/* --- Tab Bar --- */
.tab-bar {
  display: flex;
  align-items: flex-end;
  gap: 0;
  padding: 0 0 0 16px;
  position: relative;
}

.tab {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  width: 260px;
  height: 32px;
  border-radius: 8px;
  cursor: pointer;
  position: relative;
  flex-shrink: 0;
}

.tab-favicon {
  width: 16px;
  height: 16px;
  border-radius: 4px;
  flex-shrink: 0;
}

.tab-favicon-img {
  width: 16px;
  height: 16px;
  border-radius: 2px;
  flex-shrink: 0;
  object-fit: contain;
}

.tab-favicon-ppt { background: #D04423; }
.tab-favicon-pdf { background: #C4281C; }
.tab-favicon-edge {
  background: url('../assets/edge-icon.svg') center/contain no-repeat;
  border-radius: 0;
}
.tab-favicon-baidu { background: #2932E1; }
.tab-favicon-medium { background: #000; }
.tab-favicon-youtube { background: #FF0000; }
.tab-favicon-github { background: #24292e; }

.tab-title {
  font-family: var(--font-ui-sans);
  font-size: 13px;
  font-weight: 400;
  line-height: 1.38;
  letter-spacing: -0.006em;
  color: rgba(0,0,0,0.86);
  white-space: nowrap;
  overflow: hidden;
  flex: 1;
  padding: 1px 20px 3px 0;
  mask-image: linear-gradient(to right, black 80%, transparent 100%);
  -webkit-mask-image: linear-gradient(to right, black 80%, transparent 100%);
}

.tab-close {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  width: 20px;
  height: 20px;
  background: transparent;
  border: none;
  cursor: pointer;
  font-size: 18px;
  color: rgba(0,0,0,0.56);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  opacity: 0;
  transition: opacity 0.15s;
}

.tab:hover .tab-close {
  opacity: 1;
}

@media (hover: hover) and (pointer: fine) {
  .tab-close:hover {
    background: rgba(0,0,0,0.06);
  }
}

/* ===== Active Tab — connects to toolbar below ===== */
.tab.active {
  height: 34px;
  border-radius: 12px 12px 0 0;
  z-index: 2;
  background: transparent; /* Backplate handles the color */
}

.tab.active .tab-close {
  opacity: 1;
}

/* Backplate — sits behind the active tab, same color as toolbar (#F4F7FB) */
.tab.active::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 260px;
  height: 34px;
  background: #F4F7FB;
  border-radius: 8px 8px 0 0;
  z-index: -1;
}

/* Extend backplate below tab to overlap with toolbar — seamless connection */
.tab.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 4px;
  background: #F4F7FB;
  z-index: 3;
}

/* Wing connectors — curved connection between active tab and toolbar bg */
.tab-wing-left,
.tab-wing-right {
  display: none;
}

.tab.active .tab-wing-left,
.tab.active .tab-wing-right {
  display: block;
  position: absolute;
  bottom: 0;
  width: 8px;
  height: 8px;
  z-index: 1;
  pointer-events: none;
}

.tab.active .tab-wing-left {
  left: -8px;
  background: radial-gradient(circle at 0% 0%, transparent 8px, #F4F7FB 8px);
}

.tab.active .tab-wing-right {
  right: -8px;
  background: radial-gradient(circle at 100% 0%, transparent 8px, #F4F7FB 8px);
}

/* Divider between tabs */
.tab-divider {
  width: 1px;
  height: 20px;
  background: rgba(0,0,0,0.15);
  flex-shrink: 0;
  margin: 0 2px;
  align-self: center;
}

/* Add tab button */
.tab-add-btn {
  width: 32px;
  height: 32px;
  background: transparent;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(0,0,0,0.56);
  flex-shrink: 0;
  margin-left: 2px;
}

.tab-add-btn svg {
  width: 20px;
  height: 20px;
}

/* Drag and drop */
.tab.dragging {
  opacity: 0.4;
}

.tab.drag-over {
  border-left: 2px solid #0078D4;
}