/* T028 — Google Fonts: JetBrains Mono */
@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;700&display=swap');

/* T028 — CSS Custom Properties: dark terminal palette */
:root {
  --color-bg: #0d0d0d;
  --color-surface: #1a1a1a;
  --color-border: #2e2e2e;
  --color-text: #e0e0e0;
  --color-text-muted: #6b6b6b;
  --color-accent: #39ff14;
  --color-error: #ff4444;
  --font-mono: 'JetBrains Mono', 'Courier New', Courier, monospace;
  --radius: 2px;
  --transition-speed: 180ms;
}

/* Reset */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

/* T028 — Base body styles */
body {
  background-color: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  line-height: 1.5;
}

/* =====================================================================
   T029 — .todo-app layout
   ===================================================================== */

.todo-app {
  max-width: 640px;
  margin-inline: auto;
  padding: 3rem 1.25rem 4rem;
  min-height: 100vh;
}

.todo-app__header {
  margin-bottom: 2rem;
}

.todo-app__title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: 0.05em;
}

/* =====================================================================
   T030 — .todo-form BEM component
   ===================================================================== */

.todo-form {
  margin-bottom: 2rem;
}

.todo-form__label {
  display: block;
  font-size: 0.75rem;
  color: var(--color-text-muted);
  text-transform: lowercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.4rem;
}

.todo-form__row {
  display: flex;
  gap: 0.5rem;
  align-items: stretch;
}

.todo-form__input {
  flex: 1;
  background-color: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.5rem 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  outline: none;
  transition: border-color var(--transition-speed);
}

.todo-form__input::placeholder {
  color: var(--color-text-muted);
}

.todo-form__input:focus {
  border-color: var(--color-accent);
}

/* T017 — Error modifier */
.todo-form__input--error {
  border-color: var(--color-error);
}

.todo-form__btn {
  background-color: transparent;
  color: var(--color-accent);
  border: 1px solid var(--color-accent);
  border-radius: var(--radius);
  padding: 0.5rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  cursor: pointer;
  transition: background-color var(--transition-speed), color var(--transition-speed);
}

.todo-form__btn:hover,
.todo-form__btn:focus-visible {
  background-color: var(--color-accent);
  color: var(--color-bg);
  outline: none;
}

/* T017 — Error span visibility */
.todo-form__error {
  display: block;
  font-size: 0.78rem;
  color: var(--color-error);
  margin-top: 0.35rem;
  min-height: 1.1rem;
}

/* Deadline row */
.todo-form__row--deadline {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.todo-form__label--inline {
  display: inline;
  margin-bottom: 0;
  white-space: nowrap;
}

.todo-form__input--deadline {
  flex: 1;
  background-color: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 0.4rem 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  outline: none;
  transition: border-color var(--transition-speed);
  color-scheme: dark;
}

.todo-form__input--deadline:focus {
  border-color: var(--color-accent);
}

/* =====================================================================
   T031 — .todo-list and .todo-item BEM components
   ===================================================================== */

.todo-list {
  list-style: none;
  padding: 0;
}

.todo-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.65rem 0;
  border-bottom: 1px solid var(--color-border);
}

.todo-item:last-child {
  border-bottom: none;
}

/* T021 — .todo-item--done modifier */
.todo-item--done .todo-item__text {
  text-decoration: line-through;
  opacity: 0.45;
}

/* Overdue modifier */
.todo-item--overdue {
  border-left: 2px solid #ffaa00;
  padding-left: 0.5rem;
  background-color: rgba(255, 170, 0, 0.06);
}

.todo-item--overdue::after {
  content: '⚠';
  font-size: 0.7rem;
  color: #ffaa00;
  margin-left: 0.5rem;
  margin-right: 0.5rem;
  flex-shrink: 0;
}

/* Deadline label */
.todo-item__deadline {
  font-size: 0.75rem;
  color: var(--color-text-muted);
  white-space: nowrap;
  flex-shrink: 0;
}

.todo-item--overdue .todo-item__deadline {
  color: #ffaa00;
}

.todo-item__toggle {
  flex-shrink: 0;
  width: 1.1rem;
  height: 1.1rem;
  background-color: transparent;
  border: 1px solid var(--color-text-muted);
  border-radius: var(--radius);
  cursor: pointer;
  position: relative;
  transition: border-color var(--transition-speed), background-color var(--transition-speed);
}

.todo-item__toggle:hover,
.todo-item__toggle:focus-visible {
  border-color: var(--color-accent);
  outline: none;
}

.todo-item--done .todo-item__toggle {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
}

.todo-item--done .todo-item__toggle::after {
  content: '';
  display: block;
  width: 0.3rem;
  height: 0.55rem;
  border: 2px solid var(--color-bg);
  border-top: none;
  border-left: none;
  transform: rotate(45deg);
  position: absolute;
  top: 0.05rem;
  left: 0.28rem;
}

.todo-item__text {
  flex: 1;
  word-break: break-word;
  transition: opacity var(--transition-speed);
}

.todo-item__remove {
  flex-shrink: 0;
  background-color: transparent;
  border: none;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  cursor: pointer;
  padding: 0 0.2rem;
  line-height: 1;
  transition: color var(--transition-speed);
}

.todo-item__remove::before {
  content: '×';
}

.todo-item__remove:hover,
.todo-item__remove:focus-visible {
  color: var(--color-error);
  outline: none;
}

/* =====================================================================
   T032 — .todo-list__empty
   ===================================================================== */

.todo-list__empty {
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  padding: 0.65rem 0;
}

/* =====================================================================
   T033 — Microanimations
   ===================================================================== */

@keyframes todo-enter {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes todo-leave {
  from {
    opacity: 1;
    transform: translateX(0);
  }
  to {
    opacity: 0;
    transform: translateX(30px);
  }
}

.todo-item--entering {
  animation: todo-enter 200ms ease-out both;
}

.todo-item--leaving {
  animation: todo-leave 200ms ease-in both;
  pointer-events: none;
}

/* =====================================================================
   Responsive — 320px viewport (T029)
   ===================================================================== */

@media (max-width: 360px) {
  .todo-app {
    padding: 1.5rem 0.75rem 2rem;
  }

  .todo-form__row {
    flex-direction: column;
  }

  .todo-form__btn {
    width: 100%;
  }
}

/* =====================================================================
   Responsive — Mobile touch targets (T017 — US4)
   ===================================================================== */

@media (max-width: 768px) {
  /* Touch targets: remove button and add button get 44×44; toggle stays compact */
  .todo-item__remove,
  .todo-form__btn {
    min-height: 44px;
    min-width: 44px;
  }

  .todo-item__toggle {
    width: 1.4rem;
    height: 1.4rem;
    flex-shrink: 0;
  }

  .todo-item__text,
  .todo-form__input {
    font-size: 1rem;
  }

  .todo-item__deadline,
  .todo-form__error {
    font-size: 0.875rem;
  }

  .todo-item {
    gap: 0.75rem;
    padding: 0.85rem 0;
  }

  /* Deadline row: stack label above input to avoid overflow */
  .todo-form__row--deadline {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.3rem;
  }

  .todo-form__input--deadline {
    width: 100%;
    font-size: 0.8rem;
  }
}