:root[data-gantt-theme="light"] {
  /* Custom Surfaces/Text/Accents (your originals) */
  --surface-ctrl: #ededed;
  --surface-ctrl-button: #ffffff;
  --text-main: rgba(0, 0, 0, 0.7);
  --text-muted: rgba(0, 0, 0, 0.54);
  --text-weak: rgba(0, 0, 0, 0.38);
  --accent-primary: #0288d1;
  --accent-radio: #8a9ada;
  --deadline: #b42318;
  --constraint: #8a5a00;
  --success: #059669;
  --hierarchy-epic: #64748b;
  --hierarchy-story-bg: #f5fbf7;
  --hierarchy-link-ss: #9f1239;
  --hierarchy-link-fs: #475569;
  --hierarchy-link-ff: #15803d;
  --badge-text-light: #ffffff;
  --grid-line: rgba(15, 23, 42, 0.08);
  --cell-line: rgba(15, 23, 42, 0.02);

  /* DHTMLX Gantt v9 FULL Base Colors */
  --dhx-gantt-base-colors-white: #ffffff;
  --dhx-gantt-base-colors-black: #000000;
  --dhx-gantt-base-colors-gray: #f1f5f9;
  --dhx-gantt-base-colors-background: #ffffff;
  --dhx-gantt-base-colors-background-alt: #f8fafc;
  --dhx-gantt-base-colors-text-base: rgba(0, 0, 0, 0.87);
  --dhx-gantt-base-colors-text-secondary: rgba(0, 0, 0, 0.6);
  --dhx-gantt-base-colors-border: rgba(0, 0, 0, 0.12);
  --dhx-gantt-base-colors-border-light: rgba(0, 0, 0, 0.08);
  --dhx-gantt-base-colors-primary: #0288d1;
  --dhx-gantt-base-colors-success: #059669;
  --dhx-gantt-base-colors-warning: #f59e0b;
  --dhx-gantt-base-colors-error: #dc2626;
  --dhx-gantt-base-colors-icons: rgba(0, 0, 0, 0.54);
  --dhx-gantt-base-colors-icons-hover: rgba(0, 0, 0, 0.72);
  --dhx-gantt-base-colors-select: #e2f1ff; /* Selected rows highlight */

  /* Container/Grid/Scales */
  --dhx-gantt-container-background: #ffffff;
  --dhx-gantt-container-color: var(--dhx-gantt-base-colors-text-base);
  --dhx-gantt-grid-scale-background: #fafbfc;
  --dhx-gantt-grid-scale-color: var(--dhx-gantt-base-colors-text-base);
  --dhx-gantt-grid-row-background: #ffffff;
  --dhx-gantt-grid-row-background--odd: #fafbfc;
  --dhx-gantt-task-row-background: #ffffff;
  --dhx-gantt-task-row-background--odd: #fafbfc;
  --dhx-gantt-scale-background: #fafbfc;
  --dhx-gantt-scale-color: var(--dhx-gantt-base-colors-text-base);

  /* Tasks/Links */
  --dhx-gantt-task-background: #3db9d3;
  --dhx-gantt-task-color: #ffffff;
  --dhx-gantt-project-background: #6aa84f;
  --dhx-gantt-project-color: #ffffff;
  --dhx-gantt-milestone-background: #a855f7;
  --dhx-gantt-link-background: #ffa011;
  --dhx-gantt-link-background-hover: #ff9800;

  /* Borders/Selection */
  --dhx-gantt-task-cell-border: var(--dhx-gantt-base-colors-border-light);
  --dhx-gantt-scale-border-vertical: var(--dhx-gantt-base-colors-border);
}

:root[data-gantt-theme="dark"] {
  /* Custom Surfaces/Text/Accents (your darks) */
  --surface-ctrl: #0b1220;
  --surface-ctrl-button: #111827;
  --text-main: rgba(255, 255, 255, 0.88);
  --text-muted: rgba(255, 255, 255, 0.65);
  --text-weak: rgba(255, 255, 255, 0.4);
  --accent-primary: #38bdf8;
  --accent-radio: #a5b4fc;
  --deadline: #fb7185;
  --constraint: #fbbf24;
  --success: #22c55e;
  --hierarchy-epic: #94a3b8;
  --hierarchy-story-bg: color-mix(in srgb, var(--success) 95%);
  --hierarchy-link-ss: #fb7185;
  --hierarchy-link-fs: #64748b;
  --hierarchy-link-ff: #4ade80;
  --badge-text-light: #0b1220;
  --grid-line: rgba(255, 255, 255, 0.1);
  --cell-line: rgba(255, 255, 255, 0.06);

  /* DHTMLX Gantt v9 FULL Base Colors (Dark) */
  --dhx-gantt-base-colors-white: #ffffff;
  --dhx-gantt-base-colors-black: #f8fafc;
  --dhx-gantt-base-colors-gray: #1e293b;
  --dhx-gantt-base-colors-background: #0f172a;
  --dhx-gantt-base-colors-background-alt: #1e293b;
  --dhx-gantt-base-colors-text-base: rgba(255, 255, 255, 0.9);
  --dhx-gantt-base-colors-text-secondary: rgba(255, 255, 255, 0.7);
  --dhx-gantt-base-colors-border: rgba(255, 255, 255, 0.12);
  --dhx-gantt-base-colors-border-light: rgba(255, 255, 255, 0.08);
  --dhx-gantt-base-colors-primary: #38bdf8;
  --dhx-gantt-base-colors-success: #22c55e;
  --dhx-gantt-base-colors-warning: #fbbf24;
  --dhx-gantt-base-colors-error: #fb7185;
  --dhx-gantt-base-colors-icons: rgba(255, 255, 255, 0.56);
  --dhx-gantt-base-colors-icons-hover: rgba(255, 255, 255, 0.75);
  --dhx-gantt-base-colors-select: #1e40af; /* Dark blue select highlight */

  /* Container/Grid/Scales (Dark) */
  --dhx-gantt-container-background: #0f172a;
  --dhx-gantt-container-color: var(--dhx-gantt-base-colors-text-base);
  --dhx-gantt-grid-scale-background: #1e293b;
  --dhx-gantt-grid-scale-color: rgba(255, 255, 255, 0.85);
  --dhx-gantt-grid-row-background: #0f172a;
  --dhx-gantt-grid-row-background--odd: #1e293b;
  --dhx-gantt-task-row-background: #0f172a;
  --dhx-gantt-task-row-background--odd: #1e293b;
  --dhx-gantt-scale-background: #1e293b;
  --dhx-gantt-scale-color: rgba(255, 255, 255, 0.85);
  --dhx-gantt-task-cell-border: rgba(255, 255, 255, 0.08);

  /* Tasks/Links (Dark) */
  --dhx-gantt-task-background: #3db9d3;
  --dhx-gantt-task-color: #ffffff;
  --dhx-gantt-project-background: #4ade80;
  --dhx-gantt-project-color: #0f172a;
  --dhx-gantt-milestone-background: #c084fc;
  --dhx-gantt-link-background: #fbbf24;
  --dhx-gantt-link-background-hover: #f59e0b;
}