@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@400;600;700&family=Poppins:wght@500;600&display=swap');

.hz-das-principle,
.hz-das-principle * {
  box-sizing: border-box;
}

.hz-das-principle {
  --hz-orange: #ec682e;
  --hz-navy: #071d33;
  --hz-blue: #0b2f4d;
  --hz-cyan: #39c6ff;
  --hz-green: #72d572;
  --hz-purple: #a78bfa;
  --hz-red: #ff6b4a;
  --hz-yellow: #ffd166;
  --hz-text: #4b5563;
  --hz-muted: #64748b;
  --hz-border: #e5e7eb;
  --hz-soft: #f7f9fc;

  width: 100%;
  overflow: hidden;
  background: #ffffff;
  color: var(--hz-text);
  font-family: 'Open Sans', Arial, sans-serif;
  line-height: 1.65;
}

.hz-das-principle h2,
.hz-das-principle h3,
.hz-das-principle p {
  margin: 0;
}

.hz-das-principle-section {
  padding: 86px 0;
  background: #ffffff;
}

.hz-das-principle-container {
  max-width: 1380px;
  margin: 0 auto;
  padding: 0 40px;
}

.hz-das-principle-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  color: var(--hz-orange);
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 1.8px;
  text-transform: uppercase;
}

.hz-das-principle-eyebrow::before {
  content: "";
  width: 38px;
  height: 2px;
  background: var(--hz-orange);
  display: inline-block;
}

.hz-das-principle-title {
  max-width: 1080px;
  margin-bottom: 18px;
  color: var(--hz-navy);
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 44px;
  line-height: 1.18;
  font-weight: 500;
  letter-spacing: -1px;
}

.hz-das-principle-desc {
  max-width: 1080px;
  color: var(--hz-text);
  font-size: 17px;
  line-height: 1.8;
}

/* Main visual */
.hz-das-demo {
  margin-top: 46px;
  padding: 42px;
  border-radius: 28px;
  background:
    radial-gradient(circle at 88% 12%, rgba(236, 104, 46, 0.18), transparent 34%),
    linear-gradient(135deg, #071d33 0%, #0b2f4d 100%);
  box-shadow: 0 28px 80px rgba(7, 29, 51, 0.16);
  overflow: hidden;
}

.hz-das-demo-grid {
  display: grid;
  grid-template-columns: 0.88fr 1.12fr;
  gap: 42px;
  align-items: center;
}

.hz-das-demo-copy h3 {
  margin-bottom: 16px;
  color: #ffffff;
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 30px;
  line-height: 1.25;
  font-weight: 500;
}

.hz-das-demo-copy p {
  color: rgba(255, 255, 255, 0.78);
  font-size: 16px;
  line-height: 1.8;
}

.hz-das-equation {
  margin-top: 24px;
  padding: 18px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.13);
}

.hz-das-equation strong {
  display: block;
  margin-bottom: 8px;
  color: #ffffff;
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 16px;
  font-weight: 600;
}

.hz-das-equation span {
  display: block;
  color: rgba(255, 255, 255, 0.72);
  font-size: 14px;
  line-height: 1.65;
}

.hz-das-kpi-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 22px;
}

.hz-das-kpi {
  padding: 16px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.13);
}

.hz-das-kpi strong {
  display: block;
  margin-bottom: 4px;
  color: #ffffff;
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 18px;
  font-weight: 600;
}

.hz-das-kpi span {
  display: block;
  color: rgba(255, 255, 255, 0.66);
  font-size: 12.5px;
  line-height: 1.45;
}

/* Animation panel */
.hz-das-anim {
  position: relative;
  min-height: 480px;
  padding: 28px;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.13);
  overflow: hidden;
}

.hz-das-device {
  position: absolute;
  left: 28px;
  top: 38%;
  transform: translateY(-50%);
  width: 132px;
  height: 88px;
  border-radius: 14px;
  background: linear-gradient(180deg, #ffffff 0%, #d9e4ee 100%);
  box-shadow: 0 18px 38px rgba(0, 0, 0, 0.28);
  z-index: 8;
}

.hz-das-device::before {
  content: "iDAS";
  position: absolute;
  left: 18px;
  top: 18px;
  color: var(--hz-navy);
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 20px;
  font-weight: 600;
}

.hz-das-device::after {
  content: "Phase + OTDR";
  position: absolute;
  left: 18px;
  bottom: 16px;
  color: #64748b;
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.6px;
}

.hz-das-fiber {
  position: absolute;
  left: 162px;
  right: 34px;
  top: 38%;
  height: 150px;
  transform: translateY(-50%);
  z-index: 4;
}

.hz-das-fiber-line {
  position: absolute;
  left: 0;
  right: 0;
  top: 72px;
  height: 7px;
  border-radius: 999px;
  background: linear-gradient(90deg, #54c9ff, #ffffff, #54c9ff);
  box-shadow: 0 0 22px rgba(57, 198, 255, 0.62);
}

/* Laser pulse forward */
.hz-das-laser {
  position: absolute;
  top: 63px;
  left: 0;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: #ffffff;
  box-shadow:
    0 0 12px rgba(255, 255, 255, 0.95),
    0 0 30px rgba(57, 198, 255, 0.95);
  animation: hz-das-laser-move 4.8s linear infinite;
}

.hz-das-laser::before {
  content: "Laser pulse";
  position: absolute;
  left: -28px;
  top: -36px;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(57, 198, 255, 0.16);
  border: 1px solid rgba(57, 198, 255, 0.35);
  color: #e5f8ff;
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 11px;
  font-weight: 600;
  white-space: nowrap;
}

@keyframes hz-das-laser-move {
  0% { left: 0%; opacity: 0; }
  8% { opacity: 1; }
  84% { opacity: 1; }
  100% { left: calc(100% - 24px); opacity: 0; }
}

/* Vibration event */
.hz-das-vibration {
  position: absolute;
  top: 22px;
  left: 60%;
  width: 84px;
  height: 84px;
  border-radius: 50%;
  background: rgba(236, 104, 46, 0.15);
  border: 1px solid rgba(236, 104, 46, 0.62);
  box-shadow: 0 0 40px rgba(236, 104, 46, 0.48);
  animation: hz-das-vibration-pulse 1.8s ease-in-out infinite;
}

.hz-das-vibration::before {
  content: "Vibration / Sound";
  position: absolute;
  left: 50%;
  top: -36px;
  transform: translateX(-50%);
  padding: 5px 10px;
  border-radius: 999px;
  background: var(--hz-orange);
  color: #ffffff;
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 11px;
  font-weight: 600;
  white-space: nowrap;
}

.hz-das-vibration::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -42px;
  width: 2px;
  height: 62px;
  background: rgba(236, 104, 46, 0.85);
  transform: translateX(-50%);
}

@keyframes hz-das-vibration-pulse {
  0%, 100% { transform: scale(0.9); opacity: 0.72; }
  50% { transform: scale(1.08); opacity: 1; }
}

.hz-das-wave {
  position: absolute;
  left: 60%;
  top: 63px;
  width: 84px;
  height: 26px;
  transform: translateX(-8%);
  z-index: 7;
}

.hz-das-wave span {
  position: absolute;
  bottom: 0;
  width: 4px;
  border-radius: 999px;
  background: var(--hz-orange);
  animation: hz-das-wave-bars 0.9s ease-in-out infinite;
}

.hz-das-wave span:nth-child(1) { left: 0; height: 10px; animation-delay: 0s; }
.hz-das-wave span:nth-child(2) { left: 10px; height: 18px; animation-delay: 0.1s; }
.hz-das-wave span:nth-child(3) { left: 20px; height: 26px; animation-delay: 0.2s; }
.hz-das-wave span:nth-child(4) { left: 30px; height: 16px; animation-delay: 0.3s; }
.hz-das-wave span:nth-child(5) { left: 40px; height: 22px; animation-delay: 0.4s; }
.hz-das-wave span:nth-child(6) { left: 50px; height: 12px; animation-delay: 0.5s; }
.hz-das-wave span:nth-child(7) { left: 60px; height: 24px; animation-delay: 0.6s; }

@keyframes hz-das-wave-bars {
  0%, 100% { transform: scaleY(0.55); opacity: 0.55; }
  50% { transform: scaleY(1.2); opacity: 1; }
}

/* Rayleigh return signal */
.hz-das-rayleigh {
  position: absolute;
  right: 5%;
  top: 64px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--hz-purple);
  box-shadow: 0 0 24px rgba(167, 139, 250, 0.9);
  animation: hz-das-return 4.8s linear infinite;
}

.hz-das-rayleigh::before {
  content: "Rayleigh backscatter";
  position: absolute;
  top: -32px;
  right: -12px;
  padding: 4px 9px;
  border-radius: 999px;
  background: rgba(167, 139, 250, 0.2);
  border: 1px solid rgba(167, 139, 250, 0.45);
  color: #ffffff;
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 11px;
  font-weight: 600;
  white-space: nowrap;
}

.hz-das-rayleigh::after {
  content: "";
  position: absolute;
  top: 8px;
  left: 14px;
  width: 90px;
  height: 4px;
  border-radius: 999px;
  background: linear-gradient(90deg, rgba(167, 139, 250, 0.95), transparent);
}

@keyframes hz-das-return {
  0%, 44% { right: 5%; opacity: 0; }
  52% { opacity: 1; }
  100% { right: calc(100% - 20px); opacity: 0; }
}

/* Phase demodulation panel */
.hz-das-analysis {
  position: absolute;
  left: 28px;
  right: 28px;
  bottom: 24px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  z-index: 10;
}

.hz-das-panel {
  padding: 18px;
  border-radius: 18px;
  background: rgba(7, 29, 51, 0.68);
  border: 1px solid rgba(255, 255, 255, 0.13);
}

.hz-das-panel strong {
  display: block;
  margin-bottom: 8px;
  color: #ffffff;
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 15px;
  font-weight: 600;
}

.hz-das-panel span {
  display: block;
  color: rgba(255, 255, 255, 0.68);
  font-size: 13px;
  line-height: 1.55;
}

.hz-das-phase-line {
  position: relative;
  height: 50px;
  margin-top: 10px;
  border-bottom: 1px solid rgba(255,255,255,0.18);
  overflow: hidden;
}

.hz-das-phase-line::before {
  content: "";
  position: absolute;
  left: -20%;
  bottom: 12px;
  width: 140%;
  height: 26px;
  background:
    repeating-linear-gradient(
      90deg,
      transparent 0,
      transparent 12px,
      rgba(255, 209, 102, 0.95) 13px,
      rgba(255, 209, 102, 0.95) 15px
    );
  clip-path: polygon(
    0% 55%,
    8% 35%,
    16% 62%,
    24% 34%,
    32% 68%,
    40% 42%,
    48% 70%,
    56% 28%,
    64% 72%,
    72% 40%,
    80% 65%,
    88% 45%,
    100% 58%,
    100% 100%,
    0% 100%
  );
  animation: hz-das-phase-scroll 2.4s linear infinite;
}

@keyframes hz-das-phase-scroll {
  0% { transform: translateX(0); opacity: 0.72; }
  50% { opacity: 1; }
  100% { transform: translateX(14%); opacity: 0.72; }
}

.hz-das-location-line {
  position: relative;
  height: 50px;
  margin-top: 10px;
  border-bottom: 1px solid rgba(255,255,255,0.18);
}

.hz-das-location-line::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 25px;
  height: 4px;
  border-radius: 999px;
  background: rgba(255,255,255,0.22);
}

.hz-das-location-line::after {
  content: "Event @ 12.8 km";
  position: absolute;
  left: 60%;
  top: 0;
  transform: translateX(-50%);
  padding: 4px 9px;
  border-radius: 999px;
  background: rgba(236, 104, 46, 0.18);
  border: 1px solid rgba(236, 104, 46, 0.45);
  color: #ffffff;
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 11px;
  font-weight: 600;
  white-space: nowrap;
}

.hz-das-location-dot {
  position: absolute;
  left: 60%;
  top: 18px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--hz-orange);
  box-shadow: 0 0 18px rgba(236, 104, 46, 0.9);
  transform: translateX(-50%);
  animation: hz-das-location-pulse 1.4s ease-in-out infinite;
}

@keyframes hz-das-location-pulse {
  0%, 100% { transform: translateX(-50%) scale(0.85); opacity: 0.65; }
  50% { transform: translateX(-50%) scale(1.18); opacity: 1; }
}

/* Step cards */
.hz-das-step-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: 26px;
}

.hz-das-step {
  padding: 20px 22px;
  border-radius: 18px;
  background: #ffffff;
  border: 1px solid var(--hz-border);
  box-shadow: 0 14px 34px rgba(7, 29, 51, 0.045);
}

.hz-das-step span {
  display: block;
  margin-bottom: 10px;
  color: var(--hz-orange);
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 13px;
  font-weight: 600;
}

.hz-das-step h3 {
  margin-bottom: 8px;
  color: var(--hz-navy);
  font-family: 'Poppins', Arial, sans-serif;
  font-size: 18px;
  line-height: 1.3;
  font-weight: 500;
}

.hz-das-step p {
  color: var(--hz-text);
  font-size: 14.5px;
  line-height: 1.65;
}

@media (max-width: 1180px) {
  .hz-das-demo-grid {
    grid-template-columns: 1fr;
  }

  .hz-das-principle-title {
    font-size: 38px;
  }

  .hz-das-step-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .hz-das-principle-container {
    padding: 0 22px;
  }

  .hz-das-principle-section {
    padding: 62px 0;
  }

  .hz-das-principle-title {
    font-size: 30px;
    letter-spacing: -0.7px;
  }

  .hz-das-principle-desc {
    font-size: 16px;
  }

  .hz-das-demo {
    padding: 24px;
    border-radius: 22px;
  }

  .hz-das-demo-copy h3 {
    font-size: 26px;
  }

  .hz-das-anim {
    min-height: 590px;
    padding: 18px;
  }

  .hz-das-device {
    width: 92px;
    height: 68px;
    left: 18px;
  }

  .hz-das-device::before {
    left: 13px;
    top: 14px;
    font-size: 16px;
  }

  .hz-das-device::after {
    left: 13px;
    bottom: 13px;
    font-size: 9px;
  }

  .hz-das-fiber {
    left: 118px;
    right: 18px;
  }

  .hz-das-vibration {
    left: 56%;
  }

  .hz-das-analysis,
  .hz-das-step-grid,
  .hz-das-kpi-row {
    grid-template-columns: 1fr;
  }

  .hz-das-analysis {
    left: 18px;
    right: 18px;
  }
}