:root {
  --deep-blue: #02045b;
  --light-gray: #ececec;
  --header-bg: rgba(255, 255, 255, 0.92);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Noto Sans KR', sans-serif;
  background: var(--light-gray);
  color: #111;
}

img {
  display: block;
  max-width: 100%;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 20px;
  z-index: 1000;
  color: #fff;
  transition: background-color 0.25s ease, color 0.25s ease;
}

.site-header a {
  color: inherit;
  text-decoration: none;
}

.site-header.scrolled {
  background: var(--header-bg);
  color: #000;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
}

.header-logo img {
  width: 120px;
  height: 36px;
  object-fit: contain;
}

.nav-list {
  list-style: none;
  display: flex;
  gap: 16px;
  padding: 0;
  margin: 0;
  font-size: 1.7rem;
  font-weight: 500;
}

.hero {
  min-height: 100vh;
  background-image: url('banner.png');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 24px;
  position: relative;
  padding: 120px 16px 80px;
  color: #fff;
}

.hero-logo {
  width: min(520px, 80vw);
  height: 140px;
  object-fit: contain;
}

.join-button {
  color: #fff;
  text-decoration: none;
  border: 4px solid #fff;
  border-radius: 16px;
  padding: 8px 24px;
  font-size: clamp(2rem, 4vw, 3.5rem);
  line-height: 1;
}


.hero-logo,
.join-button {
  filter: drop-shadow(0 3px 6px rgba(0, 0, 0, 0.35));
}
.section-light {
  background: var(--light-gray);
  text-align: center;
  padding: 48px 16px;
}

h2 {
  margin: 0 0 20px;
  font-size: clamp(2.3rem, 5vw, 4.2rem);
  font-weight: 500;
}

.intro p {
  font-size: clamp(1.3rem, 2.5vw, 2.2rem);
  margin: 0;
  line-height: 1.3;
}

.intro-lead {
  font-size: clamp(1.6rem, 3vw, 2.8rem);
}

.activities {
  padding-top: 12px;
  padding-bottom: 60px;
}

.timeline {
  max-width: 900px;
  margin: 30px auto 0;
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding-left: 72px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 34px;
  top: 10px;
  bottom: 10px;
  width: 4px;
  border-radius: 99px;
  background: linear-gradient(to bottom, #2f3c7f, #515151);
}

.timeline-item {
  position: relative;
  padding: 16px 20px;
  border-radius: 14px;
  background: #fff;
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.08);
  font-size: clamp(1.2rem, 2.2vw, 2rem);
  text-align: left;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -48px;
  top: 50%;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  transform: translateY(-50%);
  background: #2f3c7f;
  border: 3px solid #fff;
  box-shadow: 0 0 0 2px rgba(47, 60, 127, 0.35);
}

.timeline-date {
  display: inline-block;
  margin-bottom: 8px;
  padding: 2px 10px;
  border-radius: 999px;
  background: #eef1ff;
  color: #2f3c7f;
  font-size: 0.85em;
  font-weight: 700;
}

.timeline-content {
  color: #303030;
  line-height: 1.4;
}

.work {
  background-image: url('work.png');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  color: #fff;
  position: relative;
  padding: 40px 16px 80px;
}

.work-grid {
  max-width: 980px;
  margin: 20px auto 0;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.work-item {
  display: flex;
  align-items: center;
  gap: 22px;
}

.work-item.right {
  justify-content: flex-end;
}

.work-item img {
  width: 110px;
  height: 110px;
  object-fit: cover;
}

.work-item h3 {
  margin: 0 0 8px;
  font-size: clamp(2rem, 4vw, 3.2rem);
  font-weight: 500;
}

.work-item p {
  margin: 0;
  font-size: clamp(1.4rem, 3vw, 2.4rem);
}

.site-footer {
  background: #000;
  color: #fff;
  padding: 24px 18px 30px;
}

.site-footer img {
  width: 200px;
  height: 56px;
  object-fit: contain;
}

.site-footer p {
  margin: 12px 0;
  font-size: 2rem;
}

.site-footer small {
  font-size: 2rem;
  color: #9f9f9f;
}

@media (max-width: 760px) {
  .nav-list {
    font-size: 1.2rem;
    gap: 8px;
  }

  .header-logo img {
    width: 88px;
    height: 30px;
  }

  .timeline {
    padding-left: 54px;
    gap: 10px;
  }

  .timeline::before {
    left: 24px;
  }

  .timeline-item {
    font-size: 1.05rem;
    padding: 14px 16px;
  }

  .timeline-item::before {
    left: -37px;
  }

  .work-item,
  .work-item.right {
    justify-content: flex-start;
  }

  .work-item h3 {
    font-size: 1.8rem;
  }

  .work-item p,
  .site-footer p,
  .site-footer small {
    font-size: 1.25rem;
  }
}