/* ===================== RESET & BASE ===================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary: #4f46e5;
  --primary-dark: #3730a3;
  --primary-light: #818cf8;
  --accent: #06b6d4;
  --success: #10b981;
  --warning: #f59e0b;
  --danger: #ef4444;
  --bg: #0f0f1a;
  --bg2: #13131f;
  --bg3: #1a1a2e;
  --card: #1e1e2e;
  --card-border: #2a2a3e;
  --text: #e2e8f0;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --radius: 12px;
  --radius-lg: 20px;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Noto Sans KR', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 15px;
}

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

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===================== HEADER ===================== */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(15, 15, 26, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--card-border);
}

.nav {
  display: flex;
  align-items: center;
  gap: 32px;
  height: 60px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 15px;
  white-space: nowrap;
}
.brand-icon { font-size: 20px; }

.nav-links {
  display: flex;
  list-style: none;
  gap: 24px;
  margin-left: auto;
}
.nav-links a {
  color: var(--text-muted);
  font-size: 14px;
  font-weight: 500;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }

.nav-github {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--card);
  border: 1px solid var(--card-border);
  padding: 6px 14px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  transition: border-color 0.2s, background 0.2s;
  white-space: nowrap;
}
.nav-github:hover { border-color: var(--primary-light); background: var(--bg3); }

/* ===================== HERO ===================== */
.hero {
  position: relative;
  padding: 140px 0 60px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 0%, rgba(79,70,229,0.18) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  text-align: center;
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-block;
  background: rgba(79,70,229,0.2);
  border: 1px solid rgba(79,70,229,0.5);
  color: var(--primary-light);
  padding: 4px 16px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-title {
  font-size: clamp(28px, 5vw, 52px);
  font-weight: 800;
  line-height: 1.25;
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}

.gradient-text {
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  color: var(--text-muted);
  font-size: 16px;
  max-width: 660px;
  margin: 0 auto 24px;
  line-height: 1.8;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin-bottom: 32px;
}
.htag {
  background: var(--card);
  border: 1px solid var(--card-border);
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 13px;
  color: var(--text-muted);
}

.hero-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-bottom: 64px;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  padding: 12px 28px;
  border-radius: 10px;
  font-weight: 700;
  font-size: 15px;
  transition: background 0.2s, transform 0.15s;
}
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); }

.btn-secondary {
  background: transparent;
  color: var(--text);
  padding: 12px 28px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 15px;
  border: 1px solid var(--card-border);
  transition: border-color 0.2s, transform 0.15s;
}
.btn-secondary:hover { border-color: var(--primary-light); transform: translateY(-1px); }

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  position: relative;
  z-index: 1;
}

.stat-card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
}
.stat-num {
  font-size: 32px;
  font-weight: 800;
  color: var(--primary-light);
  line-height: 1;
  margin-bottom: 6px;
}
.stat-label { font-size: 12px; color: var(--text-muted); }

/* ===================== SECTION ===================== */
.section { padding: 80px 0; }
.section-dark { background: var(--bg2); }

.section-header {
  text-align: center;
  margin-bottom: 48px;
}
.section-tag {
  display: inline-block;
  color: var(--primary-light);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 12px;
  background: rgba(79,70,229,0.12);
  padding: 4px 14px;
  border-radius: 20px;
}
.section-header h2 {
  font-size: clamp(24px, 4vw, 36px);
  font-weight: 800;
  margin-bottom: 12px;
}
.section-header p {
  color: var(--text-muted);
  max-width: 560px;
  margin: 0 auto;
}

/* ===================== OVERVIEW ===================== */
.concept-box {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 32px;
  margin-bottom: 32px;
}
.concept-box h3 { font-size: 18px; font-weight: 700; margin-bottom: 20px; }

.repo-tree { margin-bottom: 20px; }
.tree-root {
  font-weight: 700;
  font-size: 15px;
  color: var(--primary-light);
  margin-bottom: 12px;
  padding-left: 8px;
  border-left: 3px solid var(--primary);
}
.tree-children { display: flex; flex-direction: column; gap: 10px; padding-left: 24px; }
.tree-child { display: flex; flex-direction: column; gap: 6px; }
.tree-node {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 8px;
}
.tree-node.active { color: var(--success); }
.tree-node.muted { color: var(--text-dim); }
.node-badge {
  background: rgba(16,185,129,0.15);
  color: var(--success);
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 10px;
}
.tree-items {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  padding-left: 20px;
}
.tree-items span {
  background: var(--bg3);
  border: 1px solid var(--card-border);
  font-size: 12px;
  padding: 2px 10px;
  border-radius: 8px;
  color: var(--text-muted);
}

.concept-note {
  background: rgba(245,158,11,0.08);
  border: 1px solid rgba(245,158,11,0.3);
  border-radius: 10px;
  padding: 14px 18px;
  font-size: 13px;
  color: var(--text-muted);
  display: flex;
  gap: 8px;
  align-items: flex-start;
}
.note-icon { font-size: 16px; flex-shrink: 0; margin-top: 1px; }
.concept-note strong { color: var(--warning); }

.exam-spec {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 32px;
}
.exam-spec h3 { font-size: 18px; font-weight: 700; margin-bottom: 20px; }

.spec-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.spec-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.spec-table th, .spec-table td {
  padding: 10px 14px;
  border: 1px solid var(--card-border);
  text-align: left;
}
.spec-table th { background: var(--bg3); color: var(--text-muted); font-weight: 600; }
.spec-table td:last-child { color: var(--primary-light); font-weight: 600; }

.subject-list { display: flex; flex-direction: column; gap: 8px; }
.subject-item {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--bg3);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  padding: 10px 14px;
}
.subj-num {
  width: 24px;
  height: 24px;
  background: var(--primary);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.subj-name { font-size: 14px; font-weight: 600; flex: 1; }
.subj-count { font-size: 13px; color: var(--text-muted); }

/* ===================== FEATURES ===================== */
.flow-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  margin-bottom: 40px;
}
.flow-col {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 28px;
}
.flow-title { font-size: 16px; font-weight: 700; margin-bottom: 20px; }
.flow-steps { display: flex; flex-direction: column; gap: 0; }
.flow-step {
  background: var(--bg3);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  padding: 10px 16px;
  font-size: 13px;
  font-weight: 500;
}
.flow-step.active {
  background: rgba(79,70,229,0.15);
  border-color: var(--primary);
  color: var(--primary-light);
}
.flow-arrow { text-align: center; color: var(--text-dim); padding: 4px 0; font-size: 16px; }

.features-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.feat-card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 28px;
}
.feat-icon { font-size: 28px; margin-bottom: 12px; }
.feat-card h3 { font-size: 17px; font-weight: 700; margin-bottom: 16px; }

.mode-table { font-size: 13px; margin-bottom: 8px; }
.mode-row {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 8px;
  padding: 7px 0;
  border-bottom: 1px solid var(--card-border);
}
.mode-row.head { color: var(--text-muted); font-weight: 600; }
.mode-row.mvp span:first-child { color: var(--success); font-weight: 600; }
.mode-row.later span:first-child { color: var(--primary-light); }
.mvp-note { font-size: 11px; color: var(--text-dim); margin-top: 8px; }

.score-formula { margin-bottom: 14px; }
.formula-item {
  background: var(--bg3);
  border-radius: 8px;
  padding: 10px 14px;
  margin-bottom: 8px;
}
.f-label { font-size: 11px; color: var(--text-muted); margin-bottom: 2px; }
.f-value { font-size: 13px; font-weight: 600; font-family: 'JetBrains Mono', monospace; color: var(--accent); }

.pass-table { display: flex; flex-direction: column; gap: 6px; }
.pass-row {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 10px;
  font-size: 12px;
  padding: 8px 12px;
  border-radius: 8px;
  align-items: center;
}
.pass-ok { background: rgba(16,185,129,0.1); }
.pass-fail { background: rgba(239,68,68,0.1); }
.pass-drop { background: rgba(245,158,11,0.1); }
.pass-row span:first-child { font-weight: 700; white-space: nowrap; }

.weakness-formula {
  background: var(--bg3);
  border-radius: 10px;
  padding: 14px;
  margin-bottom: 14px;
}
.w-title { font-size: 11px; color: var(--text-muted); font-weight: 600; margin-bottom: 10px; }
.w-items { display: flex; flex-direction: column; gap: 2px; }
.w-item {
  font-size: 13px;
  padding: 4px 8px;
  background: var(--card);
  border-radius: 6px;
  font-family: 'JetBrains Mono', monospace;
}
.w-plus { text-align: center; color: var(--primary-light); font-weight: 700; }

.priority-list { display: flex; flex-direction: column; gap: 6px; }
.pri-item {
  display: flex;
  gap: 10px;
  font-size: 13px;
  align-items: center;
}
.pri-rank {
  background: var(--primary);
  color: #fff;
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 6px;
  font-weight: 700;
  white-space: nowrap;
}

.mobile-layout { margin-bottom: 14px; }
.mobile-zone {
  padding: 10px 14px;
  font-size: 12px;
  border-radius: 8px;
  margin-bottom: 4px;
}
.mobile-zone.top { background: rgba(79,70,229,0.15); border: 1px solid rgba(79,70,229,0.3); }
.mobile-zone.mid { background: var(--bg3); border: 1px solid var(--card-border); }
.mobile-zone.bot { background: rgba(6,182,212,0.1); border: 1px solid rgba(6,182,212,0.3); }
.mobile-rules { display: flex; flex-direction: column; gap: 4px; }
.rule-item { font-size: 13px; color: var(--text-muted); }

/* ===================== ARCHITECTURE ===================== */
.arch-layout {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 48px;
  overflow-x: auto;
  padding-bottom: 8px;
}
.arch-block {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 20px;
  min-width: 180px;
  flex: 1;
}
.arch-block.frontend { border-top: 3px solid var(--primary); }
.arch-block.backend { border-top: 3px solid var(--accent); }
.arch-block.database { border-top: 3px solid var(--success); }
.arch-block.deploy { border-top: 3px solid var(--warning); }

.arch-label {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 12px;
}
.arch-items { display: flex; flex-direction: column; gap: 6px; }
.arch-items span {
  font-size: 13px;
  background: var(--bg3);
  padding: 4px 10px;
  border-radius: 6px;
}
.arch-arrow-h { color: var(--text-dim); font-size: 22px; flex-shrink: 0; }

.api-section h3 { font-size: 18px; font-weight: 700; margin-bottom: 20px; }
.api-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.api-group {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.api-title {
  font-size: 13px;
  font-weight: 700;
  color: var(--primary-light);
  margin-bottom: 8px;
}
.api-group code {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--text-muted);
  background: var(--bg3);
  padding: 4px 10px;
  border-radius: 6px;
}

/* ===================== ROADMAP ===================== */
.roadmap-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.rm-card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-lg);
  padding: 28px;
}
.rm-card.current {
  border-color: var(--primary);
  background: rgba(79,70,229,0.06);
}
.rm-phase { font-size: 16px; font-weight: 800; margin-bottom: 6px; }
.rm-status { font-size: 12px; margin-bottom: 20px; color: var(--text-muted); }
.rm-card ul { list-style: none; display: flex; flex-direction: column; gap: 8px; }
.rm-card li { font-size: 13px; color: var(--text-muted); }
.rm-card.current li { color: var(--text); }

/* ===================== FOOTER ===================== */
.footer {
  background: var(--bg2);
  border-top: 1px solid var(--card-border);
  padding: 40px 0;
}
.footer-inner { text-align: center; display: flex; flex-direction: column; gap: 12px; align-items: center; }
.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 16px;
  font-weight: 700;
}
.footer p { color: var(--text-muted); font-size: 13px; }
.footer-links { display: flex; gap: 20px; }
.footer-links a { font-size: 13px; color: var(--text-muted); transition: color 0.2s; }
.footer-links a:hover { color: var(--text); }
.footer-copy { font-size: 12px; color: var(--text-dim) !important; }

/* ===================== RESPONSIVE ===================== */
@media (max-width: 768px) {
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .nav-links { display: none; }
  .spec-grid { grid-template-columns: 1fr; }
  .flow-grid { grid-template-columns: 1fr; }
  .features-grid { grid-template-columns: 1fr; }
  .arch-layout { flex-direction: column; }
  .arch-arrow-h { transform: rotate(90deg); }
  .api-grid { grid-template-columns: 1fr; }
  .roadmap-grid { grid-template-columns: 1fr; }
}