:root {
  --ink: #17201f;
  --muted: #66706c;
  --paper: #f4f6f2;
  --panel: #ffffff;
  --line: #d8ded7;
  --graphite: #111615;
  --teal: #1d9a96;
  --teal-dark: #126b68;
  --amber: #d99b28;
  --coral: #c95c3f;
  --leaf: #657d4f;
  --shadow: 0 22px 60px rgba(22, 32, 31, 0.14);
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "Apple SD Gothic Neo", "Noto Sans KR", sans-serif;
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 64px;
  padding: 12px clamp(18px, 4vw, 54px);
  background: rgba(244, 246, 242, 0.9);
  border-bottom: 1px solid rgba(216, 222, 215, 0.86);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  font-weight: 800;
  letter-spacing: 0;
}

.brand-mark {
  width: 28px;
  height: 28px;
  flex: 0 0 auto;
  border: 2px solid var(--teal);
  border-radius: 50%;
  background:
    radial-gradient(circle at 50% 50%, var(--amber) 0 3px, transparent 4px),
    conic-gradient(from 20deg, transparent 0 22%, rgba(29, 154, 150, 0.35) 22% 34%, transparent 34% 58%, rgba(201, 92, 63, 0.35) 58% 70%, transparent 70%);
}

.top-nav {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: clamp(12px, 3vw, 28px);
  color: #34403d;
  font-size: 0.95rem;
  font-weight: 700;
}

.top-nav a {
  position: relative;
  white-space: nowrap;
}

.top-nav a::after {
  position: absolute;
  left: 0;
  bottom: -7px;
  width: 100%;
  height: 2px;
  content: "";
  background: var(--coral);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 180ms ease;
}

.top-nav a:hover::after,
.top-nav a:focus-visible::after {
  transform: scaleX(1);
}

.hero {
  position: relative;
  min-height: min(760px, 82svh);
  overflow: hidden;
  background: var(--graphite);
  color: #f7fbf8;
  isolation: isolate;
}

.hero-image,
.hero-canvas,
.hero-shade {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-image {
  object-fit: cover;
  opacity: 0.88;
  filter: saturate(1.05) contrast(1.04);
  z-index: -3;
}

.hero-canvas {
  z-index: -1;
  pointer-events: none;
}

.hero-shade {
  z-index: -2;
  background:
    linear-gradient(90deg, rgba(17, 22, 21, 0.92) 0%, rgba(17, 22, 21, 0.72) 42%, rgba(17, 22, 21, 0.2) 100%),
    linear-gradient(0deg, rgba(17, 22, 21, 0.94) 0%, rgba(17, 22, 21, 0.08) 42%);
}

.hero-content {
  position: relative;
  z-index: 2;
  width: min(760px, calc(100% - 36px));
  padding: clamp(78px, 11vw, 128px) 0 148px clamp(18px, 8vw, 104px);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--amber);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1,
h2,
h3 {
  margin: 0;
  letter-spacing: 0;
  line-height: 1.12;
}

h1 {
  max-width: 9ch;
  font-size: clamp(3.2rem, 9vw, 7.6rem);
  font-weight: 900;
}

.hero-copy {
  width: min(670px, 100%);
  margin: 24px 0 0;
  color: rgba(247, 251, 248, 0.86);
  font-size: clamp(1.05rem, 2vw, 1.32rem);
  line-height: 1.72;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.primary-link,
.secondary-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 850;
}

.primary-link {
  background: var(--amber);
  color: #1f1710;
}

.secondary-link {
  border-color: rgba(247, 251, 248, 0.36);
  color: #f7fbf8;
}

.primary-link:hover,
.secondary-link:hover,
.filter-button:hover,
.mode-button:hover {
  transform: translateY(-1px);
}

.hero-metrics {
  position: absolute;
  right: clamp(18px, 5vw, 72px);
  bottom: 28px;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(3, minmax(96px, 1fr));
  width: min(520px, calc(100% - 36px));
  overflow: hidden;
  border: 1px solid rgba(247, 251, 248, 0.22);
  border-radius: 8px;
  background: rgba(17, 22, 21, 0.48);
  backdrop-filter: blur(18px);
}

.hero-metrics div {
  min-width: 0;
  padding: 16px;
  border-right: 1px solid rgba(247, 251, 248, 0.16);
}

.hero-metrics div:last-child {
  border-right: 0;
}

.metric-value {
  display: block;
  color: #ffffff;
  font-size: clamp(1.2rem, 2vw, 1.65rem);
  font-weight: 900;
  line-height: 1.1;
}

.metric-label {
  display: block;
  margin-top: 5px;
  color: rgba(247, 251, 248, 0.72);
  font-size: 0.86rem;
  font-weight: 700;
}

.intro-section,
.tech-section,
.route-section,
.operators-section {
  width: min(1180px, calc(100% - 36px));
  margin: 0 auto;
  padding: clamp(58px, 9vw, 96px) 0;
}

.section-heading {
  display: grid;
  grid-template-columns: minmax(180px, 0.36fr) minmax(0, 0.64fr);
  gap: clamp(18px, 5vw, 62px);
  align-items: end;
  margin-bottom: 32px;
}

.section-heading h2,
.lab-copy h2 {
  font-size: clamp(2rem, 4vw, 4rem);
  font-weight: 900;
}

.principle-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.principle {
  min-height: 220px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.94), rgba(255, 255, 255, 0.78)),
    radial-gradient(circle at 100% 0%, rgba(217, 155, 40, 0.16), transparent 38%);
}

.principle-index {
  display: block;
  color: var(--coral);
  font-size: 0.82rem;
  font-weight: 900;
}

.principle h3 {
  margin-top: 28px;
  font-size: 1.55rem;
}

.principle p,
.tech-card p,
.lab-copy p,
.route-step p {
  color: var(--muted);
}

.filter-bar,
.mode-switch {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 7px;
  padding: 6px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.72);
}

.filter-bar {
  margin-bottom: 24px;
}

.filter-button,
.mode-button {
  min-height: 38px;
  padding: 0 14px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: #3a4542;
  cursor: pointer;
  font-weight: 850;
  transition:
    transform 160ms ease,
    background 160ms ease,
    color 160ms ease;
}

.filter-button.is-active,
.mode-button.is-active {
  background: var(--ink);
  color: #ffffff;
}

.tech-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.tech-card {
  display: flex;
  min-height: 372px;
  flex-direction: column;
  justify-content: space-between;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 1px 0 rgba(23, 32, 31, 0.03);
  transition:
    transform 200ms ease,
    box-shadow 200ms ease,
    border-color 200ms ease,
    opacity 200ms ease;
}

.tech-card:hover {
  transform: translateY(-4px);
  border-color: rgba(29, 154, 150, 0.42);
  box-shadow: var(--shadow);
}

.tech-card.is-hidden {
  display: none;
}

.card-topline {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: var(--leaf);
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.tech-card h3 {
  margin-top: 18px;
  font-size: 1.42rem;
}

.formula {
  display: grid;
  place-items: center;
  min-height: 104px;
  margin: 20px 0 16px;
  padding: 16px;
  overflow-x: auto;
  border: 1px solid rgba(216, 222, 215, 0.8);
  border-radius: 8px;
  background:
    linear-gradient(120deg, rgba(29, 154, 150, 0.09), rgba(217, 155, 40, 0.12)),
    #fbfcf8;
}

math {
  max-width: 100%;
  color: #14201d;
  font-family: "Times New Roman", Cambria Math, serif;
  font-size: clamp(1.05rem, 1.5vw, 1.32rem);
}

.tech-card p {
  margin: 0;
  font-size: 0.98rem;
}

.lab-section {
  display: grid;
  grid-template-columns: minmax(260px, 0.38fr) minmax(0, 0.62fr);
  gap: clamp(26px, 5vw, 72px);
  align-items: center;
  padding: clamp(64px, 10vw, 104px) clamp(18px, 6vw, 72px);
  background:
    linear-gradient(120deg, rgba(17, 22, 21, 0.96), rgba(29, 45, 41, 0.96)),
    var(--graphite);
  color: #f7fbf8;
}

.lab-copy {
  min-width: 0;
}

.lab-copy p {
  max-width: 550px;
  color: rgba(247, 251, 248, 0.74);
  font-size: 1.04rem;
}

.mode-switch {
  margin-top: 28px;
  border-color: rgba(247, 251, 248, 0.18);
  background: rgba(247, 251, 248, 0.08);
}

.mode-button {
  color: rgba(247, 251, 248, 0.78);
}

.mode-button.is-active {
  background: var(--amber);
  color: #21170c;
}

.signal-panel {
  min-width: 0;
  overflow: hidden;
  border: 1px solid rgba(247, 251, 248, 0.14);
  border-radius: 8px;
  background: rgba(247, 251, 248, 0.05);
}

#signalCanvas {
  display: block;
  width: 100%;
  aspect-ratio: 900 / 520;
  background:
    linear-gradient(rgba(247, 251, 248, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(247, 251, 248, 0.05) 1px, transparent 1px),
    #111615;
  background-size: 44px 44px;
}

.signal-readout {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  min-height: 68px;
  padding: 14px 18px;
  border-top: 1px solid rgba(247, 251, 248, 0.12);
}

.signal-readout span:first-child {
  color: var(--amber);
  font-size: 1.1rem;
  font-weight: 900;
}

.signal-readout span:last-child {
  color: rgba(247, 251, 248, 0.72);
  text-align: right;
}

.route-list {
  position: relative;
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.route-step {
  position: relative;
  min-height: 238px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.route-step::after {
  position: absolute;
  top: 32px;
  right: -13px;
  width: 14px;
  height: 2px;
  content: "";
  background: var(--coral);
}

.route-step:last-child::after {
  display: none;
}

.route-step > span {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 50%;
  background: var(--teal);
  color: #ffffff;
  font-weight: 900;
}

.route-step h3 {
  margin-top: 22px;
  font-size: 1.14rem;
}

.route-step p {
  margin-bottom: 0;
  font-size: 0.94rem;
}

.operators-section {
  padding-top: 0;
}

.operator-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.operator-card {
  min-height: 218px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.96), rgba(255, 255, 255, 0.84)),
    radial-gradient(circle at 100% 0%, rgba(29, 154, 150, 0.15), transparent 42%);
}

.operator-tag {
  display: inline-flex;
  min-height: 28px;
  align-items: center;
  padding: 0 10px;
  border-radius: 999px;
  background: rgba(29, 154, 150, 0.1);
  color: var(--teal-dark);
  font-size: 0.74rem;
  font-weight: 900;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.operator-card h3 {
  margin-top: 22px;
  font-size: 1.18rem;
}

.operator-card p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.site-footer {
  padding: 30px 18px 42px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  text-align: center;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition:
    opacity 520ms ease,
    transform 520ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 980px) {
  .section-heading,
  .lab-section {
    grid-template-columns: 1fr;
  }

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

  .route-list {
    grid-template-columns: 1fr;
  }

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

  .route-step {
    min-height: auto;
  }

  .route-step::after {
    top: auto;
    right: auto;
    bottom: -13px;
    left: 38px;
    width: 2px;
    height: 14px;
  }
}

@media (max-width: 720px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }

  .top-nav {
    width: 100%;
    justify-content: space-between;
    gap: 10px;
    font-size: 0.9rem;
  }

  .hero {
    min-height: 84svh;
  }

  .hero-content {
    width: calc(100% - 30px);
    padding: 62px 0 190px 15px;
  }

  h1 {
    max-width: 8ch;
    font-size: clamp(3rem, 18vw, 4.8rem);
  }

  .hero-copy {
    font-size: 1rem;
  }

  .hero-metrics {
    left: 15px;
    right: 15px;
    grid-template-columns: 1fr;
    width: auto;
  }

  .hero-metrics div {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    border-right: 0;
    border-bottom: 1px solid rgba(247, 251, 248, 0.16);
  }

  .hero-metrics div:last-child {
    border-bottom: 0;
  }

  .principle-grid,
  .tech-grid,
  .operator-grid {
    grid-template-columns: 1fr;
  }

  .tech-card {
    min-height: auto;
  }

  .filter-bar,
  .mode-switch {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    width: 100%;
  }

  .filter-button,
  .mode-button {
    width: 100%;
  }

  .signal-readout {
    align-items: flex-start;
    flex-direction: column;
  }

  .signal-readout span:last-child {
    text-align: left;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}