/* Reset */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-primary: #1e1e1e;
  --bg-secondary: #252526;
  --bg-tertiary: #2d2d2d;
  --bg-hover: #2a2d2e;
  --bg-active: #37373d;
  --bg-input: #3c3c3c;
  --border: #404040;
  --text-primary: #cccccc;
  --text-secondary: #969696;
  --text-muted: #6a6a6a;
  --accent: #0078d4;
  --accent-hover: #1a8adb;
  --danger: #f44747;
  --success: #73c991;
  --warning: #cca700;
  --title-bar-height: 36px;
  --tab-bar-height: 36px;
  --status-bar-height: 24px;
  --activity-bar-width: 48px;
  --sidebar-width: 220px;
  --font-mono: 'Cascadia Code', 'Fira Code', 'JetBrains Mono', 'Consolas', 'Courier New', monospace;
}

html, body {
  height: 100%;
  overflow: hidden;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 13px;
}

.hidden { display: none !important; }

/* Login Screen */
#login-screen {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  background: var(--bg-primary);
}

.login-box {
  text-align: center;
  padding: 48px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 8px;
  min-width: 320px;
}

.login-icon {
  font-size: 48px;
  margin-bottom: 12px;
}

.login-box h1 {
  font-size: 18px;
  font-weight: 400;
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.login-box input {
  width: 100%;
  padding: 8px 12px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-primary);
  font-size: 14px;
  outline: none;
  margin-bottom: 12px;
}

.login-box input:focus {
  border-color: var(--accent);
}

.login-box button {
  width: 100%;
  padding: 8px 16px;
  background: var(--accent);
  border: none;
  border-radius: 4px;
  color: #fff;
  font-size: 14px;
  cursor: pointer;
}

.login-box button:hover {
  background: var(--accent-hover);
}

.error {
  color: var(--danger);
  font-size: 12px;
  margin-top: 8px;
}

/* Dashboard Layout */
#dashboard {
  display: grid;
  grid-template-columns: var(--activity-bar-width) var(--sidebar-width) 1fr;
  grid-template-rows: var(--title-bar-height) 1fr var(--status-bar-height);
  grid-template-areas:
    "titlebar titlebar titlebar"
    "activitybar sidebar main"
    "statusbar statusbar statusbar";
  height: 100vh;
  width: 100vw;
}

#dashboard.sidebar-collapsed {
  grid-template-columns: var(--activity-bar-width) 0px 1fr;
}

#dashboard.sidebar-collapsed #sidebar {
  display: none;
}

/* Title Bar */
#title-bar {
  grid-area: titlebar;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 12px;
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border);
  -webkit-app-region: drag;
  user-select: none;
}

.title-left, .title-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.title-text {
  font-size: 13px;
  color: var(--text-secondary);
}

.title-user {
  font-size: 12px;
  color: var(--text-muted);
}

#title-bar button {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 16px;
  padding: 4px 8px;
  border-radius: 4px;
  -webkit-app-region: no-drag;
}

#title-bar button:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

/* Activity Bar */
#activity-bar {
  grid-area: activitybar;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 8px 0;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
}

.activity-btn {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 18px;
  border-radius: 4px;
  margin-bottom: 4px;
  position: relative;
}

.activity-btn:hover {
  color: var(--text-primary);
}

.activity-btn.active {
  color: var(--text-primary);
}

.activity-btn.active::before {
  content: '';
  position: absolute;
  left: -4px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: var(--accent);
  border-radius: 1px;
}

/* Sidebar */
#sidebar {
  grid-area: sidebar;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
  overflow-y: auto;
  overflow-x: hidden;
}

.sidebar-panel {
  display: none;
}

.sidebar-panel.active {
  display: block;
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 12px;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.panel-header button {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 16px;
  padding: 2px 6px;
  border-radius: 4px;
}

.panel-header button:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

/* Session List */
#session-list {
  list-style: none;
}

.session-item {
  display: flex;
  align-items: center;
  padding: 4px 12px 4px 20px;
  cursor: pointer;
  font-size: 13px;
  color: var(--text-primary);
  gap: 6px;
}

.session-item:hover {
  background: var(--bg-hover);
}

.session-item.active {
  background: var(--bg-active);
}

.session-icon {
  font-size: 14px;
  color: var(--text-muted);
  flex-shrink: 0;
}

.session-item.active .session-icon {
  color: var(--success);
}

.session-name {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.session-close {
  visibility: hidden;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 14px;
  padding: 2px 4px;
  border-radius: 4px;
  flex-shrink: 0;
}

.session-item:hover .session-close {
  visibility: visible;
}

.session-close:hover {
  background: var(--bg-active);
  color: var(--danger);
}

/* Settings */
.settings-content {
  padding: 12px;
}

.setting-group {
  margin-bottom: 16px;
}

.setting-group label {
  display: block;
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.setting-group input[type="range"] {
  width: calc(100% - 30px);
  accent-color: var(--accent);
  vertical-align: middle;
}

#font-size-value {
  font-size: 12px;
  color: var(--text-muted);
  margin-left: 4px;
}

.split-buttons {
  display: flex;
  gap: 4px;
}

.split-btn {
  width: 32px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-input);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 16px;
  border-radius: 4px;
}

.split-btn:hover {
  background: var(--bg-hover);
  color: var(--text-primary);
}

.split-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* Main Area */
#main-area {
  grid-area: main;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--bg-primary);
}

/* Tab Bar */
#tab-bar {
  display: flex;
  align-items: center;
  height: var(--tab-bar-height);
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border);
  overflow-x: auto;
  overflow-y: hidden;
  flex-shrink: 0;
}

#tab-bar::-webkit-scrollbar {
  height: 3px;
}

#tab-bar::-webkit-scrollbar-thumb {
  background: var(--border);
}

#tabs-container {
  display: flex;
  flex: 1;
  min-width: 0;
}

.tab {
  display: flex;
  align-items: center;
  padding: 0 12px;
  height: var(--tab-bar-height);
  font-size: 13px;
  color: var(--text-muted);
  cursor: pointer;
  border-right: 1px solid var(--border);
  white-space: nowrap;
  gap: 6px;
  min-width: 0;
  flex-shrink: 0;
  user-select: none;
}

.tab:hover {
  color: var(--text-primary);
}

.tab.active {
  color: var(--text-primary);
  background: var(--bg-primary);
  border-bottom: 1px solid var(--bg-primary);
  margin-bottom: -1px;
}

.tab-name {
  max-width: 120px;
  overflow: hidden;
  text-overflow: ellipsis;
}

.tab-close {
  visibility: hidden;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 14px;
  padding: 2px 4px;
  border-radius: 4px;
  flex-shrink: 0;
}

.tab:hover .tab-close {
  visibility: visible;
}

.tab-close:hover {
  background: var(--bg-active);
  color: var(--danger);
}

#btn-new-tab {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 18px;
  padding: 4px 12px;
  flex-shrink: 0;
}

#btn-new-tab:hover {
  color: var(--text-primary);
}

/* Terminal Container */
#terminal-container {
  flex: 1;
  display: grid;
  gap: 1px;
  background: var(--border);
  overflow: hidden;
}

#terminal-container.split-1 {
  grid-template-columns: 1fr;
  grid-template-rows: 1fr;
}

#terminal-container.split-2 {
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr;
}

#terminal-container.split-3 {
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr 1fr;
}

#terminal-container.split-3 .terminal-pane:last-child {
  grid-column: 1 / -1;
}

#terminal-container.split-4 {
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr 1fr;
}

.terminal-pane {
  background: var(--bg-primary);
  overflow: hidden;
  position: relative;
}

.terminal-pane.active {
  outline: 1px solid var(--accent);
  outline-offset: -1px;
}

.terminal-pane .xterm {
  height: 100%;
  padding: 4px;
}

/* Empty state */
.empty-pane {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  color: var(--text-muted);
  font-size: 13px;
  cursor: pointer;
}

.empty-pane:hover {
  color: var(--text-secondary);
  background: var(--bg-hover);
}

/* Status Bar */
#status-bar {
  grid-area: statusbar;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 12px;
  background: var(--accent);
  color: #fff;
  font-size: 12px;
}

.status-left, .status-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.status-divider {
  color: rgba(255, 255, 255, 0.4);
}

/* Context Menu */
.context-menu {
  position: fixed;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 4px 0;
  z-index: 1000;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
  min-width: 160px;
}

.context-menu-item {
  display: flex;
  align-items: center;
  padding: 6px 16px;
  font-size: 13px;
  color: var(--text-primary);
  cursor: pointer;
  gap: 8px;
}

.context-menu-item:hover {
  background: var(--accent);
}

.context-menu-separator {
  height: 1px;
  background: var(--border);
  margin: 4px 0;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--bg-active);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* Responsive */
@media (max-width: 768px) {
  #dashboard {
    grid-template-columns: var(--activity-bar-width) 0px 1fr;
  }

  #sidebar {
    position: fixed;
    left: var(--activity-bar-width);
    top: var(--title-bar-height);
    bottom: var(--status-bar-height);
    width: var(--sidebar-width);
    z-index: 100;
    display: none;
  }

  #dashboard.sidebar-open #sidebar {
    display: block;
  }

  #terminal-container {
    grid-template-columns: 1fr !important;
    grid-template-rows: 1fr !important;
  }

  #terminal-container .terminal-pane {
    grid-column: auto !important;
  }
}