/* ==========================================================================
   AprobarTodo / Dudas de Física y Química — Estilos Modernos y Alto Rendimiento
   ========================================================================== */

:root {
  --bg-primary: #070F13;
  --bg-card: #0D1C24;
  --bg-card-hover: #132A37;
  --border-card: rgba(16, 185, 129, 0.2);
  --border-focus: #10B981;
  
  --text-main: #F0FDF4;
  --text-muted: #86EFAC;
  --text-light: #D1FAE5;
  
  --accent-emerald: #10B981;
  --accent-teal: #14B8A6;
  --accent-amber: #F59E0B;
  --accent-green: #22C55E;
  --accent-red: #EF4444;

  --grad-header: linear-gradient(135deg, #10B981 0%, #059669 50%, #047857 100%);
  --grad-card: linear-gradient(180deg, rgba(13, 28, 36, 0.8) 0%, rgba(7, 15, 19, 0.95) 100%);
  --grad-cta: linear-gradient(135deg, #059669 0%, #10B981 50%, #14B8A6 100%);
  
  --radius-lg: 16px;
  --radius-md: 10px;
  --radius-sm: 6px;
  --shadow-card: 0 10px 25px -5px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 25px rgba(16, 185, 129, 0.2);
}

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

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.container {
  width: 100%;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  background: rgba(13, 28, 36, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-card);
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}
.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}
.brand-title {
  display: block;
  font-size: 1.25rem;
  font-weight: 800;
  color: #FFFFFF;
  letter-spacing: -0.02em;
}
.brand-subtitle {
  display: block;
  font-size: 0.75rem;
  color: var(--accent-emerald);
  font-weight: 600;
}
.header-nav {
  display: flex;
  align-items: center;
  gap: 18px;
}
.nav-item {
  color: var(--text-light);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 600;
  transition: color 0.2s;
}
.nav-item:hover {
  color: var(--accent-emerald);
}
.btn-primary-header {
  background: var(--grad-cta);
  color: #FFFFFF;
  font-size: 0.85rem;
  font-weight: 700;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
  transition: transform 0.2s, box-shadow 0.2s;
}
.btn-primary-header:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 16px rgba(16, 185, 129, 0.5);
}

/* Breadcrumbs */
.breadcrumb-bar {
  padding: 16px 20px 0 20px;
}
.breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  font-size: 0.85rem;
  color: var(--text-muted);
}
.breadcrumb-list a {
  color: var(--text-muted);
  text-decoration: none;
}
.breadcrumb-list a:hover {
  color: var(--accent-emerald);
}
.breadcrumb-list li::after {
  content: "/";
  margin-left: 8px;
  color: #374151;
}
.breadcrumb-list li:last-child::after {
  content: "";
}

/* Article Layout */
.main-content {
  padding-top: 24px;
  padding-bottom: 60px;
}
.duda-article {
  max-width: 860px;
  margin: 0 auto;
}
.article-badge-row {
  display: flex;
  gap: 10px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.badge-cat {
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-emerald);
  border: 1px solid rgba(16, 185, 129, 0.3);
  padding: 4px 12px;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
}
.badge-target {
  background: rgba(245, 158, 11, 0.15);
  color: var(--accent-amber);
  border: 1px solid rgba(245, 158, 11, 0.3);
  padding: 4px 12px;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
}
.article-title {
  font-size: 2.25rem;
  font-weight: 900;
  line-height: 1.25;
  color: #FFFFFF;
  margin-bottom: 24px;
  letter-spacing: -0.03em;
}

/* Quick Answer Card */
.quick-answer-card {
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.15) 0%, rgba(20, 184, 166, 0.1) 100%);
  border: 1px solid rgba(16, 185, 129, 0.4);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 36px;
  box-shadow: var(--shadow-glow);
}
.quick-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}
.quick-icon {
  font-size: 1.5rem;
}
.quick-title {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--accent-emerald);
}
.quick-lead {
  font-size: 1.15rem;
  color: var(--text-main);
  line-height: 1.7;
}

/* Content Sections */
.content-section {
  margin-bottom: 40px;
}
.section-title {
  font-size: 1.45rem;
  font-weight: 800;
  color: #FFFFFF;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}
.prose-content {
  color: var(--text-light);
  font-size: 1.05rem;
}
.prose-content p {
  margin-bottom: 16px;
}
.prose-content em {
  color: var(--accent-emerald);
  font-style: normal;
  font-weight: 600;
}
.prose-content strong {
  color: #FFFFFF;
}

/* Trick Box */
.trick-box {
  background: linear-gradient(135deg, rgba(245, 158, 11, 0.12) 0%, rgba(217, 119, 6, 0.08) 100%);
  border: 1px solid rgba(245, 158, 11, 0.4);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  gap: 18px;
  margin-bottom: 40px;
}
.trick-icon {
  font-size: 2.2rem;
  flex-shrink: 0;
}
.trick-title {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--accent-amber);
  margin-bottom: 8px;
}
.trick-text {
  color: var(--text-main);
  font-size: 1.05rem;
  line-height: 1.65;
}

/* Contrast Table */
.table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-card);
  background: var(--bg-card);
  margin-bottom: 40px;
}
.contrast-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.95rem;
}
.contrast-table th, .contrast-table td {
  padding: 14px 18px;
  border-bottom: 1px solid rgba(16, 185, 129, 0.1);
}
.contrast-table th {
  background: rgba(13, 28, 36, 0.9);
  font-weight: 800;
  text-transform: uppercase;
  font-size: 0.8rem;
  letter-spacing: 0.05em;
}
.th-correct { color: var(--accent-green); width: 35%; }
.th-wrong { color: var(--accent-red); width: 35%; }
.th-desc { color: var(--text-muted); width: 30%; }
.td-correct { color: #A7F3D0; font-weight: 700; }
.td-wrong { color: #FECACA; text-decoration: line-through; opacity: 0.9; }
.td-desc { color: var(--text-muted); }

/* Penalty Alert */
.penalty-alert {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.35);
  border-radius: var(--radius-lg);
  padding: 20px;
  display: flex;
  gap: 16px;
  margin-bottom: 40px;
}
.penalty-icon {
  font-size: 1.8rem;
  flex-shrink: 0;
}
.penalty-title {
  font-size: 1.05rem;
  font-weight: 800;
  color: #F87171;
  margin-bottom: 6px;
}
.penalty-text {
  color: var(--text-light);
  font-size: 0.95rem;
}

/* Quiz Card */
.quiz-card {
  background: var(--bg-card);
  border: 2px solid rgba(16, 185, 129, 0.35);
  border-radius: var(--radius-lg);
  padding: 28px;
  margin-bottom: 45px;
  box-shadow: var(--shadow-card);
}
.quiz-badge {
  display: inline-block;
  background: rgba(16, 185, 129, 0.2);
  color: var(--accent-emerald);
  font-size: 0.8rem;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  text-transform: uppercase;
}
.quiz-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: #FFFFFF;
  margin-bottom: 10px;
}
.quiz-question {
  font-size: 1.1rem;
  color: var(--text-main);
  margin-bottom: 20px;
  font-weight: 600;
}
.quiz-options-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.quiz-btn {
  background: rgba(19, 42, 55, 0.7);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 12px 18px;
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--text-main);
  font-size: 0.95rem;
  text-align: left;
  cursor: pointer;
  transition: all 0.2s;
  width: 100%;
}
.quiz-btn:hover:not(:disabled) {
  background: rgba(16, 185, 129, 0.15);
  border-color: var(--accent-emerald);
  transform: translateX(4px);
}
.quiz-opt-letter {
  background: rgba(255, 255, 255, 0.1);
  color: var(--accent-emerald);
  font-weight: 800;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.btn-is-correct {
  background: rgba(16, 185, 129, 0.25) !important;
  border-color: var(--accent-green) !important;
  color: #A7F3D0 !important;
}
.btn-is-wrong {
  background: rgba(239, 68, 68, 0.25) !important;
  border-color: var(--accent-red) !important;
  color: #FECACA !important;
}
.quiz-feedback-box {
  margin-top: 18px;
  padding: 16px;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  line-height: 1.6;
}
.feedback-success {
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid var(--accent-green);
  color: #D1FAE5;
}
.feedback-error {
  background: rgba(239, 68, 68, 0.15);
  border: 1px solid var(--accent-red);
  color: #FEE2E2;
}

/* Conversion Box */
.conversion-box {
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.25) 0%, rgba(20, 184, 166, 0.2) 100%);
  border: 2px solid rgba(16, 185, 129, 0.5);
  border-radius: var(--radius-lg);
  padding: 32px;
  margin-bottom: 50px;
  box-shadow: 0 10px 30px rgba(16, 185, 129, 0.25);
}
.conversion-inner {
  display: grid;
  grid-template-columns: 80px 1fr auto;
  gap: 24px;
  align-items: center;
}
.conversion-icon {
  width: 84px;
  height: 84px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.conv-title {
  font-size: 1.4rem;
  font-weight: 800;
  color: #FFFFFF;
  margin-bottom: 8px;
}
.conv-desc {
  color: var(--text-light);
  font-size: 0.95rem;
  line-height: 1.6;
}
.conv-action {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}
.btn-cta-big {
  background: var(--grad-cta);
  color: #FFFFFF;
  font-weight: 800;
  font-size: 1.05rem;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  text-decoration: none;
  box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4);
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  transition: transform 0.2s, box-shadow 0.2s;
}
.btn-cta-big:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 25px rgba(16, 185, 129, 0.6);
}
.conv-guarantee {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Related */
.related-section {
  margin-bottom: 50px;
}
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 16px;
}
.related-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 20px;
  text-decoration: none;
  transition: all 0.2s;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}
.related-card:hover {
  border-color: var(--accent-emerald);
  transform: translateY(-3px);
  background: var(--bg-card-hover);
}
.rel-tag {
  color: var(--accent-emerald);
  font-size: 0.75rem;
  font-weight: 700;
  margin-bottom: 8px;
}
.rel-title {
  color: #FFFFFF;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 12px;
}
.rel-arrow {
  color: var(--accent-emerald);
  font-size: 0.85rem;
  font-weight: 600;
}

/* Hub Styles */
.hub-hero {
  padding: 50px 0 35px 0;
  text-align: center;
  background: radial-gradient(circle at 50% 0%, rgba(16, 185, 129, 0.2) 0%, transparent 70%);
}
.hub-kicker {
  display: inline-block;
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-emerald);
  font-size: 0.85rem;
  font-weight: 800;
  padding: 4px 14px;
  border-radius: 999px;
  margin-bottom: 16px;
}
.hub-title {
  font-size: 2.75rem;
  font-weight: 900;
  color: #FFFFFF;
  letter-spacing: -0.03em;
  margin-bottom: 14px;
}
.hub-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  max-width: 720px;
  margin: 0 auto 30px auto;
  line-height: 1.6;
}
.search-box-wrapper {
  max-width: 640px;
  margin: 0 auto 24px auto;
}
.hub-search-input {
  width: 100%;
  padding: 16px 22px;
  background: var(--bg-card);
  border: 2px solid var(--border-card);
  border-radius: var(--radius-lg);
  color: #FFFFFF;
  font-size: 1.05rem;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.hub-search-input:focus {
  border-color: var(--accent-emerald);
  box-shadow: 0 0 20px rgba(16, 185, 129, 0.25);
}
.category-pills-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
}
.filter-pill {
  background: rgba(19, 42, 55, 0.7);
  border: 1px solid var(--border-card);
  color: var(--text-light);
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}
.filter-pill:hover {
  background: rgba(16, 185, 129, 0.15);
  color: #FFFFFF;
}
.filter-pill.active {
  background: var(--accent-emerald);
  color: #070F13;
  border-color: var(--accent-emerald);
  font-weight: 800;
}

/* Hub Grid */
.hub-main {
  padding-bottom: 80px;
}
.hub-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 20px;
}
.hub-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.2s;
}
.hub-card:hover {
  border-color: var(--accent-emerald);
  transform: translateY(-4px);
  box-shadow: var(--shadow-card);
}
.hub-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
}
.hub-cat-pill {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-emerald);
  background: rgba(16, 185, 129, 0.1);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
}
.hub-check-icon {
  font-size: 1.1rem;
}
.hub-card-title {
  font-size: 1.15rem;
  font-weight: 800;
  line-height: 1.4;
  margin-bottom: 10px;
}
.hub-card-title a {
  color: #FFFFFF;
  text-decoration: none;
}
.hub-card-snippet {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin-bottom: 18px;
}
.hub-card-btn {
  color: var(--accent-emerald);
  font-size: 0.9rem;
  font-weight: 700;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}
.hub-card-btn:hover {
  text-decoration: underline;
}

/* Footer */
.site-footer {
  background: #04090C;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 45px 0 25px 0;
}
.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 40px;
  margin-bottom: 30px;
}
.footer-brand-title {
  font-size: 1.2rem;
  font-weight: 800;
  color: #FFFFFF;
  display: block;
  margin-bottom: 8px;
}
.footer-desc {
  color: var(--text-muted);
  font-size: 0.9rem;
  max-width: 400px;
}
.footer-heading {
  font-size: 0.95rem;
  font-weight: 800;
  color: #FFFFFF;
  margin-bottom: 12px;
  text-transform: uppercase;
}
.footer-links {
  list-style: none;
}
.footer-links li {
  margin-bottom: 8px;
}
.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.85rem;
  transition: color 0.2s;
}
.footer-links a:hover {
  color: var(--accent-emerald);
}
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 20px;
  text-align: center;
  color: #4B5563;
  font-size: 0.8rem;
}

/* Responsive */
@media (max-width: 768px) {
  .article-title { font-size: 1.75rem; }
  .hub-title { font-size: 2rem; }
  .conversion-inner { grid-template-columns: 1fr; text-align: center; }
  .conversion-icon { margin: 0 auto; }
  .conv-action { margin-top: 12px; }
  .footer-inner { grid-template-columns: 1fr; }
  .header-nav .nav-item { display: none; }
}

/* ==========================================================================
   ESTILOS OFICIALES DE MARCA APROBARTODO (SSOT)
   ========================================================================== */
.brand-header-link:hover div[style*="filter"] {
  filter: drop-shadow(0 4px 14px rgba(46, 213, 115, 0.5)) !important;
  transform: scale(1.03);
  transition: all 0.2s ease;
}
.btn-cta-big:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 210, 255, 0.5) !important;
}
.btn-cta-big:active {
  transform: translateY(0);
}

@media (max-width: 860px) {
  .conversion-box .conversion-inner {
    flex-direction: column !important;
    text-align: center !important;
    padding: 22px 18px !important;
    gap: 16px !important;
  }
  .conversion-box .conversion-icon {
    margin: 0 auto;
  }
  .conversion-box .conv-action {
    width: 100% !important;
  }
  .conversion-box .btn-cta-big {
    width: 100% !important;
    justify-content: center !important;
  }
}