/* ============================================================
   The Journey of Electricity — styles
   Dark "control-room" theme with glass overlays on a 3D scene
   ============================================================ */

:root{
  --accent: #4db8ff;
  --bg-glass: rgba(12, 17, 26, 0.74);
  --bg-glass-solid: rgba(14, 19, 29, 0.92);
  --border: rgba(255, 255, 255, 0.10);
  --text: #e9eff7;
  --muted: #9fb1c6;
  --shadow: 0 12px 40px rgba(0, 0, 0, 0.45);
}

*{ box-sizing: border-box; }

html, body{
  margin: 0;
  height: 100%;
  overflow: hidden;
  background: #0a0e16;
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

#scene{
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  touch-action: none;
}

/* ---------- Floating 3D labels ---------- */
#labels{ position: fixed; inset: 0; pointer-events: none; z-index: 5; }
.label{
  position: absolute;
  transform: translate(-50%, -120%);
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-left: 3px solid var(--lc, #fff);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  padding: 5px 10px;
  border-radius: 9px;
  font-size: 12px;
  white-space: nowrap;
  pointer-events: auto;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: transform .12s ease, opacity .2s ease;
  user-select: none;
}
.label:hover{ transform: translate(-50%, -130%) scale(1.04); }
.label .lname{ font-weight: 700; letter-spacing: .2px; }
.label .lvolt{ color: var(--muted); font-size: 11px; margin-left: 4px; }
.label::after{
  content: "";
  position: absolute;
  left: 50%; bottom: -6px;
  width: 10px; height: 10px;
  background: var(--bg-glass);
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  transform: translateX(-50%) rotate(45deg);
}

/* ---------- Top bar ---------- */
#topbar{
  position: fixed;
  top: 16px; left: 18px;
  z-index: 10;
  pointer-events: none;
  max-width: 60vw;
}
#topbar .title{
  font-size: 22px;
  font-weight: 800;
  letter-spacing: .3px;
  text-shadow: 0 2px 18px rgba(0,0,0,.6);
}
#topbar .subtitle{
  margin-top: 4px;
  font-size: 12.5px;
  color: var(--muted);
  text-shadow: 0 1px 10px rgba(0,0,0,.7);
}
#topbar .subtitle b{ color: var(--text); font-weight: 600; }

/* ---------- HUD (live instruments) ---------- */
#hud{
  position: fixed;
  top: 16px; right: 16px;
  z-index: 10;
  width: 260px;
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-top: 3px solid var(--accent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-radius: 14px;
  padding: 12px 14px 10px;
  box-shadow: var(--shadow);
}
.hud-stage{ display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 14px; }
.hud-stage .dot{ width: 11px; height: 11px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 12px var(--accent); }
.hud-readouts{ display: flex; gap: 8px; margin-top: 12px; }
.readout{ flex: 1; background: rgba(255,255,255,.04); border: 1px solid var(--border); border-radius: 10px; padding: 8px 6px; text-align: center; }
.rlabel{ font-size: 10px; text-transform: uppercase; letter-spacing: .6px; color: var(--muted); }
.rvalue{ font-size: 15px; font-weight: 800; margin-top: 3px; font-variant-numeric: tabular-nums; }
.hud-foot{ margin-top: 10px; font-size: 11px; color: var(--muted); line-height: 1.4; }

/* ---------- Stage stepper ---------- */
#stepper{
  position: fixed;
  left: 18px; top: 50%;
  transform: translateY(-50%);
  z-index: 10;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.step{
  display: flex; align-items: center; gap: 10px;
  background: var(--bg-glass);
  border: 1px solid var(--border);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-radius: 12px;
  padding: 8px 12px 8px 10px;
  cursor: pointer;
  min-width: 184px;
  box-shadow: var(--shadow);
  transition: transform .14s ease, border-color .14s ease, background .14s ease;
}
.step:hover{ transform: translateX(4px); }
.step.active{ border-color: var(--sc); background: rgba(255,255,255,.08); }
.step .sdot{
  width: 14px; height: 14px; border-radius: 50%;
  background: var(--sc); flex: none;
  box-shadow: 0 0 0 3px rgba(255,255,255,.06);
  transition: box-shadow .2s ease;
}
.step.active .sdot{ box-shadow: 0 0 14px var(--sc), 0 0 0 3px rgba(255,255,255,.10); }
.step .stext .sname{ font-size: 13px; font-weight: 700; }
.step .stext .svolt{ font-size: 11px; color: var(--muted); }
.step .snum{ margin-left: auto; font-size: 11px; color: var(--muted); font-weight: 700; }

/* ---------- Toolbar ---------- */
#toolbar{
  position: fixed;
  left: 50%; bottom: 18px;
  transform: translateX(-50%);
  z-index: 10;
  display: flex; gap: 8px; flex-wrap: wrap; justify-content: center;
  background: var(--bg-glass);
  border: 1px solid var(--border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-radius: 14px;
  padding: 8px;
  box-shadow: var(--shadow);
}
.tbtn{
  font: inherit; font-size: 13px; font-weight: 600;
  color: var(--text);
  background: rgba(255,255,255,.05);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 9px 13px;
  cursor: pointer;
  transition: background .14s ease, transform .1s ease, border-color .14s ease;
  white-space: nowrap;
}
.tbtn:hover{ background: rgba(255,255,255,.12); }
.tbtn:active{ transform: translateY(1px); }
.tbtn.primary{ background: var(--accent); color: #03121f; border-color: transparent; }
.tbtn.primary:hover{ filter: brightness(1.08); background: var(--accent); }
.tbtn.live{ background: #ff5a5f; color: #fff; }

/* ---------- Info panel ---------- */
#infoPanel{
  position: fixed;
  top: 92px; right: 16px;
  z-index: 11;
  width: 330px;
  max-height: calc(100vh - 120px);
  overflow-y: auto;
  background: var(--bg-glass-solid);
  border: 1px solid var(--border);
  border-top: 4px solid var(--accent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-radius: 16px;
  box-shadow: var(--shadow);
  transition: transform .28s cubic-bezier(.2,.8,.2,1), opacity .24s ease;
}
#infoPanel.hidden{ transform: translateX(380px); opacity: 0; pointer-events: none; }
.info-body{ padding: 18px 18px 20px; }
.info-kicker{ font-size: 11px; letter-spacing: 1.2px; font-weight: 700; color: var(--accent); text-transform: uppercase; }
#infoTitle{ margin: 6px 0 12px; font-size: 21px; line-height: 1.15; }
.info-stats{ display: flex; gap: 8px; margin-bottom: 14px; flex-wrap: wrap; }
.info-stat{ background: rgba(255,255,255,.05); border: 1px solid var(--border); border-radius: 10px; padding: 7px 10px; min-width: 78px; }
.info-stat .k{ font-size: 10px; text-transform: uppercase; letter-spacing: .5px; color: var(--muted); }
.info-stat .v{ font-size: 14px; font-weight: 800; margin-top: 2px; }
#infoText{ font-size: 13.5px; line-height: 1.6; color: #dbe5f1; margin: 0 0 16px; }
#infoText b{ color: #fff; }
.info-terms-label{ font-size: 11px; text-transform: uppercase; letter-spacing: .6px; color: var(--muted); margin-bottom: 8px; }
.info-terms{ display: flex; flex-wrap: wrap; gap: 6px; }
.term-chip{
  font-size: 12px; font-weight: 600;
  background: rgba(77,184,255,.12);
  border: 1px solid rgba(77,184,255,.30);
  color: #cfeaff;
  border-radius: 999px; padding: 5px 11px; cursor: pointer;
  transition: background .12s ease;
}
.term-chip:hover{ background: rgba(77,184,255,.24); }

/* ---------- Close buttons ---------- */
.close{
  position: absolute; top: 10px; right: 10px;
  width: 30px; height: 30px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: rgba(255,255,255,.06);
  color: var(--text); font-size: 19px; line-height: 1;
  cursor: pointer; z-index: 2;
}
.close:hover{ background: rgba(255,255,255,.15); }

/* ---------- Tour caption ---------- */
#tourCaption{
  position: fixed;
  left: 50%; bottom: 84px;
  transform: translateX(-50%);
  z-index: 12;
  max-width: 640px; width: max-content;
  background: var(--bg-glass-solid);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 12px;
  padding: 12px 18px;
  font-size: 14px; line-height: 1.5;
  text-align: center;
  box-shadow: var(--shadow);
  transition: opacity .3s ease, transform .3s ease;
}
#tourCaption.hidden{ opacity: 0; transform: translateX(-50%) translateY(10px); pointer-events: none; }
#tourCaption b{ color: var(--accent); }

/* ---------- Modal (glossary / calculators) ---------- */
.modal{
  position: fixed; inset: 0; z-index: 30;
  background: rgba(4, 7, 12, 0.62);
  backdrop-filter: blur(4px);
  display: flex; align-items: center; justify-content: center;
  padding: 24px;
  transition: opacity .2s ease;
}
.modal.hidden{ opacity: 0; pointer-events: none; }
.modal-card{
  position: relative;
  width: min(720px, 96vw);
  max-height: 86vh;
  overflow-y: auto;
  background: var(--bg-glass-solid);
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 24px 26px 28px;
}
.modal-card h2{ margin: 0 0 16px; font-size: 22px; }

/* glossary */
.gloss-search{
  width: 100%; font: inherit; font-size: 14px;
  background: rgba(255,255,255,.05);
  border: 1px solid var(--border); border-radius: 10px;
  color: var(--text); padding: 11px 13px; margin-bottom: 16px;
}
.gloss-search::placeholder{ color: var(--muted); }
.gloss-list{ display: grid; gap: 10px; }
.gloss-item{ background: rgba(255,255,255,.04); border: 1px solid var(--border); border-radius: 12px; padding: 12px 14px; }
.gloss-item.flash{ border-color: var(--accent); box-shadow: 0 0 0 2px rgba(77,184,255,.25); }
.gloss-term{ font-weight: 800; font-size: 14.5px; }
.gloss-term .sym{ color: var(--accent); font-weight: 700; margin-left: 6px; font-size: 13px; }
.gloss-def{ font-size: 13px; color: #d4dfec; line-height: 1.55; margin-top: 4px; }
.gloss-empty{ color: var(--muted); text-align: center; padding: 20px; }

/* calculators */
.tabs{ display: flex; gap: 6px; margin-bottom: 18px; flex-wrap: wrap; }
.tab{ font: inherit; font-size: 12.5px; font-weight: 600; padding: 8px 12px; border-radius: 9px; cursor: pointer;
  background: rgba(255,255,255,.05); border: 1px solid var(--border); color: var(--text); }
.tab.active{ background: var(--accent); color: #03121f; border-color: transparent; }
.calc{ display: none; }
.calc.active{ display: block; }
.calc p.lead{ font-size: 13.5px; color: #d4dfec; line-height: 1.6; margin: 0 0 16px; }
.ctrl{ margin: 14px 0; }
.ctrl label{ display: flex; justify-content: space-between; font-size: 13px; margin-bottom: 7px; }
.ctrl label b{ color: var(--accent); font-variant-numeric: tabular-nums; }
.ctrl input[type=range]{ width: 100%; accent-color: var(--accent); }
.ctrl input[type=number]{
  width: 110px; font: inherit; background: rgba(255,255,255,.06);
  border: 1px solid var(--border); border-radius: 8px; color: var(--text); padding: 7px 9px;
}
.bar-wrap{ margin: 10px 0; }
.bar-label{ font-size: 12px; color: var(--muted); display: flex; justify-content: space-between; margin-bottom: 4px; }
.bar{ height: 16px; border-radius: 8px; background: rgba(255,255,255,.06); overflow: hidden; }
.bar > span{ display: block; height: 100%; border-radius: 8px; transition: width .25s ease, background .25s ease; }
.calc-out{
  background: rgba(77,184,255,.10); border: 1px solid rgba(77,184,255,.28);
  border-radius: 12px; padding: 14px 16px; margin-top: 16px; font-size: 14px; line-height: 1.6;
}
.calc-out .big{ font-size: 26px; font-weight: 800; color: #fff; }
.presets{ display: flex; gap: 6px; flex-wrap: wrap; margin-top: 10px; }
.preset{ font: inherit; font-size: 12px; padding: 6px 10px; border-radius: 8px; cursor: pointer;
  background: rgba(255,255,255,.05); border: 1px solid var(--border); color: var(--text); }
.preset:hover{ background: rgba(255,255,255,.12); }

/* info-panel hint + toggle-button active state */
.info-hint{ font-size: 11.5px; color: var(--muted); line-height: 1.45; margin: 0 0 12px; }
.tbtn.active{ background: var(--accent); color: #03121f; border-color: transparent; }
.tbtn.active:hover{ filter: brightness(1.08); }

/* ---------- Loading ---------- */
#loading{
  position: fixed; inset: 0; z-index: 50;
  background: radial-gradient(circle at 50% 40%, #16233a, #080c14);
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 18px;
  transition: opacity .5s ease;
}
#loading.hidden{ opacity: 0; pointer-events: none; }
.spinner{ width: 46px; height: 46px; border: 4px solid rgba(255,255,255,.12); border-top-color: var(--accent); border-radius: 50%; animation: spin 1s linear infinite; }
.loadtext{ color: var(--muted); font-size: 14px; letter-spacing: .4px; }
@keyframes spin{ to{ transform: rotate(360deg); } }

.hidden{ display: none; }
#infoPanel.hidden{ display: block; } /* keep for slide transition */

/* ---------- Scrollbars ---------- */
::-webkit-scrollbar{ width: 10px; height: 10px; }
::-webkit-scrollbar-thumb{ background: rgba(255,255,255,.16); border-radius: 8px; }
::-webkit-scrollbar-track{ background: transparent; }

/* ---------- Responsive ---------- */
@media (max-width: 820px){
  #topbar{ max-width: 90vw; }
  #topbar .title{ font-size: 18px; }
  #hud{ width: 200px; top: 12px; right: 12px; padding: 10px; }
  .rvalue{ font-size: 13px; }
  #stepper{ left: 8px; gap: 6px; }
  .step{ min-width: 0; padding: 7px 9px; }
  .step .stext .svolt{ display: none; }
  .step .snum{ display: none; }
  #infoPanel{ width: calc(100vw - 24px); right: 12px; top: auto; bottom: 84px; max-height: 52vh; }
  #infoPanel.hidden{ transform: translateY(120%); }
  #toolbar{ bottom: 10px; gap: 6px; padding: 6px; }
  .tbtn{ padding: 8px 10px; font-size: 12px; }
  #tourCaption{ bottom: 74px; font-size: 13px; max-width: 92vw; }
}
@media (max-width: 520px){
  #topbar .subtitle{ display: none; }
  #stepper{ top: auto; bottom: 64px; transform: none; flex-direction: row; left: 8px; right: 8px; overflow-x: auto; }
  .step{ flex: none; }
}

/* ---------- RTL (Arabic) ---------- */
html[dir="rtl"] body{ direction: rtl; }
html[dir="rtl"] #topbar{ left: auto; right: 18px; text-align: right; }
html[dir="rtl"] #hud{ right: auto; left: 16px; }
html[dir="rtl"] #stepper{ left: auto; right: 18px; }
html[dir="rtl"] .step:hover{ transform: translateX(-4px); }
html[dir="rtl"] #infoPanel{ right: auto; left: 16px; }
html[dir="rtl"] #infoPanel.hidden{ transform: translateX(-380px); }
html[dir="rtl"] .info-body,
html[dir="rtl"] .modal-card,
html[dir="rtl"] #tourCaption{ text-align: right; }
html[dir="rtl"] #tourCaption{ border-left: none; border-right: 4px solid var(--accent); }
html[dir="rtl"] .label{ direction: rtl; }
@media (max-width: 820px){
  html[dir="rtl"] #infoPanel{ left: 12px; right: 12px; }
  html[dir="rtl"] #stepper{ right: 8px; }
}