/* Shell · topbar, left rail, breadcrumbs, layout */

.app {
  display: grid;
  grid-template-columns: var(--rail-w) 1fr;
  grid-template-rows: var(--topbar-h) 1fr;
  grid-template-areas:
    "rail topbar"
    "rail main";
  min-height: 100vh;
  background: var(--canvas);
}

.app[data-rail-collapsed="true"] {
  grid-template-columns: var(--rail-w-collapsed) 1fr;
}

/* ============ TOPBAR ============ */
.topbar {
  grid-area: topbar;
  background: var(--panel);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 var(--s-5);
  gap: var(--s-4);
  position: sticky;
  top: 0;
  z-index: 20;
}
.topbar-left { display: flex; align-items: center; gap: var(--s-3); flex: 1; min-width: 0; }
.topbar-right { display: flex; align-items: center; gap: var(--s-2); }

.crumbs {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  font-size: var(--fs-13);
  color: var(--text-tertiary);
  min-width: 0;
}
.crumbs > * { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.crumbs .sep { color: var(--border-strong); }
.crumbs .current { color: var(--text-primary); font-weight: var(--fw-semibold); }

.copilot-trigger {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  height: 32px;
  padding: 0 var(--s-3);
  background: linear-gradient(180deg, #FFFFFF 0%, #F8FAF9 100%);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  font-size: var(--fs-13);
  font-weight: var(--fw-medium);
  color: var(--text-primary);
  cursor: pointer;
  transition: all var(--dur-fast) var(--ease);
  position: relative;
}
.copilot-trigger:hover {
  border-color: var(--accent);
  color: var(--accent-strong);
  box-shadow: 0 0 0 3px var(--accent-soft);
}
.copilot-trigger .spark {
  width: 14px; height: 14px;
  color: var(--accent);
}
.copilot-trigger kbd {
  display: inline-block;
  padding: 1px 5px;
  font-family: var(--font-mono);
  font-size: 10px;
  background: var(--panel-muted);
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  color: var(--text-tertiary);
  margin-left: var(--s-1);
}

.icon-btn {
  width: 32px; height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--r-md);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--dur-fast) var(--ease);
}
.icon-btn:hover {
  background: var(--panel-muted);
  color: var(--text-primary);
}

/* Text size control */
.ts-control { position: relative; }
.ts-trigger {
  width: 32px; height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--r-md);
  color: var(--text-secondary);
  cursor: pointer;
  font-family: var(--font-ui);
  font-weight: 700;
  letter-spacing: -0.02em;
  transition: all var(--dur-fast) var(--ease);
  padding: 0;
}
.ts-trigger:hover { background: var(--panel-muted); color: var(--text-primary); }
.ts-trigger .Aa-small { font-size: 11px; line-height: 1; }
.ts-trigger .Aa-large { font-size: 15px; line-height: 1; margin-left: -1px; }

.ts-menu {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  min-width: 220px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-3);
  padding: var(--s-2);
  z-index: 40;
  display: none;
}
.ts-menu.open { display: block; }
.ts-menu-label {
  font-size: 10px;
  font-weight: var(--fw-semibold);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  padding: 6px 10px 4px;
}
.ts-option {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 8px 10px;
  background: transparent;
  border: none;
  border-radius: var(--r-md);
  font-family: var(--font-ui);
  color: var(--text-primary);
  cursor: pointer;
  text-align: left;
  transition: background var(--dur-fast) var(--ease);
}
.ts-option:hover { background: var(--panel-muted); }
.ts-option.active { background: var(--accent-soft); color: var(--accent-strong); }
.ts-option .name { font-weight: var(--fw-medium); }
.ts-option .sample { font-family: var(--font-ui); color: var(--text-tertiary); font-weight: var(--fw-medium); }
.ts-option.active .sample { color: var(--accent-strong); }
.ts-option[data-size="small"]   .sample { font-size: 11px; }
.ts-option[data-size="normal"]  .sample { font-size: 13px; }
.ts-option[data-size="large"]   .sample { font-size: 15px; }
.ts-option[data-size="largest"] .sample { font-size: 17px; }
.ts-option .check {
  width: 14px; height: 14px;
  margin-left: var(--s-2);
  opacity: 0;
}
.ts-option.active .check { opacity: 1; color: var(--accent); }

.user-chip {
  display: inline-flex;
  align-items: center;
  gap: var(--s-2);
  padding: 0 var(--s-2) 0 var(--s-1);
  height: 32px;
  border-radius: var(--r-pill);
  background: transparent;
  border: 1px solid var(--border);
  cursor: pointer;
  transition: all var(--dur-fast) var(--ease);
}
.user-chip:hover { background: var(--panel-muted); }
.user-chip .avatar {
  width: 24px; height: 24px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 10px;
  font-weight: var(--fw-semibold);
}
.user-chip .name {
  font-size: var(--fs-13);
  font-weight: var(--fw-medium);
}

/* ============ RAIL ============ */
.rail {
  grid-area: rail;
  background: var(--primary);
  color: rgba(255, 255, 255, 0.85);
  display: flex;
  flex-direction: column;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow: hidden;
  z-index: 30;
}

.rail-brand {
  display: flex;
  align-items: center;
  gap: var(--s-3);
  height: var(--topbar-h);
  padding: 0 var(--s-5);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  flex-shrink: 0;
}
.rail-brand img {
  height: 28px;
  filter: brightness(0) invert(1) saturate(0); /* monochrome white logo */
  opacity: 0.92;
}
.rail-brand .product {
  font-size: var(--fs-15);
  font-weight: var(--fw-semibold);
  letter-spacing: -0.01em;
  color: #fff;
}
.rail-brand .version {
  font-size: var(--fs-12);
  color: rgba(255, 255, 255, 0.55);
  margin-left: auto;
  font-family: var(--font-mono);
}

.rail-nav {
  flex: 1;
  overflow-y: auto;
  padding: var(--s-4) var(--s-3);
  display: flex;
  flex-direction: column;
  gap: var(--s-4);
}

.rail-stage { }
.rail-stage-header {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  padding: 0 var(--s-3);
  margin-bottom: var(--s-2);
  cursor: pointer;
  user-select: none;
  background: none;
  border: none;
  width: 100%;
  text-align: left;
}
.rail-stage-header .label {
  font-size: 10.5px;
  font-weight: var(--fw-semibold);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.55);
  flex: 1;
}
.rail-stage-header .chevron {
  width: 12px; height: 12px;
  color: rgba(255, 255, 255, 0.45);
  transition: transform var(--dur-fast) var(--ease);
}
.rail-stage[data-collapsed="true"] .rail-stage-header .chevron {
  transform: rotate(-90deg);
}
.rail-stage[data-collapsed="true"] .rail-stage-items { display: none; }

.rail-stage-step {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.08);
  font-family: var(--font-mono);
  font-size: 10px;
  color: rgba(255, 255, 255, 0.7);
}

.rail-stage-items {
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.rail-link {
  display: flex;
  align-items: center;
  gap: var(--s-3);
  padding: var(--s-2) var(--s-3);
  color: rgba(255, 255, 255, 0.78);
  font-size: var(--fs-13);
  font-weight: var(--fw-medium);
  border-radius: var(--r-md);
  text-decoration: none;
  transition: all var(--dur-fast) var(--ease);
  position: relative;
}
.rail-link:hover {
  background: rgba(255, 255, 255, 0.06);
  color: #fff;
  text-decoration: none;
}
.rail-link.active {
  background: rgba(15, 122, 77, 0.22);
  color: #fff;
  box-shadow: inset 2px 0 0 var(--accent);
}
.rail-link .dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.25);
  flex-shrink: 0;
}
.rail-link.active .dot { background: var(--accent); }
.rail-link.coming {
  opacity: 0.55;
  cursor: default;
}
.rail-link.coming::after {
  content: 'Soon';
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 9px;
  padding: 1px 5px;
  border-radius: var(--r-sm);
  background: rgba(255, 255, 255, 0.08);
  color: rgba(255, 255, 255, 0.5);
}

.rail-footer {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: var(--s-3);
  flex-shrink: 0;
}
.rail-footer .rail-link { color: rgba(255, 255, 255, 0.55); }

/* ============ MAIN ============ */
.main {
  grid-area: main;
  overflow-x: hidden;
  padding: var(--s-6) var(--s-8);
  min-width: 0;
}

.main-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--s-4);
  margin-bottom: var(--s-6);
  flex-wrap: wrap;
}
.main-header h1 {
  font-size: var(--fs-24);
  font-weight: var(--fw-semibold);
  letter-spacing: -0.015em;
  margin: 0 0 var(--s-1) 0;
  color: var(--text-primary);
}
.main-header .subtitle {
  color: var(--text-tertiary);
  font-size: var(--fs-14);
  margin: 0;
}
.main-header .actions {
  display: flex;
  gap: var(--s-2);
}

/* ============ MOBILE DRAWER ============ */
.rail-backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.5);
  z-index: 25;
  opacity: 0;
  transition: opacity var(--dur-base) var(--ease);
}
.rail-backdrop.open { display: block; opacity: 1; }

.menu-btn {
  display: none;
  width: 32px; height: 32px;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  cursor: pointer;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 1024px) {
  .app { grid-template-columns: 1fr; grid-template-areas: "topbar" "main"; }
  .rail {
    position: fixed;
    top: 0; left: 0;
    width: 280px;
    transform: translateX(-100%);
    transition: transform var(--dur-base) var(--ease);
    box-shadow: var(--shadow-3);
  }
  .rail.open { transform: translateX(0); }
  .menu-btn { display: inline-flex; }
}
@media (max-width: 768px) {
  .main { padding: var(--s-5) var(--s-4); }
  .main-header h1 { font-size: var(--fs-20); }
  .copilot-trigger .label-text { display: none; }
  .copilot-trigger { padding: 0 var(--s-2); }
  .copilot-trigger kbd { display: none; }
  .crumbs .crumb-stage { display: none; }
  .user-chip .name { display: none; }
}
@media (max-width: 414px) {
  .main { padding: var(--s-4) var(--s-3); }
  .topbar { padding: 0 var(--s-3); gap: var(--s-2); }
}