:root {
  --blue: #2f7bff;
  --blue-soft: #6aa8ff;
  --bg: #05070d;
  --panel: rgba(10, 16, 34, 0.72);
  --text: #f2f5fb;
  --text-dim: #a9b4c8;
  --border: rgba(140, 180, 255, 0.18);
  --danger: #ff6b6b;
  --ok: #4ade80;
}

* {
  box-sizing: border-box;
  margin: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: "Pretendard Variable", Pretendard, -apple-system, "Segoe UI", "Malgun Gothic", sans-serif;
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

/* ---------- Background ---------- */

.bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
}

.bg__image {
  --shift: 0px;
  position: absolute;
  inset: -60px -24px;
  background: url("bg.webp") center / cover no-repeat;
  filter: blur(5px) saturate(0.85) brightness(0.75);
  transform: translateY(var(--shift));
  will-change: transform;
}

.bg__glow {
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  mix-blend-mode: screen;
}

.bg__glow--a {
  width: 60vw;
  height: 60vw;
  left: -15vw;
  top: -20vw;
  background: rgba(47, 123, 255, 0.55);
}

.bg__glow--b {
  width: 50vw;
  height: 50vw;
  right: -12vw;
  bottom: -22vw;
  background: rgba(20, 70, 255, 0.5);
}

.bg__shade {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(5, 7, 13, 0.55) 0%, rgba(5, 10, 26, 0.35) 45%, rgba(5, 7, 13, 0.9) 100%),
    rgba(12, 40, 110, 0.28);
}

/* ---------- Shared pieces ---------- */

.logo {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.logo span,
.outro__logo span {
  color: var(--blue-soft);
}

.accent {
  background: linear-gradient(90deg, #8fc0ff, var(--blue));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.eyebrow {
  color: var(--blue-soft);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 30px;
  border: 0;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.2s, background 0.2s;
}

.btn--primary {
  background: var(--blue);
  color: #fff;
  box-shadow: 0 8px 32px rgba(47, 123, 255, 0.45);
}

.btn--primary:hover {
  background: #4a8dff;
  transform: translateY(-1px);
  box-shadow: 0 10px 40px rgba(47, 123, 255, 0.6);
}

.btn--sm {
  padding: 10px 20px;
  font-size: 0.9rem;
}

.btn--lg {
  padding: 18px 44px;
  font-size: 1.05rem;
}

/* ---------- Nav ---------- */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 22px 56px;
}

/* ---------- Hero ---------- */

main,
section {
  position: relative;
  z-index: 1;
}

.hero {
  --fade: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 28px;
  padding: 120px 24px 80px;
  text-align: center;
  opacity: calc(1 - var(--fade));
  transform: translateY(calc(var(--fade) * -40px));
}

.hero__title {
  display: flex;
  flex-direction: column;
  font-size: clamp(3rem, 7vw, 5.5rem);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.035em;
  text-shadow: 0 4px 40px rgba(0, 0, 0, 0.5);
  word-break: keep-all;
}

.hero__lead {
  max-width: 520px;
  color: var(--text-dim);
  font-size: 1.1rem;
  word-break: keep-all;
}

.hero__scroll {
  position: absolute;
  bottom: 32px;
  color: var(--text-dim);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.3em;
}

.stats {
  width: 640px;
  max-width: 100%;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  margin-top: 20px;
  padding: 18px 0;
  border: 1px solid var(--border);
  border-radius: 16px;
  background: rgba(8, 14, 30, 0.55);
  backdrop-filter: blur(14px);
}

.stats > div {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.stats > div + div {
  border-left: 1px solid var(--border);
}

.stats strong {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.stats span {
  color: var(--text-dim);
  font-size: 0.8rem;
  font-weight: 600;
}

/* ---------- Features ---------- */

.features {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 56px 10vh;
}

.feature {
  min-height: 62vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 16px;
  opacity: 0.16;
  transform: translateY(36px) scale(0.97);
  transform-origin: left center;
  filter: blur(3px);
  transition: opacity 0.5s ease, transform 0.6s cubic-bezier(0.2, 0.7, 0.2, 1), filter 0.5s ease;
}

.feature.is-active {
  opacity: 1;
  transform: none;
  filter: none;
}

.feature__index {
  color: var(--blue-soft);
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 0.18em;
}

.feature h2 {
  font-size: clamp(2.6rem, 6vw, 4.5rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  transition: text-shadow 0.5s ease;
}

.feature.is-active h2 {
  text-shadow: 0 0 60px rgba(47, 123, 255, 0.55);
}

.feature__tag {
  align-self: flex-start;
  padding: 6px 16px;
  border: 1px solid var(--blue);
  border-radius: 999px;
  background: rgba(47, 123, 255, 0.14);
  color: var(--text);
  font-size: 1rem;
  font-weight: 700;
}

.feature p:not(.feature__tag) {
  max-width: 560px;
  color: var(--text-dim);
  font-size: 1.1rem;
  word-break: keep-all;
}

/* ---------- Outro ---------- */

.blackout {
  position: fixed;
  inset: 0;
  z-index: 0;
  background: #000;
  opacity: 0;
  pointer-events: none;
}

.outro {
  --reveal: 0;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.outro__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 28px;
  text-align: center;
  opacity: var(--reveal);
  transform: translateY(calc((1 - var(--reveal)) * 30px));
}

.outro__logo {
  font-size: clamp(2.2rem, 6.5vw, 4.5rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.035em;
  text-shadow: 0 0 80px rgba(47, 123, 255, 0.6);
}

.outro__points {
  color: var(--text-dim);
  font-weight: 600;
  word-break: keep-all;
}

/* ---------- Mobile ---------- */

@media (max-width: 720px) {
  .nav {
    padding: 16px;
  }

  .logo {
    font-size: 1.05rem;
  }

  .hero {
    align-items: flex-start;
    gap: 24px;
    padding: 96px 20px 72px;
    text-align: left;
  }

  .hero__title {
    font-size: clamp(2.2rem, 10.5vw, 3.2rem);
    line-height: 1.15;
  }

  .hero__lead {
    font-size: 1rem;
  }

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

  .hero__scroll {
    display: none;
  }

  .stats strong {
    font-size: 0.95rem;
  }

  .stats span {
    font-size: 0.7rem;
  }

  .features {
    padding: 0 20px 10vh;
  }

  .feature {
    min-height: 58vh;
    gap: 12px;
  }

  .feature h2 {
    font-size: clamp(1.9rem, 10vw, 2.8rem);
  }

  .feature__tag {
    font-size: 0.9rem;
  }

  .feature p:not(.feature__tag) {
    font-size: 1rem;
  }

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

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

  .bg__image,
  .hero,
  .outro__inner {
    transform: none;
  }

  .feature {
    transform: none;
    filter: none;
  }
}