/* App shell: sidebar rail + main column. */
#app { display: flex; height: 100vh; }

/* ------------------------------------------------------------- sidebar */
#sidebar {
  width: 232px; flex: none;
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  padding: var(--s4) var(--s3);
  transition: width var(--t-med) var(--ease), padding var(--t-med) var(--ease);
  overflow: hidden;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  padding: var(--s2) var(--s2) var(--s5);
  font-size: calc(17px * var(--scale)); font-weight: 700; letter-spacing: -0.02em;
}
.brand-name { flex: 1; white-space: nowrap; }
#collapse-btn {
  color: var(--text-3); padding: 4px; border-radius: var(--r-sm);
  transition: color var(--t-fast) var(--ease),
              background var(--t-fast) var(--ease),
              transform var(--t-med) var(--ease);
}
#collapse-btn:hover { color: var(--text); background: var(--raised); }

/* Icon-only rail (Phase 24): labels hide, everything stays one click away. */
.sb-collapsed #sidebar { width: 58px; padding: var(--s4) var(--s2); }
.sb-collapsed .brand { flex-direction: column; gap: var(--s2);
                       padding: var(--s2) 0 var(--s4); }
.sb-collapsed .brand-name { display: none; }
.sb-collapsed #collapse-btn { transform: rotate(180deg); }
.sb-collapsed .nav-item { justify-content: center; padding: 10px 0; }
.sb-collapsed .nav-label { display: none; }
.sb-collapsed .sidebar-actions .btn { padding: 9px 0; }
.sb-collapsed .sidebar-actions .btn-label,
.sb-collapsed #undo-label { display: none; }
.brand-badge {
  width: 30px; height: 30px; border-radius: 9px;
  background: linear-gradient(135deg, var(--accent), #7C5CFF);
  display: flex; align-items: center; justify-content: center;
  color: #fff; box-shadow: var(--shadow-1);
}
.brand-badge svg { width: 16px; height: 16px; }

#nav { display: flex; flex-direction: column; gap: 2px; }
.nav-item {
  display: flex; align-items: center; gap: 11px;
  padding: 9px 12px; border-radius: var(--r-sm);
  color: var(--text-2); font-weight: 600; font-size: var(--fs-md);
  transition: background var(--t-fast) var(--ease), color var(--t-fast) var(--ease);
}
.nav-item svg { width: 17px; height: 17px; flex: none;
                transition: transform var(--t-fast) var(--ease); }
.nav-item:hover { background: var(--raised); color: var(--text); }
.nav-item:hover svg { transform: translateX(2px) scale(1.06); }
.nav-item.active { background: var(--accent-dim); color: var(--accent); }

.sidebar-spacer { flex: 1; }
.sidebar-actions {
  display: flex; flex-direction: column; gap: var(--s2);
  padding-top: var(--s4); border-top: 1px solid var(--border);
}
.sidebar-actions .btn { width: 100%; }

/* ---------------------------------------------------------------- main */
#main { flex: 1; display: flex; flex-direction: column; min-width: 0; }
#topbar {
  display: flex; align-items: center; gap: var(--s4);
  padding: var(--s5) var(--s5) var(--s4);
}
#topbar .range { color: var(--text-2); font-size: var(--fs-lg); }
#topbar .spacer { flex: 1; }
#toolbar { display: flex; align-items: center; gap: var(--s2); }

#content { flex: 1; min-height: 0; padding: 0 var(--s5) var(--s5); position: relative; }
.view { height: 100%; animation: view-in var(--t-med) var(--ease); }
@keyframes view-in { from { opacity: 0; transform: translateY(6px); } }

/* ------------------------------------------------------- day slide-over */
.day-panel {
  position: absolute; top: 0; right: var(--s5); bottom: var(--s5);
  width: 320px; z-index: 20;
  background: var(--overlay); border: 1px solid var(--border-strong);
  border-radius: var(--r-lg); box-shadow: var(--shadow-2);
  display: flex; flex-direction: column;
  animation: panel-in var(--t-med) var(--ease);
}
@keyframes panel-in { from { opacity: 0; transform: translateX(16px); } }
.day-panel header {
  display: flex; align-items: center; justify-content: space-between;
  padding: var(--s4); border-bottom: 1px solid var(--border);
}
.day-panel header .title { font-weight: 700; font-size: var(--fs-lg); }
.day-panel .items { flex: 1; overflow-y: auto; padding: var(--s3); }
.day-panel footer { display: flex; gap: var(--s2); padding: var(--s3); border-top: 1px solid var(--border); }
.day-panel footer .btn { flex: 1; }