/* ============================================
   Todo Desktop — FHD-optimized 3-pane layout
   ============================================ */

:root {
  /* palette */
  --bg-sidebar: #f7f7f5;
  --bg-main: #ffffff;
  --bg-detail: #fbfbf9;
  --bg-hover: #efefec;
  --bg-active: #e6eef8;
  --bg-quick-add: #f3f4f6;

  --border: #e5e5e2;
  --border-strong: #d4d4d0;

  --text-primary: #1f2024;
  --text-secondary: #6b6e76;
  --text-tertiary: #9aa0a6;
  --text-inverse: #ffffff;

  --accent: #1e6fff;
  --accent-hover: #155ee0;
  --accent-soft: #e6efff;

  --priority-1: #e0392c; /* high */
  --priority-2: #f59f0b; /* mid */
  --priority-3: #1e6fff; /* low */
  --priority-4: #c2c5cb; /* none */

  --danger: #d93b3b;
  --success: #1f9d55;

  /* metrics */
  --sidebar-w: 280px;
  --detail-w: 360px;
  --row-h: 44px;
  --radius: 8px;
  --radius-lg: 12px;
  --shadow-panel: 0 1px 0 rgba(0,0,0,0.04);
  --shadow-modal: 0 24px 64px rgba(15, 20, 40, 0.18);
  --transition: 140ms cubic-bezier(.2,.6,.2,1);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { margin: 0; padding: 0; height: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Pretendard",
    "Apple SD Gothic Neo", "Noto Sans KR", "Segoe UI", Roboto, sans-serif;
  font-size: 14px;
  line-height: 1.5;
  color: var(--text-primary);
  background: var(--bg-main);
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

button { font-family: inherit; cursor: pointer; }
input, textarea, select, button { font-family: inherit; font-size: inherit; color: inherit; }
input:focus, textarea:focus, select:focus { outline: none; }
ul { list-style: none; margin: 0; padding: 0; }
h1, h2, h3 { margin: 0; font-weight: 600; }

/* ============================================
   App shell — 3-column grid
   ============================================ */
.app {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr var(--detail-w);
  height: 100vh;
  min-width: 1280px;
  background: var(--bg-main);
  transition: grid-template-columns var(--transition);
}
.app:not(.has-detail) { grid-template-columns: var(--sidebar-w) 1fr 0; }
.app:not(.has-detail) .detail { display: none; }

/* ============================================
   SIDEBAR
   ============================================ */
.sidebar {
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  padding: 22px 14px 14px;
  overflow-y: auto;
}
.sidebar__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 10px 22px;
}
.sidebar__brand-mark {
  width: 26px; height: 26px;
  border-radius: 7px;
  background: var(--accent);
  color: white;
  display: grid; place-items: center;
  font-size: 14px; font-weight: 700;
}
.sidebar__brand-name {
  font-size: 16px; font-weight: 700; letter-spacing: -.02em;
}

.nav { flex: 1; }
.nav__section-title {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .05em;
  text-transform: uppercase;
  color: var(--text-tertiary);
  padding: 14px 10px 6px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.nav__section-title--with-action { padding-right: 4px; }
.nav__list { display: flex; flex-direction: column; gap: 1px; }
.nav__item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  border-radius: 6px;
  color: var(--text-primary);
  cursor: pointer;
  user-select: none;
  transition: background var(--transition);
  position: relative;
}
.nav__item:hover { background: var(--bg-hover); }
.nav__item--active { background: var(--bg-active); color: var(--accent); font-weight: 600; }
.nav__item__icon {
  width: 18px;
  display: inline-grid;
  place-items: center;
  font-size: 14px;
}
.nav__item__name { flex: 1; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.nav__item__count {
  font-size: 11px;
  color: var(--text-tertiary);
  background: transparent;
  min-width: 18px;
  text-align: right;
}
.nav__item--active .nav__item__count { color: var(--accent); }
.nav__item__dot {
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--priority-4);
  flex: 0 0 auto;
}
.nav__item__delete {
  opacity: 0;
  font-size: 12px;
  color: var(--text-tertiary);
  background: transparent;
  border: 0;
  padding: 2px 4px;
  border-radius: 4px;
  transition: opacity var(--transition);
}
.nav__item:hover .nav__item__delete { opacity: 1; }
.nav__item__delete:hover { background: rgba(0,0,0,.06); color: var(--danger); }

.sidebar__footer {
  display: flex;
  gap: 6px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}

/* ============================================
   MAIN
   ============================================ */
.main {
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow-y: auto;
  background: var(--bg-main);
}
.main__header {
  padding: 36px 56px 12px;
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  max-width: 1080px;
  width: 100%;
  margin: 0 auto;
}
.main__heading { display: flex; flex-direction: column; gap: 4px; }
.main__title {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -.02em;
}
.main__subtitle {
  font-size: 13px;
  color: var(--text-secondary);
}

.main__tools { display: flex; align-items: center; gap: 8px; }
.sort { display: flex; align-items: center; gap: 6px; }
.sort__label { font-size: 12px; color: var(--text-secondary); }
.sort__select {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 5px 8px;
  font-size: 13px;
  cursor: pointer;
  transition: border-color var(--transition);
}
.sort__select:hover { border-color: var(--border-strong); }

/* Quick add */
.quick-add {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  margin: 8px auto 16px;
  background: var(--bg-quick-add);
  border: 1px solid transparent;
  border-radius: var(--radius-lg);
  max-width: 1080px;
  width: calc(100% - 112px);
  transition: border-color var(--transition), background var(--transition);
}
.quick-add:focus-within {
  border-color: var(--accent);
  background: #ffffff;
  box-shadow: 0 0 0 4px rgba(30, 111, 255, 0.12);
}
.quick-add__plus {
  font-size: 18px;
  color: var(--text-tertiary);
  width: 20px; text-align: center;
}
.quick-add__input {
  flex: 1;
  background: transparent;
  border: 0;
  font-size: 15px;
  padding: 2px 0;
}
.quick-add__input::placeholder { color: var(--text-tertiary); }
.quick-add__hint {
  font-size: 11px;
  color: var(--text-tertiary);
  background: rgba(0,0,0,0.05);
  padding: 2px 8px;
  border-radius: 4px;
  font-family: ui-monospace, "SF Mono", Menlo, monospace;
}
.quick-add--shake { animation: shake .35s ease; border-color: var(--danger) !important; }
@keyframes shake {
  10%,90% { transform: translateX(-1px); }
  20%,80% { transform: translateX(2px); }
  30%,50%,70% { transform: translateX(-4px); }
  40%,60% { transform: translateX(4px); }
}

/* Task list */
.tasks {
  max-width: 1080px;
  width: calc(100% - 112px);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
}
.tasks--completed { margin-top: 4px; opacity: .92; }

.task {
  display: grid;
  grid-template-columns: 22px 1fr auto;
  align-items: center;
  gap: 12px;
  padding: 10px 8px;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  position: relative;
  transition: background var(--transition);
}
.task:hover { background: #fafafa; }
.task--selected { background: var(--accent-soft) !important; }
.task--selected::before {
  content: "";
  position: absolute;
  left: -8px; top: 0; bottom: 0;
  width: 3px;
  background: var(--accent);
  border-radius: 2px;
}

.task__check {
  width: 20px; height: 20px;
  border: 1.6px solid var(--border-strong);
  border-radius: 50%;
  background: transparent;
  display: grid; place-items: center;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
  padding: 0;
}
.task__check:hover { border-color: var(--accent); }
.task__check[data-priority="1"] { border-color: var(--priority-1); }
.task__check[data-priority="2"] { border-color: var(--priority-2); }
.task__check[data-priority="3"] { border-color: var(--priority-3); }
.task--done .task__check {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
  font-size: 12px;
}

.task__body { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.task__title {
  font-size: 14.5px;
  line-height: 1.4;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.task--done .task__title {
  color: var(--text-tertiary);
  text-decoration: line-through;
}
.task__meta {
  display: flex;
  gap: 10px;
  font-size: 12px;
  color: var(--text-secondary);
  align-items: center;
}
.task__meta-item { display: inline-flex; align-items: center; gap: 4px; }
.task__meta-item--overdue { color: var(--danger); font-weight: 600; }
.task__list-dot {
  width: 8px; height: 8px; border-radius: 50%;
  display: inline-block;
}

.task__right { display: flex; align-items: center; gap: 8px; }
.task__priority-flag {
  font-size: 12px;
  padding: 2px 6px;
  border-radius: 4px;
  font-weight: 600;
}
.task__priority-flag[data-priority="1"] { color: var(--priority-1); background: #fde9e7; }
.task__priority-flag[data-priority="2"] { color: var(--priority-2); background: #fff3e0; }
.task__priority-flag[data-priority="3"] { color: var(--priority-3); background: var(--accent-soft); }
.task__priority-flag[data-priority="4"] { display: none; }

/* Completed toggle */
.completed-wrap {
  max-width: 1080px;
  width: calc(100% - 112px);
  margin: 24px auto 0;
}
.completed-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  border: 0;
  padding: 6px 8px;
  color: var(--text-secondary);
  font-size: 13px;
  font-weight: 600;
  border-radius: 6px;
}
.completed-toggle:hover { background: var(--bg-hover); }
.completed-toggle__chev { transition: transform var(--transition); display: inline-block; }
.completed-toggle[aria-expanded="true"] .completed-toggle__chev { transform: rotate(90deg); }
.completed-toggle__count {
  background: rgba(0,0,0,0.06);
  border-radius: 10px;
  padding: 1px 8px;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-secondary);
}

/* Empty state */
.empty {
  max-width: 480px;
  margin: 80px auto;
  text-align: center;
  color: var(--text-secondary);
}
.empty__icon { font-size: 42px; margin-bottom: 12px; }
.empty__title { font-size: 16px; font-weight: 600; color: var(--text-primary); margin-bottom: 4px; }
.empty__desc { font-size: 13px; }

/* ============================================
   DETAIL PANEL
   ============================================ */
.detail {
  background: var(--bg-detail);
  border-left: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}
.detail__header {
  padding: 14px 18px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border);
}
.detail__breadcrumb {
  font-size: 12px;
  color: var(--text-secondary);
  font-weight: 600;
  letter-spacing: .03em;
  text-transform: uppercase;
}
.detail__body {
  padding: 20px 22px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  flex: 1;
}
.detail__field { display: flex; flex-direction: column; gap: 6px; }
.detail__field--half { flex: 1; }
.detail__row { display: flex; gap: 12px; }
.detail__label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-secondary);
  letter-spacing: .04em;
  text-transform: uppercase;
}
.detail__title-input {
  font-size: 18px;
  font-weight: 600;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 6px;
  padding: 8px 10px;
  margin-left: -10px;
  transition: border-color var(--transition), background var(--transition);
}
.detail__title-input:hover, .detail__title-input:focus { background: white; border-color: var(--border); }
.detail__notes {
  background: white;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 10px 12px;
  font-size: 13.5px;
  line-height: 1.55;
  resize: vertical;
  min-height: 120px;
  transition: border-color var(--transition);
}
.detail__notes:focus { border-color: var(--accent); }
.detail__input {
  background: white;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 7px 10px;
  font-size: 13px;
  transition: border-color var(--transition);
}
.detail__input:focus { border-color: var(--accent); }

.detail__meta {
  font-size: 12px;
  color: var(--text-tertiary);
  padding: 8px 0 0;
  border-top: 1px dashed var(--border);
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.detail__footer {
  padding: 14px 22px;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 8px;
  justify-content: space-between;
}

/* ============================================
   Buttons
   ============================================ */
.icon-btn {
  width: 26px; height: 26px;
  border: 0;
  background: transparent;
  border-radius: 6px;
  color: var(--text-secondary);
  display: grid; place-items: center;
  font-size: 14px;
  transition: background var(--transition), color var(--transition);
}
.icon-btn:hover { background: var(--bg-hover); color: var(--text-primary); }

.ghost-btn {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 12px;
  font-size: 12px;
  color: var(--text-secondary);
  transition: all var(--transition);
}
.ghost-btn:hover { border-color: var(--border-strong); color: var(--text-primary); background: white; }

.primary-btn {
  background: var(--accent);
  color: white;
  border: 0;
  border-radius: 6px;
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 600;
  transition: background var(--transition);
}
.primary-btn:hover { background: var(--accent-hover); }

.danger-btn {
  background: transparent;
  color: var(--danger);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 7px 14px;
  font-size: 13px;
  transition: all var(--transition);
}
.danger-btn:hover { background: #fdeceb; border-color: var(--danger); }

/* ============================================
   Toast
   ============================================ */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(20, 24, 32, .94);
  color: white;
  padding: 10px 18px;
  border-radius: 8px;
  font-size: 13px;
  box-shadow: 0 8px 24px rgba(0,0,0,.18);
  z-index: 1000;
  animation: toast-in .25s ease;
}
.toast--error { background: var(--danger); }
@keyframes toast-in {
  from { opacity: 0; transform: translate(-50%, 10px); }
  to { opacity: 1; transform: translate(-50%, 0); }
}

/* ============================================
   Modal
   ============================================ */
.modal {
  position: fixed; inset: 0;
  z-index: 999;
  display: grid;
  place-items: center;
}
.modal__backdrop {
  position: absolute; inset: 0;
  background: rgba(20, 24, 32, .35);
  animation: fade .15s ease;
}
.modal__panel {
  position: relative;
  background: white;
  border-radius: 12px;
  width: 420px;
  padding: 22px 24px;
  box-shadow: var(--shadow-modal);
  display: flex;
  flex-direction: column;
  gap: 16px;
  animation: pop .18s cubic-bezier(.2,.7,.2,1.2);
}
.modal__panel--sm { width: 360px; }
.modal__title { font-size: 16px; font-weight: 700; }
.modal__desc { color: var(--text-secondary); font-size: 13.5px; margin: 0; }
.modal__actions { display: flex; gap: 8px; justify-content: flex-end; margin-top: 4px; }
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }
@keyframes pop {
  from { opacity: 0; transform: scale(.96); }
  to { opacity: 1; transform: scale(1); }
}

.color-picker { display: flex; gap: 8px; flex-wrap: wrap; }
.color-swatch {
  width: 26px; height: 26px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform var(--transition), border-color var(--transition);
}
.color-swatch:hover { transform: scale(1.1); }
.color-swatch--selected { border-color: var(--text-primary); }

/* ============================================
   Scrollbar polish
   ============================================ */
*::-webkit-scrollbar { width: 10px; height: 10px; }
*::-webkit-scrollbar-track { background: transparent; }
*::-webkit-scrollbar-thumb { background: rgba(0,0,0,.12); border-radius: 8px; border: 2px solid transparent; background-clip: padding-box; }
*::-webkit-scrollbar-thumb:hover { background: rgba(0,0,0,.22); border: 2px solid transparent; background-clip: padding-box; }

/* ============================================
   FHD optimization (1920x1080+)
   ============================================ */
@media (min-width: 1600px) {
  :root {
    --sidebar-w: 300px;
    --detail-w: 380px;
  }
  .main__header, .quick-add, .tasks, .completed-wrap { max-width: 1180px; }
}
@media (min-width: 1900px) {
  :root {
    --sidebar-w: 320px;
    --detail-w: 400px;
  }
}