/* ============ Design tokens ============ */
:root {
  --bg: #f8fafc;
  --bg-elev: #ffffff;
  --bg-hover: #f1f5f9;
  --bg-active: #e2e8f0;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --text: #0f172a;
  --text-muted: #64748b;
  --text-subtle: #94a3b8;

  --primary: #7c3aed;
  --primary-fg: #ffffff;
  --primary-soft: #f3e8ff;

  --success: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;
  --info: #0ea5e9;

  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow: 0 1px 3px rgba(15, 23, 42, 0.06), 0 8px 24px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 8px 32px rgba(15, 23, 42, 0.10);

  --radius: 10px;
  --radius-lg: 14px;
  --radius-sm: 6px;

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;

  --nav-h: 56px;
  --sidebar-w: 260px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0f17;
    --bg-elev: #121826;
    --bg-hover: #1a2233;
    --bg-active: #232d42;
    --border: #1f2937;
    --border-strong: #334155;
    --text: #e5e7eb;
    --text-muted: #94a3b8;
    --text-subtle: #64748b;
    --primary: #a78bfa;
    --primary-fg: #0b0f17;
    --primary-soft: #2a1e4a;
    --shadow: 0 1px 3px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.2);
    --shadow-lg: 0 8px 32px rgba(0,0,0,.4);
  }
}

/* ============ Reset ============ */
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; height: 100%; }
body {
  font-family: var(--font);
  font-size: 14px;
  line-height: 1.5;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: 5px; }
::-webkit-scrollbar-track { background: transparent; }

/* ============ Icons (inline svg helpers) ============ */
.icon { width: 16px; height: 16px; flex: 0 0 auto; stroke: currentColor; fill: none; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.icon-sm { width: 14px; height: 14px; }
.icon-lg { width: 20px; height: 20px; }

/* ============ Buttons ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 14px;
  border: 1px solid var(--border);
  background: var(--bg-elev);
  color: var(--text);
  border-radius: var(--radius);
  font-weight: 500;
  transition: background 120ms, border-color 120ms, transform 60ms;
  white-space: nowrap;
}
.btn:hover { background: var(--bg-hover); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn-primary { background: var(--primary); color: var(--primary-fg); border-color: transparent; }
.btn-primary:hover { filter: brightness(1.08); background: var(--primary); }
.btn-ghost { background: transparent; border-color: transparent; color: var(--text-muted); }
.btn-ghost:hover { background: var(--bg-hover); color: var(--text); }
.btn-danger { color: var(--danger); border-color: color-mix(in srgb, var(--danger) 30%, transparent); }
.btn-danger:hover { background: color-mix(in srgb, var(--danger) 10%, transparent); }
.btn-icon { padding: 6px; width: 30px; height: 30px; border-radius: var(--radius-sm); }
.btn-sm { padding: 4px 10px; font-size: 12px; }

/* ============ Inputs ============ */
.input, .select, .textarea {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border);
  background: var(--bg-elev);
  border-radius: var(--radius);
  transition: border-color 120ms, box-shadow 120ms;
  color: var(--text);
}
.input:focus, .select:focus, .textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 20%, transparent);
}
.textarea { resize: vertical; min-height: 60px; }

/* ============ Layout ============ */
.app {
  display: grid;
  grid-template-columns: var(--sidebar-w) 1fr;
  grid-template-rows: var(--nav-h) 1fr;
  grid-template-areas: "nav nav" "sidebar main";
  height: 100vh;
}
.topnav {
  grid-area: nav;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  background: var(--bg-elev);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
  z-index: 10;
}
.topnav .brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 16px;
}
.brand-logo {
  width: 30px; height: 30px; border-radius: 8px;
  background: linear-gradient(135deg, var(--primary), #ec4899);
  display: grid; place-items: center;
  color: white; font-weight: 700;
}
.topnav .actions { display: flex; align-items: center; gap: 8px; }

.sidebar {
  grid-area: sidebar;
  background: var(--bg-elev);
  border-right: 1px solid var(--border);
  padding: 16px 12px;
  overflow-y: auto;
}
.sidebar-section-title {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-subtle);
  padding: 8px 12px;
  margin-top: 8px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.sidebar-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  color: var(--text-muted);
  border: 1px solid transparent;
  transition: background 100ms, color 100ms;
  user-select: none;
}
.sidebar-item:hover { background: var(--bg-hover); color: var(--text); }
.sidebar-item.active {
  background: var(--primary-soft);
  color: var(--primary);
  font-weight: 500;
}
.sidebar-item .icon { color: currentColor; }
.sidebar-item .count {
  margin-left: auto;
  background: var(--bg-hover);
  padding: 1px 8px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
}
.sidebar-item.active .count { background: color-mix(in srgb, var(--primary) 25%, transparent); color: var(--primary); }
.project-swatch { width: 22px; height: 22px; border-radius: 6px; display: grid; place-items: center; font-size: 13px; flex: 0 0 auto; }

.main {
  grid-area: main;
  overflow-y: auto;
  padding: 24px 32px 60px;
}
.main-inner { max-width: 900px; margin: 0 auto; }
.page-head {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 20px; gap: 20px; flex-wrap: wrap;
}
.page-head h2 { margin: 0; font-size: 22px; font-weight: 700; }
.page-head .subtitle { color: var(--text-muted); font-size: 13px; margin-top: 2px; }

/* ============ Filter tabs ============ */
.tabs {
  display: flex; gap: 4px;
  background: var(--bg-hover);
  padding: 4px;
  border-radius: 10px;
}
.tabs .tab {
  padding: 6px 12px;
  border-radius: 7px;
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 500;
  border: none; background: transparent;
  transition: background 120ms, color 120ms;
}
.tabs .tab:hover { color: var(--text); }
.tabs .tab.active { background: var(--bg-elev); color: var(--text); box-shadow: var(--shadow-sm); }

/* ============ New task inline ============ */
.new-task {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 12px;
  box-shadow: var(--shadow);
  margin-bottom: 20px;
  transition: border-color 120ms, box-shadow 120ms;
}
.new-task:focus-within {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--primary) 15%, transparent);
}
.new-task .row { display: flex; align-items: center; gap: 8px; }
.new-task .input-title {
  flex: 1;
  border: none;
  padding: 6px 4px;
  background: transparent;
  font-size: 15px;
}
.new-task .input-title:focus { outline: none; }
.new-task .extras {
  display: flex; gap: 6px; align-items: center; flex-wrap: wrap;
  padding-top: 8px; margin-top: 8px;
  border-top: 1px dashed var(--border);
}
.new-task .extras.hidden { display: none; }
.chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 4px 10px;
  border-radius: 999px;
  background: var(--bg-hover);
  border: 1px solid transparent;
  font-size: 12px;
  color: var(--text-muted);
  cursor: pointer;
}
.chip:hover { background: var(--bg-active); }
.chip.active { background: var(--primary-soft); color: var(--primary); border-color: color-mix(in srgb, var(--primary) 25%, transparent); }
.chip input, .chip select { border: none; background: transparent; padding: 0; margin: 0; color: inherit; font-size: 12px; width: auto; }
.chip input[type=date] { min-width: 130px; }

/* ============ Task groups ============ */
.task-group { margin-bottom: 24px; }
.task-group-head {
  display: flex; align-items: center; gap: 8px;
  padding: 4px 8px 8px;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}
.task-group-head .count { color: var(--text-subtle); font-weight: 500; }
.task-group.overdue .task-group-head { color: var(--danger); }
.task-group.today .task-group-head { color: var(--primary); }

.task-list { display: flex; flex-direction: column; gap: 6px; }
.task {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 10px;
  align-items: center;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 12px;
  transition: background 120ms, border-color 120ms, transform 100ms;
  animation: fadeIn 180ms ease-out;
}
.task:hover { background: var(--bg-hover); border-color: var(--border-strong); }
.task.done { opacity: 0.6; }
.task.done .title { text-decoration: line-through; color: var(--text-muted); }
.task .checkbox {
  --check-color: var(--text-subtle);
  width: 20px; height: 20px; border-radius: 50%;
  border: 2px solid var(--check-color);
  background: transparent;
  cursor: pointer;
  padding: 0;
  display: grid; place-items: center;
  transition: background 120ms, border-color 120ms;
  flex: 0 0 auto;
}
.task .checkbox:hover { --check-color: var(--primary); }
.task[data-priority="2"] .checkbox { --check-color: var(--danger); }
.task[data-priority="1"] .checkbox { --check-color: var(--warning); }
.task .checkbox svg { width: 12px; height: 12px; stroke: currentColor; opacity: 0; transition: opacity 120ms; color: white; }
.task.done .checkbox { background: var(--success); border-color: var(--success); }
.task.done .checkbox svg { opacity: 1; }

.task .body { min-width: 0; }
.task .title-row { display: flex; align-items: center; gap: 8px; }
.task .title { font-weight: 500; word-wrap: break-word; overflow-wrap: anywhere; }
.task .badges { display: flex; gap: 6px; flex-wrap: wrap; margin-top: 4px; align-items: center; }
.task .badge {
  display: inline-flex; align-items: center; gap: 4px;
  font-size: 11px; padding: 2px 8px;
  background: var(--bg-hover);
  border-radius: 999px;
  color: var(--text-muted);
}
.task .badge-due.overdue { background: color-mix(in srgb, var(--danger) 15%, transparent); color: var(--danger); font-weight: 600; }
.task .badge-due.today { background: color-mix(in srgb, var(--primary) 15%, transparent); color: var(--primary); font-weight: 600; }
.task .badge-project { background: color-mix(in srgb, var(--proj-color, var(--primary)) 15%, transparent); color: var(--proj-color, var(--primary)); }
.task .note-preview { color: var(--text-muted); font-size: 12px; margin-top: 3px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

.task .actions {
  display: flex; gap: 2px;
  opacity: 0;
  transition: opacity 120ms;
}
.task:hover .actions, .task .actions:focus-within { opacity: 1; }

/* ============ Avatar ============ */
.avatar {
  width: 24px; height: 24px;
  border-radius: 50%;
  display: grid; place-items: center;
  color: white;
  font-weight: 600;
  font-size: 11px;
  flex: 0 0 auto;
  user-select: none;
}
.avatar.lg { width: 32px; height: 32px; font-size: 13px; }
.avatar.xl { width: 40px; height: 40px; font-size: 15px; }

/* ============ Empty state ============ */
.empty {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-muted);
}
.empty .emoji { font-size: 48px; margin-bottom: 12px; }
.empty h3 { margin: 0 0 6px; font-weight: 600; }

/* ============ Dialog / modal ============ */
.dialog {
  border: none;
  background: var(--bg-elev);
  color: var(--text);
  border-radius: var(--radius-lg);
  padding: 0;
  max-width: 92vw;
  width: 520px;
  max-height: 92vh;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}
.dialog::backdrop { background: rgba(2, 6, 23, 0.55); backdrop-filter: blur(4px); }
.dialog-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border);
}
.dialog-head h3 { margin: 0; font-size: 16px; font-weight: 600; }
.dialog-body { padding: 20px; display: flex; flex-direction: column; gap: 12px; overflow-y: auto; max-height: 65vh; }
.dialog-foot { display: flex; justify-content: flex-end; gap: 8px; padding: 12px 20px; border-top: 1px solid var(--border); background: var(--bg); }
.dialog-body label { display: flex; flex-direction: column; gap: 4px; font-size: 12px; color: var(--text-muted); font-weight: 500; }
.dialog-body label > input, .dialog-body label > select, .dialog-body label > textarea { color: var(--text); }
.dialog-body .row { display: flex; gap: 10px; }
.dialog-body .row > * { flex: 1; }

/* ============ Login ============ */
.login-page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 20px;
  background:
    radial-gradient(1200px 600px at 10% -10%, color-mix(in srgb, var(--primary) 15%, transparent), transparent 60%),
    radial-gradient(800px 400px at 90% 100%, color-mix(in srgb, #ec4899 15%, transparent), transparent 60%),
    var(--bg);
}
.login-card {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 32px;
  width: 100%;
  max-width: 380px;
  box-shadow: var(--shadow-lg);
}
.login-card h1 { margin: 0 0 4px; font-size: 22px; }
.login-card .sub { color: var(--text-muted); margin-bottom: 24px; font-size: 13px; }
.login-card .brand-logo { margin-bottom: 16px; width: 48px; height: 48px; font-size: 22px; }
.login-card form { display: flex; flex-direction: column; gap: 12px; }
.login-card .error { color: var(--danger); font-size: 13px; padding: 8px 12px; background: color-mix(in srgb, var(--danger) 10%, transparent); border-radius: var(--radius); }

/* ============ Share page ============ */
.share-page {
  min-height: 100vh;
  padding: 40px 20px;
  background: var(--bg);
}
.share-card {
  max-width: 640px; margin: 0 auto;
  background: var(--bg-elev); border: 1px solid var(--border);
  border-radius: var(--radius-lg); overflow: hidden;
  box-shadow: var(--shadow);
}
.share-head { padding: 20px 24px; border-bottom: 1px solid var(--border); background: linear-gradient(135deg, color-mix(in srgb, var(--primary) 6%, transparent), transparent); }
.share-head .from { color: var(--text-muted); font-size: 13px; margin-bottom: 4px; }
.share-head h1 { margin: 0; font-size: 22px; }
.share-body { padding: 20px 24px; display: flex; flex-direction: column; gap: 14px; }
.share-body .meta { display: flex; gap: 16px; flex-wrap: wrap; color: var(--text-muted); font-size: 13px; }
.share-body .note {
  padding: 12px; background: var(--bg); border-radius: var(--radius);
  white-space: pre-wrap; color: var(--text);
}
.share-body .note:empty { display: none; }
.share-actions { display: flex; gap: 8px; align-items: center; padding: 16px 24px; border-top: 1px solid var(--border); }
.share-events { padding: 0 24px 24px; }
.share-events h4 { color: var(--text-muted); font-size: 12px; text-transform: uppercase; letter-spacing: .06em; margin: 20px 0 8px; }
.event { display: flex; gap: 10px; padding: 10px 0; border-top: 1px dashed var(--border); font-size: 13px; }
.event:first-of-type { border-top: none; }
.event .who { font-weight: 600; }
.event .when { color: var(--text-subtle); font-size: 11px; }
.event .body { color: var(--text-muted); white-space: pre-wrap; }

/* ============ Toast ============ */
.toast-container {
  position: fixed; right: 20px; bottom: 20px; z-index: 1000;
  display: flex; flex-direction: column; gap: 8px; pointer-events: none;
}
.toast {
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 10px 14px; box-shadow: var(--shadow-lg);
  animation: slideIn 200ms ease-out;
  pointer-events: auto;
  max-width: 320px;
  font-size: 13px;
}
.toast.success { border-color: var(--success); color: var(--success); }
.toast.error { border-color: var(--danger); color: var(--danger); }

/* ============ Menu ============ */
.menu {
  position: absolute;
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  padding: 4px;
  min-width: 180px;
  z-index: 100;
  animation: fadeIn 120ms ease-out;
}
.menu-item {
  display: flex; align-items: center; gap: 8px;
  width: 100%; text-align: left;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  border: none; background: transparent;
  color: var(--text); font-size: 13px;
}
.menu-item:hover { background: var(--bg-hover); }
.menu-item.danger { color: var(--danger); }
.menu-item.danger:hover { background: color-mix(in srgb, var(--danger) 10%, transparent); }
.menu-sep { height: 1px; background: var(--border); margin: 4px 0; }

/* ============ Animations ============ */
@keyframes fadeIn { from { opacity: 0; transform: translateY(-2px); } to { opacity: 1; transform: none; } }
@keyframes slideIn { from { opacity: 0; transform: translateX(8px); } to { opacity: 1; transform: none; } }
@keyframes spin { to { transform: rotate(360deg); } }
.spinner { width: 16px; height: 16px; border: 2px solid var(--border); border-top-color: var(--primary); border-radius: 50%; animation: spin 700ms linear infinite; }

/* ============ Responsive ============ */
@media (max-width: 780px) {
  .app { grid-template-columns: 1fr; grid-template-areas: "nav" "main"; }
  .sidebar {
    position: fixed; top: var(--nav-h); left: 0; bottom: 0; width: 84%; max-width: 300px;
    transform: translateX(-100%); transition: transform 200ms;
    z-index: 20;
  }
  .sidebar.open { transform: none; }
  .sidebar-backdrop { display: none; position: fixed; inset: var(--nav-h) 0 0 0; background: rgba(0,0,0,.3); z-index: 15; }
  .sidebar-backdrop.open { display: block; }
  .main { padding: 16px; }
  .page-head { flex-direction: column; align-items: stretch; }
  .btn-toggle-sidebar { display: inline-flex; }
}
@media (min-width: 781px) {
  .btn-toggle-sidebar { display: none; }
}

/* ============ Share dialog ============ */
.share-link-box {
  display: flex; gap: 6px;
  padding: 8px; background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius);
  align-items: center;
}
.share-link-box input {
  flex: 1; border: none; background: transparent; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 12px;
  color: var(--text);
}
.share-link-box input:focus { outline: none; }
.share-list { display: flex; flex-direction: column; gap: 6px; }
.share-row {
  display: grid; grid-template-columns: 1fr auto auto; gap: 8px; align-items: center;
  padding: 8px 10px; background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius);
  font-size: 13px;
}
.share-row .link { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 11px; color: var(--text-muted); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.share-row .meta { font-size: 11px; color: var(--text-subtle); }