/* =============================================
   USB - Universidad Salesiana de Bolivia
   Design System – main.css
   ============================================= */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Outfit:wght@400;600;700;800;900&display=swap');

/* ---- CSS Custom Properties ---- */
:root {
  /* Brand Colors */
  --usb-blue:        #003087;
  --usb-blue-dark:   #002060;
  --usb-blue-light:  #1a4ba8;
  --usb-red:         #C8102E;
  --usb-red-dark:    #9e0a24;
  --usb-red-light:   #e8274e;

  /* Neutrals */
  --gray-50:  #f8fafc;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1e293b;
  --gray-900: #0f172a;

  /* Semantic */
  --success:  #16a34a;
  --warning:  #d97706;
  --error:    #dc2626;
  --info:     #0284c7;

  /* Carrera Colors */
  --carrera-sistemas:    #5b21b6;
  --carrera-contaduria:  #003087;
  --carrera-derecho:     #d97706;
  --carrera-comercial:   #9a3412;
  --carrera-educacion:   #166534;
  --carrera-gastronomia: #0f766e;
  --carrera-psicomotricidad: #be185d;

  /* Typography */
  --font-body:    'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-display: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Border radius */
  --radius-sm: 0.375rem;
  --radius:    0.75rem;
  --radius-lg: 1.25rem;
  --radius-xl: 2rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm:  0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.04);
  --shadow:     0 4px 16px rgba(0,0,0,.10), 0 2px 4px rgba(0,0,0,.06);
  --shadow-md:  0 8px 30px rgba(0,0,0,.12), 0 4px 8px rgba(0,0,0,.08);
  --shadow-lg:  0 20px 60px rgba(0,0,0,.15), 0 8px 20px rgba(0,0,0,.10);
  --shadow-blue: 0 8px 32px rgba(0,48,135,.25);
  --shadow-red:  0 8px 32px rgba(200,16,46,.25);

  /* Transitions */
  --transition:       all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow:  all 0.45s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-spring: all 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);

  /* Z-index */
  --z-modal:   1000;
  --z-nav:     100;
  --z-tooltip: 50;
}

/* ---- Reset & Base ---- */
*, *::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(--font-body);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--gray-800);
  background: var(--gray-50);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

ul, ol {
  list-style: none;
}

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

input, select, textarea {
  font-family: inherit;
  font-size: inherit;
}

/* ---- Navigation ---- */
.nav {
  position: sticky;
  top: 0;
  z-index: var(--z-nav);
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--gray-200);
  transition: var(--transition);
}

.nav__inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav__logo {
  height: 48px;
  width: auto;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.nav__link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--gray-600);
  transition: var(--transition);
  position: relative;
  padding-bottom: 2px;
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--usb-blue);
  border-radius: var(--radius-full);
  transition: var(--transition);
}

.nav__link:hover {
  color: var(--usb-blue);
}

.nav__link:hover::after,
.nav__link.active::after {
  width: 100%;
}

.nav__link.active {
  color: var(--usb-blue);
  font-weight: 600;
}

.nav__cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0.6rem var(--space-5);
  background: var(--usb-blue);
  color: white;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: var(--transition-spring);
  box-shadow: var(--shadow-blue);
}

.nav__cta:hover {
  background: var(--usb-blue-dark);
  transform: translateY(-1px);
  box-shadow: 0 12px 40px rgba(0,48,135,.35);
}

/* Mobile nav toggle */
.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: var(--space-2);
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.nav__toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--gray-700);
  border-radius: var(--radius-full);
  transition: var(--transition);
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 0.75rem 1.75rem;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: var(--transition-spring);
  border: 2px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  text-decoration: none;
}

.btn-primary {
  background: var(--usb-blue);
  color: white;
  box-shadow: var(--shadow-blue);
}

.btn-primary:hover {
  background: var(--usb-blue-dark);
  transform: translateY(-2px);
  box-shadow: 0 16px 48px rgba(0,48,135,.35);
}

.btn-secondary {
  background: white;
  color: var(--usb-blue);
  border-color: var(--usb-blue);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: var(--usb-blue);
  color: white;
  transform: translateY(-2px);
  box-shadow: var(--shadow-blue);
}

.btn-red {
  background: var(--usb-red);
  color: white;
  box-shadow: var(--shadow-red);
}

.btn-red:hover {
  background: var(--usb-red-dark);
  transform: translateY(-2px);
  box-shadow: 0 16px 48px rgba(200,16,46,.35);
}

.btn-ghost {
  background: transparent;
  color: var(--gray-600);
  border-color: var(--gray-200);
}

.btn-ghost:hover {
  background: var(--gray-100);
  color: var(--gray-800);
  border-color: var(--gray-300);
}

.btn-lg {
  padding: 1rem 2.25rem;
  font-size: 1.0625rem;
}

.btn-sm {
  padding: 0.5rem 1.25rem;
  font-size: 0.8125rem;
}

/* ---- Container ---- */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.container-narrow {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* ---- Section ---- */
.section {
  padding: var(--space-20) 0;
}

.section-sm {
  padding: var(--space-12) 0;
}

/* ---- Section Header ---- */
.section-header {
  text-align: center;
  margin-bottom: var(--space-12);
}

.section-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--usb-blue);
  background: rgba(0,48,135,0.08);
  padding: 0.35rem 0.9rem;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-4);
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 800;
  color: var(--gray-900);
  line-height: 1.2;
  margin-bottom: var(--space-4);
}

.section-subtitle {
  font-size: 1.0625rem;
  color: var(--gray-500);
  max-width: 580px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ---- Cards ---- */
.card {
  background: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  overflow: hidden;
  transition: var(--transition-slow);
}

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

/* ---- Badge ---- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 0.25rem 0.625rem;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: var(--gray-100);
  color: var(--gray-600);
}

/* ---- Form Elements ---- */
.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.form-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--gray-700);
}

.form-label span.required {
  color: var(--usb-red);
  margin-left: 2px;
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 0.9375rem;
  color: var(--gray-800);
  background: white;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius);
  outline: none;
  transition: var(--transition);
  appearance: none;
  -webkit-appearance: none;
}

.form-control:focus {
  border-color: var(--usb-blue);
  box-shadow: 0 0 0 4px rgba(0,48,135,0.12);
}

.form-control:invalid:not(:placeholder-shown) {
  border-color: var(--error);
  box-shadow: 0 0 0 4px rgba(220,38,38,0.10);
}

.form-control::placeholder {
  color: var(--gray-400);
}

.form-error {
  font-size: 0.8125rem;
  color: var(--error);
  display: none;
  align-items: center;
  gap: var(--space-1);
}

.form-error.visible {
  display: flex;
}

/* ---- File Upload ---- */
.file-upload {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  padding: var(--space-8);
  border: 2px dashed var(--gray-300);
  border-radius: var(--radius-lg);
  background: var(--gray-50);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  min-height: 140px;
}

.file-upload:hover {
  border-color: var(--usb-blue);
  background: rgba(0,48,135,0.04);
}

.file-upload.dragover {
  border-color: var(--usb-blue);
  background: rgba(0,48,135,0.08);
  transform: scale(1.01);
}

.file-upload.has-file {
  border-color: var(--success);
  background: rgba(22,163,74,0.05);
}

.file-upload input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  width: 100%;
  height: 100%;
}

.file-upload__icon {
  width: 40px;
  height: 40px;
  color: var(--gray-400);
  transition: var(--transition);
}

.file-upload:hover .file-upload__icon {
  color: var(--usb-blue);
}

.file-upload__label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--gray-600);
}

.file-upload__hint {
  font-size: 0.8125rem;
  color: var(--gray-400);
}

.file-upload__filename {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--success);
  display: none;
}

.file-upload.has-file .file-upload__filename { display: block; }
.file-upload.has-file .file-upload__label,
.file-upload.has-file .file-upload__hint,
.file-upload.has-file .file-upload__icon { display: none; }

/* ---- Footer ---- */
.footer {
  background: var(--gray-900);
  color: var(--gray-400);
  padding: var(--space-12) 0 var(--space-8);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-10);
  margin-bottom: var(--space-10);
}

.footer__brand-text {
  font-family: var(--font-display);
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--gray-500);
  margin-top: var(--space-4);
  max-width: 300px;
}

.footer__heading {
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--gray-300);
  margin-bottom: var(--space-4);
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer__links a {
  font-size: 0.875rem;
  color: var(--gray-500);
  transition: var(--transition);
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
}

.footer__links a:hover {
  color: white;
}

.footer__bottom {
  border-top: 1px solid rgba(255,255,255,0.07);
  padding-top: var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8125rem;
}

.footer__logo {
  height: 36px;
  width: auto;
  filter: brightness(0) invert(1);
  opacity: 0.7;
}

/* ---- Animations ---- */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes slideInRight {
  from { opacity: 0; transform: translateX(24px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.95); }
  to   { opacity: 1; transform: scale(1); }
}

@keyframes pulse-ring {
  0%   { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(0,48,135,0.4); }
  70%  { transform: scale(1); box-shadow: 0 0 0 12px rgba(0,48,135,0); }
  100% { transform: scale(0.95); }
}

.animate-fade-in-up {
  animation: fadeInUp 0.6s ease forwards;
}

.animate-delay-100 { animation-delay: 0.1s; opacity: 0; }
.animate-delay-200 { animation-delay: 0.2s; opacity: 0; }
.animate-delay-300 { animation-delay: 0.3s; opacity: 0; }
.animate-delay-400 { animation-delay: 0.4s; opacity: 0; }
.animate-delay-500 { animation-delay: 0.5s; opacity: 0; }

/* ---- Intersection Observer Reveal ---- */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.65s ease, transform 0.65s ease;
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ---- Utilities ---- */
.text-center { text-align: center; }
.text-left   { text-align: left; }
.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;
}

.gradient-text {
  background: linear-gradient(135deg, var(--usb-blue) 0%, var(--usb-blue-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.gradient-text-red {
  background: linear-gradient(135deg, var(--usb-red) 0%, var(--usb-red-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---- Responsive ---- */
@media (max-width: 1024px) {
  .nav__links { display: none; }
  .nav__toggle { display: flex; }
  .footer__grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 640px) {
  :root { --space-6: 1.25rem; }
  .footer__grid { grid-template-columns: 1fr; }
  .footer__bottom { flex-direction: column; gap: var(--space-3); text-align: center; }
  .btn-lg { width: 100%; }
}

/* ---- Mobile Nav Overlay ---- */
.nav-mobile {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: calc(var(--z-nav) - 1);
  backdrop-filter: blur(4px);
}

.nav-mobile.open {
  display: block;
  animation: fadeIn 0.2s ease forwards;
}

.nav-mobile__panel {
  position: absolute;
  top: 72px;
  left: 0;
  right: 0;
  background: white;
  padding: var(--space-4) var(--space-6);
  border-bottom: 1px solid var(--gray-100);
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  animation: fadeInUp 0.25s ease forwards;
}

.nav-mobile__link {
  padding: var(--space-3) 0;
  font-size: 1rem;
  font-weight: 500;
  color: var(--gray-700);
  border-bottom: 1px solid var(--gray-100);
  transition: var(--transition);
}

.nav-mobile__link:hover {
  color: var(--usb-blue);
  padding-left: var(--space-2);
}

.nav-mobile__link:last-child { border-bottom: none; }

/* ---- Modal ---- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  z-index: var(--z-modal);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
  backdrop-filter: blur(4px);
}

.modal-overlay.open {
  opacity: 1;
  pointer-events: all;
}

.modal {
  background: white;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  max-width: 90vw;
  max-height: 90vh;
  overflow: auto;
  transform: scale(0.92);
  transition: transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal-overlay.open .modal {
  transform: scale(1);
}

.modal__header {
  padding: var(--space-6);
  border-bottom: 1px solid var(--gray-100);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  position: sticky;
  top: 0;
  background: white;
  z-index: 1;
}

.modal__title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--gray-900);
}

.modal__close {
  width: 36px;
  height: 36px;
  border-radius: var(--radius);
  background: var(--gray-100);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--gray-500);
  transition: var(--transition);
  flex-shrink: 0;
}

.modal__close:hover {
  background: var(--gray-200);
  color: var(--gray-800);
}

.modal__body {
  padding: var(--space-6);
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--gray-100); }
::-webkit-scrollbar-thumb { background: var(--gray-300); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background: var(--gray-400); }