/* ===== VARIÁVEIS ===== */
:root {
  --bg-primary: #121212;
  --bg-secondary: #1e1e1e;
  --bg-card: #252525;
  --accent: #4a9eff;
  --accent-hover: #6ab1ff;
  --text-primary: #f0f0f0;
  --text-secondary: #b0b0b0;
  --border: #333;
  --success: #4caf50;
  --warning: #ff9800;
  --danger: #f44336;
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  --transition-fast: all 0.15s ease;
  --transition-slow: all 0.5s cubic-bezier(0.68, -0.55, 0.265, 1.55);
  --border-radius: 12px;
}

/* ===== RESET & BASE ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  padding: 20px;
  line-height: 1.6;
  opacity: 0;
  animation: fadeIn 0.5s ease forwards;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  animation: slideInUp 0.5s ease;
  overflow-x: hidden;
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

html,
body {
  overflow-x: hidden;
  width: 100%;
  max-width: 100%;
}

/* ===== HEADER ===== */
header {
  text-align: center;
  padding: 20px 0 30px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 30px;
  animation: slideInDown 0.5s ease;
}

@keyframes slideInDown {
  from {
    opacity: 0;
    transform: translateY(-30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

h1 {
  color: var(--accent);
  font-size: 2.5rem;
  margin-bottom: 10px;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* ===== MENU PRINCIPAL ===== */
.menu {
  overflow: hidden;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
  margin-bottom: 40px;
}

.menu-btn {
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--border-radius);
  padding: 25px 20px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  color: var(--text-primary);
  position: relative;
  overflow: hidden;
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 0.5s ease forwards;
}

.menu-btn:nth-child(1) {
  animation-delay: 0.1s;
}
.menu-btn:nth-child(2) {
  animation-delay: 0.2s;
}
.menu-btn:nth-child(3) {
  animation-delay: 0.3s;
}
.menu-btn:nth-child(4) {
  animation-delay: 0.4s;
}
.menu-btn:nth-child(5) {
  animation-delay: 0.5s;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.menu-btn::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.1),
    transparent
  );
  transition: left 0.5s ease;
}

.menu-btn:hover::before {
  left: 100%;
}

.menu-btn:hover {
  transform: translateY(-8px) scale(1.02);
  box-shadow: var(--shadow);
  border-color: var(--accent);
}

.menu-btn:active {
  transform: translateY(-4px) scale(0.98);
  transition: var(--transition-fast);
}

.menu-btn i {
  font-size: 2.5rem;
  margin-bottom: 15px;
  color: var(--accent);
  transition: var(--transition);
}

.menu-btn:hover i {
  transform: scale(1.1);
}

.menu-btn h2 {
  font-size: 1.5rem;
  margin-bottom: 10px;
}

.menu-btn p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ===== PAINÉIS ===== */
.panel {
  background-color: var(--bg-secondary);
  border-radius: var(--border-radius);
  padding: 25px;
  margin-bottom: 30px;
  box-shadow: var(--shadow);
  display: none;
  position: relative;
  overflow: hidden;
}

.panel.active {
  display: block;
  animation: slideInRight 0.4s ease;
}

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

.panel.exiting {
  animation: slideOutLeft 0.4s ease forwards;
}

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

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 25px;
  padding-bottom: 15px;
  border-bottom: 1px solid var(--border);
  animation: fadeIn 0.5s ease 0.2s both;
}

.panel-header h2 {
  color: var(--accent);
  font-size: 1.8rem;
}

.close-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: 1.5rem;
  cursor: pointer;
  transition: var(--transition);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.close-btn:hover {
  color: var(--danger);
}

/* ===== FORMULÁRIOS ===== */
.form-group {
  margin-bottom: 20px;
  animation: fadeIn 0.5s ease both;
}

.form-group:nth-child(1) {
  animation-delay: 0.1s;
}
.form-group:nth-child(2) {
  animation-delay: 0.2s;
}
.form-group:nth-child(3) {
  animation-delay: 0.3s;
}

label {
  display: block;
  margin-bottom: 8px;
  color: var(--text-secondary);
  font-weight: 600;
}

input,
textarea,
select {
  width: 100%;
  padding: 12px 15px;
  background-color: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 1rem;
  transition: var(--transition);
}

input:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(74, 158, 255, 0.1);
  transform: translateY(-2px);
}

textarea {
  min-height: 120px;
  resize: vertical;
}

/* ===== BOTÕES ===== */
.btn {
  padding: 12px 24px;
  background-color: var(--accent);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 5px;
  height: 5px;
  background: rgba(255, 255, 255, 0.5);
  opacity: 0;
  border-radius: 100%;
  transform: scale(1, 1) translate(-50%);
  transform-origin: 50% 50%;
}

.btn:focus:not(:active)::after {
  animation: ripple 1s ease-out;
}

@keyframes ripple {
  0% {
    transform: scale(0, 0);
    opacity: 0.5;
  }
  100% {
    transform: scale(40, 40);
    opacity: 0;
  }
}

.btn:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.2);
}

.btn:active {
  transform: translateY(0) scale(0.95);
  transition: var(--transition-fast);
}

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

.btn-danger:hover {
  background-color: #d32f2f;
}

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

.btn-success:hover {
  background-color: #388e3c;
}

.btn-warning {
  background-color: var(--warning);
  color: #333;
}

.btn-warning:hover {
  background-color: #f57c00;
}

/* ===== LISTAS ===== */
.item-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 15px;
}

.item-card {
  background-color: var(--bg-card);
  border-radius: 10px;
  padding: 20px;
  border: 1px solid var(--border);
  transition: var(--transition);
  opacity: 0;
  transform: translateY(10px);
  animation: fadeInUp 0.5s ease forwards;
}

.item-card:hover {
  border-color: var(--accent);
  transform: translateY(-5px) scale(1.02);
  box-shadow: var(--shadow);
}

.item-card:nth-child(1) {
  animation-delay: 0.1s;
}
.item-card:nth-child(2) {
  animation-delay: 0.2s;
}
.item-card:nth-child(3) {
  animation-delay: 0.3s;
}
.item-card:nth-child(4) {
  animation-delay: 0.4s;
}
.item-card:nth-child(5) {
  animation-delay: 0.5s;
}

.item-header {
  display: flex;
  justify-content: space-between;
  align-items: start;
  margin-bottom: 10px;
}

.item-title {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--accent);
  transition: var(--transition);
}

.item-card:hover .item-title {
  color: var(--accent-hover);
}

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

.action-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 1rem;
  transition: var(--transition);
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.action-btn:hover {
  color: var(--accent);
  background-color: rgba(74, 158, 255, 0.1);
  transform: scale(1.1);
}

.empty-message {
  text-align: center;
  padding: 40px;
  color: var(--text-secondary);
  font-style: italic;
  grid-column: 1 / -1;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% {
    opacity: 0.6;
  }
  50% {
    opacity: 1;
  }
  100% {
    opacity: 0.6;
  }
}

/* ===== FLASHCARD 3D ===== */
.study-container {
  max-width: 800px;
  margin: 0 auto;
}

.card-count {
  text-align: center;
  color: var(--text-secondary);
  margin-bottom: 20px;
  animation: fadeIn 0.5s ease;
}

.flashcard-container {
  perspective: 1000px;
  margin-bottom: 30px;
  min-height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.flashcard {
  position: relative;
  width: 100%;
  max-width: 600px;
  height: 400px;
  transform-style: preserve-3d;
  transition: transform 0.8s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  cursor: pointer;
}

.flashcard.flipped {
  transform: rotateY(180deg);
}

.card-face {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 40px;
  border-radius: 15px;
  background-color: var(--bg-card);
  box-shadow: var(--shadow);
  border: 2px solid var(--border);
  top: 0;
  left: 0;
}

.card-front {
  z-index: 2;
  transform: rotateY(0deg);
}

.card-back {
  transform: rotateY(180deg);
  z-index: 1;
  background-color: var(--bg-card);
}

.card-content {
  font-size: 1.4rem;
  width: 100%;
  animation: fadeIn 0.3s ease;
}

.card-label {
  position: absolute;
  top: 15px;
  left: 15px;
  font-size: 0.8rem;
  color: var(--text-secondary);
  background-color: rgba(0, 0, 0, 0.3);
  padding: 3px 8px;
  border-radius: 10px;
}

.flashcard:hover:not(.flipped) {
  transform: scale(1.02);
}

/* ===== BOTÕES DE DIFICULDADE ===== */
.difficulty-buttons {
  display: flex;
  justify-content: center;
  gap: 15px;
  margin-top: 20px;
  animation: fadeIn 0.5s ease 0.3s both;
}

.difficulty-buttons .btn {
  min-width: 120px;
  opacity: 0;
  transform: translateY(10px);
  animation: fadeInUp 0.5s ease forwards;
}

.difficulty-buttons .btn:nth-child(1) {
  animation-delay: 0.1s;
}
.difficulty-buttons .btn:nth-child(2) {
  animation-delay: 0.2s;
}
.difficulty-buttons .btn:nth-child(3) {
  animation-delay: 0.3s;
}

/* ===== ESTATÍSTICAS ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.stat-card {
  background-color: var(--bg-card);
  border-radius: 10px;
  padding: 20px;
  text-align: center;
  transition: var(--transition);
  opacity: 0;
  transform: translateY(10px);
  animation: fadeInUp 0.5s ease forwards;
}

.stat-card:nth-child(1) {
  animation-delay: 0.1s;
}
.stat-card:nth-child(2) {
  animation-delay: 0.2s;
}
.stat-card:nth-child(3) {
  animation-delay: 0.3s;
}
.stat-card:nth-child(4) {
  animation-delay: 0.4s;
}

.stat-card:hover {
  transform: translateY(-5px) scale(1.05);
  box-shadow: var(--shadow);
}

.stat-value {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--accent);
  margin: 10px 0;
}

.stat-label {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* ===== EXPORTAÇÃO/IMPORTAÇÃO ===== */
.export-options {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  margin-bottom: 30px;
  animation: fadeIn 0.5s ease;
}

.export-btn {
  flex: 1;
  min-width: 200px;
  opacity: 0;
  transform: translateY(10px);
  animation: fadeInUp 0.5s ease forwards;
}

.export-btn:nth-child(1) {
  animation-delay: 0.1s;
}
.export-btn:nth-child(2) {
  animation-delay: 0.2s;
}
.export-btn:nth-child(3) {
  animation-delay: 0.3s;
}

.import-area {
  background-color: var(--bg-card);
  border-radius: 10px;
  padding: 20px;
  margin-top: 20px;
  border: 2px dashed var(--border);
  transition: var(--transition);
  animation: fadeIn 0.5s ease;
}

.import-area.drag-over {
  border-color: var(--accent);
  background-color: rgba(74, 158, 255, 0.05);
  animation: pulseBorder 1.5s infinite;
}

@keyframes pulseBorder {
  0% {
    border-color: var(--accent);
  }
  50% {
    border-color: var(--accent-hover);
  }
  100% {
    border-color: var(--accent);
  }
}

/* ===== LOADING OVERLAY ===== */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
}

.loading-overlay.active {
  opacity: 1;
  visibility: visible;
}

.loading-content {
  text-align: center;
  color: white;
}

.loading-spinner {
  width: 60px;
  height: 60px;
  border: 4px solid rgba(255, 255, 255, 0.1);
  border-left-color: var(--accent);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin: 0 auto 20px;
}

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

.loading-overlay p {
  font-size: 1.2rem;
  animation: pulse 2s infinite;
}

/* ===== ANIMAÇÕES DE NOTIFICAÇÃO ===== */
@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }
  10%,
  30%,
  50%,
  70%,
  90% {
    transform: translateX(-5px);
  }
  20%,
  40%,
  60%,
  80% {
    transform: translateX(5px);
  }
}

@keyframes bounce {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-20px);
  }
}

/* ===== RESPONSIVIDADE ===== */
@media (max-width: 768px) {
  .menu {
    grid-template-columns: 1fr;
  }

  .item-list {
    grid-template-columns: 1fr;
  }

  .difficulty-buttons {
    flex-wrap: wrap;
  }

  .panel {
    padding: 15px;
  }
  .flashcard {
    height: 300px;
  }

  .flashcard-container {
    min-height: 300px;
  }

  .card-content {
    font-size: 1.2rem;
  }

  .export-options {
    flex-direction: column;
  }

  .export-btn {
    min-width: 100%;
  }
}

/* ===== ANIMAÇÃO DE CARREGAMENTO PARA ELEMENTOS ===== */
[data-animate] {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

[data-animate].animated {
  opacity: 1;
  transform: translateY(0);
}
/* Animação otimizada para painéis */
.panel.active {
  display: block;
  animation: panelSlideIn 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94) forwards;
}

@keyframes panelSlideIn {
  from {
    opacity: 0;
    transform: translateX(30px) translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateX(0) translateY(0);
  }
}

/* Resetar animação quando não ativo */
.panel:not(.active) {
  animation: none !important;
}
/* ===== CHECKBOX CUSTOMIZADO ===== */
input[type="checkbox"] {
  width: 18px;
  height: 18px;
  cursor: pointer;
  accent-color: var(--accent);
}

input[type="checkbox"]:hover {
  transform: scale(1.1);
}

label {
  cursor: pointer;
  user-select: none;
}

label:has(input[type="checkbox"]) {
  display: flex;
  align-items: center;
}
/* ===== BOTÕES DE ACERTO/ERRO ===== */
.acerto-erro-buttons {
  animation: fadeIn 0.5s ease;
}

.btn-acerto,
.btn-erro {
  min-width: 140px;
  opacity: 0.7;
  transition: all 0.3s ease;
  border: 2px solid transparent;
}

.btn-acerto {
  background-color: rgba(76, 175, 80, 0.3);
  color: var(--text-primary);
}

.btn-acerto:hover {
  background-color: var(--success);
  opacity: 1;
}

.btn-acerto.active {
  background-color: var(--success);
  opacity: 1;
  border-color: #66bb6a;
  box-shadow: 0 0 15px rgba(76, 175, 80, 0.5);
}

.btn-erro {
  background-color: rgba(244, 67, 54, 0.3);
  color: var(--text-primary);
}

.btn-erro:hover {
  background-color: var(--danger);
  opacity: 1;
}

.btn-erro.active {
  background-color: var(--danger);
  opacity: 1;
  border-color: #ef5350;
  box-shadow: 0 0 15px rgba(244, 67, 54, 0.5);
}