:root {
  --bg: #0f1220;
  --panel: #171a2b;
  --panel-2: #1e2236;
  --line: #2a2f4a;
  --text: #e7e9f3;
  --muted: #9aa0bd;
  --accent: #6c8cff;
  --accent-2: #4f6fe0;
  --green: #3ddc84;
  --green-bg: #123522;
  --red: #ff6b6b;
  --red-bg: #3a1620;
  --radius: 12px;
  --font: -apple-system, "Segoe UI", "Hiragino Kaku Gothic ProN", "Noto Sans JP", Meiryo, sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.55;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--accent);
  color: #fff;
  padding: 8px 14px;
  z-index: 100;
  border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

.app {
  display: grid;
  grid-template-columns: 248px 1fr;
  height: 100vh;
}

/* Sidebar */
.sidebar {
  background: var(--panel);
  border-right: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  padding: 18px 12px;
  overflow-y: auto;
}
.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 4px 8px 16px;
  font-weight: 700;
  font-size: 18px;
}
.brand-mark { font-size: 22px; }
#nav { display: flex; flex-direction: column; gap: 2px; }
.nav-group {
  margin: 14px 8px 4px;
  font-size: 11px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--muted);
}
.nav-btn {
  text-align: left;
  background: transparent;
  border: 0;
  color: var(--text);
  padding: 10px 12px;
  border-radius: 9px;
  cursor: pointer;
  font-size: 14.5px;
  font-family: inherit;
  transition: background .12s;
}
.nav-btn:hover { background: var(--panel-2); }
.nav-btn[aria-current="true"] {
  background: var(--accent-2);
  color: #fff;
  font-weight: 600;
}
.side-foot {
  margin-top: auto;
  padding: 14px 10px 0;
  font-size: 11.5px;
  color: var(--muted);
  line-height: 1.5;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.sec-badge {
  display: inline-block;
  align-self: flex-start;
  background: var(--green-bg);
  color: var(--green);
  border: 1px solid #1f6b42;
  border-radius: 999px;
  padding: 3px 10px;
  font-size: 11px;
  font-weight: 600;
}
.sec-sub { font-size: 11px; }
.sec-verify {
  align-self: flex-start;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 5px 10px;
  font-size: 11.5px;
  font-family: inherit;
  cursor: pointer;
}
.sec-verify:hover { filter: brightness(1.2); }
.sec-result { font-size: 11px; }
.sec-result.ok { color: var(--green); }
.sec-result.warn { color: var(--red); }

/* Content */
.content {
  padding: 26px 30px;
  overflow-y: auto;
}
.tool { max-width: 1000px; margin: 0 auto; }
.tool.hidden { display: none; }
.tool-head h1 { margin: 0 0 4px; font-size: 22px; }
.tool-desc { margin: 0 0 18px; color: var(--muted); font-size: 13.5px; }

/* Toolbar & buttons */
.toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}
.spacer { flex: 1; }
.btn {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--line);
  padding: 8px 14px;
  border-radius: 9px;
  cursor: pointer;
  font-size: 13.5px;
  font-family: inherit;
  transition: filter .12s, background .12s;
  user-select: none;
}
.btn:hover { filter: brightness(1.18); }
.btn.primary { background: var(--accent-2); border-color: var(--accent); color: #fff; }
.btn.danger { color: var(--red); }
.btn:focus-visible, .nav-btn:focus-visible, textarea:focus-visible, input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

/* Editors */
.editor {
  width: 100%;
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px;
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.6;
  resize: vertical;
  min-height: 340px;
}
.editor.half { min-height: 300px; }
.editor.short { min-height: 90px; }
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }

/* Notepad tabs */
.tabs {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
  margin-bottom: 10px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 6px;
}
.tab {
  background: var(--panel-2);
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 8px 8px 0 0;
  padding: 7px 14px;
  cursor: pointer;
  font-size: 13.5px;
  font-family: inherit;
  max-width: 180px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.tab:hover { color: var(--text); }
.tab.active { background: var(--accent-2); color: #fff; border-color: var(--accent); }
.tab-add { color: var(--accent); font-weight: 700; padding: 7px 12px; }

/* Notepad body / Markdown preview */
.np-body { display: block; }
.np-body.split-view { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.preview {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 6px 18px;
  min-height: 340px;
  overflow-y: auto;
}
.preview.hidden { display: none; }
.markdown-body h1, .markdown-body h2, .markdown-body h3 { border-bottom: 1px solid var(--line); padding-bottom: .2em; }
.markdown-body code { background: var(--panel-2); padding: 2px 5px; border-radius: 4px; font-family: var(--mono); font-size: .9em; }
.markdown-body pre { background: var(--panel-2); padding: 12px; border-radius: 8px; overflow-x: auto; }
.markdown-body pre code { background: none; padding: 0; }
.markdown-body blockquote { border-left: 3px solid var(--accent); margin-left: 0; padding-left: 14px; color: var(--muted); }
.markdown-body table { border-collapse: collapse; }
.markdown-body th, .markdown-body td { border: 1px solid var(--line); padding: 5px 10px; }
.markdown-body a { color: var(--accent); }
.markdown-body img { max-width: 100%; }

/* Share panel */
.share-panel {
  margin-top: 14px;
  background: var(--panel);
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  padding: 16px 18px;
}
.share-panel.hidden { display: none; }
.share-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 4px; }

/* Backup bar */
.backup-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px dashed var(--line);
}
.backup-label { color: var(--muted); font-size: 13px; }

/* Calendar */
.cal-toolbar { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 14px; }
.cal-title { font-size: 17px; min-width: 130px; text-align: center; }
.cal-weekdays, .cal-grid { display: grid; grid-template-columns: repeat(7, 1fr); gap: 6px; }
.cal-weekdays { margin-bottom: 6px; }
.cal-weekdays span { text-align: center; font-size: 12.5px; color: var(--muted); padding: 4px 0; }
.cal-weekdays .sun { color: var(--red); }
.cal-weekdays .sat { color: var(--accent); }
.cal-cell {
  position: relative;
  min-height: 74px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 6px;
  text-align: left;
  cursor: pointer;
  color: var(--text);
  font-family: inherit;
  transition: border-color .12s, background .12s;
}
.cal-cell:hover { border-color: var(--accent); }
.cal-cell.empty { background: transparent; border: none; cursor: default; }
.cal-cell.today { border-color: var(--accent); }
.cal-cell.selected { background: var(--accent-2); border-color: var(--accent); }
.cal-cell.selected .cal-num { color: #fff; }
.cal-num { font-size: 13.5px; font-weight: 600; }
.cal-cell.sun .cal-num { color: var(--red); }
.cal-cell.sat .cal-num { color: var(--accent); }
.cal-cell.selected.sun .cal-num, .cal-cell.selected.sat .cal-num { color: #fff; }
.cal-dot {
  position: absolute; bottom: 6px; right: 7px;
  background: var(--green); color: #06210f;
  min-width: 18px; height: 18px; border-radius: 9px;
  font-size: 11px; font-weight: 700;
  display: flex; align-items: center; justify-content: center; padding: 0 4px;
}
.cal-panel {
  margin-top: 18px; background: var(--panel);
  border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 18px;
}
.cal-panel h2 { font-size: 15px; margin: 0 0 10px; }
.cal-events { margin-bottom: 12px; }
.cal-event { display: flex; align-items: center; gap: 10px; padding: 7px 0; border-bottom: 1px solid var(--line); }
.cal-event-time { font-family: var(--mono); color: var(--accent); min-width: 54px; font-size: 13px; }
.cal-event-title { flex: 1; }
.cal-event-del { background: none; border: none; color: var(--muted); cursor: pointer; font-size: 14px; }
.cal-event-del:hover { color: var(--red); }
.cal-form { display: flex; gap: 8px; flex-wrap: wrap; }
.cal-form input[type="time"] { background: var(--panel-2); color: var(--text); border: 1px solid var(--line); border-radius: 8px; padding: 8px 10px; font-family: inherit; }
.cal-form input[type="text"] { flex: 1; min-width: 160px; background: var(--panel-2); color: var(--text); border: 1px solid var(--line); border-radius: 8px; padding: 8px 12px; font-family: inherit; }
.muted { color: var(--muted); }

/* Counters / status */
.counter, .status, .saved-badge {
  font-size: 12.5px;
  color: var(--muted);
}
.saved-badge {
  color: var(--green);
  opacity: 0;
  transition: opacity .3s;
}
.saved-badge.show { opacity: 1; }
.status.ok { color: var(--green); }
.status.err { color: var(--red); }

/* Fields */
.field-row {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 14px;
}
.field-row input[type="range"] { flex: 1; max-width: 420px; accent-color: var(--accent); }
.checks {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}
.checks label { display: flex; align-items: center; gap: 6px; cursor: pointer; }
.checks input { accent-color: var(--accent); }

.big-output {
  display: block;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
  font-family: var(--mono);
  font-size: 20px;
  word-break: break-all;
  min-height: 28px;
  margin: 6px 0 12px;
}
.meter { height: 8px; background: var(--panel-2); border-radius: 6px; overflow: hidden; }
.meter-bar { height: 100%; width: 0; background: var(--red); transition: width .2s, background .2s; }

/* Diff */
.diff-out {
  margin-top: 14px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 8px 0;
  font-family: var(--mono);
  font-size: 13.5px;
  overflow-x: auto;
}
.diff-line { padding: 1px 14px; white-space: pre-wrap; word-break: break-all; }
.diff-line.add { background: var(--green-bg); }
.diff-line.add::before { content: "+ "; color: var(--green); }
.diff-line.del { background: var(--red-bg); }
.diff-line.del::before { content: "- "; color: var(--red); }
.diff-line.same::before { content: "  "; color: var(--muted); }
.diff-line.same { color: var(--muted); }

/* QR */
.qr-canvas {
  margin-top: 14px;
  display: inline-block;
  padding: 16px;
  background: #fff;
  border-radius: var(--radius);
  min-width: 60px;
  min-height: 60px;
}
.qr-canvas:empty { display: none; }

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: #000;
  color: #fff;
  padding: 10px 18px;
  border-radius: 10px;
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s, transform .2s;
  font-size: 13.5px;
  z-index: 200;
}
.toast.show { opacity: .95; transform: translateX(-50%) translateY(0); }

/* Responsive */
@media (max-width: 780px) {
  .app { grid-template-columns: 1fr; }
  .sidebar {
    flex-direction: row;
    align-items: center;
    overflow-x: auto;
    padding: 10px;
  }
  #nav { flex-direction: row; flex-wrap: nowrap; }
  .nav-group, .side-foot, .brand-name { display: none; }
  .split { grid-template-columns: 1fr; }
  .content { padding: 18px 16px; }
}