/* ==========================================================================
   USWDS & USCIS THEME STYLESHEET
   Basado en el sistema de diseño oficial U.S. Web Design System (USWDS)
   Portal Informativo USCIS en Español
   ========================================================================== */

:root {
  /* Paleta primaria institucional */
  --usa-blue-primary: #005ea2;
  --usa-blue-dark: #1a4480;
  --usa-blue-darker: #162e51;
  --usa-blue-header: #112e51;
  --usa-blue-light: #73b3e7;
  --usa-blue-lighter: #d9e8f6;
  --usa-blue-lightest: #edf4fb;

  /* Colores de acento y alertas */
  --usa-red: #d9381e;
  --usa-red-dark: #b50900;
  --usa-green: #2e8540;
  --usa-green-light: #ecf3ec;
  --usa-gold: #fdb813;
  --usa-gold-light: #fffbe6;
  --usa-cyan: #00bde3;
  --usa-warning-bg: #fff8e5;
  --usa-warning-border: #fdb813;

  /* Escala de grises y neutros */
  --usa-ink: #1b1b1b;
  --usa-gray-dark: #565c65;
  --usa-gray-medium: #71767a;
  --usa-gray-light: #a9aeb1;
  --usa-gray-lighter: #dfe1e2;
  --usa-gray-lightest: #f0f0f0;
  --usa-gray-bg: #f8f9fa;
  --usa-white: #ffffff;

  /* Tipografías y espaciados */
  --usa-font-sans: "Public Sans", "Source Sans Pro", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --usa-font-serif: "Merriweather", Georgia, "Times New Roman", serif;
  --usa-radius-sm: 4px;
  --usa-radius-md: 6px;
  --usa-radius-lg: 8px;
  --usa-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --usa-shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --usa-shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  --usa-container-max: 1240px;
}

/* Reseteo básico y modelo de cajas */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--usa-font-sans);
  font-size: 1.05rem;
  line-height: 1.6;
  color: var(--usa-ink);
  background-color: var(--usa-white);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Tipografía jerárquica */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.25;
  color: var(--usa-blue-darker);
  margin-bottom: 0.75rem;
}

h1 { font-size: 2.15rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.35rem; }
h4 { font-size: 1.15rem; }

p {
  margin-bottom: 1rem;
}

a {
  color: var(--usa-blue-primary);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.15s ease-in-out;
}

a:hover, a:focus {
  color: var(--usa-blue-dark);
  text-decoration: none;
}

/* Utilidades de contenedores */
.usa-container {
  max-width: var(--usa-container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.25rem;
  padding-right: 1.25rem;
  width: 100%;
}

/* Botones con estilo USWDS */
.usa-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--usa-font-sans);
  font-size: 1rem;
  font-weight: 700;
  text-decoration: none;
  padding: 0.75rem 1.5rem;
  border-radius: var(--usa-radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  transition: background-color 0.2s ease, transform 0.1s ease, box-shadow 0.2s ease;
  line-height: 1.2;
}

.usa-button-primary {
  background-color: var(--usa-blue-primary);
  color: var(--usa-white) !important;
}

.usa-button-primary:hover {
  background-color: var(--usa-blue-dark);
}

.usa-button-secondary {
  background-color: transparent;
  color: var(--usa-blue-primary);
  border-color: var(--usa-blue-primary);
}

.usa-button-secondary:hover {
  background-color: var(--usa-blue-lightest);
}

.usa-button-accent {
  background-color: var(--usa-red);
  color: var(--usa-white) !important;
}

.usa-button-accent:hover {
  background-color: var(--usa-red-dark);
}

.usa-button-outline-white {
  background-color: transparent;
  color: var(--usa-white);
  border-color: var(--usa-white);
}

.usa-button-outline-white:hover {
  background-color: rgba(255, 255, 255, 0.15);
}

/* Etiquetas y badges */
.usa-tag {
  display: inline-block;
  padding: 0.25rem 0.65rem;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  border-radius: 3px;
}

.usa-tag-info {
  background-color: var(--usa-blue-lighter);
  color: var(--usa-blue-darker);
}

.usa-tag-success {
  background-color: #d1fae5;
  color: #065f46;
}

.usa-tag-warning {
  background-color: #fef3c7;
  color: #92400e;
}

/* Accesibilidad y skip link */
.usa-skipnav {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--usa-blue-darker);
  color: var(--usa-white);
  padding: 0.75rem 1.25rem;
  z-index: 10000;
  text-decoration: none;
  font-weight: 700;
  border-radius: 0 0 4px 4px;
  transition: top 0.2s ease;
}

.usa-skipnav:focus {
  top: 0;
}