.gantt-page {
  min-height: 100vh;
}

.container {
  max-width: 1220px;
  margin: 0 auto;
  padding: 2rem 5% 3rem;
}

.gantt-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 260px;
  gap: 1.5rem;
  align-items: start;
}

.gantt-content {
  min-width: 0;
  grid-column: 1;
}

.gantt-page #task-editor,
.gantt-page #gantt-output,
.gantt-page #about-gantt,
.gantt-page #how-to-use,
.gantt-page #planning-guidance,
.gantt-page #faq {
  scroll-margin-top: 6rem;
}

.gantt-side-nav {
  position: sticky;
  top: 6rem;
  padding: 1rem;
}

.gantt-side-nav h2 {
  margin-bottom: 1rem;
}

.gantt-side-nav nav {
  display: grid;
  gap: .45rem;
}

.gantt-side-nav a {
  min-height: 2.35rem;
  display: flex;
  align-items: center;
  padding: .48rem .7rem;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  border-radius: 7px;
  background: var(--surface);
  font-size: .88rem;
  font-weight: 720;
  text-decoration: none;
}

.gantt-side-nav a:hover,
.gantt-side-nav a:focus {
  color: var(--blue-600);
  border-color: rgba(31, 111, 235, .28);
  background: #fff;
}

.section-header {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
}

.section-header h2 {
  margin: 0 0 .25rem;
}

.section-header p {
  margin: 0;
  color: var(--text-secondary);
}

.editor-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: .6rem;
}

.timeline-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: .6rem;
}

.secondary-action {
  min-height: 38px !important;
  padding: .55rem .85rem !important;
  border: 1px solid var(--border) !important;
  border-radius: 8px !important;
  background: #fff !important;
  color: var(--navy-950) !important;
  box-shadow: none !important;
  font-weight: 800 !important;
}

.secondary-action:hover,
.secondary-action:focus-visible {
  border-color: rgba(31, 111, 235, .36) !important;
  background: var(--surface) !important;
  color: var(--blue-600) !important;
}

.privacy-note {
  margin-bottom: 1rem;
}

.sample-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .55rem;
  margin-bottom: 1rem;
  color: var(--text-secondary);
  font-size: .9rem;
  font-weight: 700;
}

.sample-actions span {
  color: var(--navy-950);
}

.sample-actions .secondary-action {
  min-height: 34px !important;
  padding: .45rem .7rem !important;
  font-size: .82rem !important;
}

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
}

.task-table {
  width: 100%;
  min-width: 760px;
  border-collapse: collapse;
  background: #fff;
}

.task-table th,
.task-table td {
  border: 1px solid var(--border);
  padding: .65rem;
  text-align: left;
}

.task-table th {
  color: var(--text-secondary);
  background: var(--surface);
  font-size: .8rem;
  font-weight: 820;
}

.task-table td {
  color: var(--text-primary);
}

.task-table input,
.task-table select {
  width: 100%;
  min-height: 38px;
  border: 1px solid var(--border);
  border-radius: 7px;
  background: #fff;
  color: var(--text-primary);
  padding: .45rem .55rem;
}

.task-table .delete-task {
  min-height: 36px !important;
  width: 42px;
  padding: 0 !important;
  border: 1px solid #fecdca !important;
  background: #fff5f4 !important;
  color: #b42318 !important;
  box-shadow: none !important;
}

.task-table .delete-task:hover {
  background: #fee4e2 !important;
  color: #912018 !important;
}

.today-key {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  min-height: 32px;
  padding: .35rem .65rem;
  border: 1px solid #fecdca;
  border-radius: 999px;
  color: #b42318;
  background: #fff5f4;
  font-size: .82rem;
  font-weight: 800;
}

.today-key::before {
  content: "";
  width: 3px;
  height: 18px;
  border-radius: 999px;
  background: #ef4444;
}

.gantt-wrapper {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  height: var(--gantt-height, 300px);
  min-height: 220px;
  max-height: 72vh;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  overflow: hidden;
}

.gantt-page.timeline-fullscreen {
  overflow: hidden;
}

.gantt-page.timeline-fullscreen #gantt-output {
  position: fixed;
  inset: 16px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  margin: 0;
  background: #fff;
  box-shadow: 0 28px 80px rgba(6, 23, 43, .28);
}

.gantt-page.timeline-fullscreen #gantt-output .gantt-wrapper {
  flex: 1;
  height: auto;
  max-height: none;
}

.task-panel {
  border-right: 1px solid var(--border);
  overflow-y: auto;
  overflow-x: hidden;
  background: #fff;
}

.task-panel-header {
  height: 64px;
  display: flex;
  align-items: center;
  padding: 0 12px;
  background: var(--surface);
  color: var(--navy-950);
  font-weight: 820;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.task-item {
  height: 42px;
  padding: 0 12px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  color: var(--text-primary);
  font-size: .9rem;
  font-weight: 650;
}

.task-item:nth-child(even) {
  background: var(--surface);
}

.task-item .milestone-symbol {
  color: var(--warning);
  margin-right: .45rem;
}

.task-empty,
.timeline-empty {
  color: var(--text-secondary);
  font-size: .92rem;
}

.task-empty {
  min-height: 84px;
  display: flex;
  align-items: center;
  padding: 0 12px;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

.timeline-empty {
  min-height: 156px;
  display: grid;
  place-items: center;
  padding: 1.5rem;
  text-align: center;
  background: linear-gradient(180deg, #fff, var(--surface));
}

.timeline-empty strong {
  display: block;
  margin-bottom: .35rem;
  color: var(--navy-950);
  font-size: 1rem;
}

.timeline-panel {
  overflow: auto;
  position: relative;
}

.timeline-header {
  position: sticky;
  top: 0;
  background: #fff;
  z-index: 10;
}

.time-row {
  display: flex;
}

.time-cell {
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  text-align: center;
  padding: 6px;
  color: var(--text-secondary);
  font-size: 12px;
  white-space: nowrap;
}

.month-row .time-cell {
  height: 34px;
  background: var(--surface);
  color: var(--navy-950);
  font-weight: 800;
}

.week-row .time-cell {
  height: 30px;
  background: #fff;
}

.gantt-body {
  position: relative;
}

.task-row {
  height: 42px;
  border-bottom: 1px solid var(--border);
  position: relative;
}

.task-row:nth-child(even) {
  background: var(--surface);
}

.grid-line {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 1px;
  background: #eef3f9;
}

.task-bar {
  position: absolute;
  top: 9px;
  height: 24px;
  border-radius: 999px;
  background: linear-gradient(180deg, #5f9cff, var(--blue-600));
  box-shadow: 0 8px 18px rgba(31, 111, 235, .22);
  overflow: hidden;
}

.progress {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  background: var(--navy-800);
  opacity: .42;
  border-radius: 999px;
}

.task-label {
  position: absolute;
  left: 10px;
  top: 4px;
  color: #fff;
  font-size: 12px;
  font-weight: 800;
}

.milestone {
  position: absolute;
  width: 18px;
  height: 18px;
  background: var(--warning);
  transform: rotate(45deg);
  top: 12px;
  border: 2px solid #fff;
  box-shadow: 0 6px 14px rgba(245, 158, 11, .25);
}

.today-line {
  position: absolute;
  width: 3px;
  top: 0;
  bottom: 0;
  background: #ef4444;
  z-index: 5;
  box-shadow: 0 0 10px rgba(239, 68, 68, .36);
}

.content-section p,
.method-list li,
.guidance-card p,
.faq-section details p {
  color: var(--text-secondary);
}

.method-list {
  display: grid;
  gap: .6rem;
  margin: 0;
  padding-left: 1.25rem;
}

.guidance-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.guidance-card {
  min-height: 8rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
}

.guidance-card span {
  display: block;
  margin-bottom: .55rem;
  color: var(--blue-600);
  font-size: .85rem;
  font-weight: 800;
}

.faq-section {
  display: grid;
  gap: .75rem;
}

.faq-section details {
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
}

.faq-section summary {
  cursor: pointer;
  padding: .9rem 1rem;
  color: var(--navy-950);
  font-weight: 800;
}

.faq-section details p {
  margin: 0;
  padding: 0 1rem 1rem;
}

.error {
  margin: .75rem 0 0;
  color: #b42318;
  font-weight: 700;
}

.hidden {
  display: none !important;
}

@media (max-width: 1080px) {
  .gantt-layout {
    grid-template-columns: 1fr;
  }

  .gantt-side-nav {
    display: none;
  }
}

@media (max-width: 760px) {
  .container {
    padding: 1.25rem 1rem 2rem;
  }

  .section-header,
  .editor-actions,
  .timeline-actions {
    display: grid;
    justify-content: stretch;
  }

  .editor-actions button,
  .timeline-actions button,
  .sample-actions button {
    width: 100%;
  }

  .gantt-wrapper {
    grid-template-columns: 210px minmax(520px, 1fr);
    overflow-x: auto;
  }

  .gantt-page.timeline-fullscreen #gantt-output {
    inset: 8px;
  }

  .guidance-grid {
    grid-template-columns: 1fr;
  }
}