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

:root {
  --bg:         #0d1117;
  --panel:      #161b22;
  --border:     #30363d;
  --accent:     #58a6ff;
  --accent2:    #3fb950;
  --warn:       #f0883e;
  --danger:     #f85149;
  --text:       #e6edf3;
  --muted:      #8b949e;
  --input-bg:   #21262d;
  --font:       'Courier New', Courier, monospace;

  /* fluid scale: clamp(min, preferred, max) */
  --fs-xs:   clamp(9px,  1vw, 11px);
  --fs-sm:   clamp(11px, 1.1vw, 13px);
  --fs-md:   clamp(13px, 1.3vw, 16px);
  --fs-lg:   clamp(15px, 1.6vw, 20px);
  --fs-xl:   clamp(18px, 2vw,   26px);

  --sidebar-w: clamp(240px, 22vw, 380px);
  --gap:        clamp(6px, 0.8vw, 14px);
  --pad-x:      clamp(12px, 1.4vw, 20px);
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

/* ── Tabs ────────────────────────────────── */
.tab-nav {
  margin-left: auto;
  display: flex;
  gap: 4px;
}
.tab-btn {
  background: transparent;
  border: 1px solid transparent;
  border-radius: 5px;
  color: var(--muted);
  font-family: var(--font);
  font-size: var(--fs-sm);
  padding: clamp(5px, 0.6vh, 9px) clamp(12px, 1.4vw, 22px);
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s, background 0.15s;
}
.tab-btn:hover { color: var(--text); border-color: var(--border); }
.tab-btn.active { color: var(--accent); border-color: var(--accent); background: rgba(88,166,255,0.08); }

/* ── Tab panels ──────────────────────────── */
.tab-panel { display: none; flex: 1; overflow: hidden; flex-direction: column; }
.tab-panel.active { display: flex; }

/* ── Home screen ─────────────────────────── */
#tab-home {
  overflow-y: auto;
  flex-direction: column;
  align-items: center;
  padding: clamp(32px, 6vh, 72px) clamp(16px, 4vw, 48px);
  gap: clamp(32px, 5vh, 60px);
}

.home-hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: clamp(12px, 1.8vh, 24px);
  max-width: 680px;
  width: 100%;
}

.home-badge {
  display: inline-block;
  border: 1px solid var(--accent);
  color: var(--accent);
  font-size: var(--fs-xs);
  letter-spacing: 0.12em;
  padding: 4px 14px;
  border-radius: 20px;
}

.home-title {
  font-size: clamp(32px, 5vw, 62px);
  font-weight: bold;
  color: var(--text);
  line-height: 1.15;
}

.home-desc {
  color: var(--muted);
  font-size: var(--fs-md);
  line-height: 1.7;
  max-width: 560px;
}

.home-cta {
  margin-top: clamp(4px, 1vh, 12px);
  padding: clamp(10px, 1.4vh, 18px) clamp(28px, 3.5vw, 52px);
  background: var(--accent);
  color: var(--bg);
  font-family: var(--font);
  font-size: var(--fs-md);
  font-weight: bold;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s;
}
.home-cta:hover { background: #79c0ff; transform: translateY(-1px); }

.home-features {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(12px, 1.8vw, 24px);
  max-width: 960px;
  width: 100%;
}

.feature-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: clamp(16px, 2.2vh, 30px) clamp(16px, 1.8vw, 26px);
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: border-color 0.15s;
}
.feature-card:hover { border-color: var(--accent); }

.feature-icon {
  font-size: clamp(18px, 2.2vw, 28px);
  color: var(--accent);
}
.feature-title {
  font-size: var(--fs-sm);
  font-weight: bold;
  color: var(--text);
}
.feature-body {
  font-size: var(--fs-xs);
  color: var(--muted);
  line-height: 1.6;
}

@media (max-width: 800px) {
  .home-features { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 520px) {
  .home-features { grid-template-columns: 1fr; }
}

/* ── Header ─────────────────────────────── */
.header {
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.5vw, 20px);
  padding: 0 var(--pad-x);
  height: clamp(44px, 5.5vh, 68px);
  flex-shrink: 0;
}
.header-title { color: var(--accent); font-size: var(--fs-lg); font-weight: bold; }
.header-sub   { color: var(--muted);  font-size: var(--fs-xs); }

/* ── Layout ─────────────────────────────── */
.layout {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* ── Sidebar ─────────────────────────────── */
.sidebar {
  width: var(--sidebar-w);
  min-width: 200px;
  background: var(--panel);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: var(--gap) 0 calc(var(--gap) * 2);
  flex-shrink: 0;
}
.sidebar::-webkit-scrollbar { width: 4px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }

.section-btn {
  display: flex;
  align-items: center;
  width: 100%;
  background: transparent;
  border: none;
  border-top: 1px solid var(--border);
  color: var(--accent);
  font-family: var(--font);
  font-size: var(--fs-xs);
  font-weight: bold;
  letter-spacing: 0.05em;
  padding: clamp(8px, 1vh, 14px) var(--pad-x);
  cursor: pointer;
  text-align: left;
  gap: 6px;
  transition: background 0.15s;
}
.section-btn:first-child { border-top: none; }
.section-btn:hover { background: rgba(255,255,255,0.03); }

.section-btn span:first-child { flex: 1; }

.chevron {
  font-size: 11px;
  color: var(--muted);
  transition: transform 0.2s;
  display: inline-block;
}
.section-btn.collapsed .chevron { transform: rotate(-90deg); }

.section-body {
  overflow: hidden;
  max-height: 600px; /* large enough for any open section */
  transition: max-height 0.25s ease;
}

.input-group {
  display: flex;
  align-items: center;
  padding: clamp(3px, 0.4vh, 7px) var(--pad-x);
  gap: var(--gap);
}
.input-group label {
  color: var(--muted);
  font-size: var(--fs-sm);
  flex: 1;
  white-space: nowrap;
}
.input-group input[type="number"] {
  width: clamp(72px, 8vw, 120px);
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text);
  font-family: var(--font);
  font-size: var(--fs-sm);
  padding: clamp(4px, 0.5vh, 8px) clamp(6px, 0.6vw, 10px);
  text-align: right;
  outline: none;
  transition: border-color 0.15s;
  /* hide spinners — all browsers */
  -moz-appearance: textfield;
  appearance: textfield;
}
.input-group input[type="number"]:focus {
  border-color: var(--accent);
}
/* Chrome / Safari / Edge */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  appearance: none;
  margin: 0;
}

/* ── Mission type picker ─────────────────── */
.mission-picker {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  padding: 6px var(--pad-x) 10px;
}

.mission-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: clamp(8px, 1vh, 14px) 6px;
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  text-align: center;
  transition: border-color 0.15s, background 0.15s;
  font-family: var(--font);
}
.mission-card:hover { border-color: var(--muted); }
.mission-card.active {
  border-color: var(--accent);
  background: rgba(88, 166, 255, 0.08);
}

.mc-icon {
  font-size: clamp(14px, 1.6vw, 20px);
  color: var(--muted);
  line-height: 1;
}
.mission-card.active .mc-icon { color: var(--accent); }

.mc-name {
  font-size: var(--fs-xs);
  font-weight: bold;
  color: var(--text);
  white-space: nowrap;
}

.mc-desc {
  font-size: clamp(8px, 0.7vw, 10px);
  color: var(--muted);
  line-height: 1.3;
}

/* ── Chart pre-generation toggles ───────── */
.chart-toggles {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 2px var(--pad-x) 8px;
}

.chart-toggle-row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: clamp(3px, 0.4vh, 6px) 0;
  cursor: pointer;
  user-select: none;
}

.chart-toggle-row span:first-of-type {
  flex: 1;
  font-size: var(--fs-sm);
  color: var(--muted);
  transition: color 0.15s;
}

.chart-toggle-row:has(input:checked) span:first-of-type {
  color: var(--text);
}

.chart-toggle-row input[type="checkbox"] {
  display: none;
}

.toggle-switch {
  position: relative;
  width: 34px;
  height: 18px;
  background: var(--border);
  border-radius: 9px;
  flex-shrink: 0;
  transition: background 0.2s;
}

.toggle-switch::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 12px;
  height: 12px;
  background: var(--muted);
  border-radius: 50%;
  transition: transform 0.2s, background 0.2s;
}

.chart-toggle-row:has(input:checked) .toggle-switch {
  background: rgba(88, 166, 255, 0.3);
}

.chart-toggle-row:has(input:checked) .toggle-switch::after {
  transform: translateX(16px);
  background: var(--accent);
}

.btn-run {
  display: block;
  width: calc(100% - var(--pad-x) * 2);
  margin: clamp(10px, 1.2vh, 18px) var(--pad-x) clamp(4px, 0.6vh, 10px);
  padding: clamp(8px, 1.1vh, 15px) 0;
  background: var(--accent);
  color: var(--bg);
  font-family: var(--font);
  font-size: var(--fs-md);
  font-weight: bold;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  transition: background 0.15s;
}
.btn-run:hover { background: #79c0ff; }

.btn-save {
  display: block;
  width: calc(100% - var(--pad-x) * 2);
  margin: 0 var(--pad-x) clamp(4px, 0.6vh, 10px);
  padding: clamp(6px, 0.8vh, 11px) 0;
  background: var(--input-bg);
  color: var(--muted);
  font-family: var(--font);
  font-size: var(--fs-sm);
  border: 1px solid var(--border);
  border-radius: 5px;
  cursor: pointer;
  transition: background 0.15s;
}
.btn-save:hover { background: var(--border); color: var(--text); }

/* ── Stats ─────────────────────────────── */
.stats-panel { padding: 0 var(--pad-x); }
.stat-row {
  display: flex;
  align-items: center;
  padding: clamp(2px, 0.3vh, 5px) 0;
}
.stat-label { color: var(--muted); font-size: var(--fs-xs); flex: 1; }
.stat-value { color: var(--accent); font-size: var(--fs-xs); font-weight: bold; text-align: right; min-width: 44px; }
.stat-unit  { color: var(--muted); font-size: var(--fs-xs); width: 28px; text-align: right; }

/* ── Plot area ───────────────────────────── */
.plot-area {
  flex: 1;
  overflow: auto;
  padding: var(--gap);
  position: relative;
  display: flex;
  flex-direction: column;
}

.placeholder {
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  color: var(--muted);
  font-size: var(--fs-lg);
  text-align: center;
  line-height: 1.8;
}

.hidden { display: none !important; }

.plots { display: flex; flex-direction: column; gap: var(--gap); width: 100%; }

/* ── Plot wrapper ─────────────────────────── */
.plot-wrapper {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.plot-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
  flex-shrink: 0;
}

.plot-header-title {
  flex: 1;
  font-size: var(--fs-xs);
  font-weight: bold;
  color: var(--muted);
  letter-spacing: 0.04em;
}

.dl-label {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: var(--fs-xs);
  color: var(--muted);
  cursor: pointer;
  user-select: none;
  white-space: nowrap;
}
.dl-label input[type="checkbox"] {
  accent-color: var(--accent);
  width: 13px;
  height: 13px;
  cursor: pointer;
}
.dl-label:has(input:checked) { color: var(--accent); }

.plot-toggle {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--muted);
  font-family: var(--font);
  font-size: 14px;
  line-height: 1;
  width: 24px;
  height: 24px;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
  flex-shrink: 0;
}
.plot-toggle:hover { color: var(--text); border-color: var(--accent); }

.plot-body { flex: 1; min-height: 0; }

#wrap-traj .plot-body { height: clamp(200px, 30vh, 420px); }


.plot-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--gap);
}
.plot-row > div { display: flex; flex-direction: column; }
.plot-row .plot-body { height: clamp(150px, 18vh, 240px); }

@media (max-width: 1200px) {
  .plot-row { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 700px) {
  .layout { flex-direction: column; }
  .sidebar { width: 100%; min-width: unset; border-right: none; border-bottom: 1px solid var(--border); overflow-y: unset; }
  body { overflow: auto; height: auto; }
  .plot-row { grid-template-columns: 1fr; }
  #plot-traj { height: 260px; }
  .plot-row > div { height: 220px; }
}