:root {
  --bg: #111111;
  --surface: #1b1b1b;
  --surface-2: #222222;
  --border: #2e2e2e;
  --text-1: #e2e2e2;
  --text-2: #888888;
  --text-3: #444444;
  --accent: #cccccc;

  --radius: 6px;
  --transition: 0.15s ease;

  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-display: 'Space Grotesk', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

[data-theme="light"] {
  --bg: #f2f2f2;
  --surface: #ffffff;
  --surface-2: #f7f7f7;
  --border: #e0e0e0;
  --text-1: #111111;
  --text-2: #666666;
  --text-3: #bbbbbb;
  --accent: #111111;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  background: var(--bg);
  color: var(--text-1);
  font-family: var(--font-sans);
  line-height: 1.6;
  min-height: 100vh;
  transition:
    background var(--transition),
    color var(--transition);
}

button {
  cursor: pointer;
  font-family: inherit;
}

input,
select,
button {
  outline: none;
}

input:focus-visible,
select:focus-visible,
button:focus-visible {
  outline: 2px solid var(--text-3);
  outline-offset: 2px;
}

.header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.875rem 1.5rem;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  transition:
    background var(--transition),
    border-color var(--transition);
}

.main {
  max-width: 720px;
  margin: 0 auto;
  padding: 1.75rem 1.25rem 5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.header__brand {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}

.header__logo {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-1);
  letter-spacing: -0.02em;
  transition: color var(--transition);
}

.header__sub {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-3);
  letter-spacing: 0.04em;
  transition: color var(--transition);
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-2);
  font-size: 0.78rem;
  padding: 0.4rem 0.7rem;
  transition:
    background var(--transition),
    border-color var(--transition),
    color var(--transition);
}

.theme-toggle:hover {
  color: var(--text-1);
  border-color: var(--text-3);
}

.theme-icon {
  width: 13px;
  height: 13px;
  flex-shrink: 0;
  stroke: currentColor;
}

[data-theme="dark"] .theme-icon--moon {
  display: none;
}

[data-theme="dark"] .theme-icon--sun {
  display: block;
}

[data-theme="light"] .theme-icon--sun {
  display: none;
}

[data-theme="light"] .theme-icon--moon {
  display: block;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.5rem;
  transition:
    background var(--transition),
    border-color var(--transition);
}

.card__head {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  margin-bottom: 0.375rem;
}

.card__title {
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-1);
  letter-spacing: -0.01em;
  transition: color var(--transition);
}

.card__desc {
  font-size: 0.83rem;
  color: var(--text-2);
  margin-bottom: 1.25rem;
  line-height: 1.5;
  transition: color var(--transition);
}

.task-form {
  display: flex;
  gap: 0.625rem;
  align-items: center;
  margin-top: 0.875rem;
}

.task-form .input {
  flex: 1;
  min-width: 0;
}

.controls-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.controls-bar__left {
  display: flex;
  gap: 0.5rem;
  flex: 1;
  min-width: 0;
}

.controls-bar__right {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  flex-shrink: 0;
}

.input,
.select {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-1);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  padding: 0.5rem 0.75rem;
  width: 100%;
  transition:
    background var(--transition),
    border-color var(--transition),
    color var(--transition);
}

.input::placeholder {
  color: var(--text-3);
}

.input:focus,
.select:focus {
  border-color: var(--text-2);
}

.select {
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'%3E%3Cpath d='M1 1l4 4 4-4' stroke='%23888888' stroke-width='1.5' fill='none' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  padding-right: 2.25rem;
  width: auto;
}

option {
  background: var(--surface);
  color: var(--text-1);
}

.input--sm {
  font-size: 0.8rem;
  padding: 0.4rem 0.65rem;
}

.select--sm {
  font-size: 0.8rem;
  padding: 0.4rem 0.65rem;
  padding-right: 1.9rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.375rem;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 500;
  line-height: 1;
  padding: 0.5rem 1rem;
  white-space: nowrap;
  transition:
    background var(--transition),
    border-color var(--transition),
    color var(--transition),
    opacity var(--transition);
}

.btn--primary {
  background: var(--text-1);
  border-color: var(--text-1);
  color: var(--bg);
  flex-shrink: 0;
}

.btn--primary:hover {
  opacity: 0.82;
}

.btn--ghost {
  background: transparent;
  border-color: var(--border);
  color: var(--text-2);
}

.btn--ghost:hover {
  background: var(--surface-2);
  border-color: var(--text-3);
  color: var(--text-1);
}

.btn--danger {
  color: var(--text-3);
}

.btn--danger:hover {
  color: #e05555;
  border-color: rgba(224, 85, 85, 0.25);
  background: rgba(224, 85, 85, 0.06);
}

.btn--sm {
  font-size: 0.78rem;
  padding: 0.35rem 0.65rem;
}

.stat-chip {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-2);
  white-space: nowrap;
  transition: color var(--transition);
}

.stat-chip span {
  color: var(--text-1);
  font-weight: 500;
  transition: color var(--transition);
}

.task-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.empty-state {
  background: var(--surface);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: 2.75rem 1.5rem;
  text-align: center;
  transition:
    background var(--transition),
    border-color var(--transition);
}

.empty-state p {
  color: var(--text-3);
  font-size: 0.85rem;
  transition: color var(--transition);
}

.task-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  gap: 0.875rem;
  padding: 0.8rem 0.875rem;
  transition:
    background var(--transition),
    border-color var(--transition),
    opacity var(--transition);
}

.task-card:hover {
  border-color: var(--text-3);
}

.task-card__status-bar {
  width: 3px;
  min-height: 36px;
  align-self: stretch;
  border-radius: 2px;
  background: var(--border);
  flex-shrink: 0;
  transition: background var(--transition);
}

.task-card[data-status="complete"] .task-card__status-bar {
  background: #00FF7F;
}

.task-card__body {
  flex: 1;
  min-width: 0;
}

.task-card__meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.2rem;
}

.task-card__id {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-3);
  letter-spacing: 0.04em;
  transition: color var(--transition);
}

.task-card__title {
  font-size: 0.88rem;
  color: var(--text-1);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: color var(--transition);
}

.task-card[data-status="complete"] .task-card__title {
  text-decoration: line-through;
  color: var(--text-2);
}

.task-card__actions {
  display: flex;
  gap: 0.3rem;
  flex-shrink: 0;
}

.badge {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 0.15rem 0.45rem;
  border-radius: 3px;
  background: var(--surface-2);
  color: var(--text-2);
  border: 1px solid var(--border);
  transition:
    background var(--transition),
    border-color var(--transition),
    color var(--transition);
}

.tag {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  padding: 0.15rem 0.5rem;
  border-radius: 3px;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-3);
  transition:
    border-color var(--transition),
    color var(--transition);
}

.mono {
  font-family: var(--font-mono);
}

.prop-demo {
  margin-bottom: 1rem;
}

.prop-box {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.125rem;
  transition:
    border-color var(--transition),
    background var(--transition);
}

.prop-box--grandparent {
  background: var(--surface);
}

.prop-box--parent {
  background: var(--surface-2);
  margin-top: 0.75rem;
}

.prop-box--child {
  display: block;
  width: 100%;
  margin-top: 0.75rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-1);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 500;
  padding: 0.65rem 1rem;
  text-align: center;
  cursor: pointer;
  transition:
    background var(--transition),
    border-color var(--transition),
    color var(--transition);
}

.prop-box--child:hover {
  border-color: var(--text-3);
  background: var(--surface);
}

.prop-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.64rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text-3);
  margin-bottom: 0.25rem;
  transition: color var(--transition);
}

.prop-controls {
  display: flex;
  align-items: center;
  gap: 0.875rem;
}

.hint {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-3);
  transition: color var(--transition);
}

.pipeline {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-top: 1.25rem;
}

.pipeline__sources {
  display: flex;
  align-items: flex-start;
  justify-content: center;
}

.pipeline__branch {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 150px;
}

.pipeline__gap {
  width: 3rem;
  flex-shrink: 0;
}

.pipeline__merge-row {
  display: flex;
  align-items: center;
  width: 100%;
  max-width: 340px;
  margin-top: 1.5rem;
  margin-bottom: 0.25rem;
}

.pipeline__merge-line {
  flex: 1;
  height: 1px;
  background: var(--border);
  transition: background var(--transition);
}

.pipeline__merge-badge {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-2);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.25rem 0.6rem;
  white-space: nowrap;
  letter-spacing: 0.02em;
  transition:
    background var(--transition),
    border-color var(--transition),
    color var(--transition);
}

.pipeline__output {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.p-node {
  padding: 0.48rem 1.25rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text-1);
  font-size: 0.82rem;
  font-weight: 500;
  text-align: center;
  min-width: 140px;
  transition:
    background var(--transition),
    border-color var(--transition),
    color var(--transition);
}

.p-node--source {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  background: var(--surface-2);
  color: var(--text-2);
  border-color: var(--text-3);
  letter-spacing: 0.05em;
}

.p-node--output {
  border-color: var(--text-2);
  color: var(--accent);
}

.p-node--result {
  border-color: var(--text-2);
  color: var(--text-1);
  min-width: 160px;
}

.p-node--spacer {
  visibility: hidden;
  border-color: transparent;
  background: transparent;
}

.p-arrow {
  font-size: 0.85rem;
  color: var(--text-3);
  line-height: 2.1;
  user-select: none;
  transition: color var(--transition);
}

.p-arrow--hidden {
  visibility: hidden;
}

@media (max-width: 560px) {
  .header {
    padding: 0.75rem 1rem;
  }

  .main {
    padding: 1.25rem 1rem 4rem;
  }

  .task-form {
    flex-wrap: wrap;
  }

  .task-form .select {
    flex: 1;
  }

  .controls-bar {
    flex-direction: column;
    align-items: stretch;
  }

  .controls-bar__right {
    justify-content: flex-end;
  }

  .pipeline__branch {
    min-width: 120px;
  }

  .p-node {
    min-width: 110px;
    font-size: 0.78rem;
    padding: 0.4rem 0.75rem;
  }

  .pipeline__gap {
    width: 1.5rem;
  }

  .pipeline__merge-badge {
    font-size: 0.6rem;
    padding: 0.2rem 0.4rem;
  }

  .task-card__actions .btn--sm:not(.btn--danger) {
    display: none;
  }
}