/* ============================================================
   Projects — Knowledge Library Extension
   ============================================================ */

/* ── View Toggle (Projects / 全部书籍 tab) ─────────────────── */
.view-toggle {
  display: flex;
  gap: var(--space-7);
  margin-bottom: var(--space-7);
  border-bottom: 1px solid var(--line);
  padding-bottom: var(--space-4);
}
.view-toggle button {
  font-family: var(--sans);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--muted);
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2) 0;
  padding-left: 14px;
  position: relative;
  transition: color 0.2s ease;
}
.view-toggle button:hover {
  color: var(--ink);
}
.view-toggle button::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--line-2);
  transition: background 0.2s ease;
}
.view-toggle button.active {
  color: var(--ink);
}
.view-toggle button.active::before {
  background: var(--ink);
}

/* Graph link styled as tab */
.view-toggle-btn {
  font-family: var(--sans);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--muted);
  text-decoration: none;
  padding: var(--space-2) 0;
  padding-left: 14px;
  position: relative;
  transition: color 0.2s ease;
}
.view-toggle-btn::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--line-2);
  transition: background 0.2s ease;
}
.view-toggle-btn:hover {
  color: var(--ink);
}
.view-toggle-btn:hover::before {
  background: var(--ink);
}

.view-toggle-link {
  font-family: var(--sans);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--muted);
  text-decoration: none;
  padding: var(--space-2) 0;
  margin-left: auto;
  transition: color 0.2s ease;
}
.view-toggle-link:hover {
  color: var(--ink);
}

/* ── View containers ──────────────────────────────────────── */
.view-projects,
.view-all {
  animation: fadeIn 0.25s ease;
}
.view-projects.hidden,
.view-all.hidden {
  display: none;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── Project Cards (on index page) ────────────────────────── */
.projects-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.project-card {
  position: relative;
  display: block;
  padding: var(--space-6) var(--space-6) var(--space-6) var(--space-7);
  border: 1px solid var(--line);
  text-decoration: none;
  color: var(--ink);
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}
.project-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: var(--space-5);
  bottom: var(--space-5);
  width: 2px;
  background: var(--line-2);
  transition: background 0.25s ease;
}
.project-card:hover {
  border-color: var(--line-2);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.04);
}
.project-card:hover::before {
  background: var(--ink);
}

.project-card h3 {
  font-size: var(--text-xl);
  font-weight: var(--weight-medium);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-2);
}
.project-card .project-card-desc {
  font-size: var(--text-sm);
  color: var(--ink-soft);
  line-height: 1.5;
  margin-bottom: var(--space-4);
}

/* Path dots on project card */
.path-dots {
  display: flex;
  align-items: center;
  margin-bottom: var(--space-4);
}
.path-dot-item {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  border: 1.5px solid var(--muted);
  background: transparent;
  flex-shrink: 0;
  transition: border-color 0.25s ease, background 0.25s ease;
}
.path-dot-line {
  flex: 1;
  height: 1.5px;
  background: var(--line);
  margin: 0 6px;
  transition: background 0.3s ease;
}
.project-card:hover .path-dot-item {
  border-color: var(--ink);
}
.project-card:hover .path-dot-item:first-child {
  background: var(--ink);
}
.project-card:hover .path-dot-line {
  background: var(--line-2);
}

/* Dot labels */
.path-dots-labels {
  display: flex;
  align-items: flex-start;
  margin-bottom: var(--space-3);
}
.path-dot-label {
  flex: 1;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.02em;
  color: var(--muted);
  text-align: center;
  line-height: 1.3;
  padding: 0 2px;
}
.path-dot-label:first-child { text-align: left; }
.path-dot-label:last-child { text-align: right; }

/* Card meta */
.project-card-meta {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

/* ── Standalone books section ─────────────────────────────── */
.standalone-section {
  margin-top: var(--space-8);
}
.standalone-section .section-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: var(--space-5);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--line);
}

/* ── Project Detail Page ──────────────────────────────────── */
.project-detail-wrap {
  max-width: 1100px;
  margin: 0 auto;
  padding: var(--space-6) var(--gutter) var(--space-9);
}
.project-detail-wrap .back-link {
  display: inline-block;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
  margin-bottom: var(--space-4);
  transition: color 0.15s;
  text-decoration: none;
}
.project-detail-wrap .back-link:hover {
  color: var(--ink);
}

.project-header {
  margin-bottom: var(--space-6);
}
.project-header .eyebrow {
  display: block;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: var(--space-3);
}
.project-header h1 {
  font-size: var(--text-3xl);
  font-weight: var(--weight-semibold);
  letter-spacing: -0.025em;
  margin-bottom: var(--space-3);
}
.project-header .project-desc {
  font-size: var(--text-base);
  color: var(--ink-soft);
  line-height: 1.6;
  margin-bottom: var(--space-3);
}
.project-header .project-stats {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
  display: flex;
  gap: var(--space-3);
}

/* ── Two-column layout ─────────────────────────────────────── */
.project-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: var(--space-7);
  align-items: start;
}
.project-main {
  min-width: 0;
}

/* ── Project Sidebar ──────────────────────────────────────── */
.project-sidebar {
  position: sticky;
  top: 72px;
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
  padding-left: var(--space-5);
  border-left: 1px solid var(--line);
}

.sidebar-section h4 {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--line);
}
.sidebar-section ul {
  list-style: none;
  padding: 0;
}
.sidebar-section li {
  font-size: 13px;
  color: var(--ink-soft);
  line-height: 1.5;
  padding: 4px 0;
  padding-left: 12px;
  position: relative;
}
.sidebar-section li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 11px;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--line-2);
}

/* ── Path Timeline ────────────────────────────────────────── */
.path-timeline {
  padding-left: var(--space-4);
}
.path-step {
  display: flex;
  gap: var(--space-5);
  position: relative;
}
.path-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex-shrink: 0;
  width: 20px;
}
.path-step .path-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  border: 2px solid var(--ink);
  background: var(--bg);
  flex-shrink: 0;
  margin-top: 6px;
  transition: background 0.2s;
}
.path-step:first-child .path-dot {
  background: var(--ink);
}
.path-connector {
  width: 1.5px;
  flex: 1;
  background: var(--line-2);
  margin: 6px 0;
}
.path-content {
  flex: 1;
  padding-bottom: var(--space-7);
}
.path-step.last .path-content {
  padding-bottom: 0;
}
.path-step-num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-bottom: var(--space-3);
}

/* ── Book Card (inside timeline) ──────────────────────────── */
.book-card {
  display: block;
  padding: var(--space-5) var(--space-6);
  border: 1px solid var(--line);
  text-decoration: none;
  color: var(--ink);
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}
.book-card:hover {
  border-color: var(--line-2);
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.05);
}
.book-card h3 {
  font-size: var(--text-lg);
  font-weight: var(--weight-medium);
  letter-spacing: -0.01em;
  margin-bottom: var(--space-2);
  color: var(--ink);
}
.book-card-role {
  font-size: var(--text-sm);
  color: var(--ink-soft);
  line-height: 1.5;
  margin-bottom: var(--space-2);
}
.book-card-desc {
  font-size: var(--text-sm);
  color: var(--muted);
  line-height: 1.5;
  margin-bottom: var(--space-5);
}

/* Chapter thumbnails - removed, not needed */

/* Transition text between books */
.path-transition {
  margin-top: var(--space-5);
  padding: var(--space-4) 0;
  position: relative;
}
.path-transition::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: repeating-linear-gradient(
    90deg,
    var(--line) 0px,
    var(--line) 4px,
    transparent 4px,
    transparent 10px
  );
}
.path-transition p {
  font-size: var(--text-sm);
  color: var(--muted);
  line-height: 1.6;
  font-style: italic;
  margin: 0;
}

/* Card footer */
.book-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-4);
  border-top: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--muted);
}
.book-card-cta {
  color: var(--muted);
  transition: color 0.15s;
}
.book-card:hover .book-card-cta {
  color: var(--ink);
}

/* ── Responsive ───────────────────────────────────────────── */
@media (max-width: 900px) {
  .project-layout {
    grid-template-columns: 1fr;
    gap: var(--space-7);
  }
  .project-sidebar {
    position: static;
    border-left: none;
    padding-left: 0;
    border-top: 1px solid var(--line);
    padding-top: var(--space-6);
  }
}

@media (max-width: 768px) {
  .project-card {
    padding: var(--space-5) var(--space-5) var(--space-5) var(--space-6);
  }
  .path-dots-labels {
    display: none;
  }
}