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

/* =========================
   SISTEMA DE COLORES (DEFAULT: CLARO)
========================= */
:root {
  /* Identidad */
  --primary: #2563eb;
  --primary-soft: #93c5fd;
  --accent: #3b82f6;

  /* Fondos */
  --bg: #f5f7fa;
  --surface: #ffffff;
  --surface-soft: #eef2ff;

  /* Navegación */
  --nav-bg: rgba(255, 255, 255, 0.75);
  --nav-text: #0f172a;
  --nav-hover: var(--primary);

  /* Texto */
  --text-main: #0f172a;
  --text-soft: #475569;

  /* Toggle tema */
  --slider-bg: #e5e7eb;
  --slider-thumb: #ffffff;

  /* Bordes y sombras */
  --border: #e5e7eb;
  --shadow: 0 10px 30px rgba(15, 23, 42, 0.08);
}

/* =========================
   MODO OSCURO
========================= */
body.dark {
  --bg: #0f172a;
  --surface: #111827;
  --surface-soft: #243247;

  --nav-bg: rgba(15, 23, 42, 0.75);
  --nav-text: #e5e7eb;
  --nav-hover: var(--accent);

  --text-main: #e5e7eb;
  --text-soft: #94a3b8;

  --slider-bg: #334155;
  --slider-thumb: #e5e7eb;

  --border: #1f2937;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

/* =========================
   BASE
========================= */
body {
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text-main);
  line-height: 1.6;
  transition: background 0.4s ease, color 0.4s ease;
}

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

.container {
  width: 90%;
  max-width: 1100px;
  margin: auto;
}

/* =========================
   HEADER
========================= */
header {
  position: fixed;
  top: 0;
  width: 100%;
  background: var(--nav-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  z-index: 1000;
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 64px;
}

.logo {
  font-weight: 700;
  font-size: 1.3rem;
  color: var(--primary);
}

/* =========================
   NAV
========================= */
.nav {
  display: flex;
  gap: 24px;
}

.nav a {
  font-weight: 500;
  color: var(--nav-text);
  transition: color 0.3s;
}

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

/* =========================
   HAMBURGER
========================= */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
}

.hamburger span {
  width: 24px;
  height: 3px;
  background: var(--nav-text);
  transition: 0.3s;
}

/* =========================
   HERO
========================= */
.hero {
  background:
    linear-gradient(180deg, rgba(15,23,42,0.85), rgba(15,23,42,0.6)),
    url("../img/hero-zetio.jpg") center/cover no-repeat;
  color: #fff;
  padding: 130px 20px;
  text-align: center;
}

.hero h1 {
  font-size: 3.1rem;
  font-weight: 700;
  margin-bottom: 20px;
}

.hero p {
  font-size: 1.3rem;
  color: var(--primary-soft);
}

/* =========================
   BOTONES
========================= */
.btn {
  display: inline-block;
  margin-top: 30px;
  padding: 14px 34px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  border-radius: 10px;
  font-weight: 600;
  box-shadow: var(--shadow);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 40px rgba(37, 99, 235, 0.35);
}

/* =========================
   SECCIONES
========================= */
.section {
  padding: 100px 0;
  background: var(--bg);
}

.section h2 {
  text-align: center;
  margin-bottom: 50px;
  font-size: 2.2rem;
  color: var(--text-main);
}

/* =========================
   CARDS / SERVICES
========================= */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 30px;
}

.demo-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 36px;
}

.card,
.service-card {
  background: var(--surface);
  border-radius: 14px;
  overflow: hidden;
  box-shadow: var(--shadow);
  padding: 24px;
  text-align: center;
  transition: transform 0.25s ease, box-shadow 0.25s ease, background 0.3s ease;
}

.card:hover,
.service-card:hover {
  transform: translateY(-4px);
  background: var(--surface-soft);
}

.card h3,
.card h4 {
  color: var(--text-main);
}

.card p,
.card li {
  color: var(--text-soft);
}

.card i {
  font-size: 2rem;
  color: var(--primary);
  margin-bottom: 15px;
  transition: transform 0.3s ease, color 0.3s ease;
}

.card:hover i {
  transform: scale(1.1);
  color: var(--accent);
}

/* =========================
   IMÁGENES EN CARDS
========================= */
.card img,
.service-card img {
  width: 100%;
  height: 160px;
  object-fit: cover;
  border-radius: 12px 12px 0 0;
  display: block;
  transition: transform 0.4s ease;
}

.card:hover img {
  transform: scale(1.05);
}

/* =========================
   FOOTER
========================= */
footer {
  background: var(--surface-soft);
  text-align: center;
  padding: 40px 0;
  font-size: 0.9rem;
  color: var(--text-soft);
}

/* =========================
   WHATSAPP
========================= */
.whatsapp-float {
  position: fixed;
  bottom: 25px;
  right: 25px;
  background: #25D366;
  color: white;
  font-size: 26px;
  padding: 14px 18px;
  border-radius: 50%;
  z-index: 999;
  box-shadow: 0 6px 18px rgba(0,0,0,0.3);
}

/* =========================
   FORMULARIOS
========================= */
form {
  max-width: 500px;
  margin: 40px auto;
  display: flex;
  flex-direction: column;
  gap: 15px;
}

form input,
form textarea {
  padding: 12px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-main);
}

/* =========================
   TOGGLE TEMA
========================= */
.theme-switch {
  position: relative;
  display: inline-block;
  width: 50px;
  height: 26px;
  margin-left: 20px;
}

.theme-switch input {
  opacity: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  inset: 0;
  background-color: var(--slider-bg);
  border-radius: 26px;
  transition: 0.4s;
  border: 1px solid var(--border);
}

.slider::before {
  content: "";
  position: absolute;
  height: 20px;
  width: 20px;
  left: 3px;
  bottom: 3px;
  background-color: var(--slider-thumb);
  border-radius: 50%;
  transition: 0.4s;
}

input:checked + .slider::before {
  transform: translateX(24px);
  background-color: var(--accent);
}

/* =========================
   RESPONSIVE
========================= */
@media (max-width: 768px) {

  .hamburger {
    display: flex;
  }

  .nav {
    position: absolute;
    top: 64px;
    right: 0;
    background: var(--surface);
    flex-direction: column;
    width: 100%;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
  }

  .nav.active {
    max-height: 300px;
  }

  .nav a {
    padding: 16px;
    border-top: 1px solid var(--border);
  }

  .hero h1 {
    font-size: 2.2rem;
  }

  .hero p {
    font-size: 1.1rem;
  }
}

/* =========================
   ANIMACIONES
========================= */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s ease;
}

.fade-up.show {
  opacity: 1;
  transform: translateY(0);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}


/* =========================
RESPONSIVE – MOBILE
========================= */

@media (max-width: 768px) {

  .demo-card {
    position: relative;
    height: 360px;
    border-radius: 18px;
    overflow: hidden;
    box-shadow: var(--shadow);
    background: var(--surface);
  }
  
  /* imagen ocupa TODO */
  .demo-card .demo-image {
    position: absolute;
    inset: 0;
    background-size: cover;
    background-position: center;
    z-index: 1;
  }  

  .demo-card .demo-panel {
    position: static;
    width: 100%;
    height: auto;
    padding: 22px;
    border-left: none;
    border-top: 1px solid var(--border);
  }

  .demo-card:hover .demo-panel {
    right: 0;
  }
}

/* =========================
DEMO CARDS – DESPLIEGUE LATERAL (AJUSTADO)
========================= */

.demo-card {
  position: relative;
  overflow: hidden;
  border-radius: 16px;
  background: var(--surface);
  box-shadow: var(--shadow);
  min-height: 320px;
  transition: transform 0.3s ease;
}

.demo-card:hover {
  transform: translateY(-6px);
}

/* Imagen ocupa TODO el fondo */
.demo-card .demo-image {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  z-index: 1;
}

/* Oscurecido sutil para legibilidad */
.demo-card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.12);
  transition: background 0.4s ease;
  z-index: 2;
}

.demo-card:hover::after {
  background: rgba(0,0,0,0.35);
}


/* Header flotante */
.demo-card .demo-header {
  position: absolute;
  top: 18px;
  left: 18px;
  background: var(--surface);
  color: var(--text-main);
  padding: 10px 16px;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 600;
  display: flex;
  gap: 10px;
  align-items: center;
  z-index: 3;
}

.demo-card .demo-header i {
  color: var(--primary);
}

/* Panel oculto */
.demo-card .demo-panel {
  position: absolute;
  inset: 0;
  background: var(--surface);
  padding: 36px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 14px;
  transform: translateX(100%);
  transition: transform 0.45s ease;
  z-index: 4;
}

/* Hover correcto */
.demo-card:hover .demo-panel {
  transform: translateX(0);
}

/* Texto */
.demo-panel h4 {
  font-size: 1.5rem;
}

.demo-panel p {
  font-size: 1rem;
  color: var(--text-soft);
}

.demo-panel .demo-tag {
  margin-top: 10px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--primary);
}

@media (max-width: 1024px) {
  .demo-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .demo-grid {
    grid-template-columns: 1fr;
  }

  .demo-panel {
    position: static;
    transform: none;
  }

  .demo-card {
    height: auto;
  }
}

/* =========================
ANIMACIÓN HEADER DEMO
========================= */

@keyframes headerFadeIn {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.demo-card .demo-header {
  animation: headerFadeIn 0.6s ease forwards;
}

.demo-card:hover .demo-header {
  transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(0,0,0,0.18);
}

/* =========================
HERO DEMOS
========================= */

.hero-demos {
  padding: 110px 20px 80px;
  text-align: center;
  background:
    linear-gradient(180deg, rgba(15,23,42,0.75), rgba(15,23,42,0.9)),
    url("../img/banner.jpg") center/cover no-repeat;
}

.hero-demos h1 {
  font-size: 2.6rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 18px;
}

.hero-demos p {
  max-width: 720px;
  margin: 0 auto;
  font-size: 1.15rem;
  color: var(--primary-soft);
}

/* =========================
CONTACT
========================= */

.contact-form {
  max-width: 520px;
  margin: 0 auto;
}

.contact-form .form-group {
  margin-bottom: 16px;
}

.contact-form input,
.contact-form textarea,
.contact-form select {
  width: 100%;
  padding: 14px 16px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--card-bg);
  color: var(--text);
  font-family: inherit;
  font-size: 1rem;
}

.contact-form textarea {
  min-height: 140px;
  resize: vertical;
}

.contact-form .btn {
  width: 100%;
  margin-top: 10px;
}

/* Modo claro */
:root .contact-form select option {
  background-color: #ffffff;
  color: #111111;
}

/* Modo oscuro */
.dark .contact-form select option {
  background-color: #0f1117;
  color: #ffffff;
}

.contact-form select option[value=""] {
  color: #9ca3af;
}

.contact-form select:invalid {
  color: #9ca3af;
}

.contact-form select:valid {
  color: var(--text);
}

.cta-highlight {
  max-width: 700px;
  margin: 0 auto 35px;
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--accent-color);
}

.section .cta-title {
  color: var(--primary);
}