:root {
  --bg-main: #050505;
  --bg-panel: #111111;
  --bg-panel-alt: #181818;
  --accent: #39ff14;
  --accent-alt: #ff7a00;
  --accent-soft: rgba(57, 255, 20, 0.2);
  --accent-strong: rgba(57, 255, 20, 0.6);
  --text-main: #e5e5e5;
  --text-muted: #888;
  --danger: #ff3366;
  --border-radius: 12px;
  --border-radius-small: 8px;
  --shadow-soft: 0 0 20px rgba(0, 0, 0, 0.9);
  --shadow-neon: 0 0 15px rgba(57, 255, 20, 0.7);
  --font-main: system-ui, -apple-system, BlinkMacSystemFont, "SF Pro Text", "Roboto", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  background:
    radial-gradient(circle at top, rgba(255, 122, 0, 0.18) 0, transparent 38%),
    radial-gradient(circle at top right, rgba(57, 255, 20, 0.24) 0, transparent 50%),
    #050505;
  color: var(--text-main);
  font-family: var(--font-main);
  -webkit-font-smoothing: antialiased;
  overflow: hidden;
}

#app {
  width: 100%;
  height: 100%;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.app-header {
  flex: 0 0 auto;
  display: flex;
  justify-content: center;
  align-items: center;
}

.title-main {
  margin: 0;
  font-size: 2.4rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  text-align: center;
  background: linear-gradient(120deg, var(--accent) 0%, var(--accent-alt) 55%, var(--accent) 100%);
  -webkit-background-clip: text;
  color: transparent;
  text-shadow:
    0 0 8px rgba(57, 255, 20, 0.9),
    0 0 16px rgba(255, 122, 0, 0.7),
    0 0 28px rgba(57, 255, 20, 0.4);
}

/* main layout */

.layout-main {
  flex: 0 0 auto;
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1.1fr);
  gap: 8px;
}

/* panels */

.panel {
  background: linear-gradient(135deg, rgba(17, 17, 17, 0.98), rgba(24, 24, 24, 0.96));
  border-radius: var(--border-radius);
  border: 1px solid rgba(57, 255, 20, 0.12);
  padding: 10px;
  box-shadow: var(--shadow-soft);
  position: relative;
  overflow: hidden;
}

.panel::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at top left, rgba(57, 255, 20, 0.14), transparent 55%),
    radial-gradient(circle at bottom right, rgba(255, 122, 0, 0.18), transparent 60%);
  opacity: 0.9;
  pointer-events: none;
}

.panel h2 {
  margin: 0 0 6px;
  font-size: 0.95rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
}

/* description */

.panel-description p {
  margin: 0 0 6px;
  font-size: 0.78rem;
  line-height: 1.35;
  color: var(--text-muted);
}

/* status */

.panel-status {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.status-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.78rem;
  gap: 4px;
}

.status-row span:first-child {
  color: var(--text-muted);
}

.badge {
  padding: 2px 6px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 0.72rem;
  min-width: 72px;
  text-align: center;
  background: rgba(255, 255, 255, 0.02);
}

.badge-disconnected {
  color: var(--danger);
  border-color: var(--danger);
}

.badge-connected {
  color: #000;
  border-color: var(--accent-alt);
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-alt) 55%, var(--accent) 100%);
  box-shadow:
    0 0 10px rgba(57, 255, 20, 0.6),
    0 0 18px rgba(255, 122, 0, 0.7);
}

.status-actions {
  display: flex;
  gap: 6px;
  margin-top: 4px;
}

.status-logline {
  margin-top: 4px;
  font-size: 0.72rem;
  color: var(--accent-strong);
  min-height: 1em;
}

/* buttons */

.btn {
  border-radius: var(--border-radius-small);
  border: 1px solid rgba(255, 122, 0, 0.55);
  background: radial-gradient(circle at top, rgba(57, 255, 20, 0.12), rgba(0, 0, 0, 0.96));
  color: var(--text-main);
  font-size: 0.8rem;
  padding: 6px 10px;
  cursor: pointer;
  outline: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  flex: 1 1 auto;
  box-shadow: 0 0 10px rgba(57, 255, 20, 0.35);
  transition: background 0.12s ease, transform 0.08s ease, box-shadow 0.12s ease, border-color 0.12s ease;
}

.btn.primary {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-alt) 50%, #ffb347 100%);
  color: #000;
  font-weight: 600;
  box-shadow:
    0 0 12px rgba(57, 255, 20, 0.8),
    0 0 20px rgba(255, 122, 0, 0.9);
}

.btn.small {
  flex: 0 0 auto;
  padding: 4px 8px;
  font-size: 0.72rem;
}

.btn:disabled {
  opacity: 0.45;
  cursor: default;
  box-shadow: none;
}

.btn:not(:disabled):active {
  transform: translateY(1px) scale(0.99);
  box-shadow: 0 0 6px rgba(57, 255, 20, 0.5);
}

.btn:not(:disabled):hover {
  border-color: var(--accent-alt);
}

.file-btn {
  position: relative;
  overflow: hidden;
  white-space: nowrap;
}

.file-btn input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

/* odometer */

.odometer {
  display: inline-flex;
  gap: 2px;
  padding: 4px 6px;
  border-radius: 999px;
  background: radial-gradient(circle at top, rgba(57, 255, 20, 0.15), rgba(0, 0, 0, 0.9));
  border: 1px solid rgba(57, 255, 20, 0.4);
  box-shadow: 0 0 16px rgba(57, 255, 20, 0.7);
}

.odometer .digit {
  width: 14px;
  height: 20px;
  font-family: "SF Mono", Menlo, Monaco, Consolas, monospace;
  font-size: 0.85rem;
  line-height: 20px;
  text-align: center;
  color: var(--accent);
  background: rgba(0, 0, 0, 0.9);
  border-radius: 4px;
  box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.8);
  text-shadow:
    0 0 4px rgba(57, 255, 20, 0.9),
    0 0 8px rgba(57, 255, 20, 0.5);
}

/* serial monitor */

.panel-serial {
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-height: 0;
}

.serial-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 6px;
}

.serial-header h2 {
  margin: 0;
}

.serial-actions {
  display: flex;
  gap: 4px;
}

.serial-output {
  flex: 1 1 auto;
  min-height: 0;
  background: radial-gradient(circle at top left, rgba(255, 122, 0, 0.24), #000);
  border-radius: var(--border-radius-small);
  padding: 6px;
  font-family: "SF Mono", Menlo, Monaco, Consolas, monospace;
  font-size: 0.72rem;
  color: #b5f3b0;
  overflow-y: auto;
  border: 1px solid rgba(57, 255, 20, 0.3);
  box-shadow: inset 0 0 12px rgba(0, 0, 0, 0.9);
}

.serial-output-line {
  white-space: pre-wrap;
  word-break: break-word;
}

.serial-input-bar {
  display: flex;
  gap: 4px;
  margin-top: 2px;
}

.serial-input-bar input {
  flex: 1 1 auto;
  border-radius: var(--border-radius-small);
  border: 1px solid rgba(57, 255, 20, 0.35);
  background: rgba(0, 0, 0, 0.9);
  color: var(--text-main);
  font-size: 0.78rem;
  padding: 4px 6px;
  outline: none;
}

.serial-input-bar input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 8px rgba(57, 255, 20, 0.6);
}

/* mobile layout */

@media (max-width: 768px) {
  .layout-main {
    grid-template-columns: minmax(0, 1fr);
    grid-auto-rows: auto;
  }

  .title-main {
    font-size: 1.8rem;
    letter-spacing: 0.18em;
  }

  .panel {
    padding: 8px;
  }

  .status-actions {
    flex-wrap: wrap;
  }

  .btn {
    min-width: 0;
  }

  .odometer .digit {
    width: 12px;
    height: 18px;
    line-height: 18px;
    font-size: 0.78rem;
  }
}