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

body,
html {
  height: 100%;
  font-family: sans-serif;
}

/* 네비게이션 */
nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 60px;
  color: white;
  display: flex;
  align-items: center;
  padding: 0 20px;
  z-index: 3000;
  background: linear-gradient(270deg, #003366, #0066cc, #ff6600, #9900cc);
  background-size: 800% 800%;
  animation: gradientShift 20s ease infinite;
}

@keyframes gradientShift {
  0% {
    background-position: 0% 50%;
  }

  50% {
    background-position: 100% 50%;
  }

  100% {
    background-position: 0% 50%;
  }
}

nav .logo {
  display: flex;
  align-items: center;
  font-weight: bold;
  font-size: 18px;
  margin-right: 80px;
}

nav .logo a {
  display: flex;
  align-items: center;
  color: white;
  text-decoration: none;
}

nav .logo img {
  margin-right: 5px;
  width: 60px;
}

nav ul {
  list-style: none;
  display: flex;
  margin-left: auto;
}

nav ul li {
  position: relative;
  margin-right: 20px;
}

nav ul li a {
  color: white;
  text-decoration: none;
  font-size: 15px;
  padding: 8px;
  display: block;
}

nav ul li a:hover {
  background: rgba(255, 255, 255, 0.2);
  border-radius: 5px;
}

nav ul li ul {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background: white;
  min-width: 180px;
  border-radius: 4px;
  border: 1px solid #ddd;
}

nav ul li:hover>ul {
  display: block;
}

nav ul li ul li a {
  padding: 10px;
  font-size: 14px;
  color: black;
}

nav ul li ul li a:hover {
  background: #f0f0f0;
  color: black;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  cursor: pointer;
  margin-left: auto;
}

.menu-toggle span {
  width: 25px;
  height: 3px;
  background: white;
  margin: 4px 0;
}

/* 기본 (라이트 모드) 푸터 스타일 */
footer {
  position: relative;
  width: 100%;
  height: auto;
  min-height: 300px;
  display: flex;
  justify-content: center;
  align-items: center;
  border-top: 1px solid #ccc;
  /* 밝은 경계선 */
  z-index: 3000;
  transition: background-color 0.3s, color 0.3s, border-color 0.3s;
  /* 부드러운 전환 효과 */
}


/* -------------------- 1. 기본 및 색상 동적 설정 -------------------- */

/* 기본 (라이트 모드) 스타일 */
.k3a-footer {
  background-color: #f0f0f0;
  color: #333;
  padding: 30px 20px;
  font-family: Arial, sans-serif;
  line-height: 1.6;
}

.link-section a {
  color: #007bff;
  text-decoration: underline;
  text-decoration-color: #007bff;
}

/* 다크 모드 스타일 */
@media (prefers-color-scheme: dark) {
  .k3a-footer {
    background-color: #222;
    color: #fff;
  }

  .link-section a {
    color: #fff;
    text-decoration: underline;
    text-decoration-color: #f00;
  }
}

/* -------------------- 2. 데스크톱 레이아웃 (기본값) -------------------- */
/* (중간 생략 - 변경사항 없음) */

.main-header {
  position: relative;
  margin-top: 60px;
  /* nav 높이 보정 */
  width: 100%;
  height: 300px;
  background:
    linear-gradient(270deg, rgba(0, 51, 102, 0.6), rgba(0, 102, 204, 0.6), rgba(255, 102, 0, 0.6), rgba(153, 0, 204, 0.6)),
    url("images/header-bg.jpg") center/cover no-repeat;
  background-size: 800% 800%, cover;
  animation: gradientShift 20s ease infinite;
  display: flex;
  justify-content: center;
  align-items: center;
  color: white;
  text-align: center;
  z-index: 1000;
}


.main-header .header-content h3 {
  font-size: 18px;
  margin-bottom: 10px;
}

.main-header .header-content p {
  font-size: 18px;
  margin-bottom: 10px;
}

.main-header .header-content a {
  color: white;
  text-decoration: none;
}

.main-header .header-content span {
  align-items: center;
  font-size: 20px;
  border: solid 1px;
  padding: 5px 20px;
  margin: 30px auto;
}

.iframe_cover {
  display: none;
}

/* 본문 내용 스타일 */
.content-container {
  max-width: 900px;
  margin: 300px auto 100px;
  /* nav(60) + header(240) + margin */
  padding: 0 20px;
  animation: fadeIn 1s ease-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.intro-section {
  text-align: center;
  margin-bottom: 60px;
}

.intro-banner {
  margin-bottom: 30px;
}

.intro-banner img {
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  /* box-shadow: 0 10px 30px rgba(0,0,0,0.1); */
}

.intro-description {
  font-size: 1.25rem;
  line-height: 1.8;
  color: #333;
  word-break: keep-all;
}

.intro-description strong {
  color: #0066cc;
  font-weight: 800;
}

/* 갤러리 그리드 */
.gallery-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 30px;
  margin-bottom: 60px;
}

.gallery-grid figure {
  margin: 0;
  background: white;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  transition: transform 0.3s ease;
}

.gallery-grid figure:hover {
  transform: translateY(-5px);
}

.gallery-grid img {
  width: 100%;
  height: 250px;
  object-fit: cover;
}

.gallery-grid figcaption {
  padding: 15px;
  text-align: center;
  font-weight: 600;
  color: #555;
  background: #f8f9fa;
}

/* 제보 안내 박스 */
.report-alert {
  background: #fff4e5;
  border-left: 5px solid #ff6600;
  padding: 30px;
  border-radius: 8px;
  margin-bottom: 60px;
  display: flex;
  align-items: flex-start;
  gap: 20px;
}

.alert-icon {
  font-size: 2rem;
}

.alert-text {
  font-size: 1.1rem;
  line-height: 1.7;
  color: #444;
}

/* 액션 버튼 */
.action-buttons {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  margin-bottom: 60px;
}

.btn-notion {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 25px;
  background: linear-gradient(135deg, #003366, #0066cc);
  color: white;
  text-decoration: none;
  border-radius: 16px;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(0, 102, 204, 0.2);
}

.btn-notion:hover {
  transform: scale(1.02);
  box-shadow: 0 8px 25px rgba(0, 102, 204, 0.3);
  background: linear-gradient(135deg, #004080, #0073e6);
}

.btn-notion span {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 5px;
}

.btn-notion small {
  opacity: 0.8;
  font-size: 0.9rem;
}

/* 하단 링크 */
.links-footer {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  justify-content: center;
  border-top: 1px solid #eee;
  padding-top: 40px;
}

.aside-link {
  padding: 10px 20px;
  background: #f0f2f5;
  color: #666;
  text-decoration: none;
  border-radius: 20px;
  font-size: 0.9rem;
  transition: all 0.2s;
}

.aside-link:hover {
  background: #e4e6e9;
  color: #333;
}

/* 반응형 */
@media (max-width: 800px) {
  .gallery-grid {
    grid-template-columns: 1fr;
  }

  .content-container {
    margin-top: 250px;
  }

  nav ul {
    display: none;
    position: absolute;
    top: 60px;
    left: 0;
    width: 100%;
    background: white;
    flex-direction: column;
  }

  nav ul li {
    width: 100%;
    border-bottom: 1px solid #ddd;
  }

  nav ul>li>a {
    color: #222;
    font-weight: bold;
    font-size: 16px;
    padding: 14px;
    background: #f9f9f9;
  }

  nav ul li ul {
    position: static;
    border: none;
    box-shadow: none;
  }

  nav ul li ul li a {
    padding: 10px 14px 10px 30px;
    font-size: 14px;
    background: white;
    color: #444;
  }

  nav ul li ul li a:hover {
    background: #f0f0f0;
  }

  .menu-toggle {
    display: flex;
  }

  nav.active ul {
    display: flex;
  }
}

/* 다크 모드 */
@media (prefers-color-scheme: dark) {

  body,
  footer {
    background: #121212;
    color: #e0e0e0;
  }

  .intro-description {
    color: #ccc;
  }

  .gallery-grid figure {
    background: #1e1e1e;
  }

  .gallery-grid figcaption {
    background: #252525;
    color: #aaa;
  }

  .report-alert {
    background: #2a1b0a;
    border-left-color: #ff9900;
  }

  .alert-text {
    color: #ddd;
  }

  .aside-link {
    background: #2a2a2a;
    color: #aaa;
  }

  .aside-link:hover {
    background: #333;
    color: #fff;
  }
}