/* Reset & 기본 스타일 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: 'Segoe UI', sans-serif;
  background: #f5f7fa;
  color: #333;
  line-height: 1.6;
}

/* 헤더 */
header {
  background: #fff;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.logo {
  font-weight: bold;
  font-size: 1.5rem;
  color: #222;
}

/* 내비게이션 링크 */
.nav-links a {
  margin-left: 1.5rem;
  text-decoration: none;
  color: #444;
  font-weight: 500;
  position: relative;
}
.nav-links a:hover::after {
  width: 100%;
}
.nav-links a::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background-color: #28a745;
  transition: 0.3s ease;
}

/* 메뉴 토글 버튼 (모바일) */
.menu-toggle {
  display: none;
  font-size: 1.5rem;
  background: none;
  border: none;
  cursor: pointer;
  color: #28a745;

}

/* 히어로 섹션 */
.hero {
  text-align: center;
  padding: 3rem 1rem;
  background: linear-gradient(to right, #f0f4f8, #ffffff);
}
.hero h1 {
  font-size: 2.5rem;
}
.hero p {
  font-size: 1.1rem;
  color: #666;
}

/* 드롭존 */
.drop-zone {
  border: 3px dashed #cde0d8;
  background-color: #eaf6f0;
  border-radius: 20px;
  padding: 4rem;
  max-width: 850px;
  margin: 2rem auto;
  text-align: center;
  color: #2e7d32;
  font-size: 1.2rem;
}
.file-label {
  color: #2e7d32;
  font-weight: bold;
  cursor: pointer;
}

/* 드래그 시 강조 테두리 */
.drop-zone.highlight {
  border-color: #28a745;
  background-color: #d4edda;
}

/* 드래그 애니메이션 */
@keyframes pulse {
  0% { background-color: #d4edda; }
  50% { background-color: #eaf6f0; }
  100% { background-color: #d4edda; }
}
.highlight-animate {
  animation: pulse 1s ease-in-out;
}

/* 변환기 영역 */
.converter {
  max-width: 850px;
  margin: 2rem auto;
  background: #fff;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
textarea {
  width: 100%;
  min-height: 180px;
  padding: 1rem;
  border-radius: 10px;
  border: 2px solid #ccc;
  font-size: 1rem;
  resize: vertical;
  margin-bottom: 1rem;
}
textarea:focus {
  border-color: #28a745;
  outline: none;
}

/* 버튼과 셀렉트 박스 */
.buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1rem;
}
select, button {
  padding: 0.7rem 1.2rem;
  font-size: 1rem;
  border: none;
  border-radius: 8px;
  background: #28a745;
  color: white;
  font-weight: 500;
  cursor: pointer;
}
button:hover, select:hover {
  background: #1e7e34;
}

/* 정보 카드 섹션 */
.info-card {
  max-width: 850px;
  margin: 3rem auto;
  background: #fff;
  border-radius: 12px;
  padding: 2rem;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.info-card h2 {
  color: #2e7d32;
  margin-bottom: 0.5rem;
}
.info-card p {
  font-size: 1rem;
  color: #444;
}

/* 푸터 */
footer {
  text-align: center;
  padding: 2rem;
  font-size: 0.9rem;
  background: #f0f0f0;
  color: #666;
}

/* 반응형 (모바일) */
@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }
  
  .nav-links a {
    padding: 0.5rem 0;
  }
  .nav-open 
}


.nav-links {
  display: flex;
  flex-wrap: nowrap;
  overflow-x: auto;
  white-space: nowrap;
  gap: 16px;
}
.nav-links a {
  white-space: nowrap;
}


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


/* Card Layout for Certificate Types */
.card-layout {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-top: 2rem;
}
.card {
  flex: 1 1 300px;
  background-color: #f9f9f9;
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}
.card h2 {
  margin-top: 0;
  font-size: 1.4rem;
}
.card.full {
  flex: 1 1 100%;
}
.intro {
  font-size: 1.1rem;
  line-height: 1.6;
  margin-bottom: 1rem;
}


/* Unified card layout for entire article */
.card.full {
  max-width: 960px;
  margin: 0 auto;
  background: #ffffff;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  line-height: 1.7;
  font-size: 1.05rem;
}
.card.full h2 {
  margin-top: 2rem;
  font-size: 1.4rem;
  border-bottom: 1px solid #ddd;
  padding-bottom: 0.5rem;
}
.card.full code {
  background-color: #f4f4f4;
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-family: monospace;
}


/* Screenshot-inspired article card layout */
.article-card {
  max-width: 820px;
  margin: 3rem auto;
  background: #ffffff;
  padding: 2.5rem;
  border-radius: 10px;
  box-shadow: 0 4px 30px rgba(0,0,0,0.08);
  font-size: 1.05rem;
  line-height: 1.8;
}
.article-card h1 {
  font-size: 1.8rem;
  margin-bottom: 1rem;
  font-weight: 700;
}
.article-card h2 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-top: 2rem;
  margin-bottom: 0.5rem;
}
.article-card code {
  background-color: #f5f5f5;
  padding: 2px 6px;
  border-radius: 4px;
  font-family: monospace;
}


/* Full single card layout */
.card.full {
  max-width: 860px;
  margin: 3rem auto;
  background-color: #fff;
  padding: 2.5rem;
  border-radius: 10px;
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.1);
  line-height: 1.8;
  font-size: 1.05rem;
}
.card.full h1 {
  font-size: 1.75rem;
  margin-bottom: 1rem;
  font-weight: 700;
}
.card.full h2 {
  font-size: 1.3rem;
  margin-top: 2rem;
}
.card.full code {
  background: #f2f2f2;
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
}
.footer {
  text-align: center;
  padding: 2rem 0;
  font-size: 0.9rem;
  color: #666;
  margin-top: 4rem;
  background: none;
}