:root {
  --bg: #ffffff;
  --paper: #fdfcf9;
  --panel: #ffffff;
  --ink: #1f2937;
  --muted: #6b7280;
  --line: #e5e7eb;
  --accent: #f97316;
  --accent-strong: #ea580c;
  --accent-soft: #fff7ed;
  --accent-line: rgba(249, 115, 22, 0.16);
  --grid-line: rgba(31, 41, 55, 0.045);
  --code-bg: #f3f4f6;
  --radius: 12px;
  --serif: ui-serif, "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial,
    sans-serif;
  --mono: "SF Mono", ui-monospace, "JetBrains Mono", Menlo, Consolas, monospace;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

#app {
  display: flex;
  min-height: 100vh;
}

/* ---- sidebar (composition-book cover) ---- */
#sidebar {
  width: 280px;
  flex: 0 0 280px;
  background: #17181c;
  color: #e7e7ea;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  padding: 22px 16px;
  display: flex;
  flex-direction: column;
}

#book-head {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px;
  margin-bottom: 12px;
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.12s;
}
#book-head:hover {
  background: rgba(255, 255, 255, 0.05);
}
#book-head.active #book-title {
  color: #fdba74;
}

#book-logo {
  width: 40px;
  height: 40px;
  object-fit: contain;
  flex: 0 0 auto;
}

#book-title {
  font-weight: 700;
  font-size: 15px;
  letter-spacing: -0.01em;
  color: #ffffff;
}

#tree {
  flex: 1;
  padding-top: 8px;
}

#tree a {
  display: block;
  padding: 6px 10px;
  border-radius: 8px;
  color: #c3c4cb;
  text-decoration: none;
  font-size: 14px;
  transition: background 0.12s, color 0.12s;
}

#tree a:hover {
  background: rgba(255, 255, 255, 0.06);
  color: #ffffff;
}

#tree a.active {
  background: rgba(249, 115, 22, 0.16);
  color: #fdba74;
  font-weight: 600;
}

#tree .depth-1 {
  padding-left: 22px;
}
#tree .depth-2 {
  padding-left: 34px;
}
#tree .depth-3 {
  padding-left: 46px;
}


/* ---- content ---- */
#content {
  flex: 1;
  display: flex;
  justify-content: center;
  padding: 48px 40px 120px;
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 26px 26px;
  background-position: center top;
}

#page {
  width: 100%;
  max-width: 760px;
}

#page h1 {
  font-family: var(--serif);
  font-size: 34px;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0 0 8px;
}

#page h2 {
  font-family: var(--serif);
  font-size: 24px;
  margin: 36px 0 10px;
}

#page h3 {
  font-size: 17px;
  font-weight: 700;
  margin: 26px 0 2px;
  letter-spacing: -0.01em;
}

#page h3::before {
  content: "";
  display: inline-block;
  width: 7px;
  height: 7px;
  border-radius: 2px;
  background: var(--accent);
  margin-right: 10px;
  vertical-align: middle;
  transform: translateY(-1px);
}

#page p {
  margin: 10px 0;
}

#page blockquote {
  margin: 14px 0;
  padding: 2px 16px;
  border-left: 3px solid #fdba74;
  color: var(--muted);
}

#page hr {
  border: none;
  border-top: 1px solid var(--line);
  margin: 30px 0 0;
}

#page code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 6px;
}

#page pre {
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px 16px;
  overflow-x: auto;
}
#page pre code {
  background: none;
  padding: 0;
}

/* ---- code blocks + collapsible accordion ---- */
#page pre.hl {
  background: #17181c;
  border: none;
  color: #e7e7ea;
  font-size: 12.5px;
  line-height: 1.55;
}
#page pre.hl code {
  color: inherit;
  font-family: var(--mono);
}
.code-accordion {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  margin: 12px 0;
  background: #17181c;
}
.code-accordion summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 10px 14px;
  font-family: var(--mono);
  font-size: 13px;
  color: #e7e7ea;
  background: #1e2027;
  user-select: none;
}
.code-accordion summary::-webkit-details-marker {
  display: none;
}
.code-accordion summary::before {
  content: "▸";
  color: var(--accent);
  transition: transform 0.12s;
}
.code-accordion[open] summary::before {
  transform: rotate(90deg);
}
.code-accordion .code-ico {
  color: var(--accent);
  font-weight: 700;
}
.code-accordion pre.hl {
  margin: 0;
  border-radius: 0;
}
.tok-comment {
  color: #7a7d87;
  font-style: italic;
}
.tok-string {
  color: #a5d6a7;
}
.tok-keyword {
  color: #fdba74;
}
.tok-number {
  color: #7fd0e0;
}

#page a {
  color: var(--accent);
}

#page ul {
  padding-left: 20px;
}

.ts {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  background: none;
  padding: 0;
}

/* ---- unfurl cards ---- */
.unfurl {
  display: block;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--panel);
  margin: 12px 0;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.14s, box-shadow 0.14s;
}
.unfurl:hover {
  border-color: #cfcbe6;
  box-shadow: 0 4px 18px rgba(30, 20, 80, 0.06);
}

.unfurl-body {
  padding: 13px 16px;
  display: flex;
  gap: 12px;
  align-items: flex-start;
}

.unfurl-ico {
  font-size: 20px;
  line-height: 1.3;
  flex: 0 0 auto;
}

.unfurl-main {
  min-width: 0;
  flex: 1;
}

.unfurl-kind {
  font-family: var(--mono);
  font-size: 10.5px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  font-weight: 600;
}

.unfurl-title {
  font-weight: 650;
  font-size: 15px;
  margin: 1px 0 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.unfurl-desc {
  color: var(--muted);
  font-size: 13.5px;
  line-height: 1.45;
}

.unfurl-meta {
  margin-top: 6px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.chip {
  font-size: 11.5px;
  background: var(--code-bg);
  border-radius: 999px;
  padding: 2px 9px;
  color: var(--muted);
  font-family: var(--mono);
}

.unfurl-raw {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--muted);
  border-top: 1px solid var(--line);
  padding: 7px 16px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.unfurl.embed {
  padding: 0;
  overflow: hidden;
}
.embed-head {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--line);
}
.embed-head .unfurl-kind {
  flex: 0 0 auto;
}
.embed-title {
  flex: 1;
  min-width: 0;
  font-weight: 650;
  font-size: 14px;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.embed-title:hover {
  color: var(--accent);
}
.embed-open {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--accent);
  text-decoration: none;
}
.embed-frame {
  display: block;
  width: 100%;
  height: 560px;
  border: 0;
  background: var(--code-bg);
}

.unfurl.image {
  padding: 0;
}
.unfurl.image img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 460px;
  object-fit: contain;
  background: var(--code-bg);
}

.artifact-chip {
  border: 1px solid var(--line);
  background: var(--panel);
  border-radius: var(--radius);
  padding: 10px 14px;
  margin: 8px 0;
  font-size: 14px;
}
.artifact-chip code {
  color: var(--accent);
}

/* ---- task board ---- */
.board-wrap {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin: 12px 0 20px;
  background: var(--panel);
}
table.board {
  border-collapse: collapse;
  width: 100%;
  font-size: 14px;
}
table.board th,
table.board td {
  text-align: left;
  padding: 9px 14px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
table.board thead th {
  background: var(--accent-soft);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #9a4a12;
  font-weight: 600;
  border-bottom: 1px solid var(--line);
}
table.board tbody tr:last-child td {
  border-bottom: none;
}
table.board .col-check {
  text-align: center;
  width: 92px;
  white-space: nowrap;
}
table.board tr.section-row td {
  background: var(--accent-soft);
  text-align: center;
  font-weight: 700;
  font-size: 13px;
  color: var(--accent-strong);
  padding: 7px 14px;
  letter-spacing: 0.02em;
}
.box {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  border: 1.5px solid #cfcbe0;
  border-radius: 5px;
  font-size: 12px;
  color: #fff;
  line-height: 1;
}
.box.on {
  background: var(--accent);
  border-color: var(--accent);
}
.who-chip {
  display: inline-block;
  padding: 3px 12px;
  border-radius: 999px;
  font-size: 12.5px;
  font-weight: 600;
  white-space: nowrap;
}
.who-chip.muted {
  background: var(--code-bg);
  color: var(--muted);
  font-weight: 500;
}

/* ---- status badges + clickable rows ---- */
table.board .col-status {
  width: 130px;
  white-space: nowrap;
}
.badge {
  display: inline-block;
  padding: 3px 11px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.01em;
}
.badge.gray {
  background: var(--code-bg);
  color: var(--muted);
}
.badge.amber {
  background: var(--accent-soft);
  color: #b45309;
}
.badge.green {
  background: #e6f7ee;
  color: #1a8a55;
}
.badge.red {
  background: #fde8ec;
  color: #c62a4b;
}
table.board tr.linked-row {
  cursor: pointer;
}
table.board tr.linked-row:hover td {
  background: var(--accent-soft);
}
table.board tr.linked-row a {
  color: var(--ink);
  font-weight: 600;
  text-decoration: none;
}
table.board tr.linked-row:hover a {
  color: var(--accent-strong);
}

/* ---- connect footer + modal ---- */
#sidebar-foot {
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

#connect-btn {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.05);
  color: #c3c4cb;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 9px;
  padding: 9px 12px;
  font-size: 13.5px;
  font-family: var(--sans);
  cursor: pointer;
  transition: background 0.12s, color 0.12s, border-color 0.12s;
}
#connect-btn:hover {
  background: rgba(249, 115, 22, 0.14);
  border-color: rgba(249, 115, 22, 0.4);
  color: #fdba74;
}
#connect-btn .ico {
  font-size: 15px;
}

#modal[hidden] {
  display: none;
}
#modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}
.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(20, 18, 30, 0.5);
  backdrop-filter: blur(2px);
}
.modal-card {
  position: relative;
  background: var(--panel);
  border-radius: 16px;
  width: 100%;
  max-width: 620px;
  max-height: 85vh;
  overflow-y: auto;
  box-shadow: 0 24px 70px rgba(20, 15, 50, 0.28);
}
.modal-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 18px 22px;
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  background: var(--panel);
}
.modal-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--serif);
  font-size: 21px;
  letter-spacing: -0.01em;
}
.modal-logo {
  width: 26px;
  height: 26px;
  object-fit: contain;
}
.modal-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}
.btn {
  font-family: var(--sans);
  font-size: 13.5px;
  font-weight: 600;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink);
  border-radius: 9px;
  padding: 8px 13px;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s, color 0.12s;
}
.btn:hover {
  border-color: var(--accent);
  color: var(--accent-strong);
}
.btn.copied {
  border-color: #1a8a55;
  color: #1a8a55;
}
.btn.icon {
  font-size: 18px;
  line-height: 1;
  padding: 6px 11px;
  font-weight: 400;
}
.modal-body {
  padding: 20px 22px 26px;
}
.modal-intro {
  margin: 0 0 20px;
  color: var(--muted);
  line-height: 1.55;
}
#connect-steps {
  list-style: none;
  margin: 0;
  padding: 0;
}
#connect-steps li {
  margin-bottom: 18px;
}
.step-title {
  font-weight: 600;
  font-size: 14.5px;
  margin-bottom: 8px;
}
.codeblock {
  display: flex;
  align-items: center;
  gap: 8px;
  background: #17181c;
  border-radius: 10px;
  padding: 11px 12px 11px 15px;
}
.codeblock code {
  flex: 1;
  min-width: 0;
  overflow-x: auto;
  white-space: nowrap;
  font-family: var(--mono);
  font-size: 13px;
  color: #f0efff;
  background: none;
  padding: 0;
}
.codeblock .copy {
  flex: 0 0 auto;
  background: rgba(255, 255, 255, 0.08);
  color: #c3c4cb;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 7px;
  width: 30px;
  height: 30px;
  font-size: 14px;
  cursor: pointer;
  transition: background 0.12s, color 0.12s;
}
.codeblock .copy:hover {
  background: rgba(249, 115, 22, 0.2);
  color: #fdba74;
}
.codeblock .copy.copied {
  color: #52d08a;
}

@media (max-width: 720px) {
  #app {
    flex-direction: column;
  }
  #sidebar {
    width: 100%;
    flex: none;
    height: auto;
    position: static;
  }
  #content {
    padding: 28px 20px 80px;
  }
}
