:root {
  --color-bg: #06141b;
  --color-text: #c2c9d1;
  --color-heading: #f0fbfa;
  --color-link: #0097A7;
  --color-link-hover: #4DD0E1;
  --shadow-light: rgba(0,0,0,0.05);
  --shadow-medium: rgba(0,0,0,0.1);

  --border-radius: 0.75rem;
  --max-width: 1200px;
  --spacing-lg: 3rem;
  --spacing-md: 2.5rem;
  --spacing-sm: 1.25rem;
  --transition-speed: 0.3s;
}

/* Base reset and body */
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  font-family: 'Poppins', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
    Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  background-color: var(--color-bg);
  color: var(--color-text);
  font-size: 1rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;

  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--spacing-lg) var(--spacing-md);
  max-width: var(--max-width);
  margin-left: auto;
  margin-right: auto;
}

a {
  color: var(--color-link);
  text-decoration: none;
  font-weight: 600;
  transition: color var(--transition-speed);
}
a:hover,
a:focus {
  color: var(--color-link-hover);
  outline: none;
  text-decoration: underline;
}

h1, h2 {
  color: var(--color-heading);
  font-weight: 700;
  margin-top: 0;
  margin-bottom: var(--spacing-sm);
  line-height: 1.1;
  user-select: none;
}

h1 {
  font-size: 3.25rem;
  margin-bottom: 1rem;
}
h2 {
  font-size: 2rem;
  border-bottom: 2px solid var(--color-link);
  padding-bottom: 0.5rem;
  margin-bottom: var(--spacing-sm);
}
h3 {
  font-weight: 600;
  color: var(--color-heading);
  font-size: 1.35rem;
  user-select: none;
}
h4 {
  font-weight: 600;
  font-size: 1.2rem;
  color: #b9c1cb;
  margin-bottom: 0.25rem;
  margin-top: 1.25rem;
  user-select: none;
}

p {
  margin-top: 0;
  margin-bottom: 3.0px;
  color: var(--color-text);
}

ul, li {
  margin-bottom: 0.5rem;
  padding: 0;
  list-style-position: inside;
  color: var(--color-text);
}

ul.skills-list {
  columns: 2;
  list-style-type: none;
  padding-left: 0;
  margin-top: 0;
  margin-bottom: 0;
  gap: var(--spacing-sm);
  font-weight: 600;
  color: var(--color-heading);
}

/* Tarjetas de diseño para secciones */
section {
  width: 100%;
  background: #1B3C53;
  border-radius: var(--border-radius);
  box-shadow: 0 8px 24px var(--shadow-light);
  padding: var(--spacing-md);
  padding-top: 1.875rem;
  margin-bottom: var(--spacing-lg);
  padding-bottom: 0;

  /* Animacion fade in */
  animation: fadeInUp 0.7s ease forwards;
  opacity: 0;
  transform: translateY(15px);
}

header {
  position: sticky;
  top: 0;
  width: 100%;
  max-width: var(--max-width);
  background-color: #234C6A;
  padding: var(--spacing-md) var(--spacing-md);
  border-radius: var(--border-radius);
  box-shadow: 0 1px 6px var(--shadow-medium);
  z-index: 10;
  text-align: center;
  margin-bottom: var(--spacing-lg);
  animation: fadeInDown 0.7s ease forwards;
  opacity: 0;
  transform: translateY(-20px);
}

header h1 {
  user-select: text;
}
header p {
  font-weight: 600;
  color: var(--color-link);
  margin-bottom: 0;
}
header p a {
  color: var(--color-link);
  font-weight: 600;
  margin: 0 0.5rem;
}
header p a:hover,
header p a:focus {
  color: var(--color-link-hover);
  text-decoration: underline;
}

hr {
  display: none;
}

/* Links-Titulos */
section#projects h3 a {
  color: var(--color-heading);
  border-bottom: 2px solid transparent;
  transition: border-color var(--transition-speed);
  cursor: pointer;
  user-select: text;
}
section#projects h3 a:hover,
section#projects h3 a:focus {
  border-color: var(--color-link);
  outline: none;
  color: var(--color-link);
}

/* Caja */
.caja {
  background: #1a2f3b;
  border-radius: var(--border-radius);
  padding: var(--spacing-sm);
  box-shadow: 0 1px 3px var(--shadow-light);
  margin-bottom: 1.25rem;
  margin-top: var(--spacing-sm);
  transition: transform 0.3s ease, box-shadow 0.3s ease; 
  border: 1px solid transparent;
}
.caja:hover, .caja:focus-within {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px var(--shadow-medium);
  border-color: var(--color-link);
}
.caja h3 {
  margin-bottom: 0.25rem;
  margin-top: 0;
  padding-left: 0.25rem;
}
.caja span {
  font-weight: 400;
  color: var(--color-link);
  font-size: 0.9rem;
  user-select: none;
}
.caja .date {
  font-size: 0.85rem;
  color: #9ca3af;
  margin-bottom: var(--spacing-sm);
  user-select: none;
}

/* Caja2 */
.caja2 {
  background: #1a2f3b;
  border-radius: var(--border-radius);
  padding: 1rem 1rem;
  box-shadow: 0 1px 3px var(--shadow-light) inset;
  margin-bottom: var(--spacing-sm);
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-left-color 0.3s ease;
  border-left: 4px solid var(--color-link);
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.55rem;
  font-weight: 700;
  color: var(--color-link);
  user-select: none;
  position: relative;
  min-height: 85px;
  justify-content: center;
  width: 100%;
}

.caja2:hover, .caja2:focus-within {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px var(--shadow-medium);
  border-left-color: var(--color-link-hover); 
}
.caja2 span {
  font-weight: 400;
  color: var(--color-link);
  font-size: 0.9rem;
  user-select: none;
}
.caja2 .date {
  font-size: 0.85rem;
  color: #9ca3af;
  margin: 0;
  line-height: 1.1;
  font-weight: 400;
}
.caja2 h3 {
  margin: 0;
  line-height: 1.2;
  color: var(--color-heading);
}
#aboutme .caja2 p {
    margin-top: 0;
    margin-bottom: 0;
    padding: var(--spacing-md) 1rem; 
    align-items: center;
}

/* Animaciones */
@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
@keyframes fadeInDown {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Estilo para el enlace del certificado (mantiene el estilo de texto normal) */
.certificado-link {
    color: inherit; 
    text-decoration: none; 
}

.certificado-link:hover {
    color: var(--color-link-hover); 
    text-decoration: underline;
}

/* Footer */
footer {
  width: 100%;
  max-width: var(--max-width);
  text-align: center;
  padding: var(--spacing-sm);
  font-size: 0.9rem;
  color: #9ca3af;
  user-select: none;
  margin-top: var(--spacing-md);
}

footer a {
  color: var(--color-link);
  font-weight: 600;
}
footer a:hover,
footer a:focus {
  color: var(--color-link-hover);
  text-decoration: underline;
}

.flag-icon {
    width: 50px; /* Define un tamaño fijo de la bandera */
    height: auto;
    vertical-align: middle;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
}

.language-switcher {
    position: fixed; /* Posición Fija en la ventana (no se mueve al hacer scroll) */
    bottom: var(--spacing-sm);
    right: var(--spacing-sm);
    
    /* Diseño */
    color: var(--color-heading) !important;
    text-decoration: none !important;
    background-color: #234C6A;
    padding: 0.2rem 0.3rem;
    font-size: 0;
    border-radius: var(--border-radius);
    z-index: 1000; 
    box-shadow: 0 4px 6px var(--shadow-medium);
    transition: background-color var(--transition-speed);
}

.language-switcher:hover,
.language-switcher:focus {
    background-color: var(--color-link);
    color: white !important;
    text-decoration: none !important;
}

/* Ajuste para centrar las banderas */
.language-switcher {
    font-size: 1.2rem;
    line-height: 2.0rem; /* Centrado vertical */
    padding: 0.4rem 0.5rem; 
}

/* AJUSTE PARA MÓVILES */
@media (max-width: 640px) {
    .language-switcher {
        padding: 0.3rem 0.5rem;
        top: 92.5%}
}
  
/* Responsive: AJUSTES GLOBALES PARA PANTALLAS PEQUEÑAS */
@media (max-width: 640px) {
    /* 1. Ajustes del Body y Layout General */
    body {
        padding: var(--spacing-sm) var(--spacing-sm); 
    }

    /* 2. Ajustes de Tipografía */
    h1 {
        font-size: 2rem; 
    }
    h2 {
        font-size: 1.5rem; 
        margin-bottom: var(--spacing-sm); 
    }
    h3 {
        font-size: 1.15rem;
    }

    /* 3. Ajustes de Espaciado */
    section {
        padding: var(--spacing-sm); 
        margin-bottom: var(--spacing-sm); 
    }

    /* 4. Ajustes Específicos del Header */
    header {
        padding: var(--spacing-sm) var(--spacing-sm); /* Reduce el padding vertical */
        margin-bottom: var(--spacing-md);
    }
    
    header p {
        margin-bottom: 0.5rem; 
    }
    
    header p a {
        /* Hace los enlaces de contacto más compactos */
        font-size: 0.9rem;
        margin: 0 0.3rem; 
    }

    /* 5. Ajustes de Componentes */
    ul.skills-list {
        columns: 1;
    }

    .caja, .caja2 {
        margin-bottom: var(--spacing-sm);
    }

}