:root {
  color-scheme: dark;
  --ink: #f5f2e9;
  --muted: #aaa99f;
  --line: #383a36;
  --panel: #1a1c19;
  --accent: #d4ff4f;
  --bg: #111310;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    radial-gradient(circle at 85% 5%, rgba(212, 255, 79, .08), transparent 28rem),
    linear-gradient(rgba(255,255,255,.018) 1px, transparent 1px),
    var(--bg);
  background-size: auto, 100% 48px, auto;
  font-family: "Yu Gothic UI", "Hiragino Kaku Gothic ProN", sans-serif;
}

button, textarea { font: inherit; }

.shell { width: min(1260px, calc(100% - 40px)); margin: 0 auto; }

.hero { padding: 72px 0 42px; border-bottom: 1px solid var(--line); }
.eyebrow, .step { margin: 0 0 12px; color: var(--accent); font: 700 11px/1.2 ui-monospace, monospace; letter-spacing: .18em; }
h1 { margin: 0; font-size: clamp(42px, 7vw, 84px); line-height: .95; letter-spacing: -.065em; }
h1 span { color: var(--accent); font-weight: 400; }
.lead { max-width: 650px; margin: 24px 0 0; color: var(--muted); font-size: 16px; line-height: 1.8; }

.workspace { display: grid; grid-template-columns: 1fr 54px 1fr; padding: 40px 0 30px; }
.panel { min-width: 0; }
.panel-heading { display: flex; align-items: flex-end; justify-content: space-between; min-height: 58px; margin-bottom: 18px; }
h2 { margin: 0; font-size: 20px; letter-spacing: .02em; }
.text-button { padding: 6px 0; color: var(--muted); border: 0; border-bottom: 1px solid var(--muted); background: none; cursor: pointer; }
.text-button:hover { color: var(--ink); }

textarea {
  display: block;
  width: 100%;
  height: 440px;
  padding: 22px;
  resize: vertical;
  border: 1px solid var(--line);
  border-radius: 3px;
  outline: none;
  color: var(--ink);
  background: var(--panel);
  font: 14px/1.7 "BIZ UDGothic", "Yu Gothic UI", monospace;
  transition: border-color .2s, box-shadow .2s;
}
textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(212,255,79,.08); }
#result { color: #e6f4ba; background: #151713; }
.hint { margin: 13px 0 0; color: #777a72; font-size: 12px; }
.divider { display: grid; place-items: center; color: var(--accent); font-size: 24px; }
.status { display: flex; align-items: center; gap: 7px; color: var(--muted); font-size: 12px; }
.status::before { width: 7px; height: 7px; border-radius: 50%; background: var(--accent); content: ""; }

.copy-button {
  display: flex;
  justify-content: space-between;
  width: 100%;
  margin-top: 12px;
  padding: 15px 18px;
  border: 1px solid var(--accent);
  border-radius: 3px;
  color: #111310;
  background: var(--accent);
  font-weight: 700;
  cursor: pointer;
}
.copy-button:hover { filter: brightness(1.08); }
.copy-button:active { transform: translateY(1px); }

footer { padding: 22px 0 48px; border-top: 1px solid var(--line); color: #777a72; font-size: 12px; }

@media (max-width: 780px) {
  .shell { width: min(100% - 28px, 620px); }
  .hero { padding: 48px 0 32px; }
  .workspace { grid-template-columns: 1fr; padding-top: 28px; }
  .divider { height: 54px; transform: rotate(90deg); }
  textarea { height: 340px; }
}