.topik-hero, .topik-hero * { box-sizing: border-box; margin: 0; padding: 0; }
  
  .topik-hero-page { margin: 0; min-height: 100vh; background: #043c59; font-family: "Noto Sans KR", "Malgun Gothic", "Microsoft YaHei", Arial, sans-serif; }
  .topik-hero.scene {
    position: relative;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    background:
      radial-gradient(circle at 50% 22%, rgba(255,255,255,.08), transparent 28%),
      radial-gradient(circle at 18% 70%, rgba(255,255,255,.05), transparent 22%),
      linear-gradient(180deg, #1b91b8 0%, #086f96 52%, #043c59 100%);
  }
  .topik-hero canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
  .topik-hero .ui {
    position: absolute;
    inset: 0;
    z-index: 5;
    pointer-events: none;
  }
  .topik-hero .title {
    position: absolute;
    top: clamp(14px, 2.8vh, 32px);
    left: clamp(16px, 3vw, 34px);
    width: min(560px, calc(100vw - 190px));
    color: rgba(255,255,255,.76);
    text-shadow: 0 2px 10px rgba(0,60,90,.18);
  }
  .topik-hero .hero-row {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    gap: 14px;
  }
  .topik-hero .hero-copy { min-width: 0; text-align: left; }
  .topik-hero .brand-subtitle {
    margin-bottom: 4px;
    color: rgba(255,255,255,.68);
    font-size: clamp(10px, .95vw, 12px);
    font-weight: 800;
    letter-spacing: .02em;
  }
  .topik-hero .main {
    font-weight: 900;
    letter-spacing: .08em;
    font-size: clamp(12px, 1.4vw, 16px);
  }
  .topik-hero .sub {
    margin-top: 6px;
    color: rgba(255,255,255,.48);
    font-size: clamp(11px, 1vw, 13px);
    line-height: 1.45;
    letter-spacing: .02em;
  }
  .topik-hero .start-btn {
    pointer-events: auto;
    position: fixed;
    top: clamp(14px, 2.8vh, 30px);
    right: clamp(14px, 2.8vw, 30px);
    flex: 0 0 auto;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 104px;
    height: 38px;
    padding: 0 16px;
    border-radius: 999px;
    text-decoration: none;
    background: rgba(255, 225, 0, 0.96);
    color: #043c59;
    font-weight: 900;
    font-size: 13px;
    letter-spacing: .06em;
    box-shadow: 0 8px 18px rgba(0, 65, 90, 0.14);
  }
  .topik-hero .vignette {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 4;
    background:
      radial-gradient(circle at center, transparent 55%, rgba(0,30,55,.16)),
      linear-gradient(to bottom, rgba(0,0,0,.02), transparent 40%, rgba(0,35,60,.15));
  }
  @media (max-width: 760px) {
    .topik-hero .hero-row { align-items: center; flex-direction: column; gap: 14px; }
    .topik-hero .hero-copy { text-align: left; width: 100%; }
    .topik-hero .title { left: 14px; width: calc(100vw - 148px); }
    .topik-hero .sub {
      display: block;
      margin-top: 4px;
      font-size: 10px;
      line-height: 1.4;
      white-space: nowrap;
    }
    .topik-hero .start-btn { min-width: 94px; height: 36px; }
  }

/* Homepage integration: keep the demo scene contained inside the existing app shell. */
body.topik-intro-active {
  overflow: hidden;
  background: #043c59;
}

body.topik-intro-active .mobile-header,
body.topik-intro-active .mobile-nav-backdrop,
body.topik-intro-active .app-sidebar {
  display: none !important;
}

body.topik-intro-active .app-shell {
  display: block;
  min-height: 100vh;
}

body.topik-intro-active .app-main {
  width: 100vw;
  max-width: none;
  min-height: 100vh;
  padding: 0;
}

.app-main .topik-hero.scene {
  width: 100%;
  height: min(72vh, 720px);
  min-height: 460px;
  border-radius: 16px;
  margin-bottom: 28px;
  box-shadow: 0 18px 40px rgba(10, 52, 70, 0.16);
}

.app-main .topik-hero-intro.scene {
  height: 100vh;
  min-height: 620px;
  margin-bottom: 0;
}

body.topik-intro-active .app-main .topik-hero-intro.scene {
  width: 100vw;
  height: 100vh;
  min-height: 100vh;
  border-radius: 0;
  box-shadow: none;
}

body.topik-intro-active .topik-hero .title {
  left: var(--topik-countdown-left, 6vw);
  width: min(680px, calc(100vw - var(--topik-countdown-left, 6vw) - 28px));
  transform: none;
}

body.topik-intro-active .topik-hero .hero-row {
  justify-content: flex-start;
  align-items: flex-start;
}

body.topik-intro-active .topik-hero .hero-copy {
  text-align: left;
}

body.topik-intro-active .app-main .topik-hero .start-btn {
  position: fixed;
  left: min(
    calc(var(--topik-countdown-right, 62vw) + 32px),
    calc(100vw - 160px)
  );
  top: var(--topik-countdown-mid-y, 22vh);
  right: auto;
  transform: translateY(-50%);
}

.app-main .topik-hero .start-btn {
  position: absolute;
  top: clamp(14px, 2.8vh, 30px);
  right: clamp(14px, 2.8vw, 30px);
}

@media (max-width: 760px) {
  .app-main .topik-hero.scene {
    height: 420px;
    min-height: 420px;
    border-radius: 12px;
  }

  .app-main .topik-hero-intro.scene {
    height: 100vh;
    min-height: 520px;
  }

  body.topik-intro-active .app-main .topik-hero-intro.scene {
    height: 100vh;
    min-height: 100vh;
  }

  body.topik-intro-active .topik-hero .title {
    left: var(--topik-countdown-left, 18px);
    width: calc(100vw - 28px);
  }

  body.topik-intro-active .topik-hero .hero-copy {
    text-align: left;
    width: auto;
  }

  body.topik-intro-active .app-main .topik-hero .start-btn {
    left: var(--topik-countdown-left, 18px);
    top: calc(var(--topik-countdown-mid-y, 22vh) + 96px);
    transform: none;
  }
}