/* ============================================
   NIT — Nebraska Institute of Technology
   Mobile-first responsive stylesheet
   ============================================ */

/* --- Custom Properties --- */
:root {
  --color-navy: #1E3A5F;
  --color-navy-dark: #152C4A;
  --color-navy-light: #2A4F7A;
  --color-accent: #3B82F6;
  --color-accent-hover: #2563EB;
  --color-white: #FFFFFF;
  --color-gray-50: #F9FAFB;
  --color-gray-100: #F3F4F6;
  --color-gray-200: #E5E7EB;
  --color-gray-300: #D1D5DB;
  --color-gray-500: #6B7280;
  --color-gray-600: #4B5563;
  --color-gray-700: #374151;
  --color-gray-800: #1F2937;
  --color-gray-900: #111827;
  --color-success: #10B981;
  --color-error: #EF4444;

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

  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);

  --transition: 200ms ease;
  --header-height: 4rem;
}

/* --- Alpine.js cloak --- */
[x-cloak] {
  display: none !important;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}

body {
  font-family: var(--font-sans);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-gray-800);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-accent-hover);
}

ul, ol {
  list-style: none;
}

button {
  cursor: pointer;
  font-family: inherit;
  border: none;
  background: none;
}

/* --- Utilities --- */
.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;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* --- Skip to content --- */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-md);
  background: var(--color-navy);
  color: var(--color-white);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  z-index: 1000;
  font-weight: 600;
}

.skip-link:focus {
  top: var(--space-sm);
  color: var(--color-white);
}

/* --- Header / Nav --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-white);
  border-bottom: 1px solid var(--color-gray-200);
  height: var(--header-height);
  transition: box-shadow var(--transition);
}

.site-header.scrolled {
  box-shadow: var(--shadow-md);
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-navy);
  text-decoration: none;
}

.nav-logo:hover {
  color: var(--color-navy);
}

.nav-logo svg {
  width: 2rem;
  height: 2rem;
  flex-shrink: 0;
}

.nav-links {
  display: none;
  gap: var(--space-lg);
}

.nav-links a {
  color: var(--color-gray-700);
  font-weight: 500;
  font-size: 0.9375rem;
  padding: var(--space-xs) 0;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-navy);
  transition: width var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-navy);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  color: var(--color-gray-700);
}

.nav-toggle svg {
  width: 1.5rem;
  height: 1.5rem;
}

/* Mobile nav overlay */
.mobile-nav {
  position: fixed;
  inset: 0;
  top: var(--header-height);
  background: var(--color-white);
  z-index: 99;
  display: flex;
  flex-direction: column;
  padding: var(--space-xl);
  gap: var(--space-md);
  transform: translateX(100%);
  transition: transform 300ms ease;
}

.mobile-nav.open {
  transform: translateX(0);
}

.mobile-nav a {
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--color-gray-800);
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--color-gray-100);
}

.mobile-nav a:hover,
.mobile-nav a.active {
  color: var(--color-navy);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.9375rem;
  transition: all var(--transition);
  text-decoration: none;
}

.btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.btn-primary {
  background: var(--color-navy);
  color: var(--color-white);
}

.btn-primary:hover {
  background: var(--color-navy-dark);
  color: var(--color-white);
}

.btn-outline {
  border: 2px solid var(--color-navy);
  color: var(--color-navy);
  background: transparent;
}

.btn-outline:hover {
  background: var(--color-navy);
  color: var(--color-white);
}

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.0625rem;
}

/* --- Hero --- */
.hero {
  padding: var(--space-3xl) 0;
  background: linear-gradient(135deg, var(--color-gray-50) 0%, var(--color-white) 100%);
}

.hero-content {
  max-width: 42rem;
}

.hero-badge {
  display: inline-block;
  background: var(--color-navy);
  color: var(--color-white);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: var(--space-xs) var(--space-md);
  border-radius: 9999px;
  margin-bottom: var(--space-md);
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 800;
  line-height: 1.15;
  color: var(--color-gray-900);
  margin-bottom: var(--space-md);
}

.hero h1 .highlight {
  color: var(--color-navy);
}

.hero p {
  font-size: 1.125rem;
  color: var(--color-gray-600);
  margin-bottom: var(--space-xl);
  max-width: 36rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

/* --- Section shared --- */
.section {
  padding: var(--space-3xl) 0;
}

.section-alt {
  background: var(--color-gray-50);
}

.section-header {
  text-align: center;
  max-width: 40rem;
  margin: 0 auto var(--space-2xl);
}

.section-header h2 {
  font-size: clamp(1.5rem, 3.5vw, 2.25rem);
  font-weight: 700;
  color: var(--color-gray-900);
  margin-bottom: var(--space-sm);
}

.section-header p {
  font-size: 1.0625rem;
  color: var(--color-gray-500);
}

/* --- Value Pillars --- */
.pillars-grid {
  display: grid;
  gap: var(--space-lg);
}

.pillar-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  text-align: center;
  transition: transform var(--transition), box-shadow var(--transition);
}

.pillar-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.pillar-icon {
  width: 3rem;
  height: 3rem;
  margin: 0 auto var(--space-md);
  color: var(--color-navy);
}

.pillar-card h3 {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--color-gray-900);
  margin-bottom: var(--space-sm);
}

.pillar-card p {
  color: var(--color-gray-600);
  font-size: 0.9375rem;
}

/* --- About --- */
.about-content {
  max-width: 48rem;
  margin: 0 auto;
}

.about-content h2 {
  font-size: clamp(1.5rem, 3.5vw, 2.25rem);
  font-weight: 700;
  color: var(--color-gray-900);
  margin-bottom: var(--space-md);
}

.about-content p {
  color: var(--color-gray-600);
  margin-bottom: var(--space-md);
  font-size: 1.0625rem;
  line-height: 1.7;
}

.about-content p:last-of-type {
  margin-bottom: var(--space-xl);
}

/* --- Testimonials --- */
.testimonials-grid {
  display: grid;
  gap: var(--space-lg);
}

.testimonial-card {
  background: var(--color-white);
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
}

.testimonial-card blockquote {
  font-size: 1rem;
  color: var(--color-gray-700);
  line-height: 1.7;
  margin-bottom: var(--space-md);
  font-style: italic;
}

.testimonial-card blockquote::before {
  content: '\201C';
  font-size: 2rem;
  color: var(--color-navy);
  line-height: 0;
  vertical-align: -0.5rem;
  margin-right: 0.15rem;
}

.testimonial-author {
  font-weight: 600;
  color: var(--color-gray-900);
  font-size: 0.9375rem;
}

.testimonial-role {
  color: var(--color-gray-500);
  font-size: 0.8125rem;
}

/* --- Course Page Hero --- */
.page-hero {
  padding: var(--space-2xl) 0;
  background: linear-gradient(135deg, var(--color-navy) 0%, var(--color-navy-light) 100%);
  color: var(--color-white);
}

.page-hero h1 {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 800;
  margin-bottom: var(--space-sm);
}

.page-hero p {
  font-size: 1.0625rem;
  opacity: 0.85;
  max-width: 36rem;
}

/* --- Accordion --- */
.accordion {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  max-width: 48rem;
  margin: 0 auto;
}

.accordion-item {
  border: 1px solid var(--color-gray-200);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--color-white);
}

.accordion-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg);
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-gray-900);
  text-align: left;
  transition: background var(--transition);
}

.accordion-trigger:hover {
  background: var(--color-gray-50);
}

.accordion-trigger:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: -2px;
}

.accordion-trigger .chevron {
  width: 1.25rem;
  height: 1.25rem;
  flex-shrink: 0;
  color: var(--color-gray-500);
  transition: transform 300ms ease;
}

.accordion-trigger[aria-expanded="true"] .chevron {
  transform: rotate(180deg);
}

.accordion-panel {
  padding: 0 var(--space-lg) var(--space-lg);
}

.accordion-panel p {
  color: var(--color-gray-600);
  font-size: 0.9375rem;
  line-height: 1.7;
  margin-bottom: var(--space-sm);
}

.accordion-panel .course-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
}

.course-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  background: var(--color-gray-100);
  color: var(--color-gray-700);
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 0.25rem 0.625rem;
  border-radius: 9999px;
}

/* --- Benefits --- */
.benefits-grid {
  display: grid;
  gap: var(--space-lg);
}

.benefit-card {
  display: flex;
  gap: var(--space-md);
  align-items: flex-start;
}

.benefit-icon {
  width: 2.5rem;
  height: 2.5rem;
  flex-shrink: 0;
  color: var(--color-navy);
}

.benefit-card h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-gray-900);
  margin-bottom: var(--space-xs);
}

.benefit-card p {
  color: var(--color-gray-600);
  font-size: 0.9375rem;
}

/* --- CTA Section --- */
.cta-section {
  padding: var(--space-3xl) 0;
  background: var(--color-navy);
  color: var(--color-white);
  text-align: center;
}

.cta-section h2 {
  font-size: clamp(1.5rem, 3.5vw, 2.25rem);
  font-weight: 700;
  margin-bottom: var(--space-sm);
}

.cta-section p {
  opacity: 0.85;
  margin-bottom: var(--space-xl);
  max-width: 32rem;
  margin-left: auto;
  margin-right: auto;
}

.cta-section .btn-primary {
  background: var(--color-white);
  color: var(--color-navy);
}

.cta-section .btn-primary:hover {
  background: var(--color-gray-100);
}

/* --- Contact Form --- */
.contact-grid {
  display: grid;
  gap: var(--space-2xl);
}

.form-group {
  margin-bottom: var(--space-lg);
}

.form-group label {
  display: block;
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--color-gray-700);
  margin-bottom: var(--space-xs);
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  color: var(--color-gray-800);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

.form-group textarea {
  min-height: 8rem;
  resize: vertical;
}

.form-group .error-msg {
  color: var(--color-error);
  font-size: 0.8125rem;
  margin-top: var(--space-xs);
}

.form-group input.invalid,
.form-group textarea.invalid {
  border-color: var(--color-error);
}

.form-success {
  background: var(--color-gray-50);
  border: 1px solid var(--color-success);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  text-align: center;
  color: var(--color-gray-800);
}

.form-success h3 {
  color: var(--color-success);
  margin-bottom: var(--space-sm);
}

/* Contact info card */
.contact-info-card {
  background: var(--color-gray-50);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
}

.contact-info-card h2 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-gray-900);
  margin-bottom: var(--space-lg);
}

.contact-info-item {
  display: flex;
  gap: var(--space-md);
  align-items: flex-start;
  margin-bottom: var(--space-lg);
}

.contact-info-item:last-child {
  margin-bottom: 0;
}

.contact-info-item svg {
  width: 1.25rem;
  height: 1.25rem;
  flex-shrink: 0;
  color: var(--color-navy);
  margin-top: 0.15rem;
}

.contact-info-item h3 {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-gray-900);
  margin-bottom: 0.125rem;
}

.contact-info-item p,
.contact-info-item a {
  font-size: 0.9375rem;
  color: var(--color-gray-600);
}

/* --- FAQ --- */
.faq-section {
  padding: var(--space-3xl) 0;
}

/* --- Footer --- */
.site-footer {
  background: var(--color-gray-900);
  color: var(--color-gray-300);
  padding: var(--space-2xl) 0 var(--space-lg);
}

.footer-grid {
  display: grid;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.footer-brand {
  max-width: 20rem;
}

.footer-brand .nav-logo {
  color: var(--color-white);
  margin-bottom: var(--space-sm);
}

.footer-brand p {
  font-size: 0.875rem;
  color: var(--color-gray-500);
  line-height: 1.6;
}

.footer-links h4 {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: var(--space-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links a {
  display: block;
  font-size: 0.875rem;
  color: var(--color-gray-400);
  padding: var(--space-xs) 0;
}

.footer-links a:hover {
  color: var(--color-white);
}

.footer-bottom {
  border-top: 1px solid var(--color-gray-800);
  padding-top: var(--space-lg);
  font-size: 0.8125rem;
  color: var(--color-gray-500);
  text-align: center;
}

/* --- Scroll to Top --- */
.scroll-top {
  position: fixed;
  bottom: var(--space-lg);
  right: var(--space-lg);
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 50%;
  background: var(--color-navy);
  color: var(--color-white);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition), visibility var(--transition), transform var(--transition);
  z-index: 50;
}

.scroll-top.visible {
  opacity: 1;
  visibility: visible;
}

.scroll-top:hover {
  transform: translateY(-2px);
  background: var(--color-navy-dark);
}

.scroll-top svg {
  width: 1.25rem;
  height: 1.25rem;
}

/* --- Animation placeholders --- */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(1.5rem);
}

.animate-on-scroll.animated {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 600ms ease, transform 600ms ease;
}

/* ============================================
   Responsive Breakpoints
   ============================================ */

@media (min-width: 480px) {
  .pillars-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 768px) {
  .nav-links {
    display: flex;
  }

  .nav-toggle {
    display: none;
  }

  .mobile-nav {
    display: none !important;
  }

  .hero {
    padding: var(--space-4xl) 0;
  }

  .section {
    padding: var(--space-4xl) 0;
  }

  .pillars-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .testimonials-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .benefits-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .contact-grid {
    grid-template-columns: 1fr 1fr;
  }

  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr;
  }
}

@media (min-width: 1024px) {
  .container {
    padding: 0 var(--space-xl);
  }

  .hero-content {
    max-width: 48rem;
  }
}