/**
 * SEVA /demo — TactiLink interactive walkthrough (see js/seva-tactilink-sim.js)
 * Loaded only on the TactiLink demo page.
 *
 * The devices are CSS-drawn so the tablet screen can render live transcript
 * text. State is driven by classes the JS toggles:
 *   .is-on / .is-ready / .is-connected / .is-linked / .is-tx / .is-rx / .is-complete
 */

.seva-sim {
  padding: 4.5rem 0;
  background:
    radial-gradient(120% 90% at 50% 0%, #142033 0%, #0b1220 55%, #080d17 100%);
  color: #e2e8f0;
  position: relative;
  overflow: hidden;
}

/* Faint grid so the section reads as an ops surface, not a flat panel. */
.seva-sim::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(56, 189, 248, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(56, 189, 248, 0.07) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(80% 60% at 50% 40%, #000 0%, transparent 100%);
  -webkit-mask-image: radial-gradient(80% 60% at 50% 40%, #000 0%, transparent 100%);
  pointer-events: none;
}

.seva-sim > .container {
  position: relative;
  z-index: 1;
}

.seva-sim__head {
  text-align: center;
  max-width: 46rem;
  margin: 0 auto 2.75rem;
}
.seva-sim__eyebrow {
  display: inline-block;
  margin-bottom: 0.6rem;
  padding: 0.2rem 0.7rem;
  border-radius: 999px;
  background: rgba(56, 189, 248, 0.14);
  color: #7dd3fc;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.seva-sim__title {
  color: #fff;
  font-weight: 700;
  margin-bottom: 0.6rem;
}
.seva-sim__lead {
  color: #94a3b8;
  margin: 0;
}

.seva-sim__body {
  display: grid;
  grid-template-columns: minmax(15rem, 20rem) 1fr;
  gap: 2.25rem;
  align-items: start;
}
@media (max-width: 991.98px) {
  .seva-sim__body { grid-template-columns: 1fr; }
}

/* ---- Step list ----------------------------------------------------------- */
.seva-sim__steps {
  list-style: none;
  margin: 0 0 1.25rem;
  padding: 0;
  counter-reset: none;
}
.seva-sim__step {
  display: flex;
  gap: 0.85rem;
  align-items: flex-start;
  padding: 0.7rem 0.85rem;
  border-radius: 0.7rem;
  border: 1px solid transparent;
  transition: background-color 0.3s ease, border-color 0.3s ease, opacity 0.3s ease;
  opacity: 0.5;
}
.seva-sim__step.is-active {
  opacity: 1;
  background: rgba(56, 189, 248, 0.08);
  border-color: rgba(56, 189, 248, 0.35);
}
.seva-sim__step.is-done { opacity: 0.85; }

.seva-sim__step-num {
  flex: 0 0 auto;
  width: 1.65rem;
  height: 1.65rem;
  border-radius: 999px;
  display: grid;
  place-items: center;
  font-size: 0.8rem;
  font-weight: 700;
  background: rgba(148, 163, 184, 0.18);
  color: #cbd5e1;
  transition: background-color 0.3s ease, color 0.3s ease;
}
.seva-sim__step.is-active .seva-sim__step-num {
  background: #38bdf8;
  color: #06121f;
}
.seva-sim__step.is-done .seva-sim__step-num {
  background: #22c55e;
  color: #052e16;
}
/* Checkmark replaces the number once the step is complete. */
.seva-sim__step.is-done .seva-sim__step-num { font-size: 0; }
.seva-sim__step.is-done .seva-sim__step-num::after {
  content: "\2713";
  font-size: 0.85rem;
  line-height: 1;
}

.seva-sim__step-body { display: flex; flex-direction: column; }
.seva-sim__step-title { color: #f1f5f9; font-size: 0.95rem; font-weight: 600; }
.seva-sim__step-hint { color: #8a97ab; font-size: 0.78rem; }
.seva-sim__step.is-done .seva-sim__step-hint { text-decoration: line-through; }

.seva-sim__reset {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.5rem 1rem;
  border-radius: 999px;
  border: 1px solid rgba(148, 163, 184, 0.3);
  background: transparent;
  color: #cbd5e1;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.25s ease, border-color 0.25s ease, color 0.25s ease;
}
.seva-sim__reset:hover { background: rgba(148, 163, 184, 0.12); color: #fff; }
.seva-sim__reset.is-ready { border-color: rgba(56, 189, 248, 0.6); color: #7dd3fc; }

/* ---- Stage --------------------------------------------------------------- */
.seva-sim__stage {
  display: grid;
  grid-template-columns: minmax(8rem, 11rem) minmax(4rem, 1fr) minmax(13rem, 22rem);
  align-items: center;
  gap: 0.5rem;
  padding: 1.5rem 1rem;
  border-radius: 1rem;
  background: rgba(9, 14, 24, 0.6);
  border: 1px solid rgba(148, 163, 184, 0.14);
}
@media (max-width: 767.98px) {
  .seva-sim__stage {
    grid-template-columns: 1fr;
    justify-items: center;
    gap: 1rem;
  }
}

.seva-sim__label {
  display: block;
  margin-top: 0.6rem;
  text-align: center;
  color: #64748b;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* ---- Radio --------------------------------------------------------------- */
.seva-sim__radio {
  position: relative;
  padding: 0.9rem 0.75rem 0.75rem;
  border-radius: 0.6rem;
  background: linear-gradient(180deg, #2a3446 0%, #1a2130 100%);
  border: 1px solid rgba(148, 163, 184, 0.18);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.06), 0 10px 24px rgba(0, 0, 0, 0.35);
  width: 100%;
  max-width: 11rem;
}
.seva-sim__antenna {
  position: absolute;
  top: -2.6rem;
  right: 1rem;
  width: 3px;
  height: 2.8rem;
  border-radius: 3px;
  background: linear-gradient(180deg, #475569 0%, #1e293b 100%);
}
.seva-sim__radio-top {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.6rem;
}
.seva-sim__led {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 999px;
  background: #334155;
  transition: background-color 0.3s ease, box-shadow 0.3s ease;
}
.seva-sim__radio.is-on .seva-sim__led {
  background: #22c55e;
  box-shadow: 0 0 8px rgba(34, 197, 94, 0.9);
}
.seva-sim__radio.is-tx .seva-sim__led {
  background: #ef4444;
  box-shadow: 0 0 10px rgba(239, 68, 68, 0.95);
}
.seva-sim__radio.is-rx .seva-sim__led {
  background: #38bdf8;
  box-shadow: 0 0 10px rgba(56, 189, 248, 0.95);
}
.seva-sim__radio-screen {
  flex: 1;
  padding: 0.15rem 0.4rem;
  border-radius: 0.25rem;
  background: #0a1120;
  color: #4ade80;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-align: center;
}
.seva-sim__grille {
  height: 2.2rem;
  border-radius: 0.3rem;
  background: repeating-linear-gradient(
    180deg, #131a27 0 3px, #1e2637 3px 6px
  );
  margin-bottom: 0.7rem;
}
.seva-sim__radio-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.seva-sim__knob,
.seva-sim__ptt,
.seva-sim__tablet-power {
  cursor: pointer;
  border: 0;
  transition: transform 0.2s ease, background-color 0.25s ease,
    box-shadow 0.25s ease, color 0.25s ease, opacity 0.25s ease;
}
.seva-sim__knob:disabled,
.seva-sim__ptt:disabled,
.seva-sim__tablet-power:disabled,
.seva-sim__cable:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.seva-sim__knob {
  width: 2.1rem;
  height: 2.1rem;
  border-radius: 999px;
  background: radial-gradient(circle at 35% 30%, #475569, #1e293b);
  color: #94a3b8;
  font-size: 0.8rem;
  display: grid;
  place-items: center;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.12);
}
.seva-sim__radio.is-on .seva-sim__knob { color: #4ade80; }

.seva-sim__ptt {
  flex: 1;
  padding: 0.4rem 0.5rem;
  border-radius: 0.35rem;
  background: #334155;
  color: #cbd5e1;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.1em;
}
.seva-sim__radio.is-tx .seva-sim__ptt { background: #dc2626; color: #fff; }

/* Pulsing ring marks whichever control is the current step. */
.seva-sim__knob.is-ready,
.seva-sim__ptt.is-ready,
.seva-sim__tablet-power.is-ready,
.seva-sim__cable.is-ready {
  animation: seva-sim-pulse 1.8s ease-in-out infinite;
}
@keyframes seva-sim-pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(56, 189, 248, 0.55); }
  50%      { box-shadow: 0 0 0 8px rgba(56, 189, 248, 0); }
}
/* The very first step needs a nudge too — the radio knob starts actionable. */
.seva-sim__stage:not(.is-linked) .seva-sim__radio:not(.is-on) .seva-sim__knob {
  animation: seva-sim-pulse 1.8s ease-in-out infinite;
}

/* ---- Cable --------------------------------------------------------------- */
.seva-sim__cable {
  position: relative;
  width: 100%;
  min-height: 7rem;
  background: transparent;
  border: 0;
  padding: 0;
  display: block;
}
.seva-sim__cable-svg { width: 100%; height: 7rem; display: block; overflow: visible; }

.seva-sim__cable-jacket {
  fill: none;
  stroke: #0f1622;
  stroke-width: 7;
  stroke-linecap: round;
  opacity: 0.55;
  transition: opacity 0.4s ease, d 0.5s ease;
}
.seva-sim__cable.is-connected .seva-sim__cable-jacket { opacity: 1; }

.seva-sim__cable-pulse {
  fill: none;
  stroke: #38bdf8;
  stroke-width: 3;
  stroke-linecap: round;
  opacity: 0;
  stroke-dasharray: 26 260;
}
/* Data pulse runs radio -> tablet on transmit, and back on receive. */
.seva-sim__stage.is-tx .seva-sim__cable-pulse {
  opacity: 1;
  animation: seva-sim-flow 1s linear infinite;
}
.seva-sim__stage.is-rx .seva-sim__cable-pulse {
  opacity: 1;
  stroke: #4ade80;
  animation: seva-sim-flow 1s linear infinite reverse;
}
@keyframes seva-sim-flow {
  from { stroke-dashoffset: 286; }
  to   { stroke-dashoffset: 0; }
}

.seva-sim__cable-hint {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  background: rgba(56, 189, 248, 0.16);
  border: 1px solid rgba(56, 189, 248, 0.45);
  color: #7dd3fc;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  transition: opacity 0.3s ease;
}
.seva-sim__cable.is-connected .seva-sim__cable-hint { opacity: 0; }

/* ---- Tablet -------------------------------------------------------------- */
.seva-sim__tablet {
  position: relative;
  padding: 0.6rem;
  border-radius: 0.8rem;
  background: linear-gradient(180deg, #232b3b 0%, #151b28 100%);
  border: 1px solid rgba(148, 163, 184, 0.2);
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.4);
  width: 100%;
}
.seva-sim__tablet-power {
  position: absolute;
  top: 0.55rem;
  right: -0.55rem;
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 999px;
  background: radial-gradient(circle at 35% 30%, #475569, #1e293b);
  color: #94a3b8;
  font-size: 0.6rem;
  display: grid;
  place-items: center;
}
.seva-sim__tablet.is-on .seva-sim__tablet-power { color: #4ade80; }

.seva-sim__screen {
  border-radius: 0.45rem;
  background: #05090f;
  min-height: 12.5rem;
  padding: 0.6rem 0.7rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  /* Screen is dark until powered — mirrors a real device. */
  opacity: 0.35;
  transition: opacity 0.5s ease;
}
.seva-sim__tablet.is-on .seva-sim__screen { opacity: 1; }

.seva-sim__screen-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid rgba(148, 163, 184, 0.16);
}
.seva-sim__brand {
  color: #38bdf8;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}
.seva-sim__meta { display: flex; gap: 0.5rem; align-items: center; }
.seva-sim__status,
.seva-sim__signal,
.seva-sim__count {
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 0.1rem 0.4rem;
  border-radius: 0.25rem;
  background: rgba(148, 163, 184, 0.16);
  color: #94a3b8;
}
/* Transmission counter — hidden until the first press. */
.seva-sim__count { display: none; }
.seva-sim__count.is-shown {
  display: inline-block;
  background: rgba(56, 189, 248, 0.16);
  color: #7dd3fc;
}
.seva-sim__tablet.is-ready .seva-sim__status { background: rgba(34, 197, 94, 0.18); color: #4ade80; }

/* ---- Waveform ------------------------------------------------------------ */
.seva-sim__wave {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2px;
  height: 2rem;
  padding: 0 0.1rem;
}
.seva-sim__wave-bar {
  flex: 1;
  height: 12%;
  border-radius: 2px;
  background: rgba(148, 163, 184, 0.25);
  transition: height 0.2s ease, background-color 0.3s ease;
}
/* Bars only dance while audio is actually flowing. */
.seva-sim__stage.is-tx .seva-sim__wave-bar,
.seva-sim__stage.is-rx .seva-sim__wave-bar {
  animation: seva-sim-bar 0.9s ease-in-out infinite;
  animation-delay: calc(var(--i) * 0.045s);
}
.seva-sim__stage.is-tx .seva-sim__wave-bar { background: #f87171; }
.seva-sim__stage.is-rx .seva-sim__wave-bar { background: #38bdf8; }
@keyframes seva-sim-bar {
  0%, 100% { height: 14%; }
  50%      { height: 82%; }
}

/* ---- Transcript ---------------------------------------------------------- */
.seva-sim__log {
  flex: 1;
  overflow-y: auto;
  max-height: 8.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  font-size: 0.72rem;
  line-height: 1.45;
  scrollbar-width: thin;
}
.seva-sim__line { display: flex; flex-direction: column; }
.seva-sim__who {
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  margin-bottom: 0.1rem;
}
.seva-sim__line--tx .seva-sim__who { color: #f87171; }
.seva-sim__line--rx .seva-sim__who { color: #38bdf8; }
/* Unlisted station (easter egg) — amber, so it reads as off-net traffic. */
.seva-sim__line--egg .seva-sim__who { color: #fbbf24; }
.seva-sim__line--egg .seva-sim__said { color: #fde68a; }
.seva-sim__said { color: #e2e8f0; }
.seva-sim__line--sys {
  color: #64748b;
  font-size: 0.66rem;
  font-style: italic;
  border-left: 2px solid rgba(148, 163, 184, 0.3);
  padding-left: 0.45rem;
}

.seva-sim__boot {
  color: #4ade80;
  font-size: 0.68rem;
  min-height: 1rem;
}

/* Completed run gets a soft confirmation glow. */
.seva-sim__stage.is-complete {
  border-color: rgba(34, 197, 94, 0.4);
  box-shadow: 0 0 0 1px rgba(34, 197, 94, 0.15);
}

/* ---- Focus + reduced motion ---------------------------------------------- */
.seva-sim :focus-visible {
  outline: 2px solid #7dd3fc;
  outline-offset: 2px;
  border-radius: 0.3rem;
}

@media (prefers-reduced-motion: reduce) {
  .seva-sim__knob,
  .seva-sim__ptt,
  .seva-sim__tablet-power,
  .seva-sim__cable,
  .seva-sim__stage:not(.is-linked) .seva-sim__radio:not(.is-on) .seva-sim__knob,
  .seva-sim__cable-pulse,
  .seva-sim__wave-bar {
    animation: none !important;
  }
  .seva-sim__stage.is-tx .seva-sim__wave-bar,
  .seva-sim__stage.is-rx .seva-sim__wave-bar { height: 48%; }
  .seva-sim__cable-jacket { transition: none; }
}