/* ═══════════════════════════════════════════════
   DNA VIEWER — NeuroArt Research Lab
   Virginia Tech Neuroscience
   ═══════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Nunito:wght@400;600;700;800&family=DM+Sans:opsz,wght@9..40,400;9..40,500&family=Space+Mono:wght@400;700&family=DynaPuff:wght@400..700&display=swap');

:root {
  --bg: #07070e;
  --panel: #0e0c1c;
  --panel-2: #141228;
  --text: #dcd8ee;
  --muted: #5e5b78;
  --accent: #8872e8;
  --accent-glow: #6352c4;
  --accent-dim: rgba(136, 114, 232, 0.1);
  --green: #5aad82;
  --amber: #b89050;
  --red: #b85f5f;
  --border: rgba(255, 255, 255, 0.06);
  --border-2: rgba(255, 255, 255, 0.09);
  --font-head: 'DynaPuff', sans-serif;
  --font-body: 'DM Sans', sans-serif;
  --font-mono: 'DynaPuff', sans-serif;
  --radius: 10px;
  --topbar-h: 56px;
  --footer-h: 44px;
}

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

html,
body {
  height: 100%;
  margin: 0;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 13px;
  overflow: hidden;
}

/* ── TOPBAR ──────────────────────────────────── */
.topbar {
  position: fixed;
  inset: 0 0 auto 0;
  height: var(--topbar-h);
  background: rgba(7, 7, 14, 0.94);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-2);
  display: flex;
  align-items: center;
  padding: 0 1.25rem;
  gap: 1.25rem;
  z-index: 200;
  overflow: visible;
}

.brand {
  display: flex;
  align-items: center;
  gap: .5rem;
  flex-shrink: 0;
}

.brand-helix {
  font-size: 1.1rem;
  color: var(--accent);
  opacity: 0.8;
}

.topbar h1 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 1.1rem;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--text);
}

.brand-sub {
  font-weight: 400;
  color: var(--muted);
  margin-left: 1px;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: 'DM Sans', sans-serif;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.18s;
}

.back-link:hover {
  color: var(--text);
}

/* Controls row */
.controls {
  display: flex;
  align-items: center;
  gap: .75rem;
  margin-left: auto;
  flex-wrap: nowrap;
  overflow-x: visible;
  overflow-y: visible;
  padding: 4px 4px 4px 0;
}

.controls::-webkit-scrollbar {
  height: 3px;
}

.controls::-webkit-scrollbar-track {
  background: transparent;
}

.controls::-webkit-scrollbar-thumb {
  background: var(--border-2);
  border-radius: 2px;
}

.btn-pill {
  display: flex;
  align-items: center;
  gap: .4rem;
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border-2);
  padding: .3rem .7rem;
  border-radius: 100px;
  cursor: pointer;
  font-family: var(--font-body);
  font-size: .78rem;
  letter-spacing: .03em;
  transition: color .2s, border-color .2s, background .2s;
  white-space: nowrap;
  text-decoration: none;
}

.btn-pill:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-dim);
}

.control-group {
  display: flex;
  align-items: center;
  gap: .4rem;
  white-space: nowrap;
}

.control-group label {
  font-size: .72rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .08em;
}

.control-group select {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border-2);
  padding: .28rem .5rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: .78rem;
  font-family: var(--font-body);
  transition: border-color .2s;
  appearance: none;
  padding-right: 1.5rem;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M0 0l5 6 5-6z' fill='%237a8499'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right .5rem center;
}

.control-group select:hover,
.control-group select:focus {
  border-color: var(--accent);
  outline: none;
}

/* Toggle switch */
.toggle-label {
  display: flex;
  align-items: center;
  gap: .5rem;
  cursor: pointer;
  font-size: .78rem;
  color: var(--muted);
  white-space: nowrap;
  user-select: none;
}

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

.toggle-track {
  width: 32px;
  height: 18px;
  background: var(--panel-2);
  border: 1px solid var(--border-2);
  border-radius: 100px;
  position: relative;
  transition: background .2s, border-color .2s;
}

.toggle-thumb {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--muted);
  transition: transform .2s, background .2s;
}

.toggle-label input:checked~.toggle-track {
  background: var(--accent-dim);
  border-color: var(--accent);
}

.toggle-label input:checked~.toggle-track .toggle-thumb {
  transform: translateX(14px);
  background: var(--accent);
}

/* ── LAYOUT ──────────────────────────────────── */
.layout {
  position: fixed;
  inset: var(--topbar-h) 0 var(--footer-h) 0;
  display: grid;
  grid-template-columns: 1fr 420px;
}

/* ── VIEWER ──────────────────────────────────── */
#viewer {
  width: 100%;
  height: 100%;
  position: relative;
}

/* Loading overlay */
#loading-overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg);
  z-index: 50;
  transition: opacity .6s ease;
}

#loading-overlay.done {
  opacity: 0;
  pointer-events: none;
}

.loader-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.loader-wrap p {
  color: var(--muted);
  font-size: .8rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  animation: blink 1.5s ease-in-out infinite;
}

@keyframes blink {

  0%,
  100% {
    opacity: .4;
  }

  50% {
    opacity: 1;
  }
}

.helix-loader {
  position: relative;
  width: 40px;
  height: 60px;
}

.helix-strand {
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  top: 0;
  left: 16px;
}

.strand-a {
  background: var(--accent);
  animation: helix-a 1.2s ease-in-out infinite;
  box-shadow: 0 0 10px var(--accent);
}

.strand-b {
  background: var(--green);
  animation: helix-b 1.2s ease-in-out infinite;
  box-shadow: 0 0 10px var(--green);
}

@keyframes helix-a {
  0% {
    transform: translateY(0) translateX(0);
  }

  25% {
    transform: translateY(13px) translateX(14px);
  }

  50% {
    transform: translateY(26px) translateX(0);
  }

  75% {
    transform: translateY(39px) translateX(-14px);
  }

  100% {
    transform: translateY(52px) translateX(0);
    opacity: 0;
  }
}

@keyframes helix-b {
  0% {
    transform: translateY(0) translateX(0);
    opacity: 0;
  }

  25% {
    transform: translateY(13px) translateX(-14px);
    opacity: 1;
  }

  50% {
    transform: translateY(26px) translateX(0);
  }

  75% {
    transform: translateY(39px) translateX(14px);
  }

  100% {
    transform: translateY(52px) translateX(0);
  }
}

/* ── XYZ NAVIGATOR ───────────────────────────── */
#xyz-nav {
  position: absolute;
  bottom: 14px;
  left: 14px;
  width: 72px;
  height: 72px;
  background: rgba(9, 12, 18, 0.70);
  border: 1px solid rgba(255, 255, 255, 0.07);
  border-radius: 50%;
  pointer-events: none;
  z-index: 10;
  backdrop-filter: blur(12px);
  overflow: hidden;
}

#orientation-canvas {
  width: 100%;
  height: 100%;
  display: block;
}

/* ── ZOOM CONTROL ────────────────────────────── */
#zoom-control {
  position: absolute;
  bottom: 14px;
  right: 14px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  z-index: 20;
  user-select: none;
  pointer-events: auto;
  isolation: isolate;
}

.zoom-btn {
  width: 28px;
  height: 28px;
  background: rgba(9, 12, 18, 0.80);
  border: 1px solid rgba(255, 255, 255, 0.10);
  border-radius: 7px;
  color: var(--muted);
  font-size: 1.15rem;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(10px);
  transition: color .15s, border-color .15s, background .15s;
  font-family: var(--font-mono);
}

.zoom-btn:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-dim);
}

.zoom-btn:active {
  background: rgba(91, 138, 255, 0.25);
}


/* ── LEGEND (dynamic color key — stacks below chem-legend) ── */
.legend {
  position: absolute;
  top: auto;
  /* override previous top:14px */
  left: 14px;
  /* positioned by JS after chem-legend height is known — fallback below */
  background: rgba(9, 12, 18, 0.92);
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  padding: .6rem .8rem;
  z-index: 10;
  backdrop-filter: blur(8px);
  min-width: 120px;
  transition: opacity .3s;
  /* Default stacking position — chem-legend is ~110px tall + 14px top + 8px gap */
  margin-top: 0;
}

.legend.hidden {
  opacity: 0;
  pointer-events: none;
}

.legend-title {
  font-size: .68rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--muted);
  margin-bottom: .5rem;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: .5rem;
  margin-bottom: .3rem;
  font-size: .78rem;
  color: var(--text);
}

.legend-chip {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* ── INFO PANEL ──────────────────────────────── */
#info {
  border-left: 1px solid var(--border);
  background: var(--panel);
  overflow: auto;
  display: flex;
  flex-direction: column;
}

.info-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1rem .6rem;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  background: var(--panel);
  z-index: 5;
}

.info-header h2 {
  margin: 0;
  font-family: 'Nunito', sans-serif;
  font-size: .85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--muted);
}

.info-badge {
  font-size: .7rem;
  font-family: 'Nunito', sans-serif;
  background: var(--accent-dim);
  color: var(--accent);
  border: 1px solid rgba(91, 138, 255, 0.25);
  padding: .15rem .5rem;
  border-radius: 100px;
  letter-spacing: .05em;
  transition: all .3s;
}

/* Empty state */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2.5rem 1.5rem;
  gap: 1rem;
  color: var(--muted);
}

.empty-icon {
  opacity: .35;
}

.empty-state p {
  margin: 0;
  font-size: .82rem;
  line-height: 1.6;
  font-family: 'Nunito', sans-serif;
}

/* Info content */
#info-content {
  flex: 1;
}

.info-section {
  padding: .85rem 1rem;
  border-bottom: 1px solid var(--border);
}

.info-section:last-child {
  border-bottom: none;
}

.info-label {
  font-size: .65rem;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--muted);
  margin-bottom: .35rem;
  font-family: 'Nunito', sans-serif;
}

.info-value {
  font-size: .88rem;
  color: var(--text);
  line-height: 1.5;
  font-family: 'Nunito', sans-serif;
}

.info-value.large {
  font-family: var(--font-head);
  font-size: 1.15rem;
  font-weight: 600;
  color: #fff;
}

.info-value.mono {
  font-family: 'Nunito', sans-serif;
  font-size: .82rem;
}

.info-value.accent {
  color: var(--accent);
}

.info-value.green {
  color: var(--green);
}

.info-value.amber {
  color: var(--amber);
}

/* Description block */
.desc-block {
  padding: .85rem 1rem;
  border-bottom: 1px solid var(--border);
}

.desc-label {
  font-size: .65rem;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--muted);
  margin-bottom: .5rem;
  font-family: 'Nunito', sans-serif;
}

.desc-text {
  font-size: .8rem;
  line-height: 1.75;
  color: #b0bcd4;
  font-family: 'Nunito', sans-serif;
  font-weight: 400;
}

/* Pair info */
.pair-indicator {
  display: flex;
  align-items: center;
  gap: .5rem;
  font-size: .82rem;
  font-family: 'Nunito', sans-serif;
}

.pair-base {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 6px;
  font-family: 'Nunito', sans-serif;
  font-weight: 700;
  font-size: .9rem;
}

.base-A {
  background: rgba(255, 107, 107, 0.15);
  color: #ff6b6b;
  border: 1px solid rgba(255, 107, 107, 0.3);
}

.base-T {
  background: rgba(91, 138, 255, 0.15);
  color: #5b8aff;
  border: 1px solid rgba(91, 138, 255, 0.3);
}

.base-G {
  background: rgba(61, 255, 160, 0.15);
  color: #3dffa0;
  border: 1px solid rgba(61, 255, 160, 0.3);
}

.base-C {
  background: rgba(255, 209, 102, 0.15);
  color: #ffd166;
  border: 1px solid rgba(255, 209, 102, 0.3);
}

.pair-arrow {
  color: var(--muted);
  font-size: .9rem;
}

/* Measure */
#measure-section {
  padding: .85rem 1rem 1rem;
  border-top: 1px solid var(--border);
  margin-top: auto;
}

#measure-section.hidden {
  display: none;
}

.btn-measure {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: .4rem;
  background: var(--accent-dim);
  color: var(--accent);
  border: 1px solid rgba(91, 138, 255, 0.3);
  padding: .5rem;
  border-radius: var(--radius);
  cursor: pointer;
  font-family: 'Nunito', sans-serif;
  font-size: .78rem;
  letter-spacing: .03em;
  transition: all .2s;
}

.btn-measure:hover {
  background: rgba(91, 138, 255, 0.2);
  border-color: var(--accent);
}

.measure-result {
  margin-top: .6rem;
  background: var(--panel-2);
  border: 1px solid var(--border-2);
  border-radius: 6px;
  padding: .5rem .7rem;
  font-size: .8rem;
  color: var(--green);
  font-family: 'Nunito', sans-serif;
  text-align: center;
  animation: fade-in .3s ease;
}

.measure-result.hidden {
  display: none;
}

@keyframes fade-in {
  from {
    opacity: 0;
    transform: translateY(4px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ── FOOTER ──────────────────────────────────── */
.footer {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  height: var(--footer-h);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: .6rem;
  color: var(--muted);
  font-size: .72rem;
  border-top: 1px solid var(--border);
  background: var(--panel);
  letter-spacing: .04em;
}

.footer-dot {
  opacity: .35;
}

.footer-source {
  margin-left: 1rem;
  color: rgba(91, 138, 255, 0.6);
  font-size: .7rem;
}

/* ── TOPBAR DIVIDER ──────────────────────────── */
.topbar-divider {
  width: 1px;
  height: 20px;
  background: var(--border-2);
  flex-shrink: 0;
}

/* ── CHEMICAL ANATOMY LEGEND ─────────────────── */
#chem-legend {
  position: absolute;
  top: 14px;
  left: 14px;
  background: rgba(9, 12, 18, 0.88);
  border: 1px solid rgba(255, 255, 255, 0.07);
  border-radius: var(--radius);
  padding: .55rem .7rem;
  z-index: 10;
  backdrop-filter: blur(10px);
  pointer-events: none;
}

.chem-legend-title {
  font-size: .62rem;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--muted);
  margin-bottom: .45rem;
}

.chem-legend-grid {
  display: grid;
  grid-template-columns: 10px 1fr;
  gap: .28rem .5rem;
  align-items: center;
  font-size: .75rem;
  color: #b0bcd4;
}

.chem-chip {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  display: block;
}

/* ── BASE SVG DIAGRAM ────────────────────────── */
.base-diagram-wrap {
  padding: .85rem 1rem .5rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: .9rem;
}

.base-diagram-svg {
  flex-shrink: 0;
  width: 80px;
  height: 80px;
}

.base-diagram-meta {
  flex: 1;
}

.base-diagram-name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 1.05rem;
  color: #fff;
  line-height: 1.2;
  word-break: break-word;
  overflow-wrap: break-word;
}

.base-diagram-type {
  font-size: .72rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: .08em;
  margin-top: .2rem;
  font-family: 'Nunito', sans-serif;
}

/* ── HBOND / GROOVE STATUS PILL ──────────────── */
.feature-pills {
  display: flex;
  gap: .35rem;
  padding: .5rem 1rem;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}

.feature-pill {
  font-size: .68rem;
  padding: .15rem .5rem;
  border-radius: 100px;
  border: 1px solid;
  letter-spacing: .05em;
  font-family: 'Nunito', sans-serif;
}

.feature-pill.hbond {
  color: #a8d8ff;
  border-color: rgba(168, 216, 255, 0.3);
  background: rgba(168, 216, 255, 0.08);
}

.feature-pill.groove {
  color: #b0ff90;
  border-color: rgba(176, 255, 144, 0.3);
  background: rgba(176, 255, 144, 0.08);
}

/* ── RESPONSIVE ──────────────────────────────── */
@media (max-width: 900px) {
  .layout {
    grid-template-columns: 1fr;
    grid-template-rows: 60vh 1fr;
  }

  #info {
    border-left: none;
    border-top: 1px solid var(--border);
  }

  .footer-source {
    display: none;
  }
}

@media (max-width: 600px) {
  .controls {
    gap: .5rem;
  }

  .control-group label {
    display: none;
  }
}

/* ── FUN FACT BLOCK ──────────────────────────────── */
.fun-fact-block {
  padding: .75rem 1rem;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(135deg, rgba(61, 255, 160, 0.05) 0%, rgba(91, 138, 255, 0.05) 100%);
  border-left: 3px solid var(--green);
  animation: fact-slide-in .35s ease;
}

@keyframes fact-slide-in {
  from {
    opacity: 0;
    transform: translateY(6px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fun-fact-label {
  display: flex;
  align-items: center;
  gap: .35rem;
  font-size: .62rem;
  text-transform: uppercase;
  letter-spacing: .12em;
  color: var(--green);
  margin-bottom: .35rem;
  font-family: 'Nunito', sans-serif;
}

.fun-fact-text {
  font-size: .8rem;
  line-height: 1.75;
  color: #c8d8b8;
  font-family: 'Nunito', sans-serif;
}