/* ==========================================================================
   HISTORY TIMELINE — Editorial redesign
   ========================================================================== */
.ht {
  --ht-blue: #0059a9;
  --ht-blue-deep: #003d75;
  --ht-ink: #10151f;
  --ht-ink-soft: #4a5160;
  --ht-mute: #8891a0;
  --ht-line: #e4e7ec;
  --ht-bg: #ffffff;
  --ht-card: #ffffff;
  font-family: 'Open Sans', sans-serif;
  color: var(--ht-ink);
  background: var(--ht-bg);
}

/* ---------- HERO ---------- */
.ht-hero {
  position: relative;
  padding: 4.5rem 0 3.5rem;
  text-align: center;
  overflow: hidden;
}
.ht-hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.28em;
  color: var(--ht-blue);
  margin-bottom: 1.25rem;
}
.ht-hero-eyebrow::before,
.ht-hero-eyebrow::after {
  content: '';
  display: block;
  width: 1.5rem;
  height: 1px;
  background: var(--ht-blue);
}
.ht-hero-title {
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--ht-ink);
  margin-bottom: 1rem;
}
.ht-hero-desc {
  max-width: 34rem;
  margin: 0 auto;
  font-size: 1rem;
  line-height: 1.7;
  color: var(--ht-ink-soft);
  word-break: keep-all;
}
.ht-hero-bignum {
  position: absolute;
  top: -3rem;
  left: 50%;
  transform: translateX(-50%);
  font-size: 12rem;
  font-weight: 800;
  color: var(--ht-blue);
  opacity: 0.04;
  letter-spacing: -0.05em;
  pointer-events: none;
  white-space: nowrap;
  z-index: 0;
}
.ht-hero > * { position: relative; z-index: 1; }

/* ---------- STATS STRIP ---------- */
.ht-stats {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0;
  border-top: 1px solid var(--ht-line);
  border-bottom: 1px solid var(--ht-line);
  margin-bottom: 4rem;
}
.ht-stat {
  flex: 1 1 50%;
  text-align: center;
  padding: 1.75rem 1rem;
  border-left: 1px solid var(--ht-line);
}
.ht-stat:first-child { border-left: 0; }
.ht-stat-num {
  display: block;
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--ht-blue);
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
}
.ht-stat-label {
  font-size: 0.8125rem;
  color: var(--ht-mute);
  letter-spacing: 0.02em;
}

/* ---------- ERA LAYOUT ---------- */
.ht-body {
  display: flex;
  align-items: flex-start;
  gap: 0;
}

/* Sticky year rail (desktop) */
.ht-rail {
  position: sticky;
  top: 6.5rem;
  flex: 0 0 8.5rem;
  display: none;
}
.ht-rail-list {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  border-left: 2px solid var(--ht-line);
  padding-left: 1.1rem;
}
.ht-rail-link {
  font-size: 1.0625rem; /* ← 숫자 크기: 원하는 값(rem)으로 조절 */
  font-weight: 700;
  color: var(--ht-mute);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s, transform 0.2s, font-size 0.2s;
  position: relative;
}
.ht-rail-link.is-active {
  font-size: 1.1875rem; /* ← 선택된(활성) 숫자만 더 키우고 싶을 때 조절 */
}
.ht-rail-link::before {
  content: '';
  position: absolute;
  left: -1.35rem;
  top: 0.35rem;
  width: 0.4rem;
  height: 0.4rem;
  border-radius: 100%;
  background: var(--ht-line);
  transition: background 0.2s, transform 0.2s;
}
.ht-rail-link.is-active {
  color: var(--ht-blue);
  transform: translateX(0.2rem);
}
.ht-rail-link.is-active::before {
  background: var(--ht-blue);
  transform: scale(1.35);
}
.ht-rail-link:hover {
  color: var(--ht-blue);
  font-size: 1.1875rem; /* ← hover 시 숫자 크기: 원하는 값(rem)으로 조절 */
  transform: translateX(0.2rem);
}
.ht-rail-link:hover::before {
  background: var(--ht-blue);
  transform: scale(1.35);
}

/* Mobile chip nav */
.ht-chip-nav {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  padding: 0 0 1.5rem;
  margin-bottom: 2.5rem;
  border-bottom: 1px solid var(--ht-line);
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.ht-chip-nav::-webkit-scrollbar { display: none; }
.ht-chip {
  flex: 0 0 auto;
  padding: 0.5rem 1rem;
  border-radius: 999px;
  border: 1px solid var(--ht-line);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--ht-ink-soft);
  text-decoration: none;
  white-space: nowrap;
  transition: all 0.2s;
}
.ht-chip.is-active {
  background: var(--ht-blue);
  border-color: var(--ht-blue);
  color: #fff;
}

/* ---------- ERAS ---------- */
.ht-eras {
  flex: 1 1 auto;
  min-width: 0;
}
.ht-era {
  position: relative;
  scroll-margin-top: 7rem; /* ← 상단 고정/스티키 영역 높이에 맞춰 조절 */
  padding-bottom: 5rem;
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.ht-era.is-visible {
  opacity: 1;
  transform: translateY(0);
}
.ht-era:last-child { padding-bottom: 0; }

.ht-era-head {
  display: flex;
  align-items: baseline;
  gap: 1.25rem;
  margin-bottom: 2rem;
}
.ht-era-index {
  font-size: 3.25rem;
  font-weight: 800;
  color: var(--ht-line);
  line-height: 1;
  letter-spacing: -0.03em;
}
.ht-era-heading {
  flex: 1 1 auto;
  min-width: 0;
}
.ht-era-range {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--ht-blue);
  margin-bottom: 0.35rem;
}
.ht-era-title {
  font-size: 1.375rem;
  font-weight: 800;
  color: var(--ht-ink);
  letter-spacing: -0.01em;
  word-break: keep-all;
}

/* Year groups within an era */
.ht-year {
  position: relative;
  padding: 1.75rem 0 1.75rem 1.75rem;
  border-left: 2px solid var(--ht-line);
  margin-left: 0.15rem;
}
.ht-year:first-of-type { padding-top: 0; }
.ht-year::before {
  content: '';
  position: absolute;
  left: -0.4375rem;
  top: 0.15rem;
  width: 0.75rem;
  height: 0.75rem;
  border-radius: 100%;
  background: var(--ht-card);
  border: 2px solid var(--ht-blue);
}
.ht-year:first-of-type::before { top: -1.6rem; }
.ht-year-label {
  font-size: 1.375rem;
  font-weight: 800;
  color: var(--ht-ink);
  margin-bottom: 0.9rem;
  letter-spacing: -0.01em;
}
.ht-event-list {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}
.ht-event {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}
.ht-event-month {
  flex: 0 0 auto;
  font-size: 0.8125rem;
  font-weight: 700;
  color: #fff;
  background: var(--ht-blue);
  border-radius: 0.375rem;
  padding: 0.2rem 0.5rem;
  letter-spacing: 0.02em;
  min-width: 2.5rem;
  text-align: center;
}
.ht-event-text {
  flex: 1 1 auto;
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--ht-ink-soft);
  word-break: keep-all;
  padding-top: 0.05rem;
}
.ht-event-text .ht-project {
  display: block;
  margin-top: 0.2rem;
  font-size: 0.95rem;
  color: var(--ht-ink);
  font-weight: 450;
}

/* ---------- AWARDS ---------- */
.ht-awards {
  margin-top: 1rem;
  padding: 4rem 0 1rem;
  border-top: 1px solid var(--ht-line);
}
.ht-awards-head {
  text-align: center;
  margin-bottom: 2.5rem;
}
.ht-awards-title {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--ht-ink);
  letter-spacing: -0.01em;
  margin-top: 0.5rem;
}
.ht-award-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.85rem;
}
.ht-award-card {
  background: var(--ht-card);
  border: 1px solid var(--ht-line);
  border-radius: 0.875rem;
  padding: 1.5rem 1.25rem;
  transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s;
}
.ht-award-card:hover {
  border-color: var(--ht-blue);
  box-shadow: 0 0.75rem 1.75rem rgba(0, 89, 169, 0.1);
  transform: translateY(-3px);
}
.ht-award-date {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--ht-blue);
  background: rgba(0, 89, 169, 0.08);
  border-radius: 999px;
  padding: 0.25rem 0.65rem;
  margin-bottom: 0.85rem;
  letter-spacing: 0.02em;
}
.ht-award-org {
  font-size: 0.8125rem;
  color: var(--ht-mute);
  margin-bottom: 0.3rem;
}
.ht-award-title {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--ht-ink);
  line-height: 1.5;
  word-break: keep-all;
}

/* ---------- RESPONSIVE ---------- */
@media screen and (min-width: 576px) {
  .ht-hero-title { font-size: 3rem; }
  .ht-award-grid { grid-template-columns: repeat(2, 1fr); }
}

@media screen and (min-width: 768px) {
  .ht-hero { padding: 6rem 0 4.5rem; }
  .ht-hero-title { font-size: 3.5rem; }
  .ht-hero-desc { font-size: 1.0625rem; }
  .ht-stats { margin-bottom: 5.5rem; }
  .ht-stat { flex: 1 1 25%; padding: 2.25rem 1rem; }
  .ht-stat-num { font-size: 2.25rem; }
  .ht-chip-nav { display: none; }
  .ht-rail { display: block; }
  .ht-body { gap: 2.5rem; }
  .ht-era-index { font-size: 4.5rem; }
  .ht-era-title { font-size: 1.75rem; }
  .ht-year { padding: 2.5rem 0 2.5rem 2.5rem; }
  .ht-year-label { font-size: 1.625rem; }
  .ht-event-text { font-size: 1rem; }
  .ht-award-grid { grid-template-columns: repeat(3, 1fr); }
  .ht-awards-title { font-size: 2.25rem; }
}

@media screen and (min-width: 1024px) {
  .ht-rail { flex: 0 0 10.5rem; }
  .ht-award-grid { grid-template-columns: repeat(5, 1fr); }
}