:root {
  --bg-0: #020713;
  --bg-1: #06101f;
  --panel: rgba(5, 17, 34, 0.82);
  --panel-strong: rgba(7, 22, 43, 0.94);
  --line: rgba(38, 188, 255, 0.24);
  --line-strong: rgba(64, 214, 255, 0.66);
  --cyan: #52dcff;
  --cyan-soft: #8be8ff;
  --blue: #238cff;
  --text: #e8f8ff;
  --muted: #9bb6c8;
  --shadow: rgba(0, 0, 0, 0.48);
}

* {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  background: var(--bg-0);
}

body {
  position: relative;
  isolation: isolate;
  margin: 0;
  min-height: 100vh;
  overflow-x: hidden;
  color: var(--text);
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background:
    radial-gradient(circle at 80% 12%, rgba(0, 162, 255, 0.17), transparent 27%),
    linear-gradient(rgba(2, 7, 19, 0.68), rgba(2, 7, 19, 0.9)),
    url("bg.png");
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  background-attachment: fixed;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background: radial-gradient(circle at center, transparent 38%, rgba(0, 0, 0, 0.62) 100%);
}

.background-grid,
.background-stripes,
.background-glow,
.background-rings {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
}

details p {
  color: #e8f8ff;
}

.background-grid {
  opacity: 0.72;
  background-image:
    linear-gradient(rgba(57, 190, 255, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(57, 190, 255, 0.055) 1px, transparent 1px),
    linear-gradient(rgba(57, 190, 255, 0.022) 1px, transparent 1px),
    linear-gradient(90deg, rgba(57, 190, 255, 0.022) 1px, transparent 1px);
  background-size: 44px 44px, 44px 44px, 11px 11px, 11px 11px;
}

.background-stripes {
  opacity: 0.75;
  background: repeating-linear-gradient(
    -45deg,
    transparent 0 28px,
    rgba(46, 183, 255, 0.018) 28px 30px
  );
}

.background-glow {
  background:
    radial-gradient(circle at 88% 14%, rgba(43, 181, 255, 0.16), transparent 23%),
    radial-gradient(circle at 50% 40%, rgba(16, 90, 166, 0.08), transparent 44%);
}

.background-rings {
  left: auto;
  top: -34vh;
  right: -18vw;
  width: 85vw;
  height: 85vw;
  opacity: 0.12;
  border-radius: 50%;
  background: repeating-radial-gradient(
    circle at center,
    transparent 0 8.5%,
    rgba(75, 207, 255, 0.35) 8.7% 8.85%,
    transparent 9.05% 17.5%
  );
}

#signal-source {
  position: fixed;
  left: 90%;
  top: 15%;
  width: 5px;
  height: 5px;
  z-index: 0;
  pointer-events: none;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  background: #f0fbff;
  box-shadow:
    0 0 5px rgba(240, 251, 255, 1),
    0 0 16px rgba(96, 220, 255, 0.96),
    0 0 40px rgba(40, 162, 255, 0.62);
  animation: transmitter-flicker 2.8s ease-in-out infinite;
}

#signal-waves {
  position: fixed;
  left: 90%;
  top: 15%;
  width: 620px;
  aspect-ratio: 1;
  z-index: 0;
  pointer-events: none;
  border-radius: 50%;
  background: repeating-radial-gradient(
    circle at center,
    transparent 0 10.7%,
    rgba(113, 218, 255, 0.24) 10.9% 11.12%,
    transparent 11.35% 21.8%
  );
  background-position: center;
  background-repeat: no-repeat;
  background-size: 100% 100%;
  opacity: 0.05;
  filter: blur(0.25px);
  transform: translate(-50%, -50%) rotate(-8deg);
  transition: opacity 0.15s linear, filter 0.15s linear;
  animation: signal-expansion 18s ease-in-out infinite alternate;
}

.container {
  position: relative;
  z-index: 1;
  max-width: 1020px;
  margin: 0 auto;
  padding: 28px 28px 44px;
}

.panel {
  position: relative;
  margin-bottom: 18px;
  padding: 22px 24px;
  overflow: hidden;
  background:
    linear-gradient(180deg, rgba(16, 42, 69, 0.11), transparent 32%),
    linear-gradient(135deg, rgba(0, 180, 255, 0.045), transparent 42%),
    var(--panel);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow:
    0 24px 70px var(--shadow),
    inset 0 0 0 1px rgba(112, 220, 255, 0.035),
    inset 0 1px 0 rgba(164, 235, 255, 0.06);
  backdrop-filter: blur(16px) saturate(120%);
}

.panel::before,
.panel::after {
  content: "";
  position: absolute;
  width: 44px;
  height: 44px;
  pointer-events: none;
}

.panel::before {
  top: 10px;
  left: 10px;
  border-top: 2px solid var(--line-strong);
  border-left: 2px solid var(--line-strong);
  clip-path: polygon(0 0, 100% 0, 100% 2px, 12px 2px, 2px 12px, 2px 100%, 0 100%);
}

.panel::after {
  right: 10px;
  bottom: 10px;
  border-right: 2px solid var(--line-strong);
  border-bottom: 2px solid var(--line-strong);
  clip-path: polygon(100% 100%, 0 100%, 0 calc(100% - 2px), calc(100% - 12px) calc(100% - 2px), calc(100% - 2px) calc(100% - 12px), calc(100% - 2px) 0, 100% 0);
}

.panel-title {
  background:
    linear-gradient(100deg, rgba(18, 80, 129, 0.15), transparent 46%),
    var(--panel-strong);
}

.distance-panel {
  padding-bottom: 14px;
}

.distance-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 24px;
}

.distance-status {
  padding: 7px 11px;
  color: #b8ff9b;
  font-size: 0.75rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
  background: rgba(112, 255, 139, 0.06);
  border: 1px solid rgba(142, 255, 162, 0.22);
  border-radius: 999px;
}

.distance-scale {
  position: relative;
  height: 112px;
  margin: 18px 22px 0;
}

.distance-axis {
  position: absolute;
  top: 50px;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, #238cff, #52dcff);
  border-radius: 999px;
  box-shadow: 0 0 12px rgba(82, 220, 255, 0.55);
}

.distance-landmark,
.range-marker {
  position: absolute;
  top: 50px;
  left: var(--position);
}

.landmark-tick {
  position: absolute;
  left: -1px;
  width: 2px;
  height: 15px;
  background: rgba(139, 232, 255, 0.78);
}

.distance-landmark.upper .landmark-tick {
  bottom: 0;
}

.distance-landmark.lower .landmark-tick {
  top: 3px;
}

.distance-landmark.major .landmark-tick {
  height: 21px;
  background: #e8f8ff;
}

.landmark-label {
  position: absolute;
  left: 0;
  min-width: max-content;
  color: #c8dbe7;
  font-size: 0.65rem;
  line-height: 1.2;
  transform: translateX(-50%);
  text-align: center;
  white-space: nowrap;
}

.upper .landmark-label {
  bottom: 21px;
}

.lower .landmark-label {
  top: 23px;
}

@media (min-width: 761px) {
  .distance-landmark.stagger .landmark-label {
    top: 43px;
  }
}

.landmark-label strong,
.landmark-label small {
  display: block;
}

.landmark-label strong {
  color: #d8edf6;
  font-weight: 400;
}

.landmark-label small {
  margin-top: 2px;
  color: var(--muted);
  font-size: 0.6rem;
}

.distance-landmark.major .landmark-label strong {
  color: var(--cyan-soft);
}

.distance-landmark.edge-start .landmark-label {
  transform: none;
  text-align: left;
}

.distance-landmark.edge .landmark-label {
  transform: translateX(-100%);
  text-align: right;
}

.range-marker {
  z-index: 4;
  transition: left 0.28s ease-out;
}

.range-marker-line {
  position: absolute;
  left: -2px;
  bottom: -9px;
  width: 4px;
  height: 67px;
  background: linear-gradient(to bottom, #b8ff9b, rgba(184, 255, 155, 0.2));
  border-radius: 999px;
  box-shadow: 0 0 9px rgba(184, 255, 155, 0.78);
}

.range-marker-label {
  position: absolute;
  bottom: 63px;
  left: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 5px 8px;
  color: #8fffb9;
  font-size: 0.62rem;
  font-weight: 800;
  white-space: nowrap;
  transform: translateX(-50%);
  background: rgba(4, 22, 27, 0.94);
  border: 1px solid rgba(143, 255, 185, 0.5);
  border-radius: 6px;
  box-shadow: 0 0 18px rgba(105, 255, 155, 0.16);
}

.range-marker-label strong {
  color: #d9ffc9;
  font-size: 0.7rem;
  font-variant-numeric: tabular-nums;
  font-weight: 400;
}

.range-marker.below-scale .range-marker-label {
  transform: none;
}

.range-marker.above-scale .range-marker-label {
  transform: translateX(-100%);
}

.range-marker.invalid {
  display: none;
}

.panel-kicker,
.result-label {
  display: inline-block;
  margin-bottom: 8px;
  color: var(--cyan);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.18em;
}

h1,
h2 {
  margin: 0;
  color: var(--text);
  text-shadow: 0 0 18px rgba(73, 205, 255, 0.2);
}

h2 {
  font-size: clamp(1.35rem, 2.2vw, 1.75rem);
  font-weight: 650;
  letter-spacing: 0.02em;
}

.section-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 16px;
}

.status-chip {
  padding: 7px 11px;
  color: #8fffb9;
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.15em;
  background: rgba(44, 255, 128, 0.06);
  border: 1px solid rgba(76, 255, 151, 0.26);
  border-radius: 999px;
  box-shadow: inset 0 0 18px rgba(44, 255, 128, 0.04);
}

.formula {
  position: relative;
  margin-top: 16px;
  padding: 16px 20px;
  color: #c9f5ff;
  font-family: "Courier New", Courier, monospace;
  background:
    linear-gradient(90deg, rgba(24, 115, 179, 0.09), transparent 36%),
    rgba(4, 18, 36, 0.9);
  border: 1px solid rgba(82, 220, 255, 0.25);
  border-radius: 9px;
  box-shadow:
    inset 0 0 26px rgba(0, 158, 255, 0.035),
    0 0 24px rgba(0, 139, 255, 0.025);
}

.formula::before {
  content: "LINK EQUATION";
  position: absolute;
  top: -9px;
  left: 16px;
  padding: 0 8px;
  color: rgba(117, 224, 255, 0.72);
  font: 700 0.62rem "Segoe UI", sans-serif;
  letter-spacing: 0.16em;
  background: #061222;
}

.formula p {
  margin: 0;
  line-height: 1.8;
}

.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 11px 13px;
}

label {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 11px 12px;
  color: #c7d9e5;
  font-size: 0.84rem;
  font-weight: 650;
  background:
    linear-gradient(145deg, rgba(25, 101, 157, 0.055), transparent 45%),
    rgba(3, 15, 29, 0.56);
  border: 1px solid rgba(60, 184, 237, 0.12);
  border-radius: 10px;
}

label::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 32px;
  height: 1px;
  background: rgba(83, 219, 255, 0.55);
  box-shadow: 0 0 12px rgba(67, 201, 255, 0.34);
}

input[type="number"],
input[type="text"] {
  width: 100%;
  margin-top: 7px;
  padding: 8px 10px;
  color: var(--cyan-soft);
  font-size: 0.91rem;
  font-variant-numeric: tabular-nums;
  background:
    linear-gradient(180deg, rgba(21, 62, 92, 0.18), rgba(2, 13, 26, 0.68));
  border: 1px solid rgba(59, 191, 244, 0.28);
  border-radius: 7px;
  outline: none;
  box-shadow:
    inset 0 0 18px rgba(0, 137, 255, 0.035),
    0 0 0 1px rgba(0, 0, 0, 0.22);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

input[type="number"]:focus,
input[type="text"]:focus {
  border-color: var(--cyan);
  background: rgba(4, 25, 45, 0.9);
  box-shadow:
    0 0 0 3px rgba(67, 201, 255, 0.08),
    0 0 22px rgba(24, 154, 255, 0.12),
    inset 0 0 18px rgba(0, 155, 255, 0.06);
}

input[type="range"] {
  width: 100%;
  height: 4px;
  margin-top: 10px;
  appearance: none;
  -webkit-appearance: none;
  background: linear-gradient(90deg, rgba(37, 157, 240, 0.8), rgba(61, 214, 255, 0.32));
  border-radius: 999px;
  box-shadow: inset 0 0 8px rgba(0, 0, 0, 0.5);
}

input[type="range"]::-webkit-slider-thumb {
  width: 13px;
  height: 13px;
  appearance: none;
  -webkit-appearance: none;
  border: 1px solid #a7f4ff;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow:
    0 0 0 3px rgba(40, 199, 255, 0.12),
    0 0 15px rgba(40, 199, 255, 0.76);
  cursor: pointer;
}

input[type="range"]::-moz-range-thumb {
  width: 13px;
  height: 13px;
  border: 1px solid #a7f4ff;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 15px rgba(40, 199, 255, 0.76);
  cursor: pointer;
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  appearance: none;
  -webkit-appearance: none;
  margin: 0;
}

input[type="number"] {
  appearance: textfield;
  -moz-appearance: textfield;
}

.reset-container {
  grid-column: 1 / -1;
  display: flex;
  justify-content: center;
  padding-top: 1px;
}

button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-width: 150px;
  padding: 9px 18px;
  color: var(--text);
  font-size: 0.86rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.11em;
  cursor: pointer;
  background:
    linear-gradient(180deg, rgba(28, 137, 201, 0.24), rgba(5, 30, 54, 0.72));
  border: 1px solid rgba(82, 220, 255, 0.42);
  border-radius: 8px;
  box-shadow:
    0 12px 28px rgba(0, 0, 0, 0.25),
    inset 0 0 18px rgba(0, 167, 255, 0.055),
    0 0 16px rgba(0, 158, 255, 0.05);
  transition: transform 0.18s ease, border-color 0.18s ease, box-shadow 0.18s ease;
}

button:hover {
  transform: translateY(-1px);
  border-color: var(--cyan);
  box-shadow:
    0 15px 34px rgba(0, 0, 0, 0.32),
    0 0 24px rgba(39, 184, 255, 0.14),
    inset 0 0 22px rgba(0, 167, 255, 0.08);
}

.button-icon {
  color: var(--cyan);
  font-size: 1.08rem;
}

.result {
  position: relative;
  margin-top: 14px;
  padding: 15px 20px;
  color: #dceef7;
  background:
    linear-gradient(90deg, rgba(13, 90, 144, 0.1), transparent 55%),
    rgba(3, 17, 33, 0.86);
  border: 1px solid rgba(65, 202, 255, 0.27);
  border-radius: 9px;
  box-shadow: inset 0 0 24px rgba(0, 151, 255, 0.035);
}

.result::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 86px;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), transparent);
  box-shadow: 0 0 12px rgba(64, 214, 255, 0.7);
}

.result p {
  margin: 6px 0 0;
  line-height: 1.65;
  font-variant-numeric: tabular-nums;
}

.result strong {
  color: var(--cyan);
  text-shadow: 0 0 14px rgba(73, 215, 255, 0.3);
}

.notes ul {
  display: grid;
/*  grid-template-columns: repeat(2, minmax(0, 1fr)); */
  gap: 10px 24px;
  padding-left: 18px;
  margin: 22px 0 0;
}

.notes li {
  color: #aac0ce;
  line-height: 1.55;
}

.notes li::marker {
  color: var(--cyan);
}

.nowrap {
  white-space: nowrap;
}

@media (max-width: 1080px) {
  .container {
    max-width: 920px;
  }

  .grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 760px) {
  body {
    background-attachment: scroll;
  }

  .container {
    padding: 24px 16px 40px;
  }

  .panel {
    padding: 24px 18px;
  }

  .grid,
  .notes ul {
    grid-template-columns: 1fr;
  }

  .section-heading {
    align-items: center;
  }

  .status-chip {
    display: none;
  }

  .distance-heading {
    display: block;
  }

  .distance-status {
    display: inline-block;
    margin-top: 12px;
  }

  .distance-scale {
    height: 270px;
    margin: 18px 8px 0 24px;
  }

  .distance-axis {
    top: 0;
    bottom: 0;
    left: 0;
    right: auto;
    width: 3px;
    height: auto;
    background: linear-gradient(180deg, #238cff, #52dcff);
  }

  .distance-axis::after {
    top: auto;
    bottom: 0;
    left: 26px;
    transform: none;
  }

  .distance-landmark,
  .range-marker {
    top: var(--position);
    left: 0;
  }

  .landmark-tick,
  .distance-landmark.upper .landmark-tick,
  .distance-landmark.lower .landmark-tick {
    top: -1px;
    bottom: auto;
    left: -8px;
    width: 17px;
    height: 2px;
  }

  .distance-landmark.major .landmark-tick {
    width: 23px;
    height: 2px;
    left: -11px;
  }

  .landmark-label,
  .upper .landmark-label,
  .lower .landmark-label,
  .distance-landmark.edge-start .landmark-label,
  .distance-landmark.edge .landmark-label {
    top: 0;
    bottom: auto;
    left: 17px;
    transform: translateY(-50%);
    text-align: left;
  }

  .range-marker-line {
    top: -2px;
    bottom: auto;
    left: -97px;
    width: 194px;
    height: 4px;
    background: linear-gradient(90deg, rgba(184, 255, 155, 0.12), #b8ff9b, rgba(184, 255, 155, 0.12));
  }

  .range-marker-label,
  .range-marker.below-scale .range-marker-label,
  .range-marker.above-scale .range-marker-label {
    bottom: auto;
    top: -7px;
    left: -96px;
    transform: translateY(-100%);
  }

  #signal-waves {
    top: 40px;
    left: 92%;
    width: 390px;
  }

  #signal-source {
    top: 40px;
    left: 92%;
  }

  .background-rings {
    top: -10vh;
    right: -50vw;
    width: 150vw;
    height: 150vw;
  }
}

@keyframes signal-expansion {
  from { background-size: 100% 100%; }
  to { background-size: 120% 120%; }
}

@keyframes transmitter-flicker {
  0%, 100% {
    opacity: 0.82;
    transform: translate(-50%, -50%) scale(0.9);
  }
  50% {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1.18);
  }
}