/* ============================================
   LABORATORIO VIRTUAL DE CIENCIAS
   Diseño: Modo Claro · Profesional · Clean
============================================ */

/* === VARIABLES === */
:root {
  --bg:            #f0f4f8;
  --bg-white:      #ffffff;
  --bg-section:    #f7f9fc;
  --border:        #e2e8f0;
  --border-hover:  #c7d2e0;
  --blue:          #2563eb;
  --blue-light:    #3b82f6;
  --blue-pale:     #eff6ff;
  --blue-mid:      #dbeafe;
  --green:         #16a34a;
  --green-pale:    #f0fdf4;
  --green-mid:     #bbf7d0;
  --orange:        #ea580c;
  --orange-pale:   #fff7ed;
  --purple:        #7c3aed;
  --purple-pale:   #f5f3ff;
  --teal:          #0d9488;
  --teal-pale:     #f0fdfa;
  --red:           #dc2626;
  --red-pale:      #fef2f2;
  --yellow:        #d97706;
  --yellow-pale:   #fffbeb;
  --text-primary:  #0f172a;
  --text-secondary:#334155;
  --text-muted:    #64748b;
  --text-light:    #94a3b8;
  --font-display:  'Inter', 'Segoe UI', system-ui, sans-serif;
  --font-body:     'Inter', 'Segoe UI', system-ui, sans-serif;
  --radius-sm:     8px;
  --radius:        12px;
  --radius-lg:     16px;
  --radius-xl:     24px;
  --shadow-sm:     0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
  --shadow:        0 4px 6px rgba(0,0,0,0.05), 0 2px 4px rgba(0,0,0,0.04);
  --shadow-md:     0 10px 25px rgba(0,0,0,0.08), 0 4px 10px rgba(0,0,0,0.04);
  --shadow-lg:     0 20px 40px rgba(0,0,0,0.1), 0 8px 16px rgba(0,0,0,0.05);
  --transition:    all 0.2s ease;
  --transition-md: all 0.3s ease;

  /* Colores por área */
  --c1-bg:#eff6ff; --c1-accent:#2563eb; --c1-border:#bfdbfe;
  --c2-bg:#f0fdf4; --c2-accent:#16a34a; --c2-border:#bbf7d0;
  --c3-bg:#fff7ed; --c3-accent:#ea580c; --c3-border:#fed7aa;
  --c4-bg:#f5f3ff; --c4-accent:#7c3aed; --c4-border:#ddd6fe;
  --c5-bg:#fef9c3; --c5-accent:#d97706; --c5-border:#fde68a;

  /* ── Compatibilidad con variables del tema anterior ── */
  --bg-dark:        #f7f9fc;
  --bg-panel:       #ffffff;
  --bg-card:        #ffffff;
  --bg-card-hover:  #f7f9fc;
  --border-bright:  #93c5fd;        /* antes era cyan brillante */
  --neon-cyan:      #2563eb;
  --neon-green:     #16a34a;
  --neon-orange:    #ea580c;
  --neon-purple:    #7c3aed;
  --neon-blue:      #2563eb;
  --text-primary-c: #0f172a;
  --text-dim:       #94a3b8;
  --accent:         #2563eb;
  --success:        #16a34a;
  --warning:        #d97706;
  --danger:         #dc2626;
  --shadow-neon:    0 4px 12px rgba(37,99,235,0.15);
  --shadow-card:    0 10px 25px rgba(0,0,0,0.08);
}

/* === RESET === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }

/* === CANVAS FONDO (desactivado en modo claro) === */
.canvas-fondo { display: none; }

/* === CONTAINER === */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

/* ============================================
   HEADER
============================================ */
.header-principal {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: var(--bg-white);
  border-bottom: 1px solid var(--border);
  padding: 0;
  box-shadow: var(--shadow-sm);
}
.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  height: 64px;
  gap: 1rem;
}
.logo-area {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  flex-shrink: 0;
}
.icono-logo {
  width: 36px; height: 36px;
  background: var(--blue-pale);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
}
.titulo-lab {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.01em;
  line-height: 1.2;
}
.subtitulo-lab {
  font-size: 0.62rem;
  color: var(--text-muted);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.nav-principal {
  display: flex;
  align-items: center;
  gap: 0.1rem;
  margin-left: 1.5rem;
  flex: 1;
  height: 100%;
}
.nav-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  padding: 0.5rem 0.9rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 0.35rem;
  position: relative;
  height: 100%;
  align-items: center;
}
.nav-link:hover { color: var(--text-primary); }
.nav-link.activo { color: var(--blue); font-weight: 600; }
.nav-link.activo::after {
  content: '';
  position: absolute;
  bottom: 0; left: 0; right: 0;
  height: 2px;
  background: var(--blue);
  border-radius: 2px 2px 0 0;
}
/* Nav actions (right side of header) */
.nav-actions-right {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-left: auto;
}
.modo-btn {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.4rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-white);
  font-size: 0.8rem;
  color: var(--text-muted);
  cursor: pointer;
  font-family: var(--font-body);
  transition: var(--transition);
}
.modo-btn:hover { border-color: var(--border-hover); color: var(--text-primary); }
.avatar {
  width: 36px; height: 36px;
  background: var(--blue);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 0.78rem;
  font-weight: 700;
  cursor: pointer;
  flex-shrink: 0;
}

/* ============================================
   HERO
============================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 6rem 0 4rem;
  background: linear-gradient(135deg, #f8faff 0%, #eef3ff 50%, #f5f8ff 100%);
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  top: -100px; right: -100px;
  width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(37,99,235,0.07) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}
.hero-inner {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  gap: 4rem;
}
.hero-content { flex: 1; max-width: 580px; }
.badge-hero {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--blue-pale);
  border: 1px solid var(--blue-mid);
  color: var(--blue);
  font-size: 0.78rem;
  font-weight: 600;
  padding: 0.35rem 0.9rem;
  border-radius: 100px;
  margin-bottom: 1.5rem;
  letter-spacing: 0.02em;
  animation: fadeInUp 0.5s ease both;
}
.hero-titulo {
  font-size: clamp(2rem, 4.5vw, 3rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 1.2rem;
  animation: fadeInUp 0.5s 0.1s ease both;
}
.acento { color: var(--blue); }
.hero-desc {
  color: var(--text-muted);
  font-size: 1rem;
  max-width: 460px;
  margin-bottom: 2rem;
  line-height: 1.7;
  animation: fadeInUp 0.5s 0.2s ease both;
}
.hero-btns {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 3rem;
  animation: fadeInUp 0.5s 0.3s ease both;
}
.btn-principal {
  background: var(--blue);
  color: white;
  font-size: 0.875rem;
  font-weight: 600;
  padding: 0.75rem 1.6rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  box-shadow: 0 4px 14px rgba(37,99,235,0.3);
}
.btn-principal:hover { background: #1d4ed8; transform: translateY(-1px); box-shadow: 0 6px 20px rgba(37,99,235,0.4); }
.btn-secundario {
  background: var(--bg-white);
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 600;
  padding: 0.75rem 1.6rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}
.btn-secundario:hover { border-color: var(--border-hover); background: var(--bg-section); }

.hero-stats {
  display: flex;
  align-items: center;
  gap: 2rem;
  animation: fadeInUp 0.5s 0.4s ease both;
}
.stat { text-align: left; }
.stat-num {
  display: block;
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
  letter-spacing: -0.02em;
}
.stat-label { font-size: 0.75rem; color: var(--text-muted); }
.stat-div { width: 1px; height: 36px; background: var(--border); }

.hero-visual {
  flex: 0 0 380px;
  height: 340px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.8s 0.4s ease both;
}
.tubo-animado {
  width: 70px; height: 200px;
  background: linear-gradient(180deg, rgba(37,99,235,0.06), rgba(37,99,235,0.14));
  border: 2px solid rgba(37,99,235,0.2);
  border-radius: 35px 35px 6px 6px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-md);
}
.liquido { background: linear-gradient(180deg, rgba(37,99,235,0.5), rgba(16,185,129,0.6)); }
.burbuja { background: rgba(37,99,235,0.4); }
.orbita { border: 1px dashed var(--border); }
.planeta { filter: none; }

/* ============================================
   FEATURES BANNER
============================================ */
.features-banner {
  background: var(--bg-white);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 0;
}
.features-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}
.feature-item {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding: 1.4rem 1.5rem;
  border-right: 1px solid var(--border);
}
.feature-item:last-child { border-right: none; }
.feature-icon {
  width: 44px; height: 44px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}
.fi-blue   { background: var(--blue-pale); }
.fi-green  { background: var(--green-pale); }
.fi-purple { background: var(--purple-pale); }
.fi-orange { background: var(--orange-pale); }
.feature-text strong { display: block; font-size: 0.875rem; font-weight: 700; color: var(--text-primary); }
.feature-text span { font-size: 0.78rem; color: var(--text-muted); line-height: 1.4; }

/* ============================================
   SECCIONES
============================================ */
.seccion-practicas,
.seccion-objetivos,
.seccion-bioseguridad {
  padding: 5rem 0;
  position: relative;
  z-index: 1;
}
.seccion-practicas   { background: var(--bg-white); }
.seccion-objetivos   { background: var(--bg-section); }
.seccion-bioseguridad { background: var(--bg-white); }

.seccion-header { text-align: center; margin-bottom: 3rem; }
.seccion-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--blue);
  background: var(--blue-pale);
  border: 1px solid var(--blue-mid);
  padding: 0.3rem 0.9rem;
  border-radius: 100px;
  margin-bottom: 1rem;
}
.seccion-titulo {
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}
.seccion-desc { color: var(--text-muted); max-width: 500px; margin: 0 auto; font-size: 0.925rem; }

/* ============================================
   CARDS DE PRÁCTICAS
============================================ */
.grid-practicas {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.2rem;
}

.card-practica[data-num="1"] { --c-bg:var(--c1-bg); --c-accent:var(--c1-accent); --c-border:var(--c1-border); }
.card-practica[data-num="2"] { --c-bg:var(--c2-bg); --c-accent:var(--c2-accent); --c-border:var(--c2-border); }
.card-practica[data-num="3"] { --c-bg:var(--c3-bg); --c-accent:var(--c3-accent); --c-border:var(--c3-border); }
.card-practica[data-num="4"] { --c-bg:var(--c4-bg); --c-accent:var(--c4-accent); --c-border:var(--c4-border); }
.card-practica[data-num="5"] { --c-bg:var(--c5-bg); --c-accent:var(--c5-accent); --c-border:var(--c5-border); }

.card-practica {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.6rem;
  display: flex;
  flex-direction: column;
  cursor: pointer;
  transition: var(--transition-md);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}
.card-practica::before { display: none; }
.card-practica:hover {
  border-color: var(--c-border, var(--border-hover));
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
}

.card-icono-wrap {
  width: 60px; height: 60px;
  border-radius: 50%;
  background: var(--c-bg, var(--bg-section));
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.1rem;
  font-size: 1.7rem;
  flex-shrink: 0;
}
.card-icono { font-size: 1.7rem; display: none; }

.card-num {
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--c-accent, var(--blue));
  letter-spacing: 0.06em;
  margin-bottom: 0.35rem;
  text-transform: uppercase;
}
.card-titulo {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.35;
  margin-bottom: 0.55rem;
}
.card-desc {
  font-size: 0.845rem;
  color: var(--text-muted);
  line-height: 1.6;
  flex: 1;
  margin-bottom: 1rem;
}
.card-tags { display: flex; gap: 0.4rem; flex-wrap: wrap; margin-bottom: 1rem; }
.tag {
  font-size: 0.72rem;
  font-weight: 500;
  padding: 0.22rem 0.65rem;
  background: var(--c-bg, var(--bg-section));
  border: 1px solid var(--c-border, var(--border));
  border-radius: 100px;
  color: var(--c-accent, var(--text-muted));
}
.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 0.9rem;
  border-top: 1px solid var(--border);
}
.dificultad { font-size: 0.78rem; font-weight: 500; }
.facil  { color: var(--green); }
.medio  { color: var(--yellow); }
.dificil{ color: var(--red); }
.card-ir {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--c-accent, var(--blue));
}

/* ============================================
   OBJETIVOS
============================================ */
.grid-objetivos {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 1rem;
}
.obj-card {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}
.obj-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.obj-icono {
  width: 44px; height: 44px;
  background: var(--blue-pale);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  margin-bottom: 0.9rem;
}
.obj-card h3 { font-size: 0.9rem; font-weight: 700; color: var(--text-primary); margin-bottom: 0.4rem; }
.obj-card p  { font-size: 0.83rem; color: var(--text-muted); line-height: 1.6; }

/* ============================================
   BIOSEGURIDAD
============================================ */
.grid-normas {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 0.9rem;
}
.norma-item {
  display: flex;
  align-items: flex-start;
  gap: 0.9rem;
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}
.norma-item:hover { border-color: var(--border-hover); box-shadow: var(--shadow); }
.norma-icono {
  font-size: 1.3rem;
  flex-shrink: 0;
  width: 36px; height: 36px;
  background: var(--bg-section);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
}
.norma-item div { font-size: 0.845rem; color: var(--text-muted); line-height: 1.55; }
.norma-item strong { color: var(--text-primary); }

/* ============================================
   FOOTER
============================================ */
.footer {
  background: #0f172a;
  color: #64748b;
  padding: 3rem 0 1.5rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1.5fr;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}
.footer-logo { font-size: 0.95rem; font-weight: 700; color: white; margin-bottom: 0.6rem; }
.footer-desc { font-size: 0.83rem; line-height: 1.6; }
.footer-titulo { font-size: 0.7rem; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; color: #475569; margin-bottom: 0.9rem; }
.footer-lista li { margin-bottom: 0.4rem; }
.footer-lista a { font-size: 0.83rem; transition: var(--transition); }
.footer-lista a:hover { color: white; }
.footer-competencia { font-size: 0.875rem; font-style: italic; color: #38bdf8; line-height: 1.55; border-left: 2px solid #38bdf8; padding-left: 0.8rem; }
.footer-bottom { border-top: 1px solid #1e293b; padding-top: 1.5rem; text-align: center; font-size: 0.8rem; color: #334155; }

/* ============================================
   ESTILOS COMPARTIDOS — PRÁCTICAS INTERNAS
============================================ */
.practica-layout {
  max-width: 1050px;
  margin: 0 auto;
  padding: 7rem 1.5rem 4rem;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}
.breadcrumb a { color: var(--blue); font-weight: 500; }
.breadcrumb a:hover { text-decoration: underline; }
.breadcrumb span { color: var(--text-light); }

.panel-practica {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.75rem 2rem;
  margin-bottom: 1.2rem;
  box-shadow: var(--shadow-sm);
}
.panel-titulo {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.panel-titulo::before {
  content: '';
  display: inline-block;
  width: 3px; height: 1em;
  background: var(--blue);
  border-radius: 2px;
}

.practica-header {
  background: linear-gradient(135deg, #f0f7ff 0%, #e8f4fd 100%);
  border: 1px solid var(--blue-mid);
  border-radius: var(--radius-lg);
  padding: 2rem 2.5rem;
  margin-bottom: 1.5rem;
  position: relative;
  overflow: hidden;
}
.practica-header::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--blue), #38bdf8);
}
.practica-num {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 0.5rem;
}
.practica-titulo-main {
  font-size: clamp(1.3rem, 3vw, 1.8rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 0.7rem;
}
.practica-icono-grande { font-size: 3.2rem; }

.info-grid { display: grid; grid-template-columns: repeat(auto-fill,minmax(150px,1fr)); gap: 0.7rem; margin-top: 1.1rem; }
.info-box {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.9rem;
  box-shadow: var(--shadow-sm);
}
.info-box label { display: block; font-size: 0.65rem; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-light); margin-bottom: 0.2rem; }
.info-box span { font-size: 0.875rem; font-weight: 600; color: var(--text-primary); }

.pasos-lista { display: flex; flex-direction: column; gap: 0.55rem; }
.paso-item {
  display: flex;
  gap: 0.85rem;
  align-items: flex-start;
  padding: 0.8rem 1rem;
  background: var(--bg-section);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: var(--transition);
}
.paso-item.activo { border-color: var(--blue); background: var(--blue-pale); }
.paso-num {
  flex-shrink: 0;
  width: 26px; height: 26px;
  background: var(--blue);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.72rem;
  font-weight: 700;
}
.paso-texto { font-size: 0.875rem; color: var(--text-muted); line-height: 1.5; }
.paso-item.activo .paso-texto { color: var(--text-primary); }

.tabla-datos { width: 100%; border-collapse: collapse; font-size: 0.875rem; }
.tabla-datos th {
  background: var(--bg-section);
  color: var(--text-muted);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.7rem 1rem;
  text-align: left;
  border-bottom: 2px solid var(--border);
}
.tabla-datos td { padding: 0.65rem 1rem; border-bottom: 1px solid var(--border); color: var(--text-secondary); transition: var(--transition); }
.tabla-datos tr:hover td { background: var(--bg-section); }
.tabla-datos tr:last-child td { border-bottom: none; }

.btn-accion {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.62rem 1.3rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: 0.855rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--transition);
}
.btn-cyan  { background: var(--blue); color: white; box-shadow: 0 2px 8px rgba(37,99,235,0.25); }
.btn-cyan:hover { background: #1d4ed8; transform: translateY(-1px); }
.btn-green { background: var(--green); color: white; }
.btn-green:hover { background: #15803d; transform: translateY(-1px); }
.btn-outline { background: var(--bg-white); color: var(--text-secondary); border: 1px solid var(--border); }
.btn-outline:hover { border-color: var(--border-hover); background: var(--bg-section); }
.btn-danger { background: var(--red-pale); color: var(--red); border: 1px solid #fecaca; }
.btn-danger:hover { background: #fee2e2; }

.btns-grupo { display: flex; gap: 0.7rem; flex-wrap: wrap; }

.feedback-box { padding: 0.85rem 1.1rem; border-radius: var(--radius-sm); font-size: 0.875rem; font-weight: 500; margin-top: 0.9rem; display: none; }
.feedback-box.visible { display: block; }
.feedback-correcto  { background: var(--green-pale); border: 1px solid var(--green-mid); color: var(--green); }
.feedback-incorrecto { background: var(--red-pale); border: 1px solid #fecaca; color: var(--red); }
.feedback-info      { background: var(--blue-pale); border: 1px solid var(--blue-mid); color: var(--blue); }

.variables-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 1rem; }
.var-box { background: var(--bg-section); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 1rem; }
.var-box label { display: block; font-size: 0.68rem; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase; color: var(--blue); margin-bottom: 0.35rem; }
.var-box p { font-size: 0.85rem; color: var(--text-muted); line-height: 1.55; }

.textarea-respuesta {
  width: 100%;
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.875rem;
  padding: 0.8rem 1rem;
  resize: vertical;
  min-height: 80px;
  transition: var(--transition);
  outline: none;
}
.textarea-respuesta:focus { border-color: var(--blue); box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }

.control-select {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.875rem;
  padding: 0.58rem 1rem;
  cursor: pointer;
  outline: none;
  transition: var(--transition);
}
.control-select:focus { border-color: var(--blue); box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }

.control-range {
  -webkit-appearance: none;
  width: 100%;
  height: 5px;
  border-radius: 3px;
  background: var(--border);
  outline: none;
  cursor: pointer;
}
.control-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: var(--blue);
  cursor: pointer;
  box-shadow: 0 2px 6px rgba(37,99,235,0.3);
}

.grafico-canvas {
  width: 100%;
  background: var(--bg-section);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  max-height: 220px;
}

/* Print */
@media print {
  .header-principal, .btn-accion, .btns-grupo, .breadcrumb { display: none !important; }
  body { background: #fff; }
  .panel-practica { box-shadow: none; border: 1px solid #e2e8f0; }
}

/* ============================================
   ANIMACIONES
============================================ */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(18px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes subeBurbuja {
  0%   { bottom: 10px; opacity: 0.7; }
  100% { bottom: 95%; opacity: 0; }
}
@keyframes burbujeaLiquido {
  0%,100% { transform: translateY(0); }
  50%      { transform: translateY(-3px); }
}
@keyframes rotaOrbita {
  from { transform: rotate(0deg); }
  to   { transform: rotate(360deg); }
}

/* ============================================
   RESPONSIVE
============================================ */
@media (max-width: 1024px) {
  .features-inner { grid-template-columns: 1fr 1fr; }
  .feature-item:nth-child(2) { border-right: none; }
  .feature-item:nth-child(3) { border-right: 1px solid var(--border); border-top: 1px solid var(--border); }
}
@media (max-width: 900px) {
  .hero { flex-direction: column; padding-top: 6rem; text-align: center; }
  .hero-desc { margin: 0 auto 1.5rem; }
  .hero-btns { justify-content: center; }
  .hero-stats { justify-content: center; }
  .hero-visual { display: none; }
  .footer-grid { grid-template-columns: 1fr; gap: 1.5rem; }
  .variables-grid { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .nav-principal { display: none; }
  .features-inner { grid-template-columns: 1fr; }
  .feature-item { border-right: none; border-bottom: 1px solid var(--border); padding: 1rem 1.2rem; }
  .feature-item:last-child { border-bottom: none; }
  .practica-header { padding: 1.5rem; }
  .panel-practica { padding: 1.2rem; }
}

/* ============================================
   OVERRIDES: SIMULADORES EN MODO CLARO
   Corrige backgrounds oscuros hardcodeados en las prácticas
============================================ */

/* Simulador pH */
.ph-simulator {
  background: var(--bg-section) !important;
  border-color: var(--border) !important;
}
.sustancia-btn {
  background: var(--bg-white) !important;
  border-color: var(--border) !important;
  color: var(--text-muted) !important;
}
.sustancia-btn:hover  { border-color: var(--blue) !important; color: var(--text-primary) !important; }
.sustancia-btn.seleccionada { border-color: var(--blue) !important; background: var(--blue-pale) !important; color: var(--blue) !important; }
.tubo-ph {
  border-color: rgba(37,99,235,0.3) !important;
  background: rgba(255,255,255,0.6) !important;
  box-shadow: var(--shadow-md) !important;
}
.ph-resultado {
  background: var(--bg-white) !important;
  border-color: var(--border) !important;
  box-shadow: var(--shadow-sm) !important;
}
.escala-ph { box-shadow: var(--shadow-sm); }
.escala-marcador { box-shadow: 0 0 6px rgba(0,0,0,0.25) !important; }

/* Simulador Fotosíntesis */
.acuario {
  border-color: rgba(37,99,235,0.25) !important;
}
.agua-fondo {
  background: linear-gradient(180deg, rgba(14,165,233,0.15) 0%, rgba(2,132,199,0.3) 100%) !important;
}
.tallo { background: linear-gradient(180deg,#22c55e,#16a34a) !important; }
.hoja  { background: rgba(34,197,94,0.8) !important; }
.lampara { filter: drop-shadow(0 0 8px rgba(255,200,0,0.6)) !important; }
.burbuja-o2 { border-color: rgba(37,99,235,0.6) !important; background: rgba(219,234,254,0.5) !important; }

/* Simulador Proteínas */
.placa-calefactora {
  background: linear-gradient(180deg,#fff7ed,#ffedd5) !important;
  border-color: rgba(234,88,12,0.3) !important;
}
.vasito {
  border-color: rgba(180,160,130,0.6) !important;
  background: rgba(255,255,255,0.5) !important;
}
.termometro {
  background: var(--bg-section) !important;
  border-color: rgba(234,88,12,0.4) !important;
}

/* Simulador Mezclas */
.lab-visual {
  background: linear-gradient(180deg,#f0f9ff,#e0f2fe) !important;
  border-color: var(--border) !important;
}
.estado-separacion {
  background: var(--bg-white) !important;
  border-color: var(--border) !important;
  box-shadow: var(--shadow-sm) !important;
}

/* Simulador Reacciones */
.mezcla-visual {
  background: linear-gradient(180deg,#f8faff,#f0f4ff) !important;
  border-color: var(--border) !important;
}
.beaker {
  border-color: rgba(100,116,139,0.4) !important;
}
.reactivo-btn {
  background: var(--bg-white) !important;
  border-color: var(--border) !important;
  color: var(--text-muted) !important;
}
.reactivo-btn:hover { border-color: var(--blue) !important; color: var(--text-primary) !important; }
.reactivo-btn.sel-a { border-color: #dc2626 !important; background: #fef2f2 !important; }
.reactivo-btn.sel-b { border-color: #2563eb !important; background: var(--blue-pale) !important; }
.reaccion-ecuacion {
  background: var(--bg-section) !important;
  border-color: var(--border) !important;
  color: var(--green) !important;
}
.cambio-item {
  background: var(--bg-white) !important;
  border-color: var(--border) !important;
  color: var(--text-muted) !important;
}
.cambio-item.activo {
  border-color: var(--green) !important;
  color: var(--green) !important;
  background: var(--green-pale) !important;
}

/* Metodos de separación */
.metodo-btn {
  background: var(--bg-white) !important;
  border-color: var(--border) !important;
  color: var(--text-muted) !important;
}
.metodo-btn:hover { border-color: var(--blue) !important; color: var(--text-primary) !important; }
.metodo-btn.activo { border-color: var(--blue) !important; background: var(--blue-pale) !important; color: var(--blue) !important; }

/* Controles comunes */
.sim-grid, .sim2-grid, .sim3-grid { color: var(--text-primary); }
.control-label { color: var(--text-muted) !important; }
.valor-display  { color: var(--blue) !important; }
.lectura-burbujas { color: var(--green) !important; text-shadow: none !important; }
.temp-num { text-shadow: none !important; }
.nivel-desnat { color: var(--orange) !important; }
.resultado-separacion { color: var(--text-primary) !important; }

/* Info boxes dentro de simuladores */
.info-box span { color: var(--text-primary) !important; }

/* Textos genéricos oscuros que quedaron blancos */
[style*="color:var(--neon-cyan)"]   { color: var(--blue) !important; }
[style*="color: var(--neon-cyan)"]  { color: var(--blue) !important; }
[style*="color:var(--neon-green)"]  { color: var(--green) !important; }
[style*="color: var(--neon-green)"] { color: var(--green) !important; }
[style*="color:var(--text-dim)"]    { color: var(--text-light) !important; }

/* Fondo de materiales */
[style*="rgba(0,200,255,0.05)"]  { background: var(--bg-section) !important; }
[style*="rgba(0,200,255,0.06)"]  { background: var(--blue-pale) !important; }
[style*="rgba(0,200,255,0.1)"]   { background: var(--blue-pale) !important; }
[style*="rgba(0,200,255,0.12)"]  { background: var(--blue-pale) !important; }

/* Equation code blocks */
code[style] { background: var(--green-pale) !important; color: var(--green) !important; border-color: var(--green-mid) !important; }

/* Grafico canvas */
.grafico-canvas { background: var(--bg-section) !important; }


/* === ANIMACIÓN DE ENTRADA VÍA CLASES (no inline opacity) === */
.anim-entry {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.4s ease, transform 0.4s ease;
}
.anim-entry.visible {
  opacity: 1;
  transform: translateY(0);
}

/* === FILTROS DE ÁREA === */
.filtro-btn {
  background: var(--bg-white); border: 2px solid var(--border); border-radius: 100px;
  padding: 0.45rem 1.1rem; cursor: pointer; font-family: var(--font-body);
  font-size: 0.82rem; font-weight: 600; color: var(--text-muted);
  transition: var(--transition);
}
.filtro-btn:hover { border-color: var(--blue); color: var(--blue); }
.filtro-btn.activo { background: var(--blue); border-color: var(--blue); color: white; }

/* === PALETA EXTENDIDA (prácticas 6-14) === */
.card-practica[data-num="6"]  { --c-bg:var(--c1-bg); --c-accent:#0891b2; --c-border:#a5f3fc; }
.card-practica[data-num="7"]  { --c-bg:var(--c2-bg); --c-accent:var(--c2-accent); --c-border:var(--c2-border); }
.card-practica[data-num="8"]  { --c-bg:var(--c3-bg); --c-accent:var(--c3-accent); --c-border:var(--c3-border); }
.card-practica[data-num="9"]  { --c-bg:var(--c1-bg); --c-accent:var(--c1-accent); --c-border:var(--c1-border); }
.card-practica[data-num="10"] { --c-bg:var(--c4-bg); --c-accent:var(--c4-accent); --c-border:var(--c4-border); }
.card-practica[data-num="11"] { --c-bg:#fff1f2; --c-accent:#e11d48; --c-border:#fda4af; }
.card-practica[data-num="12"] { --c-bg:var(--c2-bg); --c-accent:var(--c2-accent); --c-border:var(--c2-border); }
.card-practica[data-num="13"] { --c-bg:var(--c2-bg); --c-accent:#15803d; --c-border:#86efac; }
.card-practica[data-num="14"] { --c-bg:var(--c1-bg); --c-accent:var(--c1-accent); --c-border:var(--c1-border); }