/*~ 1. RESET & GLOBAL */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

body {
  background-color: var(--bg-color);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color 0.2s ease, color 0.2s ease;
}

i[class*="fa"] {
  pointer-events: none;
}

/*~ 2. VARIABLES (LIGHT + DARK) */

:root {
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --bg-color: #f9fafb;
  --card-bg: #ffffff;
  --text-main: #111827;
  --text-muted: #6b7280;
  --warning: #f59e0b;
  --danger: #ef4444;
  --success: #10b981;
  --border-radius: 12px;
}

body.dark {
  --primary: #818cf8;
  --primary-hover: #6366f1;
  --bg-color: #0f172a;
  --card-bg: #111827;
  --text-main: #f9fafb;
  --text-muted: #9ca3af;
  --danger: #f87171;
  --warning: #fbbf24;
  --success: #34d399;
}

/*~ 3.1. LAYOUT header */

header {
  background-color: var(--card-bg);
  backdrop-filter: blur(10px);
  padding: 15px 5%;
  box-shadow: 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  display: flex;
  justify-content: space-around;
  align-items: center;
  gap: 20px;
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

/* *first div */
header>div:first-child {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

#toggleDarkMode {
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 1.3rem;
  cursor: pointer;
  padding: 8px;
  border-radius: var(--border-radius);
  transition: background 0.2s ease;
}

/* *searching tasks */
#searchContainer {
  position: relative;
  flex: 1;
  max-width: 400px;
  display: flex;
  align-items: center;
}

#searchContainer i {
  position: absolute;
  left: 12px;
  color: var(--text-muted);
  font-size: 0.9rem;
}

#searchInput {
  width: 100%;
  padding: 10px 15px 10px 38px;
  border: 1px solid #d1d5db;
  border-radius: var(--border-radius);
  background-color: var(--bg-color);
  color: var(--text-main);
  outline: none;
  transition: all 0.2s ease;
}

#searchInput:focus {
  border-color: var(--primary);
  background-color: var(--card-bg);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* *filters selections */
.filtersDiv {
  display: flex;
  gap: 10px;
}

select {
  padding: 8px 12px;
  border: 1px solid #d1d5db;
  border-radius: var(--border-radius);
  background-color: var(--card-bg);
  color: var(--text-main);
  cursor: pointer;
  outline: none;
  transition: border 0.2s ease, box-shadow 0.2s ease;
}

select:focus {
  border-color: var(--primary);
}

/*~ 3.2. LAYOUT main */
main {
  flex: 1;
  width: 100%;
  max-width: 900px;
  margin: 30px auto;
  padding: 0 20px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* *list of tasks */
#tasksUl {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 15px;
  padding: 0 0 40px 0;
  margin: 0;
}

.task_li {
  background-color: var(--card-bg);
  padding: 20px;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-md);
  border-left: 5px solid var(--primary);
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1),
    box-shadow 0.3s ease;
  position: relative;
  overflow: hidden;
}

.task_li.completed {
  border-left-color: var(--success);
  opacity: 0.70;
}

/** styling tasks*/
.task_li.completed {
  border-left-color: var(--success);
  opacity: 0.65;
}

.task_li.completed .task-title {
  color: var(--text-muted);
  font-style: italic;
}

.task-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
}

.task-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 10px;
  margin-bottom: 10px;
}

.task-details {
  display: flex;
  align-items: center;
  gap: 12px;
}

.task-checkbox {
  width: 18px;
  height: 18px;
  cursor: pointer;
  accent-color: var(--success);
  transition: all 0.2s ease;
  border-radius: 4px;
}

.task-checkbox:checked {
  transform: scale(1.1);
}

.task-actions {
  display: flex;
  gap: 8px;
}

.task-actions .btn {
  padding: 8px 12px;
  font-size: 0.855rem;
}

.task-content {
  display: flex;
  gap: 15px;
  padding-left: 30px;
  font-size: 0.85rem;
  color: var(--text-muted);
  flex-wrap: wrap;
}

.task-content span {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 12px;
  border-radius: 20px;
  background-color: var(--bg-color);
  color: var(--text-muted);
  border: 1px solid transparent;
  display: flex;
  align-items: center;
  gap: 5px;
}

.task-actions {
  gap: 12px;
  padding-left: 10px;
}

/* * styling dead line date */
.got-time {
  background-color: rgba(16, 185, 129, 0.1) !important;
  color: var(--success) !important;
  border: 1px solid var(--success);
}

.due-today {
  background-color: rgba(245, 158, 11, 0.1) !important;
  color: var(--warning) !important;
  border: 1px solid var(--warning);
}

.overdue {
  background-color: rgba(239, 68, 68, 0.1) !important;
  color: var(--danger) !important;
  border: 1px solid var(--danger);
}

/*~ 3.3. LAYOUT footer */
footer {
  margin-top: auto;
  padding: 30px 20px;
  background-color: var(--card-bg);
  border-top: 1px solid rgba(0, 0, 0, 0.05);
  transition: background-color 0.3s ease;
}

.footer-content {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  text-align: center;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.1rem;
  color: var(--primary);
}

.footer-logo img {
  border-radius: 6px;
}

.footer-links {
  display: flex;
  gap: 20px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-links a {
  display: flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
  color: inherit;
  transition: 0.2s ease;
}

.copyright {
  font-size: 0.75rem;
  color: var(--text-muted);
  opacity: 0.7;
}

.footer-links a i {
  font-size: 1.1rem;
}

/*~ 4. COMPONENTS */
/** buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background-color: var(--primary);
  color: white;
  border: none;
  padding: 10px 18px;
  border-radius: var(--border-radius);
  cursor: pointer;
  font-weight: 600;
  font-size: 0.9rem;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  white-space: nowrap;
}

.btn,
.task-checkbox,
#toggleDarkMode {
  min-width: 25px;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.btn:active {
  transform: translateY(0);
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.1);
}

#cancelForm,
#cancelDelete,
#resetForm {
  background-color: var(--text-muted);
  color: white;
}

#confirmDelete {
  background-color: var(--danger);
}

.task-actions .btn {
  padding: 5px 13px;
  font-size: 1rem;
}

/** forms */
#taskForm table {
  width: 100%;
  border-spacing: 0 10px;
}

#taskForm td:first-child {
  font-weight: 600;
  width: 30%;
  color: var(--text-main);
  vertical-align: middle;
}

#taskForm td:nth-child(2) {
  width: 70%;
}

#taskForm :where([type="text"], input[type="date"]) {
  width: 100%;
  padding: 10px;
  border: 1px solid #d1d5db;
  border-radius: var(--border-radius);
  outline: none;
  background-color: var(--bg-color);
  color: var(--text-main);
  transition: border 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

table tr:last-of-type td input {
  display: block;
  margin: auto;
}

#taskForm input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
  background-color: var(--card-bg);
}

/*range style */
#rangeTd {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  width: 100%;
  padding: 5px 0;
}

#priorityPreview {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  min-width: 80px;
  padding: 5px 10px;
  background-color: var(--primary);
  color: white;
  font-size: 0.75rem;
  font-weight: 800;
  text-transform: uppercase;
  border-radius: 6px;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

input[type="range"] {
  appearance: none;
  flex: 1;
  height: 6px;
  background: #e2e8f0;
  border-radius: 10px;
  outline: none;
  cursor: pointer;
  border: none;
}

body.dark input[type="range"] {
  background: #374151;
}

/* validation error styling */
.wronginput {
  border: 1.5px solid var(--danger) !important;
  background-color: rgba(239, 68, 68, 0.05) !important;
}

.errorText {
  display: none;
  color: var(--danger);
  font-size: 0.8rem;
  margin-top: 5px;
  font-weight: 600;
}

.errorText.show {
  display: block;
}

/** modals */
@keyframes modalFade {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.98);
  }

  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.modal {
  border: none;
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  padding: 25px;
  border-radius: 12px;
  background-color: var(--card-bg);
  color: var(--text-main);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.2);
  width: 90%;
  max-width: 500px;
  animation: modalFade 0.25s ease;
  z-index: 1000;
}

.modal::backdrop {
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  margin-top: 15px;
  gap: 10px;
}

/** toast */
.toast {
  position: fixed;
  bottom: 30px;
  right: 30px;
  padding: 14px 22px;
  border-radius: var(--border-radius);
  font-weight: bold;
  color: white;
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
  opacity: 0;
  transform: translateY(100px) scale(0.9);
  pointer-events: none;
  transition: all 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  z-index: 50;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
  pointer-events: none;
}

.toast.hidden {
  opacity: 0;
  transform: translateY(100px);
  pointer-events: none;
}

.toast.success {
  background-color: var(--success);
}

.toast.error {
  background-color: var(--danger);
}

/*~ 6. Dark mode style */

body.dark #searchInput {
  border-color: #374151;
}

body.dark .toast {
  box-shadow: 0 0 10px rgba(81, 79, 79, 0.8);
}

body.dark .task-content span {
  background-color: rgba(255, 255, 255, 0.05);
  border-color: rgba(255, 255, 255, 0.1);
}

body.dark :where(input[type="text"], input[type="date"], select, datalist) {
  background-color: #1e293b;
  color: #f9fafb;
  border: 1px solid #374151;
}

body.dark input::-webkit-calendar-picker-indicator {
  filter: invert(1);
}

body.dark #taskForm input:focus {
  border-color: var(--primary);
  background-color: #1e293b;
}

body.dark .empty {
  border-color: #374151;
  background-color: rgba(30, 41, 59, 0.5);
}

body.dark footer {
  border-top-color: rgba(255, 255, 255, 0.05);
}

/*~ 7. MEDIA QUERIES */
@media (max-width: 768px) {
  header {
    flex-direction: column;
    padding: 15px;
    gap: 12px;
  }

  header>div:first-child {
    width: 100%;
    justify-content: space-between;
  }

  #searchContainer {
    width: 100%;
    max-width: none;
    order: 3;
  }

  .filtersDiv {
    width: 100%;
    justify-content: space-between;
    order: 2;
  }

  .filtersDiv select {
    flex: 1;
  }

  main {
    margin: 15px auto;
    padding: 0 12px;
  }

  .task_li {
    padding: 15px;
  }

  .task-content {
    padding-left: 0;
    margin-top: 12px;
    gap: 8px;
  }

  .task-content span {
    font-size: 0.7rem;
    padding: 3px 8px;
  }

  .modal {
    width: 95%;
    padding: 20px 15px;
  }

  #taskForm td:first-child {
    width: 40%;
    font-size: 0.85rem;
  }

  .today-date {
    font-size: 1.1rem;
    justify-content: center;
    margin-bottom: 15px;
    align-self: center;
  }

  .toast {
    right: 15px;
    left: 15px;
    bottom: 20px;
    text-align: center;
    justify-content: center;
  }

  .footer-content {
    gap: 10px;
  }

  .footer-links {
    flex-direction: column;
    gap: 10px;
  }

  .footer-logo {
    justify-content: center;
  }
}

/*~ 8. HOVER EFFECTS */
@media (hover: hover) {
  .footer-links a:hover {
    color: var(--primary);
  }

  .task-content span:hover {
    transform: scale(1.05);
  }

  .task_li:hover {
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
    transform: translateY(-3px);
  }

  #cancelForm:hover,
  #cancelDelete:hover,
  #resetForm:hover {
    background-color: #4b5563;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  }

  .btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.2);
  }

  #toggleDarkMode:hover {
    background-color: rgba(255, 255, 255, 0.1);
  }

  #confirmDelete:hover {
    background-color: #dc2626;
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.2);
  }

  .footer-links a:hover {
    color: var(--primary);
    transform: translateY(-2px);
  }
}

/*~ 9. no result messages and current day styles*/
.empty {
  text-align: center;
  padding: 40px 20px;
  font-size: 1.1rem;
  color: var(--text-muted);
  background-color: var(--card-bg);
  border-radius: var(--border-radius);
  border: 2px dashed #d1d5db;
  margin-top: 20px;
  transition: all 0.3s ease;
}

.today-date {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 5px;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: 10px;
}

#todayDate {
  opacity: 0.9;
  transition: color 0.3s ease;
}