:root {
  --color-accent: #ecad0a;
  --color-primary: #209dd7;
  --color-secondary: #753991;
  --color-navy: #032147;
  --color-gray: #888888;
  --color-bg: #f4f6f9;
  --color-white: #ffffff;
  --font-sans: "Segoe UI", system-ui, -apple-system, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  color: var(--color-navy);
  background: var(--color-bg);
}

.board-header {
  border-bottom: 1px solid rgb(236 173 10 / 0.3);
  background: var(--color-white);
  padding: 1.25rem 1.5rem;
  box-shadow: 0 1px 3px rgb(3 33 71 / 0.06);
}

.board-header h1 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.board-header .accent-line {
  margin-top: 0.5rem;
  width: 4rem;
  height: 0.25rem;
  border-radius: 999px;
  background: var(--color-accent);
}

.kanban-board {
  display: flex;
  flex: 1;
  gap: 1rem;
  overflow-x: auto;
  padding: 1.5rem;
}

.kanban-column {
  display: flex;
  width: 18rem;
  flex-shrink: 0;
  flex-direction: column;
  border-radius: 0.75rem;
  background: var(--color-white);
  box-shadow: 0 4px 14px rgb(3 33 71 / 0.08);
  overflow: hidden;
}

.column-header {
  border-top: 4px solid var(--color-accent);
  border-radius: 0.75rem 0.75rem 0 0;
  padding: 0.75rem 1rem;
}

.column-title-btn {
  width: 100%;
  border: none;
  background: none;
  padding: 0;
  text-align: left;
  font: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-navy);
  cursor: pointer;
  transition: color 0.15s;
}

.column-title-btn:hover {
  color: var(--color-primary);
}

.column-count {
  margin-left: 0.5rem;
  font-size: 0.75rem;
  font-weight: 400;
  color: var(--color-gray);
}

.column-title-input {
  width: 100%;
  border: 1px solid rgb(32 157 215 / 0.3);
  border-radius: 0.25rem;
  padding: 0.25rem 0.5rem;
  font: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-navy);
}

.column-title-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary);
}

.column-footer {
  padding: 0 0.75rem 0.75rem;
}

.card-list {
  display: flex;
  min-height: 120px;
  flex: 1;
  flex-direction: column;
  gap: 0.75rem;
  background: rgb(136 136 136 / 0.05);
  padding: 0.75rem;
  transition: background 0.15s;
}

.card-list.drag-over {
  background: rgb(236 173 10 / 0.1);
}

.kanban-card {
  position: relative;
  border: 1px solid rgb(136 136 136 / 0.2);
  border-radius: 0.5rem;
  background: var(--color-white);
  padding: 1rem;
  box-shadow: 0 1px 3px rgb(3 33 71 / 0.06);
  cursor: grab;
  transition: box-shadow 0.15s;
}

.kanban-card:hover {
  box-shadow: 0 4px 12px rgb(3 33 71 / 0.1);
}

.kanban-card.sortable-ghost {
  opacity: 0.4;
}

.kanban-card.sortable-drag {
  box-shadow: 0 8px 24px rgb(3 33 71 / 0.15);
  ring: 2px solid rgb(236 173 10 / 0.5);
}

.card-title {
  margin: 0;
  padding-right: 1.5rem;
  font-size: 0.9375rem;
  font-weight: 600;
}

.card-details {
  margin: 0.25rem 0 0;
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--color-gray);
}

.card-delete {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  border: none;
  border-radius: 0.25rem;
  background: none;
  padding: 0.25rem;
  color: var(--color-gray);
  opacity: 0;
  cursor: pointer;
  transition: opacity 0.15s, background 0.15s, color 0.15s;
}

.kanban-card:hover .card-delete {
  opacity: 1;
}

.card-delete:hover {
  background: #fef2f2;
  color: #dc2626;
}

.add-card-toggle {
  margin-top: 0.5rem;
  width: 100%;
  border: none;
  border-radius: 0.5rem;
  background: none;
  padding: 0.5rem;
  font: inherit;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-primary);
  cursor: pointer;
  transition: background 0.15s;
}

.add-card-toggle:hover {
  background: rgb(32 157 215 / 0.05);
}

.add-card-form {
  margin-top: 0.5rem;
  display: none;
  flex-direction: column;
  gap: 0.5rem;
  border: 1px solid rgb(136 136 136 / 0.2);
  border-radius: 0.5rem;
  background: var(--color-white);
  padding: 0.75rem;
  box-shadow: 0 1px 3px rgb(3 33 71 / 0.06);
}

.add-card-form.open {
  display: flex;
}

.add-card-form input,
.add-card-form textarea {
  width: 100%;
  border: 1px solid rgb(136 136 136 / 0.3);
  border-radius: 0.25rem;
  padding: 0.5rem 0.75rem;
  font: inherit;
  font-size: 0.875rem;
  color: var(--color-navy);
}

.add-card-form input:focus,
.add-card-form textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary);
}

.add-card-form textarea {
  resize: vertical;
  min-height: 3rem;
}

.form-actions {
  display: flex;
  gap: 0.5rem;
}

.btn-primary {
  border: none;
  border-radius: 0.25rem;
  background: var(--color-secondary);
  padding: 0.375rem 1rem;
  font: inherit;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-white);
  cursor: pointer;
  transition: background 0.15s;
}

.btn-primary:hover {
  background: rgb(117 57 145 / 0.9);
}

.btn-secondary {
  border: none;
  border-radius: 0.25rem;
  background: none;
  padding: 0.375rem 1rem;
  font: inherit;
  font-size: 0.875rem;
  color: var(--color-gray);
  cursor: pointer;
  transition: background 0.15s;
}

.btn-secondary:hover {
  background: rgb(136 136 136 / 0.1);
}

.board-error {
  margin: 2rem;
  padding: 1rem 1.25rem;
  border-radius: 0.5rem;
  background: #fef2f2;
  color: #991b1b;
}

.board-loading {
  margin: 2rem;
  color: var(--color-gray);
}

.app-shell {
  display: flex;
  min-height: 100vh;
  flex-direction: column;
}

@media (max-width: 640px) {
  .kanban-board {
    padding: 1rem;
  }

  .kanban-column {
    width: 16rem;
  }
}