:root {
  --bg: #faf9f6;
  --panel: #ffffff;
  --border: #e3e0d8;
  --ink: #2b2925;
  --ink-soft: #6b6760;
  --accent: #8a6a4f;
  --accent-soft: #f1e8df;
  --danger: #b5483f;
  --sidebar-w: 260px;
  --radius: 8px;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Noto Sans TC", -apple-system, sans-serif;
  background: var(--bg);
  color: var(--ink);
  font-size: 15px;
}

button {
  font-family: inherit;
  font-size: 14px;
  cursor: pointer;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--ink);
  padding: 8px 12px;
  min-height: 38px;
}
button:hover { background: var(--accent-soft); }
button.primary { background: var(--accent); color: #fff; border-color: var(--accent); }
button.primary:hover { opacity: 0.9; }
button.danger { color: var(--danger); border-color: var(--danger); }
button.icon { min-width: 38px; padding: 8px; }

input, textarea {
  font-family: inherit;
  font-size: 16px; /* 避免 iOS 自動放大畫面 */
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--panel);
  color: var(--ink);
  width: 100%;
}
input:focus, textarea:focus, button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

/* ---------- 登入畫面 ---------- */
#login-screen {
  max-width: 380px;
  margin: 80px auto;
  padding: 32px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
#login-screen h1 { font-size: 20px; margin-top: 0; }
#login-screen .field { margin-bottom: 12px; }
#login-screen .error { color: var(--danger); font-size: 13px; min-height: 18px; margin-top: 4px; }
#totp-step { display: none; margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--border); }

/* ---------- 主畫面 ---------- */
#main-screen {
  display: none;
  height: 100vh;
}
#main-screen.active { display: flex; }

#sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  background: var(--panel);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}
#page-tree { flex: 1; padding: 12px 8px; }
.page-tree-node { margin-bottom: 2px; }
.page-tree-row {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 6px 8px;
  border-radius: 6px;
  cursor: pointer;
}
.page-tree-row:hover { background: var(--accent-soft); }
.page-tree-row.selected { background: var(--accent-soft); font-weight: 600; }
.page-tree-toggle { width: 16px; text-align: center; color: var(--ink-soft); font-size: 12px; }
.page-tree-title { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.page-tree-children { margin-left: 16px; display: none; }
.page-tree-children.expanded { display: block; }

#sidebar-footer {
  border-top: 1px solid var(--border);
  padding: 12px;
}

main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

#page-header {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px 24px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
  position: sticky;
  top: 0;
  z-index: 5;
}
#page-title-input {
  font-size: 22px;
  font-weight: 700;
  border: none;
  flex: 1;
  background: transparent;
  padding: 4px 0;
}
#page-title-input:focus { outline: none; border-bottom: 2px solid var(--accent); }

#presence-list { font-size: 13px; color: var(--ink-soft); white-space: nowrap; }
.presence-dot { color: #4caf50; }

#reload-banner {
  display: none;
  align-items: center;
  gap: 12px;
  background: var(--accent-soft);
  color: var(--ink);
  padding: 10px 24px;
  font-size: 14px;
}
#reload-banner.visible { display: flex; }

#editor-wrapper { flex: 1; padding: 24px; max-width: 760px; width: 100%; margin: 0 auto; }
#empty-state { padding: 60px 24px; text-align: center; color: var(--ink-soft); }

.codex-editor { font-family: "Noto Sans TC", -apple-system, sans-serif; }

/* ---------- 響應式 ---------- */
@media (max-width: 768px) {
  #main-screen.active { flex-direction: column; }
  #sidebar { width: 100%; height: 40vh; border-right: none; border-bottom: 1px solid var(--border); }
  #editor-wrapper { padding: 16px; }
}
@media (max-width: 480px) {
  #page-header { padding: 12px 16px; }
  #page-title-input { font-size: 18px; }
}