/* Reset & Base */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --blue: #0078d7;
  --blue-hover: #005a9e;
  --blue-light: #eef6fd;
  --bg: #f5f5f5;
  --sidebar-bg: #fafafa;
  --sidebar-hover: #ececec;
  --sidebar-active: #e4f0fb;
  --border: #e2e2e2;
  --text: #333;
  --text-secondary: #555;
  --text-light: #999;
  --danger: #d13438;
  --danger-hover: #a02225;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);
  --radius: 6px;
  --transition: 0.15s ease;
}
html, body {
  height: 100%;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
}
.hidden { display: none !important; }
button { font-family: inherit; }

/* Auth Screen */
.auth-screen {
  position: fixed; inset: 0;
  display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #0078d7 0%, #00a4ef 100%);
  padding: 20px;
}
.auth-card {
  background: #fff;
  border-radius: 12px;
  padding: 40px;
  width: 100%;
  max-width: 420px;
  box-shadow: 0 10px 40px rgba(0,0,0,0.15);
  text-align: center;
}
.auth-logo { color: var(--blue); margin-bottom: 10px; }
.auth-card h1 { font-size: 22px; font-weight: 600; margin-bottom: 24px; color: var(--text); }
.auth-form { display: flex; flex-direction: column; gap: 12px; }
.auth-form input[type="password"] {
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 14px;
  outline: none;
  transition: border var(--transition);
}
.auth-form input:focus { border-color: var(--blue); }
.btn-primary, .btn-secondary {
  padding: 10px 16px;
  border: none;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition), opacity var(--transition);
}
.btn-primary { background: var(--blue); color: #fff; }
.btn-primary:hover { background: var(--blue-hover); }
.btn-secondary { background: #f0f0f0; color: var(--text); }
.btn-secondary:hover { background: #e0e0e0; }
.auth-hint { font-size: 12px; color: var(--text-light); margin-top: 4px; }
.auth-card .hidden { display: none !important; }
#auth-screen.error .auth-card { animation: shake 0.4s ease; }
@keyframes shake {
  0%,100% { transform: translateX(0); }
  25% { transform: translateX(-8px); }
  75% { transform: translateX(8px); }
}

/* App Layout */
.app { display: flex; height: 100vh; flex-direction: column; }
.topbar {
  height: 48px;
  background: #fff;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 14px;
  gap: 12px;
  flex-shrink: 0;
}
.topbar-left {
  display: flex; align-items: center; gap: 16px; flex: 1; min-width: 0;
}
.brand {
  display: inline-flex; align-items: center; gap: 8px;
  color: var(--blue); font-weight: 700; font-size: 15px; white-space: nowrap;
}
.search-wrap {
  position: relative;
  max-width: 420px; width: 100%;
}
.search-icon { position: absolute; left: 10px; top: 50%; transform: translateY(-50%); color: #aaa; pointer-events: none; }
#search-input {
  width: 100%;
  padding: 7px 10px 7px 32px;
  border: 1px solid var(--border);
  border-radius: 999px;
  outline: none;
  background: #f7f7f7;
  font-size: 13px;
}
#search-input:focus { border-color: var(--blue); background: #fff; }
.topbar-actions { display: flex; align-items: center; gap: 8px; }
.toolbar-btn { height: 34px; padding: 0 12px; }
.toolbar-select {
  height: 30px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0 8px;
  background: #fff;
  font-size: 13px;
}

.workspace { display: flex; flex: 1; overflow: hidden; }

/* Button helpers */
.btn { border: none; border-radius: var(--radius); font-size: 13px; font-weight: 600; cursor: pointer; transition: background var(--transition), opacity var(--transition); }
.btn.primary { background: var(--blue); color: #fff; padding: 8px 14px; }
.btn.primary:hover { background: var(--blue-hover); }
.btn.secondary { background: #f0f0f0; color: var(--text); padding: 6px 12px; }
.btn.secondary:hover { background: #e0e0e0; }
.btn.danger { background: var(--danger); color: #fff; padding: 6px 12px; }
.btn.danger:hover { background: var(--danger-hover); }
.btn.small { padding: 5px 10px; font-size: 12px; }
.icon-btn {
  background: none; border: none; cursor: pointer;
  color: var(--text-secondary);
  border-radius: 4px;
  width: 32px; height: 32px;
  display: inline-flex; align-items: center; justify-content: center;
  transition: background var(--transition), color var(--transition);
}
.icon-btn:hover { background: var(--sidebar-hover); color: var(--text); }

/* Sidebar */
.sidebar {
  width: 260px; min-width: 260px;
  background: var(--sidebar-bg);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  overflow-y: auto;
}
.sidebar-nav { padding: 8px; flex: 1; }
.nav-section { margin-bottom: 4px; }
.nav-header {
  display: flex; align-items: center; gap: 6px;
  padding: 7px 10px;
  border-radius: var(--radius);
  cursor: pointer;
  color: var(--text-secondary);
  font-weight: 600;
  font-size: 13px;
  user-select: none;
}
.nav-header:hover { background: var(--sidebar-hover); }
.nav-header .chevron { margin-left: auto; transition: transform .15s ease; }
.nav-section.open .nav-header .chevron { transform: rotate(90deg); }
.nav-sub { display: none; padding-left: 10px; }
.nav-section.open .nav-sub { display: block; }
.nav-item {
  padding: 7px 10px;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 13px;
  color: var(--text-secondary);
  transition: all var(--transition);
}
.nav-item:hover { background: var(--sidebar-hover); color: var(--text); }
.nav-item.active { background: var(--sidebar-active); color: var(--blue); font-weight: 600; }
.sidebar-footer {
  display: flex; gap: 4px;
  padding: 8px;
  border-top: 1px solid var(--border);
  justify-content: space-around;
}

/* Task pane */
.task-pane {
  flex: 1;
  min-width: 340px;
  background: #fff;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.task-pane-header {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center; justify-content: space-between;
  background: #fafafa;
}
.task-pane-title { display: inline-flex; align-items: center; gap: 8px; font-weight: 600; font-size: 14px; }
.tag-pill {
  background: var(--blue-light);
  color: var(--blue);
  border-radius: 999px;
  padding: 2px 8px;
  font-size: 12px;
  font-weight: 600;
}
.task-input-row {
  display: flex; gap: 8px; padding: 12px 16px; border-bottom: 1px solid var(--border); background: #fff;
}
.task-input {
  flex: 1;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 9px 12px;
  font-size: 13px;
  outline: none;
  background: #fff;
}
.task-input:focus { border-color: var(--blue); }
.task-groups { flex: 1; overflow-y: auto; padding: 10px 12px; }
.task-group { margin-bottom: 14px; }
.task-group-title {
  font-size: 12px; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.04em;
  margin: 6px 6px 6px; font-weight: 700;
}
.task-row {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 10px;
  border-bottom: 1px solid #f2f2f2;
  cursor: pointer;
  border-radius: var(--radius);
}
.task-row:hover { background: #fafafa; }
.task-row.active { background: var(--sidebar-active); }
.task-row.completed .task-title { color: var(--text-light); text-decoration: line-through; }
.task-check {
  width: 18px; height: 18px; border-radius: 3px;
  border: 2px solid #c8c8c8;
  display: inline-flex; align-items: center; justify-content: center;
  cursor: pointer; flex-shrink: 0; transition: all var(--transition);
}
.task-check.checked { background: var(--blue); border-color: var(--blue); color: #fff; }
.task-title { flex: 1; font-size: 14px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.task-meta { font-size: 12px; color: var(--text-light); display: flex; gap: 8px; align-items: center; }
.fav-dot { width: 8px; height: 8px; border-radius: 50%; background: #f6c944; display: inline-block; flex-shrink: 0; }
.priority-line { width: 3px; border-radius: 3px; align-self: stretch; flex-shrink: 0; }
.priority-line.high { background: #d13438; }
.priority-line.medium { background: #f6c944; }
.priority-line.low { background: #28a745; }

/* Detail pane */
.detail-pane {
  width: 360px; min-width: 360px;
  background: #fff;
  border-left: 1px solid var(--border);
  display: flex; flex-direction: column;
  overflow: hidden;
}
.detail-empty {
  flex: 1;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  color: var(--text-light); gap: 10px;
}
.detail-container { flex: 1; display: flex; flex-direction: column; overflow: hidden; }
.detail-toolbar {
  display: flex; align-items: center; gap: 8px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
}
.detail-title-input {
  flex: 1; border: none; outline: none; font-size: 16px; font-weight: 600; padding: 6px 0;
}
.detail-title-input::placeholder { color: #bbb; }
.detail-toolbar-actions { display: flex; gap: 6px; align-items: center; }

.detail-meta { padding: 12px 14px; display: grid; gap: 10px; border-bottom: 1px solid var(--border); }
.meta-row { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.meta-label { font-size: 12px; color: var(--text-secondary); min-width: 70px; }
.meta-control {
  border: 1px solid var(--border); border-radius: var(--radius);
  padding: 6px 8px; font-size: 13px; background: #fff; width: 160px;
}
input.meta-control[type="date"] { width: auto; min-width: 140px; }

.detail-section { padding: 12px 14px; border-bottom: 1px solid var(--border); }
.detail-section-header { font-size: 12px; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.04em; font-weight: 700; margin-bottom: 8px; }
.subtask-list { display: flex; flex-direction: column; gap: 6px; margin-bottom: 8px; }
.subtask-row { display: flex; gap: 8px; align-items: center; }
.subtask-check {
  width: 16px; height: 16px; border-radius: 3px; border: 2px solid #c8c8c8;
  display: inline-flex; align-items: center; justify-content: center; cursor: pointer;
}
.subtask-check.checked { background: var(--blue); border-color: var(--blue); color: #fff; font-size: 10px; }
.subtask-text { flex: 1; font-size: 13px; outline: none; }
.subtask-text.done { color: var(--text-light); text-decoration: line-through; }
.subtask-add { display: flex; gap: 8px; }
.subtask-add input { flex: 1; border: 1px solid var(--border); border-radius: var(--radius); padding: 7px 10px; outline: none; }
.detail-notes {
  width: 100%; min-height: 120px;
  border: 1px solid var(--border); border-radius: var(--radius);
  padding: 10px; font: inherit; resize: vertical;
}

/* Responsive */
@media (max-width: 1100px) {
  .detail-pane { width: 280px; min-width: 280px; }
}
@media (max-width: 860px) {
  .sidebar { width: 210px; min-width: 210px; }
}