:root {
  --serial-bg: #000;
  --serial-surface: #0a0a0a;
  --serial-surface-2: #111;
  --serial-text: #fff;
  --serial-text-dim: #888;
  --serial-accent: #fff;
  --serial-border: rgba(255, 255, 255, 0.1);
  --serial-border-hover: rgba(255, 255, 255, 0.25);
  --serial-success: #00cc00;
  --serial-error: #ff1a1a;
  --serial-warning: #ffa500;
  --serial-info: #4fc3f7;
  --serial-font-mono: 'Share Tech Mono', 'JetBrains Mono', monospace;
  --serial-font-sans: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
  --serial-radius: 12px;
  --serial-radius-sm: 8px;
  --serial-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  background: var(--serial-bg);
  color: var(--serial-text);
  font-family: var(--serial-font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

#dotTerrain {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: 0;
  pointer-events: none;
  background: #000;
}

nav { position: relative; z-index: 2000; }

.serial-page {
  position: relative;
  z-index: 1;
  padding-top: calc(var(--nav-height, 60px) + 1rem);
  min-height: 100vh;
}

.serial-container {
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 0 1rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* Welcome Card */
.welcome-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 3rem 2rem;
  background: var(--serial-surface);
  border: 1px solid var(--serial-border);
  border-radius: var(--serial-radius);
  gap: 1.5rem;
  max-width: 500px;
  margin: 2rem auto;
}

.welcome-card.hidden { display: none; }

.welcome-icon {
  color: var(--serial-text-dim);
  opacity: 0.5;
}

.welcome-card h2 {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--serial-text);
}

.welcome-desc {
  color: var(--serial-text-dim);
  font-size: 0.95rem;
  max-width: 360px;
}

.welcome-steps {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  width: 100%;
  max-width: 300px;
}

.welcome-step {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.9rem;
  color: var(--serial-text-dim);
}

.step-num {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px; height: 24px;
  border-radius: 50%;
  background: var(--serial-surface-2);
  border: 1px solid var(--serial-border);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--serial-text);
  flex-shrink: 0;
}

.welcome-baud-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  width: 100%;
  max-width: 300px;
}

.welcome-baud-label {
  font-size: 0.85rem;
  color: var(--serial-text-dim);
  white-space: nowrap;
}

.welcome-baud-row select.btn {
  flex: 1;
}

.welcome-hint {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8rem;
  color: var(--serial-text-dim);
  opacity: 0.6;
}

.welcome-hint a {
  color: var(--serial-text);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.welcome-hint a:hover {
  color: var(--serial-info);
}

/* Buttons */
.btn {
  background: var(--serial-surface-2);
  border: 1px solid var(--serial-border);
  color: var(--serial-text);
  padding: 0.6rem 1rem;
  border-radius: var(--serial-radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 0.85rem;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  font-family: var(--serial-font-sans);
  user-select: none;
}

.btn:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--serial-border-hover);
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--serial-accent);
  border-color: var(--serial-accent);
  color: #000;
  font-weight: 600;
}

.btn-primary:hover:not(:disabled) {
  background: #ddd;
  border-color: #ddd;
  color: #000;
}

.btn-lg {
  padding: 0.85rem 2rem;
  font-size: 1rem;
}

.btn-send {
  padding: 0.6rem 0.85rem;
  min-width: auto;
}

select.btn {
  appearance: none;
  padding-right: 2rem;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23888' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.6rem center;
  background-size: 0.9em;
  cursor: pointer;
}

select.btn option {
  background: #1a1a1a;
  color: #fff;
}

/* Tabs */
.console-main { display: flex; flex-direction: column; gap: 0; }
.console-main.hidden { display: none; }

.tab-bar {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--serial-border);
  padding: 0 0.25rem;
  overflow-x: auto;
}

.tab-btn {
  background: none;
  border: none;
  color: var(--serial-text-dim);
  padding: 0.7rem 1rem;
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  border-bottom: 2px solid transparent;
  transition: all 0.2s ease;
  font-family: var(--serial-font-sans);
  white-space: nowrap;
}

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

.tab-btn.active {
  color: var(--serial-text);
  border-bottom-color: var(--serial-accent);
}

.tab-btn i { font-size: 0.9rem; }

.tab-content {
  display: none;
  flex-direction: column;
  gap: 0;
  flex: 1;
  min-height: 0;
}

.tab-content.active {
  display: flex;
}

/* Console */
.console {
  background: var(--serial-surface);
  border-radius: 0;
  padding: 0.75rem;
  font-family: var(--serial-font-mono);
  flex: 1;
  min-height: 0;
  max-height: calc(100vh - 22rem);
  overflow-y: auto;
  border-left: 1px solid var(--serial-border);
  border-right: 1px solid var(--serial-border);
}

.console-output {
  color: #d4d4d4;
  white-space: pre-wrap;
  line-height: 1.6;
  font-size: 0.85rem;
  font-feature-settings: "liga" 0;
  padding: 0.25rem;
  word-break: break-word;
}

.console-output .command-input { color: #4DB6AC; font-weight: bold; }
.console-output .status-message { color: #4FC3F7; font-weight: 500; }
.console-output .scan-summary { color: #81C784; font-weight: bold; padding: 4px 0; }
.console-output .ap-index { color: #FFB74D; font-weight: bold; }
.console-output .ap-label { color: #B0BEC5; padding-left: 16px; }
.console-output .ap-ssid { color: #4DB6AC; font-weight: 500; }
.console-output .ap-rssi { color: #FF8A65; }
.console-output .ap-company { color: #9575CD; }
.console-output .command-name { color: #8BC34A; font-weight: bold; }
.console-output .section-header { color: #F06292; font-weight: bold; font-size: 1.05em; padding: 8px 0; }
.console-output .help-section-header { color: #00BCD4; font-weight: bold; }
.console-output .command-usage { color: #81D4FA; }
.console-output .command-flag { color: #f7a8b8; }
.console-output .flag-description { color: #e2b4de; }
.console-output .connection-status { color: #90CAF9; font-weight: bold; }
.console-output .warning { color: #FFB74D; }
.console-output .separator { color: #B0BEC5; font-style: italic; }
.console-output .regular-text { color: #E0E0E0; }

/* Quick Commands */
.quick-commands {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 0.75rem;
  background: var(--serial-surface);
  border-left: 1px solid var(--serial-border);
  border-right: 1px solid var(--serial-border);
  overflow-x: auto;
}

.quick-label {
  font-size: 0.75rem;
  color: var(--serial-text-dim);
  white-space: nowrap;
  margin-right: 0.25rem;
}

.quick-cmd {
  background: var(--serial-surface-2);
  border: 1px solid var(--serial-border);
  color: var(--serial-text-dim);
  padding: 0.25rem 0.6rem;
  border-radius: 999px;
  font-size: 0.75rem;
  font-family: var(--serial-font-mono);
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.quick-cmd:hover {
  background: rgba(255, 255, 255, 0.08);
  color: var(--serial-text);
  border-color: var(--serial-border-hover);
}

/* Controls */
.controls-container {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.control-panel {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  align-items: center;
  padding: 0.5rem 0.75rem;
  background: var(--serial-surface);
  border: 1px solid var(--serial-border);
  border-top: none;
}

.input-group {
  display: flex;
  gap: 0;
  background: var(--serial-surface);
  border: 1px solid var(--serial-border);
  border-top: none;
  border-radius: 0 0 var(--serial-radius) var(--serial-radius);
  overflow: hidden;
}

.serial-input {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--serial-text);
  padding: 0.75rem 1rem;
  font-family: var(--serial-font-mono);
  font-size: 0.85rem;
  outline: none;
}

.serial-input::placeholder { color: var(--serial-text-dim); opacity: 0.5; }
.serial-input:disabled { opacity: 0.4; cursor: not-allowed; }

/* Scrollbar */
.console::-webkit-scrollbar { width: 8px; }
.console::-webkit-scrollbar-track { background: var(--serial-surface-2); }
.console::-webkit-scrollbar-thumb { background: rgba(255, 255, 255, 0.15); border-radius: 4px; }
.console::-webkit-scrollbar-thumb:hover { background: rgba(255, 255, 255, 0.3); }

/* Dialog */
.dialog-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.85);
  display: none;
  justify-content: center;
  align-items: center;
  z-index: 10000;
  backdrop-filter: blur(8px);
}

.dialog {
  background: var(--serial-surface);
  padding: 2rem;
  border-radius: var(--serial-radius);
  max-width: 440px;
  width: 90%;
  text-align: center;
  box-shadow: var(--serial-shadow);
  border: 1px solid var(--serial-border);
  animation: dialogShow 0.2s ease-out;
}

.dialog h2 { margin: 0 0 0.75rem; font-size: 1.25rem; font-weight: 600; }
.dialog p { color: var(--serial-text-dim); margin-bottom: 1.5rem; font-size: 0.9rem; line-height: 1.6; }

@keyframes dialogShow {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

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

/* Responsive */
@media (max-width: 768px) {
  .serial-page { padding-top: calc(var(--nav-height, 60px) + 0.5rem); }
  .serial-container { padding: 0 0.5rem 1rem; }

  .welcome-card { padding: 2rem 1.25rem; margin: 1rem auto; }

  .console { max-height: calc(100vh - 24rem); }

  .control-panel { flex-wrap: wrap; }
  .control-panel .btn { flex: 1; min-width: 0; }

  .tab-btn span { display: none; }
  .tab-btn { padding: 0.6rem 0.75rem; }
  .tab-btn i { font-size: 1.1rem; }
}

@media (max-width: 480px) {
  .welcome-steps { max-width: 100%; }
  .quick-commands { flex-wrap: nowrap; }
}