/* ===========================================
   Our Story (about-story.html)
   POSRI-style era timeline with sticky era nav
   =========================================== */

.story-intro {
  max-width: var(--max-width-narrow);
  margin: 0 auto 88px;
  text-align: center;
}

.story-intro .section-title {
  margin-bottom: 24px;
}

.story-intro .lead {
  margin: 0;
  font-size: var(--fs-body);
  font-weight: 400;
  line-height: 1.7;
  color: var(--color-sub);
}

/* ---------- Two-column layout: nav + timeline ---------- */
.story-eras {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
}

/* Vertical guide line on the column boundary */
.story-eras::before {
  content: '';
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 1px;
  background: var(--color-border);
  transform: translateX(-0.5px);
  pointer-events: none;
}

/* Active progress line up to the indicator */
.story-eras::after {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  width: 2px;
  height: var(--scroll-progress, 0px);
  background: var(--color-accent);
  transform: translateX(-1px);
  pointer-events: none;
  z-index: 1;
}

/* Scroll progress dot */
.scroll-indicator {
  position: absolute;
  left: 50%;
  top: 0;
  width: 14px;
  height: 14px;
  margin-left: -7px;
  margin-top: -7px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 0 8px rgba(0, 155, 223, 0.18);
  pointer-events: none;
  z-index: 2;
  will-change: top;
}

/* ---------- Left column: sticky era menu ---------- */
.story-nav {
  position: sticky;
  top: 120px;
  align-self: start;
  padding-right: 40px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.story-nav-item {
  display: block;
  text-decoration: none;
  color: inherit;
  cursor: pointer;
  opacity: 0.32;
  transition: opacity 0.3s ease;
}

.story-nav-item:hover {
  opacity: 0.6;
}

.story-nav-item.is-active {
  opacity: 1;
}

.story-nav-item .era-year {
  display: inline-block;
  margin-bottom: 6px;
  padding: 7px 16px;
  background: var(--color-muted);
  color: #fff;
  font-size: var(--fs-small);
  font-weight: 600;

  border-radius: 999px;
  transition: background 0.3s ease;
}

.story-nav-item.is-active .era-year {
  background: var(--color-primary);
}

.story-nav-item .era-title {
  margin: 0 0 18px;
  font-size: 28px;
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-primary);
  letter-spacing: -0.025em;
}

.story-nav-item .era-image {
  width: 100%;
  aspect-ratio: 16 / 9;
  margin-top: 16px;
  background: #f3f4f6 center / cover no-repeat;
  border-radius: 8px;
  overflow: hidden;
  display: none;
}

.story-nav-item .era-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.story-nav-item.is-active .era-image {
  display: block;
}

.era-image-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #eef4f9 0%, #dbe9f4 100%);
  color: var(--color-accent-text);
  font-size: var(--fs-small);

  text-transform: uppercase;
}

/* ---------- Right column: timeline ---------- */
.story-timeline {
  display: flex;
  flex-direction: column;
}

.story-era {
  position: relative;
  scroll-margin-top: 100px;
}

.story-era + .story-era {
  margin-top: 60px;
}

/* ---------- Event list ---------- */
.era-events {
  list-style: none;
  margin: 0;
  padding: 0;
}

.era-events li {
  position: relative;
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 14px;
  padding: 14px 0;
}

.era-events li:first-child {
  padding-top: 0;
}

.era-events li.year-divider {
  display: block;
  margin: 40px 0 8px;
  padding: 0;
  font-size: 32px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-primary);
}

.era-events li.year-divider:first-child {
  margin-top: 0;
}

.era-events li.year-divider + li {
  padding-top: 18px;
}

.event-date {
  font-size: var(--fs-small);
  font-weight: 600;
  color: var(--color-accent-text);

  white-space: nowrap;
}

.event-body {
  font-size: var(--fs-small);
  font-weight: 400;
  line-height: 1.4;
  letter-spacing: -0.01em;
  color: var(--color-primary);
}

.event-body strong {
  display: block;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--color-primary);
}

.event-body .event-detail {
  display: block;
  margin-top: 6px;
  font-size: var(--fs-small);
  font-weight: 400;
  color: var(--color-muted);
  line-height: 1.6;
}

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .story-eras {
    display: block;
  }

  .story-eras::before,
  .story-eras::after,
  .scroll-indicator {
    display: none;
  }

  .story-nav {
    position: static;
    max-height: none;
    padding-right: 0;
    margin-bottom: 48px;
    overflow: visible;
    gap: 16px;
  }

  .story-nav-item {
    opacity: 1;
    padding: 12px 0;
    border-bottom: 1px solid var(--color-border);
  }

  .story-nav-item:last-child {
    border-bottom: none;
  }

  .story-nav-item .era-image {
    display: none !important;
  }

  .story-nav-item .era-title {
    font-size: 1.25rem;
  }

  .story-era + .story-era {
    margin-top: 80px;
  }
}

@media (max-width: 560px) {
  .story-intro {
    margin-bottom: 56px;
  }

  .era-events li {
    grid-template-columns: 1fr;
    gap: 6px;
    padding: 18px 0;
  }

  .event-date {
    font-size: var(--fs-small);
  }

  .event-body {
    font-size: var(--fs-small);
  }
}

/* ===== 히어로 설명: 모바일에서는 둘째 문장을 축약본으로 교체 =====
   데스크탑(768px↑)은 .hero-desc-full(원문 전체)을 보이고,
   모바일(767px↓)은 .hero-desc-short(축약본)로 바꿔 한눈에 들어오게 한다.
   ※ 한국어만 적용된다(다른 언어는 i18n JSON 텍스트로 통째 교체됨). */
.hero-desc-short { display: none; }

@media (max-width: 767px) {
  .hero-desc .hero-desc-full { display: none; }
  .hero-desc .hero-desc-short { display: inline; }
}