:root {
  color-scheme: light dark;

  /* Page + surfaces */
  --bg-top: #f6f8fb;
  --bg-bottom: #e9eef6;
  --surface: #ffffff;
  --surface-raised: #f9fbff;
  --surface-muted: #edf1f7;
  --panel: #eef3fb;
  --bar: #dde5f2;
  --debug-bg: #e6edf8;

  /* Text */
  --text: #1f2a3a;
  --muted: #5e6a7f;
  --disabled-text: #7d889a;

  /* Borders */
  --border: #c7cfdb;
  --border-soft: #d6dfeb;
  --disabled-border: #c4cbd8;

  /* Accent */
  --accent: #0d5ea8;
  --accent-strong: #20598d;
  --star: #c28b00;

  /* Controls (buttons / links) */
  --control-top: #f9fcff;
  --control-bottom: #dce6f4;
  --control-border: #9aa8bf;
  --control-disabled-top: #eef2f8;
  --control-disabled-bottom: #dee5f0;
  --control-active-top: #fefefe;
  --control-active-bottom: #cfe3fb;

  /* Table */
  --table-header: #e3ebf8;
  --selected-bg: #dcecff;
  --focus-bg: #f2f8ff;

  /* Settings / info */
  --info-bg: #eef5fe;
  --info-text: #274466;
  --section-header: #edf3fc;

  /* Warning (amber / orange) */
  --warn-border: #d1a862;
  --warn-bg-top: #fff7e8;
  --warn-bg-bottom: #f6e4bf;
  --warn-text: #5b3810;
  --warn-bg: #fff4e8;
  --warn-border-2: #d97b2f;
  --warn-text-2: #61330f;
  --warn-link: #7b3f14;
  --warn-btn-top: #fff4df;
  --warn-btn-bottom: #f6d7ab;
  --warn-btn-border: #965200;

  /* Error (red) */
  --error-border: #c44a4a;
  --error-bg: #fff1f1;
  --error-bg-strong: #ffdede;
  --error-text: #982b2b;

  /* Shadows / overlays */
  --shadow-color: rgba(20, 37, 61, 0.12);
  --overlay: rgba(12, 23, 40, 0.45);
}

@media (prefers-color-scheme: dark) {
  :root {
    /* Page + surfaces */
    --bg-top: #121821;
    --bg-bottom: #0d1219;
    --surface: #1a212c;
    --surface-raised: #212a37;
    --surface-muted: #161c25;
    --panel: #161d28;
    --bar: #1b2532;
    --debug-bg: #141b25;

    /* Text */
    --text: #e7ecf3;
    --muted: #9aa6b8;
    --disabled-text: #6b7787;

    /* Borders */
    --border: #2d3848;
    --border-soft: #283143;
    --disabled-border: #333d4d;

    /* Accent */
    --accent: #4c9be8;
    --accent-strong: #74b2ef;
    --star: #e0a93a;

    /* Controls (buttons / links) */
    --control-top: #2a3543;
    --control-bottom: #222c39;
    --control-border: #3a4555;
    --control-disabled-top: #1c232e;
    --control-disabled-bottom: #181e27;
    --control-active-top: #284460;
    --control-active-bottom: #1f3650;

    /* Table */
    --table-header: #222e3d;
    --selected-bg: #234061;
    --focus-bg: #243549;

    /* Settings / info */
    --info-bg: #182636;
    --info-text: #a9cbf0;
    --section-header: #1e2937;

    /* Warning (amber / orange) */
    --warn-border: #8a6a2e;
    --warn-bg-top: #2a2113;
    --warn-bg-bottom: #221a0f;
    --warn-text: #e8c98a;
    --warn-bg: #2a2012;
    --warn-border-2: #9a5a28;
    --warn-text-2: #e6b483;
    --warn-link: #e0a26a;
    --warn-btn-top: #3a2b12;
    --warn-btn-bottom: #2e2210;
    --warn-btn-border: #8a5a1e;

    /* Error (red) */
    --error-border: #c0564f;
    --error-bg: #2e1719;
    --error-bg-strong: #3a1c1f;
    --error-text: #f0a0a0;

    /* Shadows / overlays */
    --shadow-color: rgba(0, 0, 0, 0.5);
    --overlay: rgba(0, 0, 0, 0.62);
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: linear-gradient(180deg, var(--bg-top) 0%, var(--bg-bottom) 100%);
  color: var(--text);
  font-family: "Segoe UI", Tahoma, sans-serif;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
}

.about-page {
  min-height: 100vh;
  height: auto;
  overflow: auto;
  background:
    radial-gradient(circle at top right, rgba(13, 94, 168, 0.16), transparent 45%),
    linear-gradient(180deg, var(--bg-top) 0%, var(--bg-bottom) 100%);
}

.about-shell {
  max-width: 860px;
  margin: 2.2rem auto;
  padding: 0 1rem 2rem;
}

.about-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: 0 14px 28px var(--shadow-color);
  padding: 1.5rem 1.6rem;
  line-height: 1.6;
}

.about-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.8rem;
  margin-bottom: 0.9rem;
}

.about-header h1 {
  margin: 0;
  font-size: 1.35rem;
}

.about-signoff {
  margin-top: 1.1rem;
  font-weight: 600;
}

.app-shell {
  height: 100vh;
  height: 100dvh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border);
  background: var(--bar);
  padding: 0.8rem 1rem;
}

.toolbar h1 {
  margin: 0;
  font-size: 1.1rem;
}

.toolbar-actions {
  display: flex;
  gap: 0.6rem;
}

button {
  border: 1px solid var(--control-border);
  background: linear-gradient(180deg, var(--control-top) 0%, var(--control-bottom) 100%);
  color: var(--text);
  padding: 0.45rem 0.75rem;
  border-radius: 4px;
  cursor: pointer;
}

button:not(:disabled):hover {
  border-color: var(--accent);
}

.toolbar-link {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--control-border);
  background: linear-gradient(180deg, var(--control-top) 0%, var(--control-bottom) 100%);
  color: var(--text);
  padding: 0.45rem 0.75rem;
  border-radius: 4px;
  text-decoration: none;
  font-size: 0.85rem;
}

.toolbar-link:hover {
  border-color: var(--accent);
}

.github-star-widget {
  display: inline-flex;
  align-items: stretch;
  align-self: center;
}

.github-star-button,
.github-star-count {
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  border: 1px solid var(--control-border);
  background: linear-gradient(180deg, var(--control-top) 0%, var(--control-bottom) 100%);
  color: var(--text);
  padding: 0.45rem 0.75rem;
  text-decoration: none;
  font-size: 0.85rem;
  line-height: 1;
}

.github-star-button {
  gap: 0.4rem;
  border-radius: 4px 0 0 4px;
}

.github-star-count {
  justify-content: center;
  min-width: 3.2rem;
  border-left: 0;
  border-radius: 0 4px 4px 0;
  font-variant-numeric: tabular-nums;
}

.github-star-button:hover,
.github-star-count:hover {
  border-color: var(--accent);
}

.github-star-icon {
  color: var(--star);
  font-size: 0.95rem;
}

.main-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

.left-panel {
  border-right: 1px solid var(--border);
  background: var(--panel);
  padding: 1rem;
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.left-panel-main {
  flex: 0 0 auto;
}

.left-panel h2 {
  margin-top: 0;
  font-size: 1rem;
}

/* Serial Bridge is a <details>: a static heading on desktop, a collapsible
   disclosure on mobile (the mobile breakpoint re-enables the toggle/marker). */
.left-panel-summary {
  margin: 0 0 0.6rem;
  font-size: 1rem;
  font-weight: 700;
  list-style: none;
  pointer-events: none;
}

.left-panel-summary::-webkit-details-marker {
  display: none;
}

.sidebar-warning-panel {
  margin: 0.2rem 0 0.9rem;
  padding: 0.75rem 0.8rem;
  border: 1px solid var(--warn-border);
  border-radius: 8px;
  background: linear-gradient(180deg, var(--warn-bg-top) 0%, var(--warn-bg-bottom) 100%);
  color: var(--warn-text);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.35);
  flex-shrink: 0;
}

.sidebar-warning-panel strong {
  display: block;
  margin-bottom: 0.35rem;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.sidebar-warning-panel p {
  margin: 0;
  font-size: 0.82rem;
  line-height: 1.45;
}

.serial-support-warning {
  margin: 0.35rem 0 0.8rem;
  padding: 0.55rem 0.6rem;
  border: 1px solid var(--warn-border-2);
  border-radius: 6px;
  background: var(--warn-bg);
  color: var(--warn-text-2);
  font-size: 0.82rem;
  line-height: 1.35;
}

.serial-support-warning a {
  color: var(--warn-link);
  font-weight: 600;
}

.serial-support-warning[hidden] {
  display: none;
}

#radio-make,
#radio-model {
  width: 100%;
  margin: 0.2rem 0 0.55rem;
  padding: 0.4rem 0.45rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--surface);
  color: var(--text);
}

.left-panel button:disabled,
.left-panel input:disabled,
.left-panel select:disabled {
  color: var(--disabled-text);
  border-color: var(--disabled-border);
  background: linear-gradient(180deg, var(--control-disabled-top) 0%, var(--control-disabled-bottom) 100%);
  cursor: not-allowed;
}

.serial-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  margin: 0.3rem 0 0.6rem;
}

.serial-actions > :only-child {
  grid-column: 1 / -1;
}

.serial-log {
  margin: 0.6rem 0 0;
  min-height: 92px;
  max-height: 180px;
  overflow: auto;
  background: var(--surface-raised);
  border: 1px solid var(--border);
  padding: 0.45rem;
  font-size: 0.74rem;
  line-height: 1.4;
}

.editor-panel {
  padding: 1rem;
  min-height: 0;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.editor-view-toggle {
  display: inline-flex;
  gap: 0.3rem;
  margin-bottom: 0.75rem;
}

.editor-view-toggle button {
  min-width: 8.5rem;
}

.editor-view-toggle button:disabled {
  color: var(--disabled-text);
  border-color: var(--disabled-border);
  background: linear-gradient(180deg, var(--control-disabled-top) 0%, var(--control-disabled-bottom) 100%);
  box-shadow: none;
  cursor: not-allowed;
}

.editor-view-toggle button.is-active {
  border-color: var(--accent-strong);
  background: linear-gradient(180deg, var(--control-active-top) 0%, var(--control-active-bottom) 100%);
  box-shadow: inset 0 0 0 1px rgba(32, 89, 141, 0.1);
}

.editor-view {
  min-height: 0;
  flex: 1 1 auto;
  display: none;
  flex-direction: column;
}

.editor-view.is-active {
  display: flex;
}

.channel-toolbar {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  margin-bottom: 0.6rem;
  flex: 0 0 auto;
  position: relative;
}

.mem-table-scroll {
  min-height: 0;
  overflow: auto;
  flex: 1 1 auto;
}

.settings-layout {
  min-height: 0;
  flex: 1 1 auto;
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 0.8rem;
}

.settings-tabs {
  min-height: 0;
  overflow: auto;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  padding-right: 0.2rem;
}

.settings-tab {
  width: 100%;
  text-align: left;
}

.settings-tab.is-active {
  border-color: var(--accent-strong);
  background: linear-gradient(180deg, var(--control-active-top) 0%, var(--control-active-bottom) 100%);
}

.settings-tab.has-invalid {
  border-color: var(--error-border);
  background: linear-gradient(180deg, var(--error-bg) 0%, var(--error-bg-strong) 100%);
}

.settings-panel {
  min-width: 0;
  min-height: 0;
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: 0 10px 22px var(--shadow-color);
}

.settings-summary {
  border-bottom: 1px solid var(--border);
  background: var(--info-bg);
  color: var(--info-text);
  padding: 0.7rem 0.9rem;
  font-size: 0.84rem;
}

.settings-summary.has-invalid {
  background: var(--error-bg);
  color: var(--error-text);
}

.settings-empty {
  margin: auto;
  max-width: 36rem;
  padding: 1rem;
  color: var(--muted);
  text-align: center;
  line-height: 1.45;
}

.settings-content {
  min-height: 0;
  overflow: auto;
  padding: 0.9rem;
}

.settings-group {
  margin-bottom: 1rem;
  border: 1px solid var(--border-soft);
  border-radius: 8px;
  background: var(--surface-raised);
  overflow: hidden;
}

.settings-group > h3,
.settings-subgroup > h4 {
  margin: 0;
  padding: 0.65rem 0.8rem;
  background: var(--section-header);
  font-size: 0.88rem;
}

.settings-subgroup {
  border-top: 1px solid var(--border-soft);
}

.settings-fields {
  display: grid;
  grid-template-columns: minmax(180px, 240px) minmax(0, 1fr);
  gap: 0.45rem 0.8rem;
  align-items: start;
  padding: 0.8rem;
}

.settings-field-label {
  font-size: 0.84rem;
  line-height: 1.35;
  color: var(--text);
}

.settings-field-label strong {
  display: block;
  margin-bottom: 0.1rem;
  font-size: 0.86rem;
}

.settings-field-doc {
  color: var(--muted);
}

.settings-field-control {
  min-width: 0;
}

.settings-field-control input[type="text"],
.settings-field-control input[type="number"],
.settings-field-control select {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--surface);
  color: var(--text);
  padding: 0.45rem 0.55rem;
}

.settings-field-control input[type="checkbox"] {
  width: 1rem;
  height: 1rem;
  margin-top: 0.4rem;
}

.settings-field-control.is-invalid input,
.settings-field-control.is-invalid select {
  border-color: var(--error-border);
  background: var(--error-bg);
}

.settings-field-control.is-immutable input,
.settings-field-control.is-immutable select,
.settings-field-control.is-immutable label {
  color: var(--disabled-text);
}

.settings-field-control.is-immutable input,
.settings-field-control.is-immutable select {
  background: var(--surface-muted);
}

.settings-field-error {
  margin-top: 0.25rem;
  color: var(--error-text);
  font-size: 0.78rem;
  line-height: 1.3;
}

.settings-field-warning {
  margin-top: 0.25rem;
  color: var(--warn-text-2);
  font-size: 0.78rem;
  line-height: 1.3;
}

#channel-insert,
#channel-remove {
  min-width: 2.1rem;
  padding: 0.3rem 0.45rem;
  font-size: 1rem;
  line-height: 1;
}

.channel-menu {
  position: relative;
}

.channel-menu-popup {
  position: absolute;
  top: calc(100% + 0.25rem);
  left: 0;
  z-index: 20;
  min-width: 24rem;
  padding: 0.25rem;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--surface);
  box-shadow: 0 6px 16px var(--shadow-color);
}

.channel-menu-popup.hidden {
  display: none;
}

.channel-menu-popup button {
  width: 100%;
  text-align: left;
}

.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 60;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--overlay);
  padding: 1rem;
}

.modal-overlay.hidden {
  display: none;
}

.modal-card {
  width: min(560px, 100%);
  margin: 0;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: 0 16px 36px var(--shadow-color);
  padding: 1rem;
}

.modal-card h2 {
  margin: 0 0 0.8rem;
  font-size: 1rem;
}

.modal-grid {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 0.45rem 0.7rem;
  align-items: center;
}

.modal-grid input[type="text"],
.modal-grid input[type="number"],
.modal-grid select {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--surface);
  color: var(--text);
  padding: 0.35rem 0.45rem;
}

.modal-grid input[type="checkbox"] {
  width: 1rem;
  height: 1rem;
  margin: 0;
}

.modal-geo-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.4rem;
  align-items: center;
}

.modal-geo-button {
  min-width: 2rem;
  padding: 0.35rem 0.45rem;
  line-height: 1;
}

.modal-modes {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 0.35rem 0.55rem;
}

.modal-mode-option {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.85rem;
}

.modal-actions {
  margin-top: 0.9rem;
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
}

#przemienniki-country {
  margin-bottom: 2em;
}

#przemienniki-band-list {
  margin-bottom: 2em;
}

#przemienniki-mode-list {
  margin-bottom: 2em;
}

.debug-output-panel {
  border-top: 1px solid var(--border);
  background: var(--debug-bg);
  padding: 0.7rem 0.9rem 0.9rem;
}

.debug-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.4rem;
}

.debug-actions {
  display: inline-flex;
  gap: 0.5rem;
}

.debug-header h2 {
  margin: 0;
  font-size: 0.9rem;
}

#report-issue {
  border-color: var(--warn-btn-border);
  background: linear-gradient(180deg, var(--warn-btn-top) 0%, var(--warn-btn-bottom) 100%);
}

#debug-output {
  width: 100%;
  min-height: 180px;
  resize: vertical;
  border: 1px solid var(--border);
  background: var(--surface-raised);
  color: var(--text);
  padding: 0.5rem;
  font-size: 0.78rem;
  line-height: 1.35;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

#mem-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--surface);
  border: 1px solid var(--border);
  table-layout: fixed;
}

#mem-table th,
#mem-table td {
  border: 1px solid var(--border);
  padding: 0.35rem;
  font-size: 0.85rem;
}

#mem-table th {
  background: var(--table-header);
  text-align: left;
}

#mem-table td input {
  width: 100%;
  border: none;
  background: transparent;
  color: var(--text);
  font-size: 0.85rem;
}

#mem-table td select {
  width: 100%;
  border: none;
  background: transparent;
  color: var(--text);
  font-size: 0.85rem;
}

#mem-table .channel-location-button {
  width: 100%;
  border: none;
  border-radius: 0;
  padding: 0;
  background: transparent;
  color: var(--text);
  font-size: 0.85rem;
  text-align: left;
  cursor: pointer;
}

#mem-table .channel-location-button:hover {
  color: var(--accent-strong);
  text-decoration: underline;
}

#mem-table .channel-location-button:focus-visible {
  outline: 1px solid var(--accent);
  background: var(--focus-bg);
}

#mem-table tbody tr.is-selected td {
  background: var(--selected-bg);
}

#mem-table td.is-invalid {
  background: var(--error-bg);
}

#mem-table td input:focus {
  outline: 1px solid var(--accent);
  background: var(--focus-bg);
}

#mem-table td select:focus {
  outline: 1px solid var(--accent);
  background: var(--focus-bg);
}

@media (max-width: 900px) {
  /* Let the page flow and scroll vertically instead of locking to the viewport,
     so the stacked panels are all reachable on a phone. */
  body {
    height: auto;
    min-height: 100dvh;
    overflow: auto;
  }

  .app-shell {
    height: auto;
    min-height: 100dvh;
    overflow: visible;
  }

  .toolbar {
    flex-wrap: wrap;
    gap: 0.5rem;
  }

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

  /* Stack sidebar above the editor; let both size to content and the page scroll. */
  .main-layout {
    display: block;
    overflow: visible;
  }

  .left-panel {
    display: block;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }

  .editor-panel {
    display: block;
    overflow: visible;
  }

  .editor-view.is-active {
    display: block;
  }

  /* Bound the wide channel table so it scrolls internally while the page can
     still scroll past it to the debug panel. */
  .mem-table-scroll {
    max-height: 60dvh;
    -webkit-overflow-scrolling: touch;
  }

  /* Serial Bridge disclosure becomes collapsible on mobile so the channel list
     isn't pushed down the page. */
  .left-panel-summary {
    pointer-events: auto;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
    margin-bottom: 0.4rem;
    min-height: 2.75rem;
  }

  .left-panel-summary::after {
    content: "\25BE";
    color: var(--muted);
  }

  .serial-bridge:not([open]) .left-panel-summary::after {
    content: "\25B8";
  }

  /* Don't compress the 17 columns to fit the screen (which makes them
     unreadable); let the table take its natural width and scroll horizontally,
     with readable, tappable cells. */
  #mem-table {
    width: max-content;
    min-width: 100%;
  }

  #mem-table th,
  #mem-table td {
    white-space: nowrap;
  }

  #mem-table td input,
  #mem-table td select {
    min-width: 6rem;
    min-height: 2.25rem;
  }

  /* Keep the auto-indexed Location column compact. */
  #mem-table td:first-child,
  #mem-table th:first-child {
    min-width: 2.75rem;
  }

  #mem-table td:first-child input,
  #mem-table td:first-child select,
  #mem-table .channel-location-button {
    min-width: 2.75rem;
  }

  /* Comfortable touch targets for primary controls (table cells excluded). */
  .toolbar-actions button,
  .toolbar-link,
  .editor-view-toggle button,
  .left-panel button,
  .left-panel select,
  .serial-actions button,
  .channel-toolbar > button,
  .channel-menu-popup button,
  .modal-actions button,
  .debug-actions button {
    min-height: 2.75rem;
  }

  /* The actions popup is fixed-width on desktop; keep it on-screen on phones. */
  .channel-menu-popup {
    min-width: 0;
    width: max-content;
    max-width: calc(100vw - 2rem);
  }

  #debug-output {
    min-height: 120px;
  }

  .modal-grid {
    grid-template-columns: 1fr;
  }

  .settings-layout {
    grid-template-columns: 1fr;
  }

  .settings-tabs {
    flex-direction: row;
    overflow: auto;
    padding-right: 0;
    padding-bottom: 0.2rem;
  }

  .settings-tab {
    width: auto;
    white-space: nowrap;
  }

  .settings-fields {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  /* Single-column serial actions and full-width view toggle on narrow phones. */
  .serial-actions {
    grid-template-columns: 1fr;
  }

  .editor-view-toggle {
    display: flex;
  }

  .editor-view-toggle button {
    flex: 1 1 0;
    min-width: 0;
  }

  .toolbar h1 {
    flex: 1 1 100%;
  }
}