:root {
  --bg: #F5F2EC;
  --bg-card: #FDFCF9;
  --bg-sidebar: #F0EDE6;
  --text: #1C1917;
  --text-soft: #6B6560;
  --text-muted: #A09890;
  --accent: #8B7355;
  --accent-light: #EDE8DF;
  --border: #E2DDD5;
  --shadow: 0 2px 12px rgba(0,0,0,0.07);
  --shadow-hover: 0 6px 24px rgba(0,0,0,0.12);

  --l1-bg: #E8F2E8; --l1-text: #3A6B3A; --l1-border: #C4DCC4;
  --l2-bg: #E8EEF8; --l2-text: #3A4F7A; --l2-border: #C4CFEA;
  --l3-bg: #F2E8F0; --l3-text: #6B3A6B; --l3-border: #DCC4DC;
  --l4-bg: #F8F2E2; --l4-text: #7A5A1A; --l4-border: #EAD89C;
  --l5-bg: #E8F4EC; --l5-text: #2E6B4A; --l5-border: #B8DEC8;
  --l6-bg: #EEE8F8; --l6-text: #4A3A7A; --l6-border: #CEC4EA;
  --l7-bg: #F8EEE8; --l7-text: #7A4A2E; --l7-border: #EACED0;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "PingFang TC", sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.75;
  min-height: 100vh;
}

/* ── Header ── */
#header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(245, 242, 236, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  gap: 24px;
}
.header-brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  flex: 1;
}
.brand-main {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--text);
}
.brand-sub {
  font-size: 12px;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}
.view-toggle {
  display: flex;
  background: var(--border);
  border-radius: 8px;
  padding: 3px;
  gap: 2px;
}
.toggle-btn {
  padding: 5px 16px;
  border: none;
  background: transparent;
  border-radius: 6px;
  font-size: 13px;
  color: var(--text-soft);
  cursor: pointer;
  transition: all 0.2s;
  font-family: inherit;
}
.toggle-btn.active {
  background: var(--bg-card);
  color: var(--text);
  font-weight: 500;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}
.header-team {
  display: flex;
  align-items: center;
  gap: 6px;
}
.team-tag {
  font-size: 11px;
  padding: 2px 8px;
  background: var(--accent-light);
  color: var(--accent);
  border-radius: 4px;
  font-weight: 500;
  letter-spacing: 0.03em;
}
.team-x {
  color: var(--text-muted);
  font-size: 11px;
}

/* ── Views ── */
.view { display: none; }
.view.active { display: block; }

/* ── Map View ── */
#map-view {
  padding: 32px 24px 48px;
  max-width: 1100px;
  margin: 0 auto;
}
.map-hint {
  text-align: center;
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 32px;
  letter-spacing: 0.03em;
}
#map-container {
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.map-layer {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}
.map-layer-label {
  width: 88px;
  flex-shrink: 0;
  text-align: right;
  padding-top: 12px;
}
.map-layer-num {
  display: block;
  font-size: 10px;
  color: var(--text-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.map-layer-name {
  display: block;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-soft);
}
.map-layer-line {
  width: 1px;
  background: var(--border);
  align-self: stretch;
  margin: 12px 0;
  flex-shrink: 0;
}
.map-nodes {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 8px 0;
  flex: 1;
}
.map-node {
  display: flex;
  flex-direction: column;
  padding: 10px 16px;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.2s;
  border: 1px solid transparent;
  min-width: 120px;
}
.map-node:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}
.map-node-name { font-size: 14px; font-weight: 600; }
.map-node-en { font-size: 11px; opacity: 0.7; margin-top: 1px; }
.map-node-line { font-size: 11px; opacity: 0.75; margin-top: 4px; line-height: 1.4; }

/* Layer colors for nodes */
.layer-1 { background: var(--l1-bg); color: var(--l1-text); border-color: var(--l1-border); }
.layer-2 { background: var(--l2-bg); color: var(--l2-text); border-color: var(--l2-border); }
.layer-3 { background: var(--l3-bg); color: var(--l3-text); border-color: var(--l3-border); }
.layer-4 { background: var(--l4-bg); color: var(--l4-text); border-color: var(--l4-border); }
.layer-5 { background: var(--l5-bg); color: var(--l5-text); border-color: var(--l5-border); }
.layer-6 { background: var(--l6-bg); color: var(--l6-text); border-color: var(--l6-border); }
.layer-7 { background: var(--l7-bg); color: var(--l7-text); border-color: var(--l7-border); }

/* ── Card View ── */
#card-view {
  display: none;
  height: calc(100vh - 56px);
}
#card-view.active {
  display: flex;
}

/* Sidebar */
#sidebar {
  width: 220px;
  flex-shrink: 0;
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  padding: 16px 0;
}
.sidebar-layer {
  margin-bottom: 4px;
}
.sidebar-layer-title {
  padding: 6px 16px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 6px;
}
.sidebar-layer-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  flex-shrink: 0;
}
.sidebar-card-item {
  padding: 7px 16px 7px 28px;
  font-size: 13px;
  color: var(--text-soft);
  cursor: pointer;
  transition: all 0.15s;
  border-radius: 0;
  display: block;
  text-decoration: none;
  border-left: 2px solid transparent;
}
.sidebar-card-item:hover {
  background: var(--accent-light);
  color: var(--text);
}
.sidebar-card-item.active {
  background: var(--accent-light);
  color: var(--accent);
  font-weight: 500;
  border-left-color: var(--accent);
}

/* Card Main */
#card-main {
  flex: 1;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}
#card-content {
  flex: 1;
  max-width: 720px;
  margin: 0 auto;
  padding: 40px 40px 24px;
  width: 100%;
}

/* Card Sections */
.card-layer-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 500;
  margin-bottom: 16px;
}
.card-title {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: 4px;
}
.card-en {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 32px;
  font-style: italic;
}
.card-oneliner {
  font-size: 18px;
  font-weight: 500;
  color: var(--accent);
  padding: 16px 20px;
  background: var(--accent-light);
  border-radius: 10px;
  border-left: 3px solid var(--accent);
  margin-bottom: 32px;
  line-height: 1.5;
}
.card-section {
  margin-bottom: 28px;
}
.card-section-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 10px;
}
.card-story {
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
  white-space: pre-line;
}
.card-diagram {
  background: #1C1917;
  color: #E8E3DB;
  border-radius: 10px;
  padding: 20px 24px;
  font-family: "SF Mono", "Fira Code", "Menlo", Consolas, monospace;
  font-size: 12.5px;
  line-height: 1.65;
  overflow-x: auto;
  white-space: pre;
}
.card-analogy {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 20px;
  font-size: 14px;
  line-height: 1.7;
}
.card-analogy-icon {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 6px;
}
.card-related {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.related-chip {
  padding: 5px 12px;
  border-radius: 20px;
  font-size: 12px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  cursor: pointer;
  transition: all 0.15s;
  color: var(--text-soft);
  text-decoration: none;
  display: inline-block;
}
.related-chip:hover {
  background: var(--accent-light);
  color: var(--accent);
  border-color: var(--accent);
}
.card-question {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px;
  font-size: 15px;
  font-style: italic;
  color: var(--text);
  position: relative;
}
.card-question::before {
  content: "？";
  position: absolute;
  top: -12px;
  left: 20px;
  background: var(--bg);
  padding: 0 6px;
  font-size: 18px;
  font-style: normal;
  color: var(--accent);
  font-weight: 700;
}
.card-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 24px 0;
}

/* Card Nav */
#card-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 40px;
  border-top: 1px solid var(--border);
  background: var(--bg-card);
  flex-shrink: 0;
}
#card-nav button {
  padding: 8px 20px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  border-radius: 8px;
  font-size: 13px;
  cursor: pointer;
  font-family: inherit;
  color: var(--text-soft);
  transition: all 0.15s;
}
#card-nav button:hover:not(:disabled) {
  background: var(--accent-light);
  color: var(--accent);
  border-color: var(--accent);
}
#card-nav button:disabled { opacity: 0.3; cursor: default; }
#card-counter {
  font-size: 12px;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

/* Scrollbar */
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

/* Responsive */
@media (max-width: 768px) {
  #sidebar { width: 180px; }
  #card-content { padding: 24px 20px; }
  .header-team { display: none; }
  .map-layer-label { width: 64px; }
}