:root {
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-muted: #f8fafc;
  --surface-depth-3: #f1f5f9;
  --surface-header: rgba(255, 255, 255, 0.9);
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --text: #0f172a;
  --text-muted: #64748b;
  --blue-soft: #f0fdfa;
  --blue-hover: #e0f2fe;
  --danger: #dc2626;
  --status-before: #475569;
  --status-active: #059669;
  --status-done: #0f172a;
  --status-delay: #ea580c;
  --gantt-plan: #334155;
  --gantt-actual: #10b981;
  
  --shadow-sm: 0 1px 2px 0 rgba(15, 23, 42, 0.04);
  --shadow: 0 4px 6px -1px rgba(15, 23, 42, 0.08), 0 2px 4px -2px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 10px 15px -3px rgba(15, 23, 42, 0.08), 0 4px 6px -4px rgba(15, 23, 42, 0.04);
  --shadow-lg: 0 20px 25px -5px rgba(15, 23, 42, 0.1), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
  
  --radius: 16px;
  --radius-sm: 10px;
  --radius-badge: 20px;
  --transition: 250ms cubic-bezier(0.16, 1, 0.3, 1);
  --font: "Pretendard", "Inter", -apple-system, "BlinkMacSystemFont", "Segoe UI", roboto, "Helvetica Neue", arial, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.5;
}

button,
input,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

.app-shell {
  display: flex;
  min-height: 100vh;
  flex-direction: column;
  gap: 32px;
  padding: 40px 48px;
  max-width: 2000px;
  margin: 0 auto;
}

.top-panel,
.table-section,
.modal-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.top-panel {
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.title-row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
}

.title-row h1 {
  margin: 8px 0 0;
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text);
}

.eyebrow {
  margin: 0;
  color: #2563eb;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.meta-grid {
  display: grid;
  gap: 20px;
}

.meta-grid-primary {
  grid-template-columns: minmax(320px, 2fr) repeat(2, minmax(200px, 1fr));
}

.meta-grid-secondary {
  grid-template-columns: repeat(2, minmax(220px, 1fr)) minmax(320px, 1.5fr);
}

.meta-field,
.meta-value-card,
.sync-panel {
  display: flex;
  min-height: 100px;
  flex-direction: column;
  justify-content: center;
  gap: 10px;
  border-radius: var(--radius-sm);
  background: #f8fafc;
  padding: 20px 24px;
  border: 1px solid transparent;
  transition: var(--transition);
}

.meta-field:hover,
.sync-panel:hover {
  background: #ffffff;
  border-color: var(--border);
  box-shadow: var(--shadow-sm);
}

.meta-field input {
  width: 100%;
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 0.95rem;
  transition: var(--transition);
  background: #ffffff;
}

.meta-field input:focus {
  border-color: #2563eb;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
  outline: none;
}

.meta-label,
.meta-field span,
.sync-panel span {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-muted);
}

.meta-value-card strong {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.02em;
}

.accent-card {
  color: #fff;
  border: none;
}

.accent-card .meta-label {
  color: rgba(255, 255, 255, 0.9);
}

.accent-card strong {
  color: #ffffff;
}

.plan-card {
  background: linear-gradient(135deg, #1e40af, #3b82f6);
  box-shadow: 0 4px 14px 0 rgba(37, 99, 235, 0.25);
}

.actual-card {
  background: linear-gradient(135deg, #047857, #10b981);
  box-shadow: 0 4px 14px 0 rgba(16, 185, 129, 0.25);
}

.sync-panel {
  align-items: flex-start;
  justify-content: space-between;
}

.table-section {
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.table-scroll {
  overflow: auto;
}

.wbs-table {
  width: 100%;
  min-width: 2000px;
  border-collapse: separate;
  border-spacing: 0;
}

.wbs-table thead th {
  position: sticky;
  top: 0;
  z-index: 2;
  border-bottom: 1px solid var(--border);
  background: var(--surface-header);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 18px 16px;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  text-align: left;
  white-space: nowrap;
}

.wbs-table tbody td {
  border-bottom: 1px solid var(--border);
  padding: 14px 16px;
  vertical-align: middle;
  font-size: 0.9375rem;
  color: var(--text);
  transition: background var(--transition);
}

.task-row {
  cursor: pointer;
}

.task-row.depth-1 td { background: #ffffff; }
.task-row.depth-2 td { background: #f8fafc; }
.task-row.depth-3 td { background: #f1f5f9; }

.task-row.striped-even td {
  background-image: linear-gradient(rgba(0, 0, 0, 0.015), rgba(0, 0, 0, 0.015));
}

.task-row:hover td,
.task-row:focus-within td {
  background-color: var(--blue-hover) !important;
  background-image: none;
}

.task-row.drop-target td {
  position: relative;
}
.task-row.drop-target td::after {
  content: '';
  position: absolute;
  left: 0; right: 0;
  height: 2px;
  background: #2563eb;
  z-index: 3;
}
.task-row.drop-target[data-drop-position="before"] td::after { top: -1px; }
.task-row.drop-target[data-drop-position="after"] td::after { bottom: -1px; }

.task-row.dragging {
  opacity: 0.4;
  background: #f1f5f9;
}

.col-actions {
  min-width: 180px;
}

.action-stack {
  display: flex;
  align-items: center;
  gap: 8px;
}

.drag-handle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 32px;
  color: var(--border-strong);
  cursor: grab;
  font-size: 1.1rem;
  font-weight: bold;
  letter-spacing: -2px;
  transition: color var(--transition);
  user-select: none;
}

.drag-handle:hover {
  color: var(--text-muted);
}

.drag-handle:active {
  cursor: grabbing;
}

.toggle-button,
.icon-button {
  width: 32px;
  height: 32px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #ffffff;
  color: var(--text-muted);
  transition: all var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 1px 2px 0 rgba(0,0,0,0.02);
}

.icon-button:hover:not(:disabled):not([aria-disabled="true"]),
.toggle-button:hover:not(:disabled):not([aria-disabled="true"]) {
  background: #f8fafc;
  border-color: var(--border-strong);
  color: var(--text);
  transform: translateY(-1px);
  box-shadow: 0 2px 4px 0 rgba(0,0,0,0.05);
}

.icon-button:disabled,
.icon-button[aria-disabled="true"],
.toggle-button:disabled,
.toggle-button[aria-disabled="true"] {
  opacity: 0.5;
  cursor: not-allowed;
}

.icon-button:focus-visible,
.toggle-button:focus-visible {
  border-color: #2563eb;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
  outline: none;
}

.primary-button:focus-visible,
.secondary-button:focus-visible,
input:focus-visible,
select:focus-visible,
.gantt-bar:focus-visible {
  outline: 3px solid rgba(37, 99, 235, 0.5);
  outline-offset: 2px;
}

.toggle-placeholder {
  display: inline-flex;
  width: 32px;
  height: 32px;
}

.tree-value {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  gap: 10px;
  font-weight: 500;
}

.indent-1 { padding-left: 0; }
.indent-2 { padding-left: 28px; }
.indent-3 { padding-left: 56px; }

.owner-badge,
.status-badge,
.warning-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 28px;
  border-radius: var(--radius-badge);
  padding: 0 12px;
  font-size: 0.75rem;
  font-weight: 700;
  white-space: nowrap;
  letter-spacing: 0.02em;
}

.owner-badge {
  color: #ffffff;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
  text-shadow: 0 1px 1px rgba(0, 0, 0, 0.2);
}

.status-badge.before { background: #f1f5f9; color: var(--status-before); }
.status-badge.active { background: #d1fae5; color: #047857; }
.status-badge.done { background: #e2e8f0; color: var(--status-done); }
.status-badge.delay { background: #ffedd5; color: #b45309; }

.warning-badge {
  background: #fef2f2;
  color: #b91c1c;
  border: 1px solid #fecaca;
}

.metric-text {
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-weight: 500;
}

.empty-cell {
  color: var(--text-muted);
}

.editor-row td {
  background: #f8fafc;
  padding: 0;
  border-bottom: 2px solid #2563eb;
}

.editor-panel {
  padding: 24px;
  background: #ffffff;
  box-shadow: inset 0 2px 6px 0 rgba(0, 0, 0, 0.02);
}

.editor-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(200px, 1fr));
  gap: 20px;
}

.editor-field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.editor-field span {
  color: var(--text-muted);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.editor-field .required-indicator {
  color: var(--danger);
}

.editor-field input:focus,
.editor-field select:focus,
select[data-inline-progress]:focus {
  border-color: #2563eb;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
  outline: none;
}

.editor-actions {
  margin-top: 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

.validation-message {
  min-height: 24px;
  color: var(--danger);
  font-size: 0.875rem;
  font-weight: 500;
  display: flex;
  align-items: center;
}

.primary-button,
.secondary-button {
  min-height: 44px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 0 20px;
  font-weight: 600;
  font-size: 0.9375rem;
  transition: all var(--transition);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.primary-button {
  background: #2563eb;
  color: #ffffff;
  box-shadow: 0 1px 2px 0 rgba(37, 99, 235, 0.3);
}

.primary-button:hover:not(:disabled):not([aria-disabled="true"]) {
  background: #1d4ed8;
  box-shadow: 0 4px 6px -1px rgba(37, 99, 235, 0.4);
  transform: translateY(-1px);
}

.primary-button:active:not(:disabled):not([aria-disabled="true"]) {
  transform: translateY(0);
}

.primary-button:disabled,
.primary-button[aria-disabled="true"],
.secondary-button:disabled,
.secondary-button[aria-disabled="true"] {
  opacity: 0.5;
  cursor: not-allowed;
}

.secondary-button {
  background: #ffffff;
  border-color: var(--border-strong);
  color: var(--text);
  box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}

.secondary-button:hover:not(:disabled):not([aria-disabled="true"]) {
  background: #f8fafc;
  border-color: #64748b;
  transform: translateY(-1px);
}

.secondary-button:active:not(:disabled):not([aria-disabled="true"]) {
  transform: translateY(0);
}

.bottom-action-bar {
  position: sticky;
  bottom: 32px;
  z-index: 4;
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  padding: 20px 32px;
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
  margin-top: auto;
}

.toast {
  position: fixed;
  right: 32px;
  bottom: 120px;
  z-index: 50;
  min-width: 280px;
  max-width: 400px;
  transform: translateY(20px);
  border-radius: var(--radius-sm);
  background: #0f172a;
  color: #ffffff;
  padding: 16px 20px;
  font-size: 0.9375rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  transition: opacity var(--transition), transform var(--transition);
  pointer-events: none;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link:focus-visible {
  position: absolute;
  top: 16px;
  left: 16px;
  z-index: 9999;
  width: auto;
  height: auto;
  padding: 12px 24px;
  margin: 0;
  overflow: visible;
  clip-path: none;
  background: var(--surface);
  color: var(--text);
  font-weight: 600;
  border-radius: var(--radius-sm);
  border: 2px solid #2563eb;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 0 0 3px rgba(37, 99, 235, 0.15);
  text-decoration: none;
}

#main-content:focus {
  outline: none;
}

.modal.hidden {
  display: none;
}

.modal {
  position: fixed;
  inset: 0;
  z-index: 60;
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(15, 23, 42, 0.5);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.modal-panel {
  position: relative;
  z-index: 1;
  width: min(96vw, 1600px);
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  background: #ffffff;
  border-radius: var(--radius);
  box-shadow: 0 25px 50px -12px rgba(15, 23, 42, 0.25);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border);
  padding: 24px 32px;
  background: #f8fafc;
  border-radius: var(--radius) var(--radius) 0 0;
}

.modal-header h2 {
  margin: 0 0 6px;
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.modal-header p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.9375rem;
}

.gantt-content {
  overflow: auto;
  padding: 32px;
}

.gantt-shell {
  display: grid;
  grid-template-columns: max-content max-content;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow-x: auto;
  overflow-y: hidden;
  min-width: 0;
  -webkit-overflow-scrolling: touch;
  background: #ffffff;
  box-shadow: var(--shadow-sm);
}

.gantt-meta,
.gantt-chart {
  min-width: 0;
}

.gantt-meta table {
  width: 100%;
  border-collapse: collapse;
}

.gantt-chart table {
  width: max-content;
  table-layout: fixed;
  border-collapse: collapse;
}

.gantt-meta th,
.gantt-meta td,
.gantt-chart th,
.gantt-chart td {
  border-bottom: 1px solid var(--border);
  background: #ffffff;
  white-space: nowrap;
}

.gantt-meta th,
.gantt-meta td {
  padding: 12px 16px;
  font-size: 0.875rem;
}

.gantt-chart th,
.gantt-chart td {
  min-width: 36px;
  width: 36px;
  max-width: 36px;
  box-sizing: border-box;
  padding: 4px 0;
}

.gantt-meta thead th,
.gantt-chart thead th {
  background: var(--surface-header);
  position: sticky;
  top: 0;
  z-index: 2;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: 0.75rem;
  border-bottom: 1px solid var(--border-strong);
}

.gantt-week-header {
  text-align: center;
  color: var(--text);
  font-weight: 700;
}

.gantt-chart .gantt-day-cell {
  text-align: center;
  font-family: ui-monospace, monospace;
}

.gantt-day-cell.weekend-gap {
  background: #f1f5f9;
}

.gantt-day-track {
  position: relative;
  min-height: 32px;
}

.gantt-day-track::before {
  content: '';
  position: absolute;
  inset: 6px 2px;
  border-radius: 6px;
  background: rgba(148, 163, 184, 0.08);
}

.gantt-bar {
  position: absolute;
  top: 6px;
  bottom: 6px;
  border-radius: 6px;
  transition: all var(--transition);
}

.gantt-bar:hover {
  transform: scaleY(1.1);
  filter: brightness(1.1);
}

.gantt-bar.plan { background: var(--gantt-plan); box-shadow: 0 2px 4px rgba(15, 23, 42, 0.15); }
.gantt-bar.actual { background: var(--gantt-actual); box-shadow: 0 2px 4px rgba(16, 185, 129, 0.2); }

.table-empty,
.gantt-empty {
  padding: 60px;
  text-align: center;
  color: var(--text-muted);
  font-size: 1rem;
  font-weight: 500;
}

@media (max-width: 1400px) {
  .meta-grid-primary,
  .meta-grid-secondary,
  .editor-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 800px) {
  .app-shell {
    padding: 16px;
    gap: 16px;
  }

  .meta-grid-primary,
  .meta-grid-secondary,
  .editor-grid {
    grid-template-columns: 1fr;
  }

  .wbs-table {
    min-width: 1300px;
  }

  .priority-desktop,
  .col-phase,
  .col-activity,
  .col-task {
    display: none;
  }
  
  .bottom-action-bar {
    position: static;
    border-radius: var(--radius-sm);
    padding: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  
  .icon-button:hover,
  .toggle-button:hover,
  .primary-button:hover,
  .secondary-button:hover,
  .gantt-bar:hover,
  .meta-field:hover,
  .sync-panel:hover {
    transform: none !important;
    filter: none !important;
  }
}

.empty-icon {
  font-size: 3rem;
  margin-bottom: 16px;
  opacity: 0.8;
}

.empty-title {
  margin: 0 0 8px;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
}

.empty-desc {
  margin: 0;
  line-height: 1.5;
}