/* ============================================
   MAIN.CSS - Estilos principales y base
   Versión 4 - landing_cursos_4
   ============================================ */

/* Reset y Variables */
:root {
  --bg-dark: #0a0a0a;
  --bg-dark-secondary: #1a1a1a;
  --bg-card: rgba(20, 20, 24, 0.95);
  --text-white: #ffffff;
  --text-light: #e0e0e0;
  --text-medium: #a0a0a0;
  --text-muted: #707070;
  --accent-blue: #4facfe;
  --accent-blue-hover: #6bbfff;
  --accent-purple: #a855f7;
  --accent-pink: #ec4899;
  --border-color: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(79, 172, 254, 0.4);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);

  --font-family-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-family-heading: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;

  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;

  --border-radius-sm: 0.25rem;
  --border-radius-md: 0.5rem;
  --border-radius-lg: 0.75rem;
  --border-radius-xl: 1rem;
  --border-radius-full: 9999px;

  --transition-fast: 150ms ease-in-out;
  --transition-base: 250ms ease-in-out;
  --transition-slow: 350ms ease-in-out;

  --container-max-width: 1200px;
  --container-padding: 1rem;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  height: 100%;
}

body {
  font-family: var(--font-family-base);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--text-white);
  background: linear-gradient(135deg, var(--bg-dark) 0%, var(--bg-dark-secondary) 50%, var(--bg-dark) 100%);
  background-attachment: fixed;
  min-height: 100vh;
  height: 100%;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
  overflow-x: hidden;
  overflow-y: auto;
}

body::before {
  content: "";
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background-image: radial-gradient(circle at 1px 1px, rgba(255, 255, 255, 0.03) 1px, transparent 0);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 0;
}

.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

@media (min-width: 640px) { .container { padding: 0 1.5rem; } }
@media (min-width: 1024px) { .container { padding: 0 2rem; } }

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-family-heading);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
  color: var(--text-white);
  margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }

p { margin-bottom: var(--spacing-md); color: var(--text-light); }

a { color: var(--accent-blue); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--accent-blue-hover); }
a:focus { outline: 2px solid var(--accent-blue); outline-offset: 2px; }

/* Header */
.header {
  background: var(--bg-card);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border-color);
  padding: var(--spacing-md) 0;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-md);
}

.header__content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
}

.header__nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.header__logo-link {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  color: var(--text-white);
  transition: color var(--transition-base);
}

.header__logo-link:hover { color: var(--accent-blue); }

.header__profile-indicator {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-sm) var(--spacing-md);
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-md);
  font-size: var(--font-size-sm);
  color: var(--text-light);
  backdrop-filter: blur(10px);
}

.header__profile-indicator[hidden] { display: none; }

.profile-indicator__icon { font-size: var(--font-size-lg); }

.profile-indicator__link {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition-base);
  cursor: pointer;
}

.profile-indicator__link:hover { color: var(--accent-blue); transform: translateY(-1px); }
.profile-indicator__change { font-size: var(--font-size-base); opacity: 0.6; }
.profile-indicator__link:hover .profile-indicator__change { opacity: 1; }

/* Language Selector */
.language-selector {
  display: flex;
  align-items: center;
}

.language-selector__options {
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-full);
  padding: 2px;
  gap: 2px;
}

.language-selector__option {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  height: 36px;
  padding: 0 var(--spacing-sm);
  border: none;
  border-radius: var(--border-radius-full);
  background: transparent;
  color: var(--text-medium);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.language-selector__option:hover {
  color: var(--text-light);
  background: rgba(255, 255, 255, 0.05);
}

.language-selector__option--active {
  background: var(--accent-blue);
  color: var(--bg-dark);
  box-shadow: 0 2px 8px rgba(79, 172, 254, 0.3);
}

.language-selector__option--active:hover {
  background: var(--accent-blue-hover);
  color: var(--bg-dark);
}

.language-selector__option:focus {
  outline: 2px solid var(--accent-blue);
  outline-offset: 2px;
}

.language-selector__code {
  font-weight: 600;
  letter-spacing: 0.5px;
}

/* Main */
.main {
  min-height: calc(100vh - 200px);
  padding: var(--spacing-xl) 0;
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
}

.section-title { text-align: center; margin-bottom: var(--spacing-lg); font-size: clamp(var(--font-size-2xl), 4vw, var(--font-size-3xl)); }
.section-subtitle { text-align: center; color: var(--text-light); margin-bottom: var(--spacing-2xl); font-size: var(--font-size-lg); }

/* Footer */
.footer {
  background: var(--bg-card);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-top: 1px solid var(--border-color);
  color: var(--text-light);
  padding: var(--spacing-xl) 0;
  margin-top: auto;
  position: relative;
  z-index: 1;
}

.footer__content {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  align-items: center;
  text-align: center;
}

.footer__nav { display: flex; gap: var(--spacing-lg); flex-wrap: wrap; justify-content: center; }
.footer__link { color: var(--text-light); font-size: var(--font-size-sm); transition: color var(--transition-base); }
.footer__link:hover { color: var(--accent-blue); }
.footer__text { font-size: var(--font-size-sm); color: var(--text-muted); margin: 0; }

/* Responsive */
@media (max-width: 767px) {
  html { font-size: 14px; }
  .header__content { flex-direction: row; flex-wrap: wrap; }
  .header__nav { order: 2; width: 100%; justify-content: flex-end; }
  .main { padding: var(--spacing-lg) 0; min-height: calc(100vh - 150px); }
  .footer { padding: var(--spacing-lg) 0; }
  .footer__nav { flex-direction: column; gap: var(--spacing-sm); }
  h1 { font-size: var(--font-size-3xl); }
  h2 { font-size: var(--font-size-2xl); }
}

*:focus-visible { outline: 2px solid var(--accent-blue); outline-offset: 2px; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}