/* ===================== INSIGHT (MISSION) PAGE NEO-BRUTALIST REFACTORED ===================== */
:root {
  --neo-border: 2px solid var(--black);
  --neo-shadow: 4px 4px 0px var(--black);
  --neo-shadow-hover: 6px 6px 0px var(--black);
}

.mission-page { 
  background: var(--concrete); 
  min-height: 100vh; 
  padding-top: 64px; 
}

/* Hero Section Refined - Neo-Brutalist */
.mission-hero { 
  padding: 100px 0 60px; 
  background: var(--white); 
  border-bottom: var(--neo-border);
  position: relative;
  overflow: hidden;
}

.mission-hero::after {
  content: '';
  position: absolute;
  top: -50px; right: -50px;
  width: 200px; height: 200px;
  background: var(--purple-light);
  border-radius: 50%;
  z-index: 0;
  opacity: 0.5;
}

.mission-hero .section-container { 
  max-width: 1200px; 
  margin: 0 auto; 
  padding: 0 24px; 
  position: relative;
  z-index: 1;
}

.section-tag-premium { 
  display: inline-flex; 
  align-items: center; 
  gap: 8px; 
  background: var(--white); 
  color: var(--purple); 
  padding: 8px 20px; 
  border: var(--neo-border);
  box-shadow: 2px 2px 0px var(--black);
  border-radius: 4px; 
  font-size: 14px; 
  font-weight: 800; 
  margin-bottom: 32px;
  text-transform: uppercase;
}

.mission-hero h1 { 
  font-size: 64px; 
  font-weight: 950; 
  letter-spacing: -0.04em; 
  line-height: 1.1;
  color: var(--black);
  margin-bottom: 24px;
}

.text-purple { color: var(--purple); }

.mission-hero .section-desc {
  font-size: 20px;
  color: var(--gray-700);
  max-width: 600px;
  line-height: 1.6;
}

/* Layout: Sidebar + Content */
.insight-layout {
  display: grid;
  grid-template-columns: 320px 1fr;
  max-width: 1200px;
  margin: 0 auto;
  gap: 40px;
  padding: 80px 24px 120px;
}

/* Sidebar Navigation (Sticky) */
.insight-sidebar {
  position: sticky;
  top: 100px;
  height: fit-content;
  max-height: calc(100vh - 120px);
  padding: 30px;
  background: var(--white);
  border: var(--neo-border);
  box-shadow: 6px 6px 0px var(--black);
  border-radius: 4px;
}

.sidebar-title { 
  font-size: 14px; 
  font-weight: 900; 
  color: var(--black); 
  text-transform: uppercase; 
  margin-bottom: 24px; 
  letter-spacing: 0.1em;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--black);
}

.sidebar-nav { list-style: none; padding: 0; display: flex; flex-direction: column; gap: 12px; }
.sidebar-nav li a {
  display: block;
  padding: 12px 16px;
  font-size: 16px;
  font-weight: 700;
  color: var(--black);
  border: 2px solid transparent;
  transition: all 0.15s;
  text-decoration: none;
  line-height: 1.4;
  border-radius: 4px;
}

.sidebar-nav li a:hover { background: var(--gray-100); border-color: var(--black); }
.sidebar-nav li a.active { background: var(--purple); color: var(--white); border-color: var(--black); }

/* Main Content Area */
.insight-main { 
  min-width: 0; 
  display: flex;
  flex-direction: column;
  gap: 32px;
  overflow-anchor: none; /* 방지: 모바일에서 콘텐츠 추가 시 스크롤 하단 고정 방지 */
}

/* Neo-Brutalist Toggle */
.chapter-toggle {
  background: var(--white);
  border: var(--neo-border);
  box-shadow: var(--neo-shadow);
  border-radius: 4px;
  overflow: hidden;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.chapter-toggle:hover { 
  transform: translate(-2px, -2px);
  box-shadow: var(--neo-shadow-hover);
}

.chapter-toggle.open { 
  box-shadow: 2px 2px 0px var(--black);
  transform: translate(2px, 2px);
}

.toggle-header {
  padding: 32px 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  background: var(--white);
}

.toggle-title-wrap { display: flex; flex-direction: column; gap: 8px; }
.toggle-badge { 
  font-size: 12px; 
  font-weight: 900; 
  color: var(--white); 
  background: var(--purple);
  padding: 2px 8px;
  display: inline-block;
  width: fit-content;
  border: 1px solid var(--black);
  text-transform: uppercase;
}
.toggle-title { 
  font-size: 24px; 
  font-weight: 900; 
  color: var(--black); 
  letter-spacing: -0.02em; 
  line-height: 1.2;
}
.toggle-icon { 
  width: 44px; height: 44px; 
  display: flex; align-items: center; justify-content: center;
  border: var(--neo-border);
  background: var(--white);
  transition: all 0.2s;
  color: var(--black);
  font-size: 18px;
  flex-shrink: 0;
}
.chapter-toggle.open .toggle-icon { background: var(--black); color: var(--white); transform: rotate(180deg); }

.toggle-content {
  display: none;
  padding: 0 40px 50px;
  background: var(--white);
  animation: slideDown 0.3s ease-out;
}
.chapter-toggle.open .toggle-content { display: block; border-top: var(--neo-border); padding-top: 40px; }

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Content Typography Refined */
.chapter-text { font-size: 19px; line-height: 1.8; color: var(--black); font-weight: 500; }
.chapter-text p { margin-top: 24px; }
.chapter-text p:first-child { margin-top: 0; }
.chapter-text h2 { 
  font-size: 28px; 
  font-weight: 900; 
  margin: 50px 0 24px; 
  color: var(--black); 
  background: var(--purple-light);
  display: inline-block;
  padding: 4px 12px;
  border: 1px solid var(--black);
  box-shadow: 2px 2px 0px var(--black);
}
.chapter-text h4 { 
  font-size: 20px; 
  font-weight: 850; 
  margin: 40px 0 20px; 
  color: var(--black); 
  text-decoration: underline;
  text-decoration-color: var(--purple);
  text-underline-offset: 6px;
}
.chapter-text blockquote { 
  margin: 40px 0; 
  padding: 30px; 
  background: var(--white); 
  border: var(--neo-border);
  box-shadow: 4px 4px 0px var(--purple);
  font-weight: 700; 
  font-size: 20px;
  color: var(--black); 
  line-height: 1.5;
}

.chapter-loading {
  text-align: center;
  padding: 100px 0;
}
.spinner {
  width: 50px; height: 50px;
  border: 5px solid var(--purple-light);
  border-top: 5px solid var(--purple);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto 20px;
}
@keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }

/* ===================== MOBILE OPTIMIZATION ===================== */
@media (max-width: 900px) {
  .mission-page { padding-top: 56px; }
  .insight-layout { grid-template-columns: 1fr; gap: 24px; padding: 32px 16px 80px; }
  .insight-sidebar { display: none; }
  
  .mission-hero { padding: 60px 0 40px; }
  .mission-hero h1 { font-size: 36px; letter-spacing: -0.03em; }
  .mission-hero .section-desc { font-size: 16px; }
  .section-tag-premium { font-size: 12px; padding: 6px 14px; margin-bottom: 24px; }
  
  .chapter-toggle { box-shadow: 3px 3px 0px var(--black); }
  .toggle-header { padding: 24px 20px; gap: 16px; }
  .toggle-title { font-size: 18px; line-height: 1.3; }
  .toggle-badge { font-size: 10px; padding: 1px 6px; }
  .toggle-icon { width: 32px; height: 32px; font-size: 14px; }
  
  .toggle-content { padding: 0 20px 32px; }
  .chapter-toggle.open .toggle-content { padding-top: 24px; }
  
  .chapter-text { font-size: 17px; line-height: 1.7; }
  .chapter-text h2 { font-size: 22px; margin: 32px 0 16px; }
  .chapter-text h4 { font-size: 18px; margin: 24px 0 12px; }
  .chapter-text blockquote { padding: 20px; font-size: 17px; margin: 24px 0; box-shadow: 3px 3px 0px var(--purple); }
}

@media (max-width: 480px) {
  .mission-hero h1 { font-size: 32px; }
  .toggle-header { padding: 20px 16px; }
  .toggle-title { font-size: 16px; }
}