:root {
  --primary-color: #3EB489; /* 민트 */
  --primary-hover: #2d8c6a;
  --bg-color: #f7f9f8;
  --text-main: #333333;
  --text-muted: #777777;
  --card-bg: #ffffff;
  --border-color: #eaeaea;
}

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

body {
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, 'Helvetica Neue', 'Segoe UI', 'Apple SD Gothic Neo', 'Noto Sans KR', 'Malgun Gothic', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
}

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

ul {
  list-style: none;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  background-color: var(--card-bg);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 5%;
}

.logo a {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary-color);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
  font-weight: 500;
}

.nav-links a:hover {
  color: var(--primary-color);
}

.auth-links a {
  padding: 0.5rem 1rem;
  border-radius: 8px;
  background-color: var(--primary-color);
  color: white;
  font-weight: bold;
  transition: background-color 0.2s;
}

.auth-links a:hover {
  background-color: var(--primary-hover);
}

/* Main Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 5%;
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, #e0f7fa 0%, #b2dfdb 100%);
  border-radius: 16px;
  padding: 3rem 2rem;
  text-align: center;
  margin-bottom: 3rem;
  box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.hero h1 {
  font-size: 2.5rem;
  color: #004d40;
  margin-bottom: 1rem;
}

.hero p {
  font-size: 1.1rem;
  color: #00796b;
}

/* Card Grid */
.section-title {
  font-size: 1.5rem;
  font-weight: bold;
  margin-bottom: 1.5rem;
  color: var(--text-main);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 2rem;
}

.card {
  background-color: var(--card-bg);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
  transition: transform 0.2s, box-shadow 0.2s;
  cursor: pointer;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 16px rgba(0,0,0,0.1);
}

.card-img {
  width: 100%;
  height: 200px;
  background-color: #ddd;
  object-fit: cover;
}

.card-content {
  padding: 1.5rem;
}

.tag {
  display: inline-block;
  background-color: var(--primary-color);
  color: white;
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  margin-bottom: 0.5rem;
  font-weight: bold;
}

.card-title {
  font-size: 1.25rem;
  font-weight: bold;
  margin-bottom: 0.5rem;
}

.card-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Form Styles (Login & Board) */
.form-container {
  max-width: 400px;
  margin: 4rem auto;
  background: var(--card-bg);
  padding: 2.5rem;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}

.form-title {
  text-align: center;
  font-size: 1.8rem;
  margin-bottom: 1.5rem;
  color: var(--primary-color);
}

.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
}

.form-group input, .form-group textarea {
  width: 100%;
  padding: 0.8rem;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  font-family: inherit;
  font-size: 1rem;
}

.form-group textarea {
  resize: vertical;
  min-height: 100px;
}

.form-group input:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 2px rgba(62, 180, 137, 0.2);
}

.btn-submit {
  width: 100%;
  padding: 1rem;
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1.1rem;
  font-weight: bold;
  cursor: pointer;
  transition: background-color 0.2s;
}

.btn-submit:hover {
  background-color: var(--primary-hover);
}

/* Board Styles */
.board-container {
  max-width: 800px;
  margin: 2rem auto;
}

.board-write {
  background: var(--card-bg);
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
  margin-bottom: 2rem;
}

.board-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.board-item {
  background: var(--card-bg);
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
  border-left: 4px solid var(--primary-color);
}

.board-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.board-author {
  font-weight: bold;
  color: var(--primary-color);
}

.board-content {
  font-size: 1rem;
}

/* Footer */
footer {
  text-align: center;
  padding: 2rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-color);
  margin-top: 4rem;
}