@import url('https://fonts.googleapis.com/css2?family=Orbitron:wght@400;700;900&family=Share+Tech+Mono&display=swap');

:root {
  --bg:        #050c12;
  --panel:     #08141e;
  --border:    rgba(0, 200, 255, 0.15);
  --accent:    #00c8ff;
  --accent2:   #00ff99;
  --danger:    #ff3d6b;
  --dim:       #1a4a5e;
  --text-muted:#2e7a96;
  --text-mid:  #5ab8d8;
}

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

body, html {
  height: 100%;
  font-family: 'Share Tech Mono', monospace;
  background: var(--bg);
  color: var(--accent);
  overflow: hidden;
}

/* Scanlines */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent 0px, transparent 3px,
    rgba(0,0,0,0.07) 3px, rgba(0,0,0,0.07) 4px
  );
  pointer-events: none;
  z-index: 200;
}

/* Background */
.bg-gradient {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background:
    radial-gradient(ellipse 70% 55% at 50% 0%,  rgba(0,80,120,0.3) 0%, transparent 65%),
    radial-gradient(ellipse 50% 40% at 10% 100%, rgba(0,40,80,0.2)  0%, transparent 60%),
    var(--bg);
}

/* Card */
.glass-card {
  position: relative;
  width: 400px;
  background: var(--panel);
  border: 1px solid var(--border);
  clip-path: polygon(
    0 20px, 20px 0,
    calc(100% - 20px) 0, 100% 20px,
    100% calc(100% - 20px), calc(100% - 20px) 100%,
    20px 100%, 0 calc(100% - 20px)
  );
  box-shadow: inset 0 0 80px rgba(0,20,40,0.9), 0 0 30px rgba(0,200,255,0.15);
  animation: fadeUp .7s cubic-bezier(.16,1,.3,1) both;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px) scale(.97); }
  to   { opacity: 1; transform: translateY(0)    scale(1);   }
}

/* Corner brackets */
.glass-card::before,
.glass-card::after {
  content: '';
  position: absolute;
  width: 14px; height: 14px;
  border-color: var(--accent);
  border-style: solid;
  opacity: .5;
}
.glass-card::before { top: 5px; left: 5px;     border-width: 2px 0 0 2px; }
.glass-card::after  { bottom: 5px; right: 5px; border-width: 0 2px 2px 0; }

/* Top bar */
.top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 13px 22px;
  border-bottom: 1px solid var(--dim);
  background: rgba(0,200,255,0.025);
}

.sys-id {
  font-family: 'Orbitron', monospace;
  font-size: .55rem;
  letter-spacing: .28em;
  color: var(--text-muted);
  text-transform: uppercase;
}

/* Status */
.status-container {
  display: flex;
  align-items: center;
  gap: 7px;
  font-size: .58rem;
  letter-spacing: .2em;
  color: var(--accent2);
}

.dot {
  width: 7px; height: 7px;
  background: var(--accent2);
  border-radius: 50%;
  animation: pulse 1.8s ease-in-out infinite;
}

@keyframes pulse {
  0%,100% { box-shadow: 0 0 0 0   rgba(0,255,153,.8); }
  50%      { box-shadow: 0 0 0 8px rgba(0,255,153,0);  }
}

/* Header */
header {
  padding: 20px 24px 0;
}

header h1 {
  font-family: 'Orbitron', monospace;
  font-size: .68rem;
  font-weight: 400;
  letter-spacing: .35em;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 16px;
}

/* Rule */
.rule {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--dim) 30%, var(--dim) 70%, transparent);
  margin: 0 24px;
}

/* Main */
main {
  padding: 32px 24px 22px;
  text-align: center;
}

/* Sonar rings */
.sonar-wrap {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 190px;
  height: 190px;
  margin-bottom: 16px;
}

.sonar-ring {
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(0,200,255,0.15);
  animation: sonarPulse 3s ease-out infinite;
}
.sonar-ring:nth-child(1) { width: 100%; height: 100%; animation-delay: 0s;  }
.sonar-ring:nth-child(2) { width: 68%;  height: 68%;  animation-delay: 1s;  }
.sonar-ring:nth-child(3) { width: 38%;  height: 38%;  animation-delay: 2s;  }

@keyframes sonarPulse {
  0%   { opacity: .6; transform: scale(.92); }
  60%  { opacity: .15; }
  100% { opacity: 0;  transform: scale(1.04); }
}

.value-inner {
  position: relative;
  z-index: 1;
}

#distance-display {
  font-family: 'Orbitron', monospace;
  font-size: 4.8rem;
  font-weight: 900;
  color: #fff;
  text-shadow: 0 0 20px rgba(0,200,255,.55), 0 0 60px rgba(0,200,255,.18);
  line-height: 1;
  display: block;
}

.unit {
  font-size: .8rem;
  color: var(--text-mid);
  letter-spacing: .22em;
  display: block;
  margin-top: 5px;
}

#time-stamp {
  font-size: .62rem;
  color: var(--text-muted);
  letter-spacing: .1em;
  margin-top: 6px;
}

/* Footer */
footer {
  padding: 15px 24px 22px;
  border-top: 1px solid var(--dim);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.btn-reset {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  border: 1px solid rgba(255,61,107,.4);
  color: var(--danger);
  padding: 9px 18px;
  font-family: 'Share Tech Mono', monospace;
  font-size: .62rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  cursor: pointer;
  clip-path: polygon(6px 0%, 100% 0%, calc(100% - 6px) 100%, 0% 100%);
  transition: background .2s, box-shadow .2s, border-color .2s;
}
.btn-reset:hover {
  background: rgba(255,61,107,.1);
  border-color: var(--danger);
  box-shadow: 0 0 16px rgba(255,61,107,.25);
}

.build-tag {
  font-size: .5rem;
  letter-spacing: .15em;
  color: var(--dim);
  text-align: right;
  line-height: 1.7;
}