/* ========================================================
   TASKFLOW - MODERN DESIGN SYSTEM & STYLES
   ======================================================== */

:root {
  /* Color Tokens - Dark Mode (Default) */
  --bg-primary: #0b0f19;
  --bg-secondary: #131b2e;
  --bg-card: rgba(22, 32, 54, 0.75);
  --bg-card-hover: rgba(28, 41, 70, 0.85);
  --bg-input: #1a243b;
  --border-color: rgba(255, 255, 255, 0.08);
  --border-focus: #6366f1;

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --primary: #6366f1;
  --primary-hover: #4f46e5;
  --primary-light: rgba(99, 102, 241, 0.15);

  --accent-green: #10b981;
  --accent-green-bg: rgba(16, 185, 129, 0.15);
  --accent-orange: #f59e0b;
  --accent-orange-bg: rgba(245, 158, 11, 0.15);
  --accent-red: #ef4444;
  --accent-red-bg: rgba(239, 68, 68, 0.15);
  --accent-blue: #38bdf8;
  --accent-blue-bg: rgba(56, 189, 248, 0.15);

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.35);
  --shadow-glow: 0 0 25px rgba(99, 102, 241, 0.3);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;

  --font-family: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="light"] {
  --bg-primary: #f1f5f9;
  --bg-secondary: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.85);
  --bg-card-hover: rgba(255, 255, 255, 0.98);
  --bg-input: #f8fafc;
  --border-color: rgba(148, 163, 184, 0.25);
  --border-focus: #4f46e5;

  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;

  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-light: rgba(79, 70, 229, 0.1);

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 10px 25px rgba(15, 23, 42, 0.08);
  --shadow-glow: 0 0 25px rgba(79, 70, 229, 0.15);
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.5;
  overflow-x: hidden;
  transition: background-color 0.3s ease, color 0.3s ease;
  position: relative;
}

/* Background Glowing Orbs */
.glow-orb {
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
  z-index: 0;
  opacity: 0.45;
}

.orb-1 {
  width: 450px;
  height: 450px;
  background: radial-gradient(circle, #6366f1 0%, transparent 70%);
  top: -100px;
  left: -100px;
}

.orb-2 {
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, #38bdf8 0%, transparent 70%);
  bottom: -150px;
  right: -100px;
}

/* Main Layout */
.app-layout {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

/* Header */
.app-header {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 20;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand-group {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.logo-box {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #6366f1, #3b82f6);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.4);
}

.brand-title {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.badge-node {
  font-size: 0.7rem;
  font-weight: 700;
  background: #22c55e;
  color: #0b0f19;
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-full);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.brand-subtitle {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  background: var(--accent-green-bg);
  border: 1px solid rgba(16, 185, 129, 0.3);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-green);
}

.status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--accent-green);
  box-shadow: 0 0 8px var(--accent-green);
  animation: pulseDot 2s infinite ease-in-out;
}

@keyframes pulseDot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.85); }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.6rem 1.15rem;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), #4338ca);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--primary-light);
  border-color: var(--primary);
  color: var(--primary);
}

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

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-primary);
}

.btn-icon {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition);
}

.btn-icon:hover {
  color: var(--text-primary);
  border-color: var(--primary);
  transform: translateY(-1px);
}

/* Main Container */
.main-container {
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  flex: 1;
}

/* Stats Cards */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin-bottom: 2rem;
}

.stat-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.stat-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: rgba(99, 102, 241, 0.3);
}

.stat-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.5rem;
}

.stat-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.stat-icon {
  font-size: 1.15rem;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.04);
}

.stat-value {
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--text-primary);
}

.stat-subtext {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 0.4rem;
}

.progress-bar-container {
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-top: 0.6rem;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, #10b981, #06b6d4);
  border-radius: var(--radius-full);
  transition: width 0.5s ease-out;
}

/* Controls Panel */
.controls-panel {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.75rem;
}

.search-box {
  position: relative;
  flex: 1;
  min-width: 260px;
  display: flex;
  align-items: center;
}

.search-box svg {
  position: absolute;
  left: 0.85rem;
  color: var(--text-muted);
  pointer-events: none;
}

.search-box input {
  width: 100%;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.65rem 2.2rem 0.65rem 2.5rem;
  font-family: inherit;
  font-size: 0.9rem;
  color: var(--text-primary);
  outline: none;
  transition: var(--transition);
}

.search-box input:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.clear-search {
  position: absolute;
  right: 0.75rem;
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 0.9rem;
  cursor: pointer;
  padding: 0.2rem;
}

.clear-search:hover {
  color: var(--text-primary);
}

.filter-group {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.tabs-nav {
  display: flex;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.25rem;
  gap: 0.25rem;
}

.tab-btn {
  background: transparent;
  border: none;
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 0.4rem 0.9rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}

.tab-btn:hover {
  color: var(--text-primary);
}

.tab-btn.active {
  background: var(--primary);
  color: #ffffff;
  box-shadow: var(--shadow-sm);
}

.select-wrapper select {
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.65rem 0.9rem;
  font-family: inherit;
  font-size: 0.85rem;
  color: var(--text-primary);
  outline: none;
  cursor: pointer;
  transition: var(--transition);
}

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

/* Tasks Grid */
.tasks-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.25rem;
}

.task-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.task-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 4px;
  background: var(--border-color);
  transition: var(--transition);
}

.task-card.priority-alta::before {
  background: var(--accent-red);
}
.task-card.priority-media::before {
  background: var(--accent-orange);
}
.task-card.priority-baja::before {
  background: var(--accent-green);
}

.task-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(99, 102, 241, 0.3);
}

.task-card.completed {
  opacity: 0.75;
  background: rgba(22, 32, 54, 0.4);
}

[data-theme="light"] .task-card.completed {
  background: rgba(241, 245, 249, 0.6);
}

.task-header {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin-bottom: 0.65rem;
}

/* Custom Checkbox */
.checkbox-container {
  display: inline-flex;
  align-items: center;
  position: relative;
  cursor: pointer;
  user-select: none;
  margin-top: 0.15rem;
}

.checkbox-container input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
  height: 0;
  width: 0;
}

.custom-checkbox {
  width: 22px;
  height: 22px;
  border: 2px solid var(--border-color);
  border-radius: 6px;
  background: var(--bg-input);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.checkbox-container:hover input ~ .custom-checkbox {
  border-color: var(--primary);
}

.checkbox-container input:checked ~ .custom-checkbox {
  background-color: var(--accent-green);
  border-color: var(--accent-green);
  box-shadow: 0 0 10px rgba(16, 185, 129, 0.4);
}

.custom-checkbox::after {
  content: '';
  display: none;
  width: 5px;
  height: 10px;
  border: solid #ffffff;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
  margin-bottom: 2px;
}

.checkbox-container input:checked ~ .custom-checkbox::after {
  display: block;
}

.task-title-group {
  flex: 1;
}

.task-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.35;
  word-break: break-word;
  transition: var(--transition);
}

.task-card.completed .task-title {
  text-decoration: line-through;
  color: var(--text-muted);
}

.task-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin: 0.5rem 0 1rem 0;
  line-height: 1.45;
  word-break: break-word;
}

.task-card.completed .task-desc {
  color: var(--text-muted);
}

/* Meta Badges */
.task-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.pill-badge {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  text-transform: capitalize;
}

.badge-cat {
  background: var(--bg-input);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

.badge-priority-alta {
  background: var(--accent-red-bg);
  color: var(--accent-red);
  border: 1px solid rgba(239, 68, 68, 0.25);
}

.badge-priority-media {
  background: var(--accent-orange-bg);
  color: var(--accent-orange);
  border: 1px solid rgba(245, 158, 11, 0.25);
}

.badge-priority-baja {
  background: var(--accent-green-bg);
  color: var(--accent-green);
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.task-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 0.75rem;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.task-actions {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.action-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0.35rem;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.action-btn:hover {
  background: var(--bg-input);
  color: var(--text-primary);
}

.action-btn.delete-btn:hover {
  background: var(--accent-red-bg);
  color: var(--accent-red);
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 4rem 1.5rem;
  background: var(--bg-card);
  border: 1px dashed var(--border-color);
  border-radius: var(--radius-lg);
  max-width: 500px;
  margin: 2rem auto;
}

.empty-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.empty-state h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.empty-state p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}

/* Loading State */
.loading-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-secondary);
}

.spinner {
  width: 36px;
  height: 36px;
  border: 3px solid rgba(99, 102, 241, 0.2);
  border-top-color: var(--primary);
  border-radius: 50%;
  margin: 0 auto 1rem auto;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 1.25rem;
  opacity: 1;
  transition: opacity 0.2s ease;
}

.modal-overlay.hidden {
  display: none;
  opacity: 0;
}

.modal-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 520px;
  box-shadow: var(--shadow-md);
  overflow: hidden;
  animation: modalPop 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalPop {
  from {
    transform: scale(0.95) translateY(10px);
    opacity: 0;
  }
  to {
    transform: scale(1) translateY(0);
    opacity: 1;
  }
}

.modal-header {
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-header h2 {
  font-size: 1.2rem;
  font-weight: 700;
}

.modal-close {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.6rem;
  cursor: pointer;
  line-height: 1;
  transition: var(--transition);
}

.modal-close:hover {
  color: var(--text-primary);
}

.modal-form {
  padding: 1.5rem;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 0.4rem;
}

.required {
  color: var(--accent-red);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  background: var(--bg-input);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.7rem 0.9rem;
  font-family: inherit;
  font-size: 0.9rem;
  color: var(--text-primary);
  outline: none;
  transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.modal-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.75rem;
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}

/* Toast Notification */
.toast-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  z-index: 200;
  pointer-events: none;
}

.toast {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.75rem 1.25rem;
  color: var(--text-primary);
  font-size: 0.88rem;
  font-weight: 500;
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  gap: 0.65rem;
  pointer-events: auto;
  animation: slideInRight 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.toast.success { border-left: 4px solid var(--accent-green); }
.toast.error { border-left: 4px solid var(--accent-red); }
.toast.info { border-left: 4px solid var(--primary); }

@keyframes slideInRight {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

/* Footer */
.app-footer {
  text-align: center;
  padding: 1.5rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.8rem;
  background: var(--bg-card);
}

.hidden {
  display: none !important;
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .header-container {
    flex-direction: column;
    align-items: stretch;
  }

  .header-actions {
    justify-content: space-between;
  }

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

  .filter-group {
    flex-direction: column;
    align-items: stretch;
  }

  .tabs-nav {
    width: 100%;
    justify-content: space-between;
  }

  .form-row {
    grid-template-columns: 1fr;
  }
}