:root {
  --bg-color: #0f172a;
  --card-bg: #1e293b;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --accent: #38bdf8;
  --accent-hover: #0284c7;
  --border: #334155;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
}

.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 20px;
}

/* --- Header & Logo --- */
header {
  border-bottom: 1px solid var(--border);
  padding: 40px 0;
  text-align: center;
}

.logo-img {
  max-width: 320px;
  width: 100%;
  height: auto;
  margin-bottom: 12px;
  display: inline-block;
}

.subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
  letter-spacing: 0.5px;
}

/* --- Intro Section --- */
.intro {
  margin: 40px 0;
  text-align: center;
}

.intro h2 {
  font-size: 1.8rem;
  margin-bottom: 12px;
  color: var(--accent);
}

.intro p {
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* --- Grid & Category Cards (Index 페이지 메인 영역) --- */
.categories {
  margin-bottom: 40px;
}

.categories h3 {
  font-size: 1.3rem;
  margin-bottom: 20px;
  border-left: 4px solid var(--accent);
  padding-left: 10px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  transition: transform 0.2s ease, border-color 0.2s ease;
  position: relative;
  cursor: pointer;
}

.card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
}

.card h4 {
  font-size: 1.2rem;
  margin-bottom: 8px;
}

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

.badge {
  display: inline-block;
  font-size: 0.75rem;
  text-transform: uppercase;
  color: var(--accent);
  background: rgba(56, 189, 248, 0.1);
  padding: 2px 8px;
  border-radius: 4px;
  margin-bottom: 12px;
}

/* --- Write Page Layout (글쓰기 페이지 전용) --- */
.write-container { 
  max-width: 800px; 
  margin: 40px auto; 
  padding: 0 20px; 
}

.form-group { 
  margin-bottom: 20px; 
}

.form-group label { 
  display: block; 
  margin-bottom: 8px; 
  font-weight: bold; 
  color: var(--accent); 
}

.form-control { 
  width: 100%; 
  padding: 12px; 
  background: var(--card-bg); 
  border: 1px solid var(--border); 
  border-radius: 6px; 
  color: var(--text-main); 
  font-size: 1rem; 
  box-sizing: border-box; 
}

.form-control:focus { 
  outline: none; 
  border-color: var(--accent); 
}

textarea.form-control { 
  resize: vertical; 
  font-family: inherit; 
  line-height: 1.5; 
}

.form-row { 
  display: flex; 
  gap: 20px; 
}

.form-row .form-group { 
  flex: 1; 
}

.editor-control {
  width: 100%;
  min-height: 350px;
  height: auto !important;
  padding: 16px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text-main);
  font-size: 1rem;
  line-height: 1.6;
  box-sizing: border-box;
  outline: none;
  overflow-y: auto;
}

.editor-control:focus { 
  border-color: var(--accent); 
}

.editor-control[placeholder]:empty:before {
  content: attr(placeholder);
  color: var(--text-muted);
  cursor: text;
}

.editor-control * {
  max-height: none !important;
}

.btn-group { 
  display: flex; 
  justify-content: flex-end; 
  gap: 10px; 
  margin-top: 30px; 
}

.btn-secondary { 
  background: transparent; 
  border: 1px solid var(--border); 
  color: var(--text-muted); 
}

.btn-secondary:hover { 
  border-color: var(--text-main); 
  color: var(--text-main); 
}

/* --- Post Detail Page (상세 페이지 영역) --- */
.post-detail-container { 
  max-width: 800px; 
  margin: 40px auto; 
  padding: 0 20px; 
}

.post-header { 
  border-bottom: 1px solid var(--border); 
  padding-bottom: 20px; 
  margin-bottom: 30px; 
}

.post-meta-wrap { 
  display: flex; 
  justify-content: space-between; 
  align-items: center; 
  flex-wrap: wrap; 
  margin-top: 10px; 
  gap: 10px; 
}

.post-meta { 
  display: flex; 
  gap: 15px; 
  color: var(--text-muted); 
  font-size: 0.9rem; 
  flex-wrap: wrap; 
}

.action-btn-group { 
  display: flex; 
  gap: 8px; 
}

.btn-flow-toggle {
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid #10b981;
  color: #10b981;
  padding: 5px 12px;
  border-radius: 4px;
  font-size: 0.85rem;
  font-weight: bold;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-flow-toggle:hover { 
  background: #10b981; 
  color: #ffffff; 
}

.btn-delete-post {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid #ef4444;
  color: #ef4444;
  padding: 5px 12px;
  border-radius: 4px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-delete-post:hover { 
  background: #ef4444; 
  color: #ffffff; 
}

.post-summary-box {
  margin-top: 20px;
  padding: 16px 20px;
  background: rgba(59, 130, 246, 0.08);
  border-left: 4px solid var(--accent);
  border-radius: 6px;
}

.post-summary-box strong { 
  color: var(--accent); 
  display: block; 
  margin-bottom: 6px; 
  font-size: 0.95rem; 
}

.post-summary-box p { 
  margin: 0; 
  color: var(--text-main); 
  font-size: 0.95rem; 
  line-height: 1.6; 
  white-space: pre-line; 
}

/* --- Gemini 대화 및 Rich Text 본문 스타일 보정 (첫 줄 잘림 방지) --- */
.post-content { 
  line-height: 1.8; 
  font-size: 1.05rem; 
  margin-bottom: 50px; 
  width: 100%;
  height: auto !important;
  max-height: none !important;
  overflow: visible !important;
}

.post-content * {
  max-height: none !important;
  overflow: visible !important;
}

.post-content p { 
  margin-bottom: 1em; 
}

.post-content pre, 
.post-content code, 
.post-content table { 
  max-width: 100%; 
  overflow-x: auto !important; 
}

/* --- Flow Diagram Container & Git Graph --- */
.flow-diagram-container {
  display: none;
  margin: 25px 0;
  padding: 20px;
  background: #0f172a;
  border: 1px solid var(--accent);
  border-radius: 8px;
  animation: fadeIn 0.3s ease;
}

.flow-diagram-container.active { 
  display: block !important; 
}

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

.flow-title { 
  font-size: 1.1rem; 
  color: var(--accent); 
  margin-bottom: 15px; 
  font-weight: bold; 
  display: flex; 
  align-items: center; 
  gap: 8px; 
}

.git-graph { 
  display: flex; 
  flex-direction: column; 
  gap: 14px; 
  position: relative; 
  padding-left: 10px; 
}

.git-graph::before {
  content: '';
  position: absolute;
  left: 23px;
  top: 15px;
  bottom: 15px;
  width: 3px;
  background: rgba(255, 255, 255, 0.15);
  z-index: 1;
}

.git-node {
  display: flex;
  align-items: center;
  gap: 15px;
  position: relative;
  z-index: 2;
  cursor: pointer;
  padding: 8px 12px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid transparent;
  transition: all 0.2s ease;
}

.git-node:hover {
  background: rgba(59, 130, 246, 0.12);
  border-color: var(--accent);
  transform: translateX(4px);
}

.git-node.active {
  background: rgba(59, 130, 246, 0.2);
  border-color: var(--accent);
}

.git-dot {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  border: 3px solid #0f172a;
  box-shadow: 0 0 8px rgba(59, 130, 246, 0.6);
  flex-shrink: 0;
}

.git-node.branch-main .git-dot { background: #3b82f6; }
.git-node.branch-feature .git-dot { background: #10b981; }

.git-branch-tag {
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: 12px;
  font-family: monospace;
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-muted);
}

.git-node.branch-main .git-branch-tag { background: rgba(59, 130, 246, 0.2); color: #60a5fa; }
.git-node.branch-feature .git-branch-tag { background: rgba(16, 185, 129, 0.2); color: #34d399; }

.git-node-label { 
  font-size: 0.95rem; 
  font-weight: 600; 
  color: var(--text-main); 
}

.flow-preview-card {
  margin-top: 20px;
  padding: 16px 20px;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  display: none;
}

.flow-preview-card h4 { 
  margin: 0 0 8px 0; 
  color: var(--accent); 
  font-size: 1.05rem; 
}

.flow-preview-card p { 
  margin: 0; 
  color: var(--text-main); 
  font-size: 0.95rem; 
  line-height: 1.6; 
  white-space: pre-line; 
}

/* --- Comments Section --- */
.comments-section { 
  border-top: 1px solid var(--border); 
  padding-top: 30px; 
}

.comment-card { 
  background: var(--card-bg); 
  border: 1px solid var(--border); 
  border-radius: 6px; 
  padding: 15px; 
  margin-bottom: 12px; 
}

.comment-card.reply { 
  margin-left: 30px; 
  border-left: 3px solid var(--accent); 
}

.comment-meta { 
  display: flex; 
  justify-content: space-between; 
  font-size: 0.85rem; 
  color: var(--text-muted); 
  margin-bottom: 8px; 
}

.comment-author { 
  font-weight: bold; 
  color: var(--accent); 
}

.btn-reply-toggle { 
  background: none; 
  border: none; 
  color: var(--accent); 
  font-size: 0.8rem; 
  cursor: pointer; 
  text-decoration: underline; 
  padding: 0; 
  margin-top: 8px; 
}

.comment-form { 
  margin-top: 20px; 
  display: flex; 
  flex-direction: column; 
  gap: 10px; 
}

.comment-form input, 
.comment-form textarea {
  background: var(--card-bg); 
  border: 1px solid var(--border); 
  border-radius: 6px; 
  color: var(--text-main); 
  padding: 10px;
}

.comment-form textarea { 
  height: 80px; 
  resize: vertical; 
}

.reply-form { 
  margin-top: 10px; 
  padding: 10px; 
  background: rgba(255, 255, 255, 0.02); 
  border-radius: 6px; 
  display: none; 
}

/* --- Common Buttons --- */
.btn-submit {
  background: var(--accent);
  color: #000;
  border: none;
  padding: 8px 16px;
  border-radius: 4px;
  font-weight: bold;
  cursor: pointer;
  transition: background 0.2s ease;
}

.btn-submit:hover {
  background: var(--accent-hover);
  color: #fff;
}

/* --- Footer --- */
footer {
  border-top: 1px solid var(--border);
  padding: 30px 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: 60px;
}