auto; gap: 44px; padding-block: 72px; }
  .app-window { max-width: 620px; transform: none; }
  .feature-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .showcase { grid-template-columns: 1fr; }
  .download-panel { grid-template-columns: 1fr; }
}

@media (max-width: 620px) {
  .shell { width: min(100% - 28px, 1160px); }
  .site-header .button { min-height: 42px; padding: 9px 12px; font-size: 0.9rem; }
  .brand span:last-child { display: none; }
  .hero { padding-block: 56px; }
  h1 { font-size: clamp(2.45rem, 15vw, 4rem); }
  .window-body { padding: 20px; }
  .mode-row, .send-row { align-items: flex-start; flex-direction: column; }
  .feature-grid, .steps { grid-template-columns: 1fr; }
  .feature-card { min-height: 0; }
  .feature-number { margin-bottom: 24px; }
  .showcase, .download-panel { padding: 28px 22px; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-links { grid-template-columns: 1fr; }
}

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