/* CSS Variables for Premium Design System */
:root {
  /* Dark Theme Variables (Default) */
  --bg-app: #0b0f19;
  --bg-panel: #111827;
  --bg-input: #1f2937;
  --border-color: #374151;
  --border-hover: #4b5563;
  --border-focus: #6366f1;
  --text-main: #f9fafb;
  --text-muted: #9ca3af;
  --terminal-bg: #090d16;
  --terminal-text: #e5e7eb;
  --terminal-border: #1f2937;

  /* Accent Colors */
  --accent-green: #10b981;
  --accent-green-hover: #059669;
  --accent-blue: #3b82f6;
  --accent-blue-hover: #2563eb;
  --accent-purple: #6366f1;
  --accent-purple-hover: #4f46e5;
  --accent-warn-bg: #fef3c7;
  --accent-warn-text: #b45309;
  --accent-warn-border: #f59e0b;
  --accent-danger: #ef4444;
  --accent-danger-hover: #dc2626;

  /* Layout and Styling Details */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --font-ui: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', source-code-pro, Menlo, Monaco, Consolas, monospace;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.15);
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

/* Light Theme Variables */
body.light-theme {
  --bg-app: #f3f4f6;
  --bg-panel: #ffffff;
  --bg-input: #f9fafb;
  --border-color: #d1d5db;
  --border-hover: #9ca3af;
  --border-focus: #4f46e5;
  --text-main: #111827;
  --text-muted: #6b7280;
  --terminal-bg: #f8fafc;
  --terminal-text: #0f172a;
  --terminal-border: #e2e8f0;

  --accent-warn-bg: #fffbeb;
  --accent-warn-text: #b45309;
  --accent-warn-border: #f59e0b;

  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.02);
}

/* Base resets & styling */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  background-color: var(--bg-app);
  color: var(--text-main);
  font-family: var(--font-ui);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* App container */
.app-container {
  width: 100%;
  max-width: 1200px;
  padding: 2.5rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Header */
.app-header {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  margin-bottom: 0.5rem;
}

.app-header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  color: var(--text-main);
  text-align: center;
}

#theme-toggle {
  position: absolute;
  right: 0;
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 8px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  transition: border-color var(--transition-fast), background-color var(--transition-fast), transform var(--transition-fast);
}

#theme-toggle:hover {
  border-color: var(--border-hover);
  background-color: rgba(255, 255, 255, 0.05);
  transform: scale(1.05);
}

body.light-theme #theme-toggle:hover {
  background-color: rgba(0, 0, 0, 0.03);
}

/* Toggle Sun/Moon icons depending on active class */
.sun-icon {
  display: none;
  width: 20px;
  height: 20px;
}

.moon-icon {
  display: block;
  width: 20px;
  height: 20px;
}

body.light-theme .sun-icon {
  display: block;
}

body.light-theme .moon-icon {
  display: none;
}

/* Main Content Area */
.app-main {
  background-color: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

/* Action Controls & Banner Row */
.control-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.action-buttons {
  display: flex;
  gap: 0.75rem;
  align-items: center;
}

/* Circular Connect Button */
.connect-btn {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  transition: transform var(--transition-fast), background-color var(--transition-fast), box-shadow var(--transition-fast);
  box-shadow: var(--shadow-md);
}

.connect-btn:hover {
  transform: scale(1.08);
}

.connect-btn.disconnected {
  background-color: var(--accent-green);
}

.connect-btn.disconnected:hover {
  background-color: var(--accent-green-hover);
  box-shadow: 0 0 12px rgba(16, 185, 129, 0.4);
}

.connect-btn.connected {
  background-color: var(--accent-danger);
}

.connect-btn.connected:hover {
  background-color: var(--accent-danger-hover);
  box-shadow: 0 0 12px rgba(239, 68, 68, 0.4);
}

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

/* Play/Stop SVG displays */
.connect-btn.disconnected .stop-icon {
  display: none;
}

.connect-btn.disconnected .play-icon {
  display: block;
}

.connect-btn.connected .stop-icon {
  display: block;
}

.connect-btn.connected .play-icon {
  display: none;
}

/* Download Button */
.download-btn {
  width: 48px;
  height: 48px;
  border-radius: 8px;
  border: none;
  background-color: var(--accent-blue);
  color: #ffffff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-fast), background-color var(--transition-fast), opacity var(--transition-fast);
  box-shadow: var(--shadow-md);
}

.download-btn:hover:not(:disabled) {
  background-color: var(--accent-blue-hover);
  transform: scale(1.08);
}

.download-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.download-btn svg {
  width: 22px;
  height: 22px;
}

/* Status Banner */
.status-banner {
  flex-grow: 1;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.85rem 1.25rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 500;
  line-height: 1.4;
  border: 1px solid transparent;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.status-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
}

/* Status Banner Themes */
.status-banner.warn {
  background-color: rgba(245, 158, 11, 0.1);
  border-color: rgba(245, 158, 11, 0.25);
  color: var(--accent-warn-border);
}

body.light-theme .status-banner.warn {
  background-color: var(--accent-warn-bg);
  border-color: var(--accent-warn-border);
  color: var(--accent-warn-text);
}

.status-banner.connected {
  background-color: rgba(16, 185, 129, 0.1);
  border-color: rgba(16, 185, 129, 0.25);
  color: var(--accent-green);
}

body.light-theme .status-banner.connected {
  background-color: #ecfdf5;
  border-color: var(--accent-green);
  color: #047857;
}

.status-banner.error {
  background-color: rgba(239, 68, 68, 0.1);
  border-color: rgba(239, 68, 68, 0.25);
  color: var(--accent-danger);
}

body.light-theme .status-banner.error {
  background-color: #fef2f2;
  border-color: var(--accent-danger);
  color: #b91c1c;
}

/* Port Config Dropdowns Grid */
.settings-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

@media (max-width: 600px) {
  .settings-grid {
    grid-template-columns: 1fr;
  }
  .control-row {
    flex-direction: column;
    align-items: stretch;
  }
  .action-buttons {
    justify-content: center;
  }
}

.settings-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.settings-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

/* Custom Styled Select Dropdown */
.select-wrapper {
  position: relative;
  width: 100%;
}

.select-wrapper select {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 0.95rem;
  font-weight: 500;
  font-family: var(--font-ui);
  color: var(--text-main);
  background-color: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  appearance: none;
  cursor: pointer;
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast);
}

.select-wrapper select:hover {
  border-color: var(--border-hover);
}

.select-wrapper select:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

/* Select arrow icon custom styling */
.select-wrapper::after {
  content: "";
  position: absolute;
  right: 1.25rem;
  top: 50%;
  transform: translateY(-50%);
  width: 10px;
  height: 6px;
  background-color: var(--text-muted);
  clip-path: polygon(100% 0, 0 0, 50% 100%);
  pointer-events: none;
}

/* Small Select Dropdowns in UI Controls */
.select-wrapper-sm select {
  padding: 0.4rem 2rem 0.4rem 0.75rem;
  font-size: 0.85rem;
  border-radius: var(--radius-sm);
}

.select-wrapper-sm::after {
  right: 0.75rem;
  width: 8px;
  height: 5px;
}

/* Received Data Terminal Area */
.received-data-section {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.received-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.received-header h2 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-main);
}

.received-controls {
  display: flex;
  gap: 1.25rem;
  align-items: center;
}

.control-select-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.control-select-group label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  white-space: nowrap;
}

.terminal-wrapper {
  position: relative;
  width: 100%;
}

.terminal-output {
  width: 100%;
  height: 400px;
  background-color: var(--terminal-bg);
  border: 1px solid var(--terminal-border);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  overflow-y: auto;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--terminal-text);
  white-space: pre-wrap;
  word-break: break-all;
  outline: none;
  transition: border-color var(--transition-fast), background-color var(--transition-normal), color var(--transition-normal);
}

.terminal-output:focus {
  border-color: var(--border-focus);
}

.terminal-output.empty {
  color: var(--text-muted);
  font-style: italic;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Custom Scrollbar for Terminal Output */
.terminal-output::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

.terminal-output::-webkit-scrollbar-track {
  background: var(--terminal-bg);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.terminal-output::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 5px;
  border: 2px solid var(--terminal-bg);
}

.terminal-output::-webkit-scrollbar-thumb:hover {
  background: var(--border-hover);
}

/* Send Data Controls Footer */
.send-data-section {
  margin-top: 0.25rem;
}

.send-bar {
  display: flex;
  gap: 0.75rem;
  align-items: center;
}

.input-container {
  flex-grow: 1;
  position: relative;
}

.input-container input {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 0.95rem;
  font-family: var(--font-ui);
  color: var(--text-main);
  background-color: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast);
}

.input-container input:hover {
  border-color: var(--border-hover);
}

.input-container input:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.input-container input::placeholder {
  color: var(--text-muted);
  opacity: 0.7;
}

.send-format-wrapper {
  width: 90px;
  flex-shrink: 0;
}

.send-eol-wrapper {
  width: 120px;
  flex-shrink: 0;
}

/* Button UI */
.send-btn, .clear-btn {
  width: 44px;
  height: 44px;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  transition: transform var(--transition-fast), background-color var(--transition-fast);
  box-shadow: var(--shadow-sm);
  flex-shrink: 0;
}

.send-btn {
  background-color: var(--accent-purple);
}

.send-btn:hover {
  background-color: var(--accent-purple-hover);
  transform: scale(1.05);
}

.send-btn:active {
  transform: scale(0.98);
}

.clear-btn {
  background-color: var(--bg-input);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
}

.clear-btn:hover {
  border-color: var(--accent-danger);
  color: var(--accent-danger);
  background-color: rgba(239, 68, 68, 0.05);
  transform: scale(1.05);
}

body.light-theme .clear-btn:hover {
  background-color: #fef2f2;
}

.clear-btn:active {
  transform: scale(0.98);
}

.send-btn svg, .clear-btn svg {
  width: 18px;
  height: 18px;
}

/* Terminal Line Highlights & Formatting */
.terminal-line {
  margin-bottom: 2px;
}

.terminal-line.sent {
  color: var(--accent-purple);
  font-weight: 500;
}

body.light-theme .terminal-line.sent {
  color: #4f46e5;
}

.terminal-line.error {
  color: var(--accent-danger);
  font-weight: 600;
}

.terminal-line.system {
  color: var(--text-muted);
  font-style: italic;
}

/* Toast Notification Utility */
.toast-msg {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background-color: var(--bg-panel);
  border: 1px solid var(--border-color);
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  font-size: 0.85rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transform: translateY(100px);
  opacity: 0;
  transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275), opacity 0.3s ease;
  z-index: 1000;
}

.toast-msg.show {
  transform: translateY(0);
  opacity: 1;
}

.toast-success {
  border-color: var(--accent-green);
  color: var(--accent-green);
}

.toast-error {
  border-color: var(--accent-danger);
  color: var(--accent-danger);
}

/* Sidebar and Split Layout */
.app-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 1.5rem;
  width: 100%;
  align-items: start;
}

@media (max-width: 900px) {
  .app-layout {
    grid-template-columns: 1fr;
  }
}

.app-sidebar {
  background-color: var(--bg-panel);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.sidebar-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.sidebar-header h2 {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-main);
}

.add-session-btn {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: none;
  background-color: var(--accent-purple);
  color: #ffffff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-fast), background-color var(--transition-fast);
  box-shadow: var(--shadow-sm);
}

.add-session-btn:hover {
  background-color: var(--accent-purple-hover);
  transform: scale(1.08);
}

.add-session-btn svg {
  width: 16px;
  height: 16px;
}

.session-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  max-height: 500px;
  overflow-y: auto;
  padding-right: 4px;
}

/* Custom Scrollbar for Session List */
.session-list::-webkit-scrollbar {
  width: 6px;
}
.session-list::-webkit-scrollbar-track {
  background: transparent;
}
.session-list::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}
.session-list::-webkit-scrollbar-thumb:hover {
  background: var(--border-hover);
}

.session-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background-color: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: border-color var(--transition-fast), background-color var(--transition-fast), transform var(--transition-fast);
  user-select: none;
  position: relative;
}

.session-item:hover {
  border-color: var(--border-hover);
  background-color: rgba(255, 255, 255, 0.02);
}

body.light-theme .session-item:hover {
  background-color: rgba(0, 0, 0, 0.01);
}

.session-item.active {
  border-color: var(--border-focus);
  background-color: rgba(99, 102, 241, 0.08);
  box-shadow: 0 0 0 1px var(--border-focus);
}

body.light-theme .session-item.active {
  background-color: rgba(99, 102, 241, 0.05);
}

.session-item-left {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-grow: 1;
  min-width: 0;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
  transition: background-color var(--transition-fast), box-shadow var(--transition-fast);
}

.status-dot.disconnected {
  background-color: var(--text-muted);
}

.status-dot.connected {
  background-color: var(--accent-green);
  box-shadow: 0 0 8px var(--accent-green);
}

.session-info {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.session-name {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-main);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.session-detail {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 1px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.session-delete-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color var(--transition-fast), background-color var(--transition-fast);
  opacity: 0.6;
}

.session-item:hover .session-delete-btn {
  opacity: 1;
}

.session-delete-btn:hover {
  color: var(--accent-danger);
  background-color: rgba(239, 68, 68, 0.1);
}

.session-rename-input {
  background-color: var(--bg-panel);
  border: 1px solid var(--border-focus);
  color: var(--text-main);
  font-family: var(--font-ui);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: 4px;
  outline: none;
  width: 100%;
}

/* Utilities */
.hidden {
  display: none !important;
}

/* Download Group Control Styling */
.download-group {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  background-color: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 3px 6px 3px 3px;
  height: 48px;
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.download-group:hover {
  border-color: var(--border-hover);
}

.download-group .download-btn {
  height: 40px;
  width: 40px;
  border-radius: 6px;
  box-shadow: none;
}

.download-group .download-btn:hover:not(:disabled) {
  transform: none;
}

.download-select-wrapper {
  width: 105px;
  flex-shrink: 0;
}

.download-select-wrapper select {
  background-color: transparent !important;
  border: none !important;
  padding: 0.4rem 1.75rem 0.4rem 0.5rem !important;
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--text-main);
  box-shadow: none !important;
}

.download-select-wrapper select option {
  background-color: var(--bg-panel);
  color: var(--text-main);
}

.download-select-wrapper::after {
  right: 0.5rem;
}