/* ==========================================
   Design Team Guide - Theme & Reset
   ================================---------- */
:root {
  --bg-main: #f7f8fa;
  --bg-sidebar: #ffffff;
  --bg-card: #ffffff;
  --bg-topbar: rgba(255, 255, 255, 0.92);

  --border-color: #e5e7eb;

  --text-main: #161b26;
  --text-muted: #667085;

  --primary: #3448c5;
  --primary-hover: #293aa4;
  --primary-light: #eef1ff;

  --accent-glow: rgba(52, 72, 197, 0.08);

  --transition: all 0.2s ease;
}

[data-theme="dark"] {
  --bg-main: #090d16;
  --bg-sidebar: #0f172a;
  --bg-card: #1e293b;
  --bg-topbar: rgba(15, 23, 42, 0.85);
  --border-color: #334155;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --primary: #6366f1;
  --primary-hover: #818cf8;
  --primary-light: rgba(99, 102, 241, 0.15);
  --accent-glow: rgba(99, 102, 241, 0.25);
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;
  background-color: var(--bg-main);
  color: var(--text-main);
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Layout */
.layout { display: flex; min-height: 100vh; }
.sidebar {
  width: 280px;
  background-color: var(--bg-sidebar);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0; bottom: 0; left: 0;
  z-index: 100;
  overflow-y: auto;
  transition: var(--transition);
}
.content {
  flex: 1;
  margin-left: 280px;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

/* Sidebar Brand & Nav */
.brand { padding: 24px 20px; border-bottom: 1px solid var(--border-color); }
.brand h1 { font-size: 1.15rem; font-weight: 700; line-height: 1.3; color: var(--text-main); }
.brand p { font-size: 0.8rem; color: var(--text-muted); margin-top: 6px; }

.nav-group { padding: 12px 16px; border-bottom: 1px solid var(--border-color); }
.nav-group-title { font-size: 0.75rem; font-weight: 700; text-transform: uppercase; color: var(--text-muted); margin-bottom: 8px; letter-spacing: 0.05em; }
.nav-link {
  display: flex;
  align-items: center;
  padding: 8px 10px;
  border-radius: 6px;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: var(--transition);
  margin-bottom: 2px;
}
.nav-link:hover { background-color: var(--primary-light); color: var(--primary); }
.nav-link.active { background-color: var(--primary); color: #ffffff; }
.nav-num { display: inline-block; width: 24px; font-family: monospace; font-size: 0.8rem; opacity: 0.7; }

/* Topbar */
.topbar {
  height: 58px;
  padding: 0 32px;
  background: var(--bg-topbar);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 99;
}

.action-btn,
.theme-toggle {
  height: 34px;
  padding: 0 12px;
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: 5px;
  color: var(--text-muted);
  font-size: 0.8rem;
  font-weight: 600;
}

.action-btn:hover,
.theme-toggle:hover {
  background: var(--bg-card);
  border-color: #b8c0d0;
  color: var(--text-main);
}

/* Main Container */
.main {
  width: 100%;
  max-width: 1080px;
  margin: 0 auto;
  padding: 48px 48px 80px;
}.breadcrumb { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 16px; }

/* Hero Section */
.hero {
  background: linear-gradient(135deg, var(--bg-card), var(--bg-sidebar));
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 40px;
  margin-bottom: 24px;
  box-shadow: 0 4px 20px var(--accent-glow);
  position: relative;
  overflow: hidden;
}
.hero .eyebrow { font-size: 0.75rem; font-weight: 700; color: var(--primary); text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: 8px; }
.hero h2 { font-size: 2rem; font-weight: 800; margin-bottom: 12px; letter-spacing: -0.02em; }
.hero p { color: var(--text-muted); font-size: 1.05rem; max-width: 800px; margin-bottom: 20px; }
.hero-meta { display: flex; gap: 8px; flex-wrap: wrap; }
.pill { background: var(--primary-light); color: var(--primary); padding: 4px 10px; border-radius: 20px; font-size: 0.8rem; font-weight: 600; }

/* Progress Card */
.progress-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 20px 24px;
  margin-bottom: 32px;
}
.progress-row { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; font-size: 0.9rem; font-weight: 600; }
.progress-track { background: var(--border-color); height: 8px; border-radius: 4px; overflow: hidden; }
.progress-fill { background: var(--primary); height: 100%; width: 0%; transition: width 0.4s ease; border-radius: 4px; }

/* Sections & Components */
.section {
  margin-bottom: 56px;
}

.section h3 {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 20px;
  padding: 0;
  border: 0;
  color: var(--text-main);
  font-size: 1.35rem;
  font-weight: 750;
  letter-spacing: -0.025em;
}

.section h3::before {
  content: "";
  width: 4px;
  height: 20px;
  border-radius: 2px;
  background: var(--primary);
  flex: 0 0 auto;
}

.section > p {
  max-width: 820px;
  color: var(--text-muted);
  line-height: 1.8;
}

.three-col, .two-col { display: grid; gap: 20px; }
.three-col { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.two-col { grid-template-columns: repeat(auto-fit, minmax(400px, 1fr)); }

.mini-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 24px;
  transition: var(--transition);
}
.mini-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  padding: 24px;
  transition: border-color 0.2s ease;
}

.mini-card:hover {
  transform: none;
  border-color: #b8c0d0;
  box-shadow: none;
}
.mini-card h4 { font-size: 1.05rem; font-weight: 700; margin-bottom: 10px; color: var(--text-main); }
.mini-card p { font-size: 0.9rem; margin-bottom: 0; }

/* Flow & Notes */
.flow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 20px 22px;
  margin-bottom: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
}

.flow-step {
  padding: 6px 10px;
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: 5px;
  color: var(--text-main);
  font-size: 0.84rem;
  font-weight: 600;
}

.flow-arrow {
  color: #a0a7b4;
  font-size: 0.82rem;
}
.note { background: var(--bg-card); border-left: 4px solid var(--primary); padding: 14px 18px; border-radius: 0 8px 8px 0; font-size: 0.9rem; color: var(--text-muted); border-top: 1px solid var(--border-color); border-right: 1px solid var(--border-color); border-bottom: 1px solid var(--border-color); }

/* Tables */
.table-wrap { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: 12px; overflow: hidden; }
table { width: 100%; border-collapse: collapse; text-align: left; font-size: 0.9rem; }
th, td { padding: 14px 20px; border-bottom: 1px solid var(--border-color); }
th { background: var(--bg-sidebar); font-weight: 700; color: var(--text-main); }
tr:last-child td { border-bottom: none; }
tr:hover td { background-color: var(--primary-light); }
td a { color: var(--primary); font-weight: 600; text-decoration: none; }
td a:hover { text-decoration: underline; }

/* Checklists */
.checklist {
  padding: 4px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 10px;
}

.check-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border-color);
  color: var(--text-main);
  cursor: pointer;
  font-size: 0.94rem;
  line-height: 1.55;
}

.check-item:last-child {
  border-bottom: 0;
}

.check-item input[type="checkbox"] {
  width: 17px;
  height: 17px;
  margin-top: 3px;
  accent-color: var(--primary);
  flex: 0 0 auto;
}

.check-item:has(input:checked) span {
  color: var(--text-muted);
  text-decoration: line-through;
  text-decoration-color: #b8bec8;
}

/* TOC & Footer */
.toc { background: var(--bg-card); border: 1px solid var(--border-color); border-radius: 12px; padding: 24px; margin-bottom: 32px; }
.toc h3 { font-size: 1.1rem; margin-bottom: 12px; border: none; padding: 0; }
.toc ol { padding-left: 20px; color: var(--text-muted); display: grid; gap: 6px; }
.toc a { color: var(--primary); text-decoration: none; font-weight: 500; }
.toc a:hover { text-decoration: underline; }

.page-nav { margin-top: 40px; display: flex; justify-content: flex-end; }
.page-nav .next { background: var(--bg-card); border: 1px solid var(--border-color); padding: 16px 24px; border-radius: 12px; text-decoration: none; color: var(--text-main); display: flex; flex-direction: column; gap: 4px; transition: var(--transition); }
.page-nav .next:hover { border-color: var(--primary); transform: translateY(-2px); box-shadow: 0 4px 15px var(--accent-glow); }
.page-nav small { color: var(--text-muted); font-size: 0.75rem; text-transform: uppercase; font-weight: 700; }
.page-nav strong { color: var(--primary); font-size: 1rem; }

.footer { text-align: center; padding: 40px; color: var(--text-muted); font-size: 0.85rem; border-top: 1px solid var(--border-color); margin-top: 60px; }

/* Responsive */
@media (max-width: 900px) {
  .sidebar { transform: translateX(-100%); }
  .sidebar.open { transform: translateX(0); }
  .content { margin-left: 0; }
  .main { padding: 20px 16px; }
  .topbar { padding: 0 16px; }
}