/* Layout: 4-column grid with foldable sidebar */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

/* Variables moved to /shared/css/variables.css */
:root {
  --col-list-w: 260px;
  --col-detail-w: 300px;
}

html, body {
  height: 100%;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  letter-spacing: -0.01em;
}

.app {
  position: relative;
  display: flex;
  height: 100vh;
  overflow: hidden;
}

.main {
  flex: 1;
  display: flex;
  min-width: 0;
  height: 100vh;
  overflow: hidden;
}

/* Column defaults */
.col-list, .col-detail, .col-preview, .col-merged {
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow: hidden;
}

.col-list {
  width: var(--col-list-w);
  min-width: var(--col-list-w);
  border-right: 1px solid var(--border);
  background: var(--bg-card);
}

.col-detail {
  width: var(--col-detail-w);
  min-width: var(--col-detail-w);
  border-right: 1px solid var(--border);
  background: var(--bg-card);
}

.col-preview {
  flex: 1;
  min-width: 0;
  background: var(--bg);
}

.col-merged {
  flex: 1;
  min-width: 0;
  background: var(--bg);
  overflow-y: auto;
}

.col-header {
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-card);
  font-weight: 600;
  font-size: 12px;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 56px;
  flex-shrink: 0;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.col-body {
  flex: 1;
  overflow: auto;
}

/* Scrollbar styling */
.col-body::-webkit-scrollbar, .col-merged::-webkit-scrollbar { width: 6px; }
.col-body::-webkit-scrollbar-track, .col-merged::-webkit-scrollbar-track { background: transparent; }
.col-body::-webkit-scrollbar-thumb, .col-merged::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
.col-body::-webkit-scrollbar-thumb:hover, .col-merged::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }

/* Default: hide merged, show columns */
.col-merged { display: none !important; }

/* Merged mode: show merged, hide columns */
.app.merged .col-list,
.app.merged .col-detail,
.app.merged .col-preview { display: none !important; }
.app.merged .col-merged { display: flex !important; }

/* 3-column mode: hide col-list, show detail+preview */
.app.three-col .col-list { display: none !important; }
.app.three-col .col-merged { display: none !important; }

/* 2-column mode: list + preview (hide detail) */
.app.two-col .col-detail { display: none !important; }
.app.two-col .col-merged { display: none !important; }

/* Responsive */
@media (max-width: 1200px) {
  .col-list { width: 220px; min-width: 220px; }
  .col-detail { width: 260px; min-width: 260px; }
}

@media (max-width: 900px) {
  .col-list, .col-detail { display: none; }
  .col-preview { flex: 1; }
  .shortcuts-bar { display: none !important; }
}

/* Keyboard shortcuts hint bar */
.shortcuts-bar {
  position: fixed;
  bottom: 0;
  left: var(--sidebar-w);
  right: 0;
  height: 32px;
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 0 16px;
  font-size: 11px;
  color: var(--text-muted);
  z-index: 50;
  transition: left var(--dur-slow) var(--ease-out);
}
.sidebar.folded ~ .main ~ .shortcuts-bar,
.shortcuts-bar.sidebar-folded { left: var(--sidebar-w-folded); }
.shortcuts-bar:empty { display: none; }
.shortcuts-bar kbd {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 20px;
  height: 20px;
  padding: 0 5px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 10px;
  font-family: var(--font-mono);
  color: var(--text-secondary);
  margin-right: 3px;
  box-shadow: 0 1px 0 var(--border);
}