/* ============================================
   INGLÉS · PROFOX — Sistema de Diseño Base
   ============================================ */

/* Variables globales */
:root {
  --color-primary:     #1a56db;
  --color-primary-dk:  #1347c0;
  --color-primary-lt:  #e8f0fe;
  --color-accent:      #059669;
  --color-accent-lt:   #d1fae5;
  --color-warning:     #d97706;
  --color-danger:      #dc2626;

  --color-bg:          #ffffff;
  --color-bg-alt:      #f8fafc;
  --color-bg-dark:     #0f172a;
  --color-surface:     #ffffff;
  --color-border:      #e2e8f0;
  --color-border-dk:   #cbd5e1;

  --color-text:        #0f172a;
  --color-text-muted:  #64748b;
  --color-text-light:  #94a3b8;
  --color-text-inv:    #ffffff;

  --font-sans:   'Inter', system-ui, -apple-system, sans-serif;
  --font-serif:  'Playfair Display', Georgia, serif;

  --weight-light:   300;
  --weight-regular: 400;
  --weight-medium:  500;
  --weight-semi:    600;
  --weight-bold:    700;

  --radius-sm:  6px;
  --radius-md:  10px;
  --radius-lg:  16px;
  --radius-xl:  24px;
  --radius-full: 9999px;

  --shadow-sm:  0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md:  0 4px 12px rgba(0,0,0,.08), 0 2px 4px rgba(0,0,0,.05);
  --shadow-lg:  0 10px 30px rgba(0,0,0,.10), 0 4px 8px rgba(0,0,0,.06);
  --shadow-xl:  0 20px 50px rgba(0,0,0,.12), 0 8px 16px rgba(0,0,0,.06);

  --transition: 200ms ease;
  --transition-slow: 400ms ease;

  --container-max: 1140px;
  --container-pad: clamp(1rem, 4vw, 2rem);
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: var(--font-sans);
  font-weight: var(--weight-regular);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img, svg { display: block; max-width: 100%; }

a { color: inherit; text-decoration: none; }

/* Contenedor */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
}

/* ============ TIPOGRAFÍA ============ */
h1, h2, h3, h4 {
  font-weight: var(--weight-bold);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.6rem, 3.5vw, 2.5rem); }
h3 { font-size: clamp(1.1rem, 2vw, 1.35rem); }

/* ============ BOTONES ============ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  padding: .75rem 1.5rem;
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: .9375rem;
  font-weight: var(--weight-semi);
  cursor: pointer;
  border: 2px solid transparent;
  transition: all var(--transition);
  white-space: nowrap;
  text-decoration: none;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-text-inv);
  border-color: var(--color-primary);
}
.btn-primary:hover {
  background: var(--color-primary-dk);
  border-color: var(--color-primary-dk);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border-dk);
}
.btn-ghost:hover {
  background: var(--color-bg-alt);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-accent {
  background: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}
.btn-accent:hover {
  background: #047857;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-lg {
  padding: .9rem 2rem;
  font-size: 1rem;
  border-radius: var(--radius-lg);
}

/* ============ HEADER ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 2rem;
}

.logo {
  display: flex;
  align-items: baseline;
  gap: .2rem;
  font-size: 1.25rem;
  font-weight: var(--weight-bold);
  letter-spacing: -0.03em;
  flex-shrink: 0;
}
.logo-en   { color: var(--color-primary); }
.logo-dot  { color: var(--color-text-light); font-weight: 300; }
.logo-sub  { color: var(--color-text-muted); font-weight: var(--weight-medium); font-size: .9em; }

.main-nav {
  display: flex;
  align-items: center;
  gap: 2rem;
}
.main-nav a {
  font-size: .9rem;
  font-weight: var(--weight-medium);
  color: var(--color-text-muted);
  transition: color var(--transition);
}
.main-nav a:hover { color: var(--color-primary); }

/* ============ SECCIONES GENÉRICAS ============ */
.section-title {
  text-align: center;
  margin-bottom: .75rem;
}
.section-sub {
  text-align: center;
  color: var(--color-text-muted);
  font-size: 1.0625rem;
  max-width: 560px;
  margin: 0 auto 3rem;
}

/* ============ FOOTER ============ */
.site-footer {
  background: var(--color-bg-dark);
  color: rgba(255,255,255,.7);
  padding: 3rem 0 2rem;
  margin-top: 5rem;
}
.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  text-align: center;
}
.footer-brand .logo-en  { color: #93c5fd; }
.footer-brand .logo-dot { color: rgba(255,255,255,.3); }
.footer-brand .logo-sub { color: rgba(255,255,255,.5); }
.footer-brand p { font-size: .875rem; margin-top: .5rem; color: rgba(255,255,255,.45); }
.footer-links { display: flex; gap: 2rem; }
.footer-links a { font-size: .875rem; transition: color var(--transition); }
.footer-links a:hover { color: #fff; }
.footer-copy { font-size: .8rem; color: rgba(255,255,255,.3); }

/* ============ BARRA DE PROGRESO GENÉRICA ============ */
.progress-bar {
  height: 6px;
  background: var(--color-border);
  border-radius: var(--radius-full);
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
}

/* ============ BADGES DE NIVEL ============ */
.level-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-md);
  font-weight: var(--weight-bold);
  font-size: .875rem;
  letter-spacing: .02em;
}
.badge-a1 { background: #dbeafe; color: #1d4ed8; }
.badge-a2 { background: #e0f2fe; color: #0369a1; }
.badge-b1 { background: #d1fae5; color: #065f46; }
.badge-b2 { background: #fef3c7; color: #92400e; }
.badge-c1 { background: #ede9fe; color: #5b21b6; }

/* ============ UTILIDADES ============ */
.text-primary { color: var(--color-primary); }
.text-accent  { color: var(--color-accent); }
.text-muted   { color: var(--color-text-muted); }
.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 768px) {
  .main-nav { display: none; }
  .header-inner { justify-content: center; }
}