:root {
  --bg: #f7f5ef;
  --bg-grad-a: #f5efe2;
  --bg-grad-b: #eaf6f4;
  --header-bg: #fffcf5;
  --nav-bg: #f5f0e4;
  --panel: #fffdfa;
  --line: #ddd6c6;
  --ink: #1f2a36;
  --ink-soft: #4a5a6b;
  --accent: #0f766e;
  --accent-soft: #d2f0ec;
  --shadow: rgba(0, 0, 0, 0.08);
}

body[data-theme="dark"] {
  --bg: #0f1720;
  --bg-grad-a: #131d29;
  --bg-grad-b: #0b1320;
  --header-bg: #141e2a;
  --nav-bg: #121a25;
  --panel: #17202a;
  --line: #2d3a47;
  --ink: #e8f0f7;
  --ink-soft: #afbfce;
  --accent: #4fd1c5;
  --accent-soft: #1d3b40;
  --shadow: rgba(0, 0, 0, 0.38);
}

* {
  box-sizing: border-box;
}

html,
body {
  min-height: 100%;
}

body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, sans-serif;
  color: var(--ink);
  background: linear-gradient(135deg, var(--bg-grad-a) 0%, var(--bg) 45%, var(--bg-grad-b) 100%);
}

header {
  padding: 1rem;
  border-bottom: 1px solid var(--line);
  background: var(--header-bg);
  position: sticky;
  top: 0;
  z-index: 2;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

header h1 {
  margin: 0;
  font-size: 1.1rem;
  letter-spacing: 0.01em;
}

#theme-toggle {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--panel);
  color: var(--ink);
  padding: 0.35rem 0.7rem;
  font-size: 0.85rem;
  cursor: pointer;
}

#theme-toggle:hover {
  border-color: var(--accent);
}

.layout {
  display: grid;
  grid-template-columns: minmax(200px, 300px) 1fr minmax(220px, 300px);
  height: calc(100vh - 57px);
  overflow: hidden;
}

nav {
  border-right: 1px solid var(--line);
  background: var(--nav-bg);
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

#file-list {
  display: grid;
  gap: 0.5rem;
  align-content: start;
  grid-auto-rows: max-content;
  flex: 1;
  min-height: 0;
  min-width: 0;
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-gutter: stable;
}

.search-wrap {
  display: grid;
  gap: 0.35rem;
  margin-bottom: 0.8rem;
}

.shuffle-btn {
  width: 100%;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 0.45rem;
  background: var(--panel);
  color: var(--ink);
  padding: 0.45rem 0.55rem;
  font-size: 0.86rem;
  cursor: pointer;
}

.shuffle-btn:hover {
  border-color: var(--accent);
}

.nav-actions {
  display: grid;
  gap: 0.5rem;
  margin: 0 0 0.8rem;
}

.search-label {
  font-size: 0.8rem;
  color: var(--ink-soft);
}

.search-input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 0.45rem;
  background: var(--panel);
  color: var(--ink);
  padding: 0.45rem 0.55rem;
  font-size: 0.92rem;
}

.search-input:focus {
  outline: 2px solid color-mix(in srgb, var(--accent) 50%, transparent);
  outline-offset: 1px;
}

.file-link {
  display: block;
  width: 100%;
  max-width: 100%;
  min-width: 0;
  margin-bottom: 0.5rem;
  padding: 0.6rem 0.7rem;
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  color: var(--ink-soft);
  text-decoration: none;
  background: var(--panel);
}

.file-title {
  display: block;
  font-weight: 600;
  color: var(--ink);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.file-path {
  display: block;
  font-size: 0.78rem;
  margin-top: 0.1rem;
  color: var(--ink-soft);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

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

.file-link.active {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--ink);
  font-weight: 600;
}

main {
  padding: 1.2rem;
  overflow: auto;
}

.backlinks-pane {
  border-left: 1px solid var(--line);
  background: var(--nav-bg);
  padding: 0.75rem;
  overflow: auto;
}

.backlinks-pane h3 {
  margin: 0 0 0.7rem;
  font-size: 0.92rem;
  color: var(--ink-soft);
}

.backlinks-list {
  display: grid;
  gap: 0.5rem;
}

.backlink-item {
  display: block;
  padding: 0.55rem 0.65rem;
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  background: var(--panel);
  text-decoration: none;
}

.backlink-item:hover {
  border-color: var(--accent);
}

.backlinks-empty {
  margin: 0;
  padding: 0.45rem 0.2rem;
  color: var(--ink-soft);
}

main h2 {
  margin-top: 0;
  font-size: 1.05rem;
  color: var(--ink-soft);
}

.toolbar {
  margin: 0 0 0.8rem;
}

.mode-link {
  display: inline-block;
  padding: 0.35rem 0.65rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--panel);
  color: var(--ink);
  text-decoration: none;
  font-size: 0.85rem;
}

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

.status {
  margin: 0 0 0.8rem;
  padding: 0.55rem 0.65rem;
  border: 1px solid var(--line);
  border-radius: 0.5rem;
  background: var(--panel);
}

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

.status-error {
  border-color: #c84a52;
}

.editor-form {
  display: grid;
  gap: 0.7rem;
}

.editor-box {
  width: 100%;
  min-height: 58vh;
  resize: vertical;
  padding: 0.8rem;
  border: 1px solid var(--line);
  border-radius: 0.75rem;
  background: var(--panel);
  color: var(--ink);
  font: 500 0.96rem/1.5 ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

.submit-btn {
  justify-self: start;
  border: 1px solid var(--accent);
  border-radius: 0.55rem;
  background: var(--accent);
  color: #ffffff;
  padding: 0.5rem 0.95rem;
  font-weight: 600;
  cursor: pointer;
}

.submit-btn:hover {
  filter: brightness(1.08);
}

.org-content {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 0.75rem;
  padding: 1rem;
  line-height: 1.5;
  box-shadow: 0 8px 20px var(--shadow);
}

.org-content h2,
.org-content h3,
.org-content h4,
.org-content h5,
.org-content h6 {
  margin: 1.1rem 0 0.4rem;
  color: var(--accent);
}

.org-content p {
  margin: 0.35rem 0;
}

.org-link {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.org-link:hover {
  filter: brightness(1.12);
}

.spacer {
  height: 0.5rem;
}

@media (max-width: 800px) {
  .layout {
    grid-template-columns: 1fr;
    height: auto;
    min-height: calc(100vh - 57px);
    overflow: visible;
  }

  nav {
    border-right: none;
    border-bottom: 1px solid var(--line);
    display: flex;
  }

  #file-list {
    max-height: calc((5 * 4.25rem) + (4 * 0.5rem));
    overflow-y: auto;
    overflow-x: hidden;
  }

  .backlinks-pane {
    border-left: none;
    border-top: 1px solid var(--line);
  }

  .file-link {
    margin-bottom: 0;
  }

  .editor-box {
    min-height: 48vh;
  }
}