:root {
  --primary: #0B2A4A;
  --secondary: #1C3E5C;
  --accent: #C9A959;
  --accent-light: #E5C47A;
  --accent-gradient: linear-gradient(135deg, #C9A959, #B88D3F);
  --dark: #0A1828;
  --light: #F8F4E9;
  --white: #FFFFFF;
  --success: #2E7D5E;
  --error: #B4433C;
  --gray: #6B7A8F;
  --radius-lg: 32px;
  --radius-md: 20px;
  --radius-sm: 14px;
  --shadow-xl: 0 30px 50px -15px rgba(0,0,0,0.5);
  --shadow-lg: 0 20px 40px -12px rgba(0,0,0,0.4);
  --shadow-md: 0 10px 20px -8px rgba(0,0,0,0.3);
  --shadow-gold: 0 15px 35px -8px rgba(201, 169, 89, 0.3);
}

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

body {
  font-family: 'Inter', 'DM Sans', sans-serif;
  background: var(--dark);
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
}

/* Fondo animado de lujo */
.background {
  position: fixed;
  inset: 0;
  z-index: 0;
}

.background::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 20% 30%, rgba(201, 169, 89, 0.08) 0%, transparent 40%),
              radial-gradient(circle at 80% 70%, rgba(201, 169, 89, 0.06) 0%, transparent 40%),
              linear-gradient(145deg, #0B2A4A 0%, #06192B 100%);
}

.background::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image: 
    radial-gradient(circle at 30% 40%, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    radial-gradient(circle at 70% 60%, rgba(255, 255, 255, 0.02) 1px, transparent 1px);
  background-size: 60px 60px;
  animation: moveParticles 40s linear infinite;
}

@keyframes moveParticles {
  0% { background-position: 0 0; }
  100% { background-position: 60px 60px; }
}

/* Watermark elegante */
.watermark {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) rotate(-12deg) scale(1.2);
  font-family: 'Playfair Display', serif;
  font-size: clamp(120px, 25vw, 240px);
  font-weight: 900;
  color: rgba(201, 169, 89, 0.03);
  white-space: nowrap;
  z-index: 0;
  pointer-events: none;
  letter-spacing: 20px;
  text-transform: uppercase;
  animation: watermarkFloat 20s ease-in-out infinite;
}

@keyframes watermarkFloat {
  0%, 100% { transform: translate(-50%, -50%) rotate(-12deg) scale(1.2); }
  50% { transform: translate(-50%, -50%) rotate(-10deg) scale(1.25); }
}

/* Badges esquineros */
.badge {
  position: fixed;
  z-index: 50;
  font-family: 'Playfair Display', serif;
  font-weight: 700;
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-md);
}

.badge-tl {
  top: 28px;
  left: 28px;
  background: rgba(11, 42, 74, 0.7);
  border: 1.5px solid rgba(201, 169, 89, 0.4);
  border-radius: 60px;
  padding: 10px 24px;
  font-size: 15px;
  color: var(--accent);
  letter-spacing: 3px;
}

.badge-br {
  bottom: 28px;
  right: 28px;
  background: rgba(201, 169, 89, 0.15);
  border: 1.5px solid rgba(201, 169, 89, 0.5);
  border-radius: 60px;
  padding: 12px 28px;
  font-size: 16px;
  color: var(--accent-light);
  letter-spacing: 4px;
  animation: glowPulse 3s ease-in-out infinite;
}

@keyframes glowPulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(201, 169, 89, 0.2); }
  50% { box-shadow: 0 0 35px 10px rgba(201, 169, 89, 0.3); }
}

/* Tarjeta principal */
.card {
  position: relative;
  z-index: 10;
  max-width: 900px;
  margin: 0 auto;
  padding: 40px 25px 60px;
}

/* Header con efecto cristal */
.header {
  background: linear-gradient(145deg, #0C2A4A, #123456);
  border: 1.5px solid rgba(201, 169, 89, 0.3);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  padding: 40px 35px 30px;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-xl);
}

.header::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 80%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), var(--accent-light), transparent);
  animation: shine 5s linear infinite;
}

@keyframes shine {
  0% { left: -100%; }
  50%, 100% { left: 200%; }
}

.header-label {
  font-size: 13px;
  letter-spacing: 6px;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 15px;
  font-weight: 500;
  text-shadow: 0 2px 5px rgba(0,0,0,0.3);
}

.header-title {
  font-family: 'Playfair Display', serif;
  font-size: clamp(2rem, 6vw, 3rem);
  color: var(--white);
  margin-bottom: 8px;
  text-shadow: 0 5px 15px rgba(0,0,0,0.5);
  letter-spacing: 2px;
  font-weight: 900;
}

.header-sub {
  font-size: 1rem;
  color: rgba(255,255,255,0.6);
  font-style: italic;
}

/* Timer */
.timer-container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-top: 25px;
  flex-wrap: wrap;
}

.timer-box {
  background: rgba(0,0,0,0.5);
  border: 2px solid rgba(201, 169, 89, 0.5);
  border-radius: 20px;
  padding: 12px 30px;
  font-family: 'Playfair Display', serif;
  font-size: 2.2rem;
  color: var(--accent-light);
  letter-spacing: 4px;
  min-width: 150px;
  text-align: center;
  backdrop-filter: blur(4px);
  box-shadow: 0 5px 20px rgba(0,0,0,0.4);
  transition: all 0.3s ease;
}

.timer-box.warning {
  background: rgba(180, 67, 60, 0.25);
  border-color: var(--error);
  color: #FF9E9E;
  animation: pulse 1s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); box-shadow: 0 0 30px rgba(180, 67, 60, 0.5); }
}

.student-name {
  font-size: 0.95rem;
  color: rgba(255,255,255,0.8);
  margin-top: 15px;
  font-weight: 400;
}

.student-name span {
  color: var(--accent);
  font-weight: 600;
  background: rgba(201, 169, 89, 0.15);
  padding: 5px 15px;
  border-radius: 50px;
  margin-left: 8px;
  backdrop-filter: blur(4px);
}

/* Panel body */
.panel {
  background: rgba(248, 244, 233, 0.98);
  backdrop-filter: blur(12px);
  border: 1.5px solid rgba(201, 169, 89, 0.3);
  border-top: none;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  padding: 45px 40px 50px;
  box-shadow: var(--shadow-xl);
}

/* Pantalla de acceso */
.access-screen {
  text-align: center;
}

.access-icon {
  font-size: 4rem;
  margin-bottom: 20px;
  filter: drop-shadow(0 10px 15px rgba(201, 169, 89, 0.3));
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

.access-title {
  font-family: 'Playfair Display', serif;
  font-size: 2.2rem;
  color: var(--primary);
  margin-bottom: 10px;
  font-weight: 800;
}

.access-desc {
  color: var(--gray);
  font-size: 1.1rem;
  margin-bottom: 35px;
  line-height: 1.6;
}

/* Caja de reglas */
.rules-card {
  background: linear-gradient(145deg, #FFF9EC, #FFF3E0);
  border: 2px solid var(--accent);
  border-radius: 30px;
  padding: 25px 30px;
  text-align: left;
  margin-bottom: 35px;
  box-shadow: var(--shadow-gold);
}

.rules-title {
  color: #7A621C;
  font-size: 1.1rem;
  margin-bottom: 15px;
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
}

.rules-title i {
  font-size: 1.3rem;
}

.rules-list {
  color: #5E4B1E;
  font-size: 0.95rem;
  padding-left: 25px;
  line-height: 2.1;
}

.rules-list li {
  margin-bottom: 6px;
}

/* Campo de entrada */
.input-field {
  margin-bottom: 25px;
  text-align: left;
}

.input-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 2px;
}

.input-field input {
  width: 100%;
  padding: 16px 22px;
  border: 2px solid #E2E8F0;
  border-radius: 20px;
  font-family: 'Inter', sans-serif;
  font-size: 1.1rem;
  color: var(--primary);
  background: var(--white);
  transition: all 0.3s;
  outline: none;
  box-shadow: 0 5px 12px rgba(0,0,0,0.05);
}

.input-field input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 6px rgba(201, 169, 89, 0.2);
}

/* Botón primario */
.btn-primary {
  background: var(--accent-gradient);
  color: var(--white);
  border: none;
  padding: 18px 50px;
  border-radius: 60px;
  font-family: 'Inter', sans-serif;
  font-size: 1.2rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  letter-spacing: 1px;
  box-shadow: 0 15px 30px -8px rgba(201, 169, 89, 0.4);
  border: 1px solid rgba(255,255,255,0.2);
}

.btn-primary:hover {
  transform: translateY(-4px);
  box-shadow: 0 25px 40px -8px rgba(201, 169, 89, 0.6);
  background: linear-gradient(135deg, #D8B768, #C99F4A);
}

.btn-primary:active {
  transform: translateY(0);
}

/* Barra de progreso */
.progress-section {
  margin-bottom: 30px;
}

.progress-info {
  display: flex;
  justify-content: space-between;
  font-size: 0.95rem;
  color: var(--gray);
  margin-bottom: 10px;
  font-weight: 500;
}

.progress-bar {
  background: #E2E8F0;
  border-radius: 100px;
  height: 12px;
  overflow: hidden;
  box-shadow: inset 0 2px 5px rgba(0,0,0,0.1);
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), #2C5A8C);
  border-radius: 100px;
  transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 0 15px rgba(44, 90, 140, 0.5);
}

/* Pregunta */
.question-container {
  display: none;
}

.question-badge {
  display: inline-block;
  background: var(--primary);
  color: var(--accent-light);
  font-family: 'Playfair Display', serif;
  font-size: 0.9rem;
  padding: 8px 22px;
  border-radius: 50px;
  margin-bottom: 22px;
  letter-spacing: 2px;
  box-shadow: 0 8px 15px rgba(0,0,0,0.2);
  border: 1px solid rgba(201, 169, 89, 0.3);
}

.question-text {
  font-size: 1.3rem;
  line-height: 1.7;
  color: var(--primary);
  margin-bottom: 28px;
  font-weight: 500;
  padding: 15px 20px;
  background: rgba(201, 169, 89, 0.05);
  border-left: 5px solid var(--accent);
  border-radius: 0 20px 20px 0;
}

.highlight {
  background: linear-gradient(120deg, rgba(201, 169, 89, 0.2) 0%, rgba(201, 169, 89, 0.1) 100%);
  padding: 2px 8px;
  border-radius: 8px;
  font-weight: 700;
  color: var(--primary);
}

/* Grid de respuestas */
.answers-grid {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.answer-btn {
  background: var(--white);
  border: 2px solid #E2E8F0;
  border-radius: 20px;
  padding: 18px 22px;
  text-align: left;
  cursor: pointer;
  font-family: 'Inter', sans-serif;
  font-size: 1.1rem;
  color: #2D3A4A;
  transition: all 0.25s;
  display: flex;
  align-items: center;
  gap: 20px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 5px 12px rgba(0,0,0,0.05);
}

.answer-btn::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 0;
  background: linear-gradient(90deg, rgba(44, 90, 140, 0.08), transparent);
  transition: width 0.3s;
}

.answer-btn:hover::before {
  width: 100%;
}

.answer-btn:hover {
  border-color: var(--primary);
  transform: translateX(6px);
  box-shadow: 0 10px 20px rgba(44, 90, 140, 0.15);
}

.answer-letter {
  width: 40px;
  height: 40px;
  min-width: 40px;
  border-radius: 50%;
  background: #F1F5F9;
  border: 2px solid #CBD5E1;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
  color: var(--primary);
  transition: all 0.2s;
}

/* Estados de las respuestas */
.answer-btn.selected {
  background: rgba(44, 90, 140, 0.08);
  border-color: var(--primary);
  box-shadow: 0 0 0 5px rgba(44, 90, 140, 0.15);
}

.answer-btn.selected .answer-letter {
  background: var(--primary);
  border-color: var(--primary);
  color: var(--white);
}

.answer-btn.correct {
  background: rgba(46, 125, 94, 0.1);
  border-color: var(--success);
}

.answer-btn.correct .answer-letter {
  background: var(--success);
  border-color: var(--success);
  color: var(--white);
}

.answer-btn.incorrect {
  background: rgba(180, 67, 60, 0.1);
  border-color: var(--error);
}

.answer-btn.incorrect .answer-letter {
  background: var(--error);
  border-color: var(--error);
  color: var(--white);
}

.answer-btn.disabled {
  pointer-events: none;
  opacity: 0.9;
}

/* Botón siguiente */
.btn-next {
  margin-top: 35px;
  width: 100%;
  padding: 18px;
  background: linear-gradient(135deg, var(--primary), #2C5A8C);
  color: var(--white);
  border: 2px solid var(--accent);
  border-radius: 20px;
  font-family: 'Inter', sans-serif;
  font-size: 1.2rem;
  font-weight: 600;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition: all 0.3s;
  box-shadow: 0 12px 30px rgba(0,0,0,0.3);
}

.btn-next.show {
  opacity: 1;
  pointer-events: all;
  transform: translateY(0);
}

.btn-next:hover {
  filter: brightness(1.2);
  box-shadow: 0 18px 35px rgba(201, 169, 89, 0.4);
}

/* Pantalla de resultados */
.results-screen {
  display: none;
  text-align: center;
}

.medal-icon {
  font-size: 5rem;
  margin-bottom: 15px;
  animation: dropIn 0.7s cubic-bezier(0.4, 0, 0.2, 1);
  filter: drop-shadow(0 15px 20px rgba(201, 169, 89, 0.4));
}

@keyframes dropIn {
  0% {
    transform: translateY(-60px) scale(0.5);
    opacity: 0;
  }
  100% {
    transform: translateY(0) scale(1);
    opacity: 1;
  }
}

.results-sub {
  font-size: 1rem;
  color: var(--gray);
  letter-spacing: 4px;
  text-transform: uppercase;
  margin-bottom: 10px;
  font-weight: 600;
}

/* Anillo de progreso circular */
.ring-wrapper {
  position: relative;
  width: 180px;
  height: 180px;
  margin: 20px auto 15px;
}

.ring-wrapper svg {
  width: 180px;
  height: 180px;
  transform: rotate(-90deg);
  filter: drop-shadow(0 10px 20px rgba(0,0,0,0.2));
}

.ring-bg {
  fill: none;
  stroke: #E2E8F0;
  stroke-width: 14;
}

.ring-fill {
  fill: none;
  stroke: url(#gradientRing);
  stroke-width: 14;
  stroke-linecap: round;
  transition: stroke-dashoffset 1.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.ring-text {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.ring-percentage {
  font-family: 'Playfair Display', serif;
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--primary);
  line-height: 1;
}

.ring-label-small {
  font-size: 0.85rem;
  color: var(--gray);
  font-weight: 500;
}

.grade-number {
  font-family: 'Playfair Display', serif;
  font-size: clamp(4rem, 13vw, 7rem);
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary), #2C5A8C);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
  margin: 5px 0;
  text-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

.result-message {
  font-size: 1.3rem;
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 35px;
  background: rgba(201, 169, 89, 0.15);
  display: inline-block;
  padding: 10px 35px;
  border-radius: 60px;
  box-shadow: var(--shadow-md);
}

/* Grid de estadísticas */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
  margin-bottom: 35px;
}

.stat-item {
  background: var(--white);
  border: 1px solid #E2E8F0;
  border-radius: 24px;
  padding: 22px 12px;
  box-shadow: 0 10px 25px rgba(0,0,0,0.05);
  transition: transform 0.2s;
}

.stat-item:hover {
  transform: translateY(-6px);
}

.stat-value {
  font-family: 'Playfair Display', serif;
  font-size: 2.3rem;
  color: var(--primary);
  font-weight: 700;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--gray);
  margin-top: 8px;
  font-weight: 500;
}

/* Tabla de revisión */
.details-summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--primary);
  padding: 15px 0;
  font-size: 1rem;
  letter-spacing: 1px;
}

.review-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  margin-top: 20px;
  border-radius: 20px;
  overflow: hidden;
  box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}

.review-table th {
  background: var(--primary);
  color: var(--white);
  padding: 16px 18px;
  font-weight: 600;
  font-size: 0.95rem;
}

.review-table td {
  padding: 14px 18px;
  border-bottom: 1px solid #F1F5F9;
  background: var(--white);
}

.review-table tr:last-child td {
  border-bottom: none;
}

.review-table .right td:first-child {
  color: var(--success);
  font-weight: 700;
}

.review-table .wrong td:first-child {
  color: var(--error);
  font-weight: 700;
}

.badge-result {
  display: inline-block;
  border-radius: 30px;
  padding: 4px 12px;
  font-size: 0.75rem;
  font-weight: 600;
  margin-left: 8px;
}

.badge-correct {
  background: rgba(46, 125, 94, 0.15);
  color: var(--success);
}

.badge-wrong {
  background: rgba(180, 67, 60, 0.15);
  color: var(--error);
}

details {
  background: var(--white);
  border-radius: 24px;
  padding: 8px 18px;
  margin-bottom: 30px;
  border: 1px solid #E2E8F0;
  box-shadow: var(--shadow-md);
}

/* Responsive */
@media (min-width: 640px) {
  .card {
    padding: 50px 35px 80px;
  }
  
  .stats-grid {
    grid-template-columns: repeat(4, 1fr);
  }
  
  .panel {
    padding: 50px 55px 60px;
  }
  
  .header {
    padding: 50px 55px 35px;
  }
}

/* Animaciones generales */
.fade-in {
  animation: fadeInUp 0.6s ease both;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(25px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================================
   SELECTOR DE UNIDADES
   ============================================================ */
.unit-selector {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-top: 0.5rem;
}

.unit-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.2rem;
  padding: 0.85rem 1rem;
  background: rgba(255,255,255,0.04);
  border: 2px solid rgba(255,255,255,0.1);
  border-radius: var(--radius-sm);
  color: rgba(255,255,255,0.7);
  cursor: pointer;
  transition: all 0.25s ease;
  font-family: "Inter", sans-serif;
  text-align: center;
  line-height: 1.3;
}

.unit-btn strong {
  font-size: 0.85rem;
  font-weight: 600;
  color: rgba(255,255,255,0.9);
}

.unit-btn small {
  font-size: 0.72rem;
  color: rgba(255,255,255,0.45);
}

.unit-btn:hover {
  border-color: var(--accent);
  background: rgba(201,169,89,0.08);
  color: var(--accent-light);
  transform: translateY(-2px);
}

.unit-btn.active {
  border-color: var(--accent);
  background: linear-gradient(135deg, rgba(201,169,89,0.18), rgba(184,141,63,0.10));
  color: var(--accent-light);
  box-shadow: 0 4px 18px rgba(201,169,89,0.2);
}

.unit-btn.active strong {
  color: var(--accent-light);
}

.unit-btn.active small {
  color: rgba(229,196,122,0.7);
}

@media (max-width: 480px) {
  .unit-selector {
    grid-template-columns: 1fr;
  }
}