:root {
  --bg: #070a0f;
  --bg-grad-top: #0d141d;
  --panel: #111821;
  --panel-elev: #16202c;
  --panel-input: #0a1018;

  --line: #1f3142;
  --line-bright: #2d4a66;

  --cyan: #5fb8e8;
  --cyan-bright: #8ed1f4;
  --cyan-dim: #2b6c95;
  --cyan-glow: rgba(95, 184, 232, 0.22);
  --cyan-glow-strong: rgba(95, 184, 232, 0.38);

  --amber: #ffa84a;
  --amber-dim: #b8742a;
  --amber-glow: rgba(255, 168, 74, 0.18);

  --green-pip: #57c785;
  --green-pip-dim: #2a6b46;

  --text: #d8e3ec;
  --text-dim: #6c8398;
  --text-fade: #4d6478;

  --error: #ff5d5d;
  --error-glow: rgba(255, 93, 93, 0.18);

  --font-chrome: "Roboto Condensed", "Arial Narrow", "Helvetica Neue Condensed",
                 "Liberation Sans Narrow", -apple-system, BlinkMacSystemFont,
                 "Segoe UI", sans-serif;
  --font-readout: "JetBrains Mono", "SF Mono", "Consolas",
                  "Liberation Mono", ui-monospace, monospace;

  --track: 0.14em;
  --track-tight: 0.06em;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-chrome);
  font-size: 14px;
  line-height: 1.4;
  -webkit-font-smoothing: antialiased;
}

/* ---------- shell ---------- */

.terminal {
  position: relative;
  min-height: 100vh;
  padding: 1.25rem clamp(1rem, 3vw, 2rem) 2rem;
  background:
    radial-gradient(ellipse 80% 50% at 50% 0%, var(--bg-grad-top) 0%, transparent 70%),
    linear-gradient(180deg, var(--bg) 0%, #050709 100%);
  overflow: hidden;
}

/* faint scanline overlay — sits above content, blocks no clicks */
.terminal::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    0deg,
    transparent 0,
    transparent 2px,
    rgba(255, 255, 255, 0.014) 2px,
    rgba(255, 255, 255, 0.014) 3px
  );
  z-index: 1000;
  mix-blend-mode: screen;
}

/* corner ambient glow */
.terminal::after {
  content: '';
  position: absolute;
  top: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 80%;
  height: 40%;
  background: radial-gradient(ellipse, var(--cyan-glow) 0%, transparent 60%);
  pointer-events: none;
  opacity: 0.5;
  z-index: 0;
}

/* ---------- top bar ---------- */

.top-bar {
  position: relative;
  border-bottom: 1px solid var(--line);
  padding: 0.5rem 0.5rem 0.75rem;
  margin: 0 0 1.25rem;
  display: flex;
  align-items: center;
  z-index: 1;
}

.top-bar::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 120px;
  height: 1px;
  background: linear-gradient(90deg, var(--cyan-bright), transparent);
  box-shadow: 0 0 8px var(--cyan-glow-strong);
}

.top-bar h1 {
  margin: 0;
  font-weight: 500;
  font-size: 1.05rem;
  letter-spacing: var(--track);
  text-transform: uppercase;
  color: var(--cyan-bright);
  text-shadow: 0 0 12px var(--cyan-glow-strong);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.top-bar h1::before {
  content: '';
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green-pip);
  box-shadow: 0 0 8px var(--green-pip), 0 0 2px #fff inset;
  flex-shrink: 0;
}

.top-bar h1::after {
  content: 'NAV COMPUTER';
  font-size: 0.7rem;
  letter-spacing: var(--track);
  color: var(--text-dim);
  margin-left: 0.75rem;
  padding-left: 0.75rem;
  border-left: 1px solid var(--line);
  text-shadow: none;
}

/* ---------- panels ---------- */

.panels {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(280px, 1fr) minmax(260px, 1fr) minmax(300px, 1.2fr);
  gap: 1rem;
}

.panel {
  position: relative;
  background:
    linear-gradient(180deg, rgba(95, 184, 232, 0.03) 0%, transparent 12%),
    var(--panel);
  border: 1px solid var(--line);
  padding: 1rem 1rem 1.1rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

/* top accent bar — thin cyan stripe across each panel */
.panel::before {
  content: '';
  position: absolute;
  top: -1px;
  left: -1px;
  right: -1px;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan-dim), var(--cyan) 30%, var(--cyan-bright) 50%, var(--cyan) 70%, var(--cyan-dim));
  box-shadow: 0 0 8px var(--cyan-glow);
}

/* corner bracket bottom-right */
.panel::after {
  content: '';
  position: absolute;
  right: 0;
  bottom: 0;
  width: 14px;
  height: 14px;
  border-right: 2px solid var(--cyan);
  border-bottom: 2px solid var(--cyan);
  opacity: 0.7;
  pointer-events: none;
}

.panel h2 {
  margin: 0 0 0.25rem;
  font-weight: 500;
  font-size: 0.78rem;
  letter-spacing: var(--track);
  text-transform: uppercase;
  color: var(--cyan-bright);
  display: flex;
  align-items: center;
  gap: 0.55rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--line);
}

.panel h2::before {
  content: '';
  width: 6px;
  height: 6px;
  background: var(--cyan);
  box-shadow: 0 0 6px var(--cyan-glow-strong);
  flex-shrink: 0;
  transform: rotate(45deg);
}

/* ---------- labels & inputs ---------- */

label {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  color: var(--text-dim);
  font-size: 0.78rem;
  letter-spacing: var(--track-tight);
  text-transform: uppercase;
}

label.row {
  flex-direction: row;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  text-transform: none;
  letter-spacing: 0;
  font-size: 0.85rem;
}

label.row > span {
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: var(--track-tight);
  font-size: 0.78rem;
}

input[type="text"],
input[type="number"],
input[type="search"],
select {
  background: var(--panel-input);
  color: var(--cyan-bright);
  border: 1px solid var(--line);
  border-radius: 0;
  padding: 0.45rem 0.55rem;
  font-family: var(--font-readout);
  font-size: 0.85rem;
  letter-spacing: var(--track-tight);
  outline: none;
  transition: border-color 120ms ease, box-shadow 120ms ease;
}

select {
  font-family: var(--font-chrome);
  text-transform: uppercase;
  letter-spacing: var(--track-tight);
  font-size: 0.82rem;
  cursor: pointer;
  appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, var(--cyan) 50%),
                    linear-gradient(135deg, var(--cyan) 50%, transparent 50%);
  background-position: calc(100% - 14px) 50%, calc(100% - 9px) 50%;
  background-size: 5px 5px;
  background-repeat: no-repeat;
  padding-right: 1.6rem;
}

input::placeholder { color: var(--text-fade); }

input:focus, select:focus {
  border-color: var(--cyan);
  box-shadow: 0 0 0 1px var(--cyan-glow), 0 0 12px var(--cyan-glow);
}

input[readonly] {
  color: var(--text-dim);
  background: #060a10;
}

input[type="radio"], input[type="checkbox"] {
  accent-color: var(--cyan);
  width: 14px;
  height: 14px;
}

/* ---------- buttons ---------- */

button {
  position: relative;
  background: linear-gradient(180deg, rgba(95, 184, 232, 0.06), rgba(95, 184, 232, 0.02));
  color: var(--cyan-bright);
  border: 1px solid var(--cyan-dim);
  border-radius: 0;
  padding: 0.45rem 0.85rem;
  font-family: var(--font-chrome);
  font-weight: 500;
  font-size: 0.75rem;
  letter-spacing: var(--track);
  text-transform: uppercase;
  cursor: pointer;
  transition: all 120ms ease;
}

button:hover {
  border-color: var(--cyan);
  background: linear-gradient(180deg, rgba(95, 184, 232, 0.14), rgba(95, 184, 232, 0.05));
  box-shadow: 0 0 10px var(--cyan-glow), inset 0 0 8px var(--cyan-glow);
  color: #fff;
}

button:active {
  background: var(--cyan-glow-strong);
  color: #fff;
}

button:disabled {
  color: var(--text-fade);
  border-color: var(--line);
  background: transparent;
  cursor: not-allowed;
  box-shadow: none;
}

/* primary calculate button — bigger, brighter */
#btn-calculate {
  margin-top: 0.5rem;
  padding: 0.7rem 1rem;
  font-size: 0.85rem;
  letter-spacing: var(--track);
  border-color: var(--cyan);
  background: linear-gradient(180deg, rgba(95, 184, 232, 0.16), rgba(95, 184, 232, 0.05));
  box-shadow: 0 0 10px var(--cyan-glow);
}

#btn-calculate::before { content: '▸ '; color: var(--cyan-bright); }

#btn-calculate:hover {
  background: linear-gradient(180deg, rgba(95, 184, 232, 0.28), rgba(95, 184, 232, 0.08));
  box-shadow: 0 0 18px var(--cyan-glow-strong);
}

/* ---------- layout helpers ---------- */

.row {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
}

.coords {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 0.4rem;
}

.coords label {
  text-transform: uppercase;
  font-size: 0.72rem;
  letter-spacing: var(--track);
  gap: 0.2rem;
}

.coords input { text-align: right; }

/* ---------- planet list ---------- */

.list-box {
  background: var(--panel-input);
  border: 1px solid var(--line);
  height: 200px;
  overflow-y: auto;
  position: relative;
}

.list-box::-webkit-scrollbar { width: 8px; }
.list-box::-webkit-scrollbar-track { background: var(--panel-input); }
.list-box::-webkit-scrollbar-thumb { background: var(--cyan-dim); }
.list-box::-webkit-scrollbar-thumb:hover { background: var(--cyan); }

.se-list {
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--font-readout);
  font-size: 0.82rem;
}

.se-list li {
  padding: 0.32rem 0.6rem 0.32rem 1.4rem;
  color: var(--cyan-bright);
  cursor: pointer;
  border-bottom: 1px solid #0c1620;
  position: relative;
  letter-spacing: var(--track-tight);
  transition: background 100ms ease, padding-left 120ms ease;
}

.se-list li::before {
  content: '';
  position: absolute;
  left: 0.55rem;
  top: 50%;
  width: 5px;
  height: 5px;
  border: 1px solid var(--cyan-dim);
  transform: translateY(-50%);
}

.se-list li:hover {
  background: rgba(95, 184, 232, 0.07);
  padding-left: 1.55rem;
}

.se-list li:hover::before { border-color: var(--cyan); background: var(--cyan-glow); }

.se-list li.selected {
  background: linear-gradient(90deg, var(--cyan-glow-strong), rgba(95, 184, 232, 0.08));
  color: #fff;
  text-shadow: 0 0 6px var(--cyan-glow-strong);
}

.se-list li.selected::before {
  background: var(--cyan-bright);
  border-color: var(--cyan-bright);
  box-shadow: 0 0 6px var(--cyan-bright);
}

.se-list li.readonly {
  color: var(--amber);
}

.se-list li.readonly::before { border-color: var(--amber-dim); }

.se-list li.readonly:hover::before { border-color: var(--amber); background: var(--amber-glow); }

.se-list li.readonly.selected {
  background: linear-gradient(90deg, var(--amber-glow), rgba(255, 168, 74, 0.04));
  color: var(--amber);
  text-shadow: 0 0 6px var(--amber-glow);
}

.se-list li.readonly.selected::before {
  background: var(--amber);
  border-color: var(--amber);
  box-shadow: 0 0 6px var(--amber);
}

/* ---------- fieldset (planet editor) ---------- */

fieldset {
  border: 1px solid var(--line);
  border-left: 2px solid var(--cyan-dim);
  padding: 0.75rem 0.85rem 0.85rem;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  background: rgba(95, 184, 232, 0.02);
}

fieldset legend {
  color: var(--text-dim);
  padding: 0 0.4rem;
  text-transform: uppercase;
  letter-spacing: var(--track);
  font-size: 0.7rem;
}

fieldset:disabled { opacity: 0.45; }
fieldset:disabled legend::after { content: ' [ locked ]'; color: var(--amber-dim); }

fieldset label { gap: 0.25rem; }

/* ---------- mode block ---------- */

.mode-block {
  border-top: 1px solid var(--line);
  padding-top: 0.7rem;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  position: relative;
}

.mode-block::before {
  content: '';
  position: absolute;
  top: -1px;
  left: 0;
  width: 24px;
  height: 1px;
  background: var(--cyan-bright);
  box-shadow: 0 0 6px var(--cyan-glow-strong);
}

/* radio mode-selector row */
.panel-calc > .row:first-of-type {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.panel-calc > .row:first-of-type label.row {
  padding: 0.35rem 0.5rem;
  border: 1px solid transparent;
  border-left: 2px solid var(--line);
  background: rgba(95, 184, 232, 0.015);
  transition: all 100ms ease;
  cursor: pointer;
}

.panel-calc > .row:first-of-type label.row:hover {
  border-left-color: var(--cyan-dim);
  background: rgba(95, 184, 232, 0.05);
}

.panel-calc > .row:first-of-type label.row:has(input:checked) {
  border-left-color: var(--cyan);
  background: rgba(95, 184, 232, 0.08);
  color: var(--cyan-bright);
}

/* ---------- hints ---------- */

.hint {
  color: var(--text-fade);
  font-size: 0.72rem;
  font-style: normal;
  letter-spacing: var(--track-tight);
  margin: 0.15rem 0 0.1rem;
  padding-left: 0.65rem;
  position: relative;
  line-height: 1.45;
}

.hint::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.45em;
  width: 4px;
  height: 1px;
  background: var(--cyan-dim);
}

/* ---------- detected display ---------- */

#detected-display {
  color: var(--text-dim);
  font-size: 0.8rem;
  letter-spacing: var(--track-tight);
  text-transform: uppercase;
  padding: 0.4rem 0.5rem;
  border: 1px dashed var(--line);
  background: rgba(95, 184, 232, 0.02);
}

#detected-name {
  color: var(--cyan-bright);
  font-family: var(--font-readout);
  text-shadow: 0 0 6px var(--cyan-glow);
}

/* ---------- result ---------- */

.result {
  position: relative;
  border: 1px solid var(--green-pip-dim);
  padding: 0.9rem 0.9rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  background: linear-gradient(180deg, rgba(87, 199, 133, 0.05), rgba(87, 199, 133, 0.01));
  margin-top: 0.5rem;
}

.result::before {
  content: 'SOLUTION';
  position: absolute;
  top: -0.55rem;
  left: 0.8rem;
  background: var(--panel);
  padding: 0 0.4rem;
  color: var(--green-pip);
  font-size: 0.7rem;
  letter-spacing: var(--track);
  text-shadow: 0 0 6px var(--green-pip);
}

.result::after {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 10px;
  height: 10px;
  border-right: 2px solid var(--green-pip);
  border-top: 2px solid var(--green-pip);
}

.result input { color: var(--green-pip); text-shadow: 0 0 4px var(--green-pip-dim); }
.result label { color: var(--text-dim); }

#btn-copy-result {
  border-color: var(--green-pip-dim);
  color: var(--green-pip);
  background: linear-gradient(180deg, rgba(87, 199, 133, 0.06), rgba(87, 199, 133, 0.02));
}

#btn-copy-result:hover {
  border-color: var(--green-pip);
  box-shadow: 0 0 10px rgba(87, 199, 133, 0.3);
  color: #fff;
}

/* ---------- error ---------- */

.error {
  color: var(--error);
  border: 1px solid var(--error);
  border-left: 3px solid var(--error);
  padding: 0.55rem 0.7rem;
  font-size: 0.82rem;
  letter-spacing: var(--track-tight);
  background: var(--error-glow);
  position: relative;
}

.error::before {
  content: '⚠ ';
  color: var(--error);
  margin-right: 0.2rem;
}

/* ---------- responsive ---------- */

@media (max-width: 1100px) {
  .panels { grid-template-columns: 1fr 1fr; }
  .panel-calc { grid-column: span 2; }
}

@media (max-width: 720px) {
  .panels { grid-template-columns: 1fr; }
  .panel-calc { grid-column: auto; }
  .top-bar h1::after { display: none; }
}

/* ---------- hidden attribute — must win over display:flex rules above ---------- */
[hidden] { display: none !important; }