:root {
  --bg: #f6f5f9;
  --surface: #ffffff;
  --ink: #16151d;
  --ink-muted: #5c5a68;
  --ink-soft: #8b8897;
  --line: #e8e6ef;
  --line-strong: #d4d0e0;
  --accent: #2f3a8f;
  --accent-hover: #252d6f;
  --accent-soft: #e8eafc;
  --hero-overlay: rgba(18, 20, 40, 0.72);
  --shadow-sm: 0 1px 2px rgba(22, 21, 29, 0.04);
  --shadow-md: 0 12px 40px rgba(22, 21, 29, 0.08);
  --radius: 14px;
  --radius-lg: 22px;
  --font-sans: "Noto Sans KR", system-ui, sans-serif;
  --font-display: "DM Sans", "Noto Sans KR", system-ui, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  font-size: 1rem;
  -webkit-font-smoothing: antialiased;
}

p,
h1,
h2,
h3 {
  word-break: keep-all;
  overflow-wrap: anywhere;
}

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.15em;
}

a:hover {
  color: var(--accent-hover);
}

a:focus-visible,
.btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.nav a:focus-visible {
  outline-offset: 2px;
  border-radius: 4px;
}

.bg-gradient {
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(47, 58, 143, 0.09), transparent 55%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(130, 140, 200, 0.12), transparent 50%),
    var(--bg);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem clamp(1.25rem, 4vw, 2.5rem);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid color-mix(in srgb, var(--line) 85%, transparent);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--ink);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: -0.02em;
}

.logo img {
  border-radius: 50%;
  display: block;
}

.sprite {
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
}

.icon {
  flex-shrink: 0;
  display: block;
}

.nav {
  display: flex;
  align-items: center;
  gap: clamp(0.65rem, 2.2vw, 1.35rem);
  margin-left: auto;
  min-width: 0;
}

.nav a {
  display: inline-flex;
  align-items: center;
  gap: 0.38rem;
  color: var(--ink-muted);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 600;
  white-space: nowrap;
}

.nav a:hover {
  color: var(--ink);
}

.icon--nav {
  color: currentColor;
  opacity: 0.88;
}

.nav a:hover .icon--nav {
  opacity: 1;
}

.btn .btn__icon {
  flex-shrink: 0;
}

.site-header .btn--ghost .btn__icon {
  color: var(--accent);
  opacity: 0.95;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  padding: 0.62rem 1.15rem;
  border-radius: 999px;
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition:
    background 0.15s ease,
    color 0.15s ease,
    border-color 0.15s ease;
}

.btn--primary {
  background: var(--ink);
  color: #fff;
  border-color: var(--ink);
}

.btn--primary:hover {
  background: #0e0d12;
  color: #fff;
}

.btn--secondary {
  background: transparent;
  color: var(--ink);
  border-color: var(--line-strong);
}

.btn--secondary:hover {
  background: var(--surface);
  border-color: var(--ink-soft);
  color: var(--ink);
}

.btn--small {
  padding: 0.48rem 0.95rem;
  font-size: 0.8125rem;
}

.btn--ghost {
  background: var(--surface);
  color: var(--ink);
  border-color: var(--line);
  box-shadow: var(--shadow-sm);
}

.btn--ghost:hover {
  border-color: var(--line-strong);
  background: #fafafc;
}

.hero {
  min-height: min(78vh, 720px);
  display: flex;
  align-items: flex-end;
  padding: clamp(2rem, 6vw, 4rem) clamp(1.25rem, 4vw, 2.5rem) clamp(2.5rem, 5vw, 3.5rem);
  background:
    linear-gradient(165deg, var(--hero-overlay), rgba(18, 20, 40, 0.55)),
    url("./assets/city-image.jpg") center / cover no-repeat;
  color: #fff;
}

.hero__inner {
  width: min(1080px, 100%);
  margin: 0 auto;
}

.hero__label {
  margin: 0 0 0.75rem;
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: rgba(255, 255, 255, 0.88);
  font-family: var(--font-display);
}

.hero__title {
  margin: 0;
  font-size: clamp(1.55rem, 3.8vw, 2.45rem);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: -0.03em;
  max-width: 22rem;
}

@media (min-width: 640px) {
  .hero__title {
    max-width: 38rem;
  }
}

.hero__lead {
  margin: 0.9rem 0 0;
  max-width: 38rem;
  font-size: clamp(0.9375rem, 1.35vw, 1.0625rem);
  line-height: 1.75;
  color: rgba(245, 246, 252, 0.92);
}

.hero__actions {
  margin-top: 1.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.hero .btn--primary {
  background: #fff;
  color: var(--ink);
  border-color: #fff;
}

.hero .btn--primary:hover {
  background: #f0f0f5;
  color: var(--ink);
}

.hero .btn--secondary {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.45);
}

.hero .btn--secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.65);
  color: #fff;
}

.hero__hint {
  margin: 1.65rem 0 0;
  max-width: 26rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: rgba(255, 255, 255, 0.75);
}

.icon--hint {
  color: rgba(255, 255, 255, 0.55);
}

.hero .btn--primary .btn__icon {
  color: var(--ink);
}

.hero .btn--secondary .btn__icon {
  color: #fff;
  opacity: 0.92;
}

.wrap {
  width: min(1080px, 92vw);
  margin: 0 auto;
  padding: clamp(2.25rem, 4.5vw, 3.5rem) 0 clamp(3rem, 6vw, 4.5rem);
}

#features,
#launch,
#movement,
#letter,
#about,
#contact {
  scroll-margin-top: calc(0.75rem + 52px);
}

.section {
  margin-bottom: clamp(2.5rem, 5vw, 3.75rem);
}

.section:last-child {
  margin-bottom: 0;
}

.section__head {
  margin-bottom: 1.75rem;
}

.section__title {
  margin: 0;
  font-size: clamp(1.375rem, 2.2vw, 1.625rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.section__title--icon {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  flex-wrap: wrap;
}

.section__title-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.4rem;
  border-radius: 12px;
  background: var(--accent-soft);
  color: var(--accent);
}

.icon--section {
  display: block;
}

.section__subtitle {
  margin: 0.5rem 0 0;
  color: var(--ink-muted);
  font-size: 0.9375rem;
  max-width: 36rem;
}

.section__subtitle--on-dark {
  color: rgba(245, 246, 252, 0.88);
}

.section__eyebrow {
  margin: 0 0 0.5rem;
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.65);
}

.pillar-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.pillar-card {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.85rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 1.2rem 1.25rem 1.3rem;
  box-shadow: var(--shadow-sm);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
  min-height: 100%;
}

.pillar-card__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem;
  border-radius: 12px;
  background: var(--accent-soft);
  color: var(--accent);
}

.pillar-card:hover {
  border-color: color-mix(in srgb, var(--accent) 22%, var(--line));
  box-shadow: var(--shadow-md);
}

.pillar-card__text {
  margin: 0;
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--ink-muted);
  line-height: 1.65;
}

.section--features {
  padding-top: 0.25rem;
}

.section--launch {
  margin-bottom: clamp(2rem, 4vw, 3rem);
}

.launch-panel {
  background: linear-gradient(135deg, #2a2f6e 0%, #1e2255 48%, #14173d 100%);
  color: #fff;
  border-radius: var(--radius-lg);
  padding: clamp(1.5rem, 3.5vw, 2.25rem);
  display: grid;
  gap: 1.75rem;
  box-shadow: var(--shadow-md);
}

@media (min-width: 780px) {
  .launch-panel {
    grid-template-columns: 1fr 1fr;
    align-items: start;
    gap: 2rem;
  }
}

.launch-panel__heading {
  color: #fff;
  line-height: 1.35;
}

.launch-panel__heading--icon {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.icon--launch-title {
  color: rgba(255, 255, 255, 0.92);
  flex-shrink: 0;
}

.stat__label--row {
  display: flex;
  align-items: center;
  gap: 0.45rem;
}

.launch-panel .icon--stat {
  color: rgba(255, 255, 255, 0.72);
  flex-shrink: 0;
}

.launch-panel__meta {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.stat {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius);
  padding: 1rem 1.1rem;
}

.stat--wide {
  flex: 1;
}

.stat__label {
  margin: 0;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: rgba(255, 255, 255, 0.62);
  font-family: var(--font-display);
}

.stat__value {
  margin: 0.35rem 0 0;
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.stat__value--plain {
  font-size: 1.05rem;
  font-weight: 600;
}

.pilot-logos {
  margin-top: 0.85rem;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.5rem;
}

.pilot-logos__item {
  margin: 0;
  background: #fff;
  border-radius: 10px;
  padding: 0.5rem;
  display: grid;
  place-items: center;
  min-height: 76px;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.pilot-logos__item img {
  width: 100%;
  max-height: 56px;
  object-fit: contain;
  display: block;
}

.section--movement {
  text-align: center;
  padding: clamp(1.75rem, 4vw, 2.5rem) clamp(1rem, 3vw, 2rem);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.movement__icon-wrap {
  margin: 0 auto 0.5rem;
  width: 3.5rem;
  height: 3.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
}

.icon--movement {
  display: block;
}

.movement__eyebrow {
  margin: 0;
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
}

.movement__title {
  margin: 0.45rem 0 0;
  font-size: clamp(1.2rem, 2.1vw, 1.45rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.movement__text {
  margin: 0.85rem 0 0;
  font-size: clamp(1rem, 1.65vw, 1.12rem);
  font-weight: 500;
  color: var(--ink-muted);
  line-height: 1.65;
  max-width: 40rem;
  margin-inline: auto;
}

.section--letter {
  background: var(--accent-soft);
  border: 1px solid color-mix(in srgb, var(--accent) 15%, var(--line));
  border-radius: var(--radius-lg);
  padding: clamp(1.35rem, 3vw, 1.85rem) clamp(1.1rem, 3vw, 1.75rem);
}

.section--letter .section__title {
  color: var(--accent-hover);
}

.section--letter .section__title-icon {
  background: color-mix(in srgb, var(--accent) 12%, var(--surface));
  color: var(--accent-hover);
}

.letter__lead {
  margin-top: 0.45rem;
}

.letter__examples {
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.letter__examples li {
  margin: 0;
  padding: 0.65rem 0.85rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--ink-muted);
  font-style: italic;
}

.letter__cta {
  margin: 1.15rem 0 0;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--ink);
}

.letter__tags {
  margin: 0.65rem 0 0;
  font-size: 0.875rem;
  color: var(--ink-muted);
}

.letter__tag-link {
  font-weight: 700;
  margin-right: 0.5rem;
}

.letter__tag-hash {
  font-family: var(--font-display);
  letter-spacing: 0.02em;
}

.section--about .prose {
  margin-top: 1rem;
}

.prose p {
  margin: 0 0 1rem;
  color: var(--ink-muted);
  font-size: 0.9375rem;
  line-height: 1.75;
  max-width: 52rem;
}

.prose p:last-child {
  margin-bottom: 0;
}

.section--contact .section__subtitle {
  margin-bottom: 1.25rem;
}

.contact-rows {
  list-style: none;
  margin: 0;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--surface);
}

.contact-rows li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.85rem;
  padding: 0.95rem 1.15rem;
  border-bottom: 1px solid var(--line);
  align-items: center;
}

.contact-rows__decoration {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.65rem;
  height: 2.65rem;
  border-radius: 12px;
  background: var(--accent-soft);
  color: var(--accent);
}

.contact-rows__main {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  min-width: 0;
}

.contact-rows li:last-child {
  border-bottom: none;
}

.contact-rows__key {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--ink-soft);
}

.contact-rows__val {
  font-size: 0.9375rem;
  font-weight: 500;
  text-decoration: none;
  color: var(--accent);
}

.contact-rows__val:hover {
  color: var(--accent-hover);
}

.contact-rows__val--muted {
  color: var(--ink);
  font-weight: 500;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.site-footer {
  border-top: 1px solid var(--line);
  padding: 1.75rem clamp(1.25rem, 4vw, 2.5rem) 2.5rem;
  background: color-mix(in srgb, var(--bg) 100%, #fff);
}

.site-footer__inner {
  width: min(1080px, 100%);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

@media (min-width: 640px) {
  .site-footer__inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }
}

.site-footer__brand {
  margin: 0;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.9375rem;
  color: var(--ink-muted);
}

.site-footer__brand img {
  border-radius: 50%;
}

.site-footer__legal {
  margin: 0;
  font-size: 0.8125rem;
  color: var(--ink-soft);
  line-height: 1.5;
}

@media (max-width: 720px) {
  .pillar-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 520px) {
  .site-header {
    flex-wrap: wrap;
    row-gap: 0.5rem;
  }

  .nav {
    order: 3;
    flex: 1 1 100%;
    margin-left: 0;
    padding-top: 0.35rem;
    border-top: 1px solid color-mix(in srgb, var(--line) 80%, transparent);
    justify-content: flex-start;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    gap: 0.75rem;
  }

  .nav::-webkit-scrollbar {
    display: none;
  }

  .site-header .btn--ghost {
    flex-shrink: 0;
  }
}

@media (max-width: 420px) {
  .hero__actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero .btn {
    width: 100%;
  }
}

@supports not (background: color-mix(in srgb, white 50%, black)) {
  .site-header {
    background: rgba(246, 245, 249, 0.92);
  }

  .site-footer {
    background: var(--bg);
  }

  .pillar-card:hover {
    border-color: #c8cce8;
  }

  .section--letter {
    border-color: #d8dbf0;
  }

  .section--letter .section__title-icon {
    background: #e4e8fb;
  }
}