:root {
  --bg:        #080d08;
  --panel:     #0c130c;
  --border:    #1c3a1c;
  --green:     #39ff7a;
  --green-dim: #1d7a3a;
  --green-glow:rgba(57,255,122,0.12);
  --amber:     #ffb830;
  --red:       #ff4455;
  --text:      #b8e8c0;
  --text-dim:  #4a7a52;
  --scan:      rgba(0,12,0,0.25);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Share Tech Mono', monospace;
  min-height: 100vh;
  padding: 28px 24px;
  background-image:
    repeating-linear-gradient(
      0deg, transparent, transparent 3px,
      var(--scan) 3px, var(--scan) 4px
    );
}

header {
  text-align: center;
  margin-bottom: 28px;
}

h1 {
  font-family: 'Orbitron', sans-serif;
  font-size: clamp(1.2rem, 3vw, 2rem);
  color: var(--green);
  letter-spacing: 0.25em;
  text-shadow: 0 0 16px var(--green), 0 0 40px rgba(57,255,122,0.25);
}

.subtitle {
  color: var(--text-dim);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  margin-top: 6px;
}

/* ── Layout ── */
.app {
  display: grid;
  grid-template-columns: 1fr 140px 1fr;
  gap: 14px;
  max-width: 1440px;
  margin: 0 auto;
  align-items: start;
}

@media (max-width: 800px) {
  .app { grid-template-columns: 1fr; }
}

/* ── Panels ── */
.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 14px;
  box-shadow: inset 0 0 40px rgba(0,0,0,0.6);
}

.panel-label {
  font-family: 'Orbitron', sans-serif;
  font-size: 0.62rem;
  color: var(--green-dim);
  letter-spacing: 0.18em;
  margin-bottom: 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

textarea {
  width: 100%;
  height: 520px;
  background: #040904;
  color: var(--green);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 12px;
  font-family: 'Share Tech Mono', monospace;
  font-size: 0.78rem;
  line-height: 1.55;
  resize: vertical;
  outline: none;
  caret-color: var(--green);
  transition: border-color 0.2s, box-shadow 0.2s;
}

textarea:focus {
  border-color: var(--green-dim);
  box-shadow: 0 0 12px var(--green-glow);
}

#output {
  color: var(--amber);
}

/* ── Controls column ── */
.controls {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding-top: 30px;
}

.field label {
  display: block;
  font-size: 0.6rem;
  color: var(--text-dim);
  letter-spacing: 0.12em;
  margin-bottom: 4px;
}

.field input {
  width: 100%;
  background: #040904;
  color: var(--green);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 6px 8px;
  font-family: 'Share Tech Mono', monospace;
  font-size: 0.78rem;
  outline: none;
  transition: border-color 0.2s;
}

.field input:focus { border-color: var(--green-dim); }

.check-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.62rem;
  letter-spacing: 0.1em;
  color: var(--text-dim);
  cursor: pointer;
}

.check-label input[type="checkbox"] {
  accent-color: var(--green);
  width: 14px;
  height: 14px;
  cursor: pointer;
}

button {
  font-family: 'Orbitron', sans-serif;
  font-size: 0.62rem;
  letter-spacing: 0.12em;
  padding: 10px 12px;
  background: transparent;
  color: var(--green);
  border: 1px solid var(--green-dim);
  border-radius: 2px;
  cursor: pointer;
  width: 100%;
  transition: background 0.15s, border-color 0.15s, box-shadow 0.15s;
}

button:hover {
  background: var(--green-glow);
  border-color: var(--green);
  box-shadow: 0 0 14px var(--green-glow);
}

button:active { background: rgba(57,255,122,0.18); }

#btn-convert {
  padding: 14px 12px;
  font-size: 0.7rem;
  color: var(--green);
  border-color: var(--green);
  box-shadow: 0 0 8px var(--green-glow);
}

/* ── Status ── */
#status {
  font-size: 0.68rem;
  color: var(--text-dim);
  text-align: center;
  line-height: 1.4;
  min-height: 36px;
  padding: 6px 4px;
  border-top: 1px solid var(--border);
}

#status.ok  { color: var(--green); }
#status.err { color: var(--red);   }
#status.info{ color: var(--amber); }

.falstad-btn {
  margin-top: 8px;
  font-size: 0.62rem;
  color: var(--amber);
  border-color: var(--amber);
  opacity: 0.7;
  transition: opacity 0.2s, box-shadow 0.2s;
}

.falstad-btn:hover {
  opacity: 1;
  background: rgba(255,184,48,0.08);
  border-color: var(--amber);
  box-shadow: 0 0 14px rgba(255,184,48,0.2);
  color: var(--amber);
}

/* ── Divider ── */
.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 4px 0;
}