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

body{
    font-family: Arial, sans-serif;
    background:#f8fafc;
    color:#1e293b;
}
.hero{
    background: url("world-map.png");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    color:#0f172a;
    padding:40px 10%;
    min-height:80vh;
}
.navbar a{
    color:#0f172a;
    text-decoration:none;
    border:1px solid white;
    padding:10px 20px;
    border-radius:10px;
}

.hero-content{
    margin-top:100px;
    max-width:700px;
    text-align:center;
    margin-left:auto;
    margin-right:auto;

    position:relative;
    z-index:2;
}

.badge{
    color:#93c5fd;
    margin-bottom:20px;
}

h1{
    font-size:60px;
    margin-bottom:25px;
}

.intro{
    font-size:20px;
    line-height:1.7;
    margin-bottom:35px;
}

.btn{
    display:inline-block;
    background:#2563eb;
    color:white;
    text-decoration:none;
    padding:15px 30px;
    border-radius:15px;
    font-weight:bold;
}

.services{
    padding:100px 10%;
}

.card{
    background: white;
    padding: 45px 35px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,.08);
    transition: 0.3s;
}

.card:hover{
    transform: translateY(-8px);
}

.card h3{
    font-size: 24px;
    margin-bottom: 20px;
    color: #0f172a;
}

.card p{
    font-size: 17px;
    line-height: 1.8;
    color: #64748b;
}
.cards{
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(220px,1fr));
    gap:25px;
}

.card{
    background: white;
    padding: 45px 35px;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,.08);
    transition: 0.3s;
}

.card:hover{
    transform: translateY(-8px);
}

.card h3{
    font-size: 24px;
    margin-bottom: 20px;
    color: #0f172a;
}

.card p{
    font-size: 17px;
    line-height: 1.8;
    color: #64748b;
}

.contact{
    background:white;
    text-align:center;
    padding:100px 10%;
}

.contact p{
    margin:20px 0 40px;
}.why-us{
    padding-top:120px;
    padding-bottom:120px;
}

.why-us h2{
    text-align:center;
    font-size:40px;
    margin-bottom:70px;
}
.card{
    padding:45px 35px;
    transition:0.3s;
}

.card:hover{
    transform:translateY(-8px);
}

.card h3{
    font-size:24px;
    margin-bottom:20px;
}

.card p{
    line-height:1.8;
    color:#64748b;
}
.service-card span{
    font-size:50px;
    display:block;
    margin-bottom:20px;
}

.service-card h3{
    font-size:24px;
    margin-bottom:15px;
    color:#0f172a;
}

.service-card p{
    color:#64748b;
    line-height:1.8;
    font-size:16px;
}
.process{
    padding:100px 10%;
    background:#f8fafc;
}

.process h2{
    text-align:center;
    font-size:40px;
    margin-bottom:80px;
}
<section class="faq">

    <h2>Preguntas frecuentes</h2>

    <div class="card">
        <h3>¿Puedo hacer los trámites de forma online?</h3>
        <p>Sí, ofrecemos asesoramiento y gestión 100% online para clientes de toda España.</p>
    </div>

    <div class="card">
        <h3>¿Trabajáis en toda España?</h3>
        <p>Sí, atendemos a clientes de cualquier provincia mediante videollamada, email y WhatsApp.</p>
    </div>

    <div class="card">
        <h3>¿Qué documentación necesito?</h3>
        <p>Dependerá del trámite. Revisaremos tu caso y te indicaremos toda la documentación necesaria.</p>
    </div>

    <div class="card">
        <h3>¿Cuánto tardáis en responder?</h3>
        <p>Intentamos responder todas las consultas en el menor tiempo posible.</p>
    </div>

</section>
.faq{
    padding:100px 10%;
}

.faq h2{
    text-align:center;
    font-size:40px;
    margin-bottom:80px;
}

.faq .card{
    margin-bottom:25px;
}
.faq h2{
    text-align:center;
    font-size:40px;
    margin: bottom 140px;px;
}
.faq h2{
    margin-bottom:140px !important;
}
.faq{
    padding-top:200px;
}
.contact form{
    max-width:700px;
    margin:50px auto 0;
    display:flex;
    flex-direction:column;
    gap:18px;
}

.contact input,
.contact textarea{
    width:100%;
    padding:18px 20px;
    border:1px solid #cbd5e1;
    border-radius:14px;
    font-size:16px;
    font-family:Arial, sans-serif;
}

.contact textarea{
    min-height:140px;
    resize:none;
}

.contact button{
    border:none;
    cursor:pointer;
    margin-top:10px;
}
.whatsapp-box{
    position: fixed;
    right: 25px;
bottom: 25px;
    background: white;
    color: #0f172a;
    text-decoration: none;
    padding: 10px 14px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    gap: 15px;
    box-shadow: 0 10px 35px rgba(0,0,0,.15);
    z-index: 9999;
}

.whatsapp-icon{
    background: #22c55e;
    color: white;
    width: 38px;
    height: 38px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
}

.whatsapp-box strong{
    display: block;
    font-size: 14px;
    margin-bottom: 5px;
}

.whatsapp-box p{
    margin: 0;
    color: #16a34a;
    font-weight: bold;
    font-size: 12px;
}
.logo img{
    width: 500px;
    height: auto;
}
.hero-logo{
    margin-bottom:40px;
}
.hero-logo img{
    width:500px;
    height:auto;
    display:block;
    margin:0 auto;
}

.hero-content{
    margin-top:100px;
    max-width:700px;
    text-align:center;
    margin-left:auto;
    margin-right:auto;
}

.hero-logo{
    margin-bottom:40px;
}

.hero-logo img{
    width:350px;
    height:auto;
    display:block;
    margin:0 auto;
}
<nav class="navbar">
  <a href="index.html">Inicio</a>
  <a href="quienes-somos.html">Quiénes somos</a>
  <a href="#contacto">Contacto</a>
</nav>
.menu-button{
    position:absolute;
    top:35px;
    left:35px;
    cursor:pointer;
    z-index:99999;
}
.menu-button span{
    display:block;
    width:40px;
    height:5px;
    background:#0f172a;
    margin:8px 0;
    border-radius:10px;
}
.side-menu{
    position:fixed;
    top:0;
    left:-280px;
    width:260px;
    height:100vh;
    background:white;
    padding:90px 30px;
    display:flex;
    flex-direction:column;
    gap:25px;
    box-shadow:0 10px 40px rgba(0,0,0,.2);
    transition:0.3s;
    z-index:9998;
}

.side-menu a{
    color:#0f172a;
    text-decoration:none;
    font-size:20px;
    font-weight:bold;
}

.side-menu.active{
    left:0;
}
.close-menu{
    position:absolute;
    top:25px;
    right:25px;
    font-size:35px;
    cursor:pointer;
    color:#0f172a;
}
.about-hero{
    position: relative;
    background-image: url("oficina.png");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;

    padding: 40px 10%;
    min-height: 80vh;
    overflow: hidden;
}
.about-hero::before{

    content: "";

    position: absolute;

    inset: 0;

    background: rgba(255,255,255,0.75);

}
.about-content{
    position: relative;
    z-index: 2;
}
.about-content{
  max-width:850px;
  margin:90px auto 0;
  text-align:center;
}

.about-section{
  padding:120px 10%;
  background:white;
}

.about-columns{
  max-width:1100px;
  margin:0 auto 80px;
  display:grid;
  grid-template-columns:1.3fr .7fr;
  gap:40px;
  align-items:stretch;
}

.about-text-box,
.about-highlight{
  background:#f8fafc;
  border:1px solid #e2e8f0;
  border-radius:28px;
  padding:50px;
  box-shadow:0 15px 40px rgba(15,23,42,.06);
}

.about-text-box h2{
  font-size:42px;
  margin-bottom:25px;
  color:#0f172a;
}

.about-text-box p,
.about-highlight p{
  font-size:18px;
  line-height:1.8;
  color:#64748b;
}

.about-highlight{
  background:#0f172a;
  color:white;
}

.about-highlight h3{
  font-size:40px;
  margin-bottom:25px;
}

.about-highlight p{
  color:#cbd5e1;
}

.about-cards{
  max-width:1100px;
  margin:0 auto;
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(240px,1fr));
  gap:25px;
}
.menu-button {
    position: fixed;
    top: 25px;
    left: 25px;

    width: 50px;
    height: 50px;

    display: flex;
    align-items: center;
    justify-content: center;

    background: white;
    border-radius: 50%;

    box-shadow: 0 4px 15px rgba(0,0,0,0.15);

    cursor: pointer;
    z-index: 9999;

    transition: all 0.3s ease;
}
.menu-button:hover {
    transform: scale(1.05);
}

.menu-button:hover{
    transform:scale(1.15);
}

.about-hero .side-menu{
    z-index:99998 !important;
}
.services-page{
    padding:120px 10%;
    background:white;
}

.section-title{
    max-width:850px;
    margin:0 auto 80px;
    text-align:center;
}

.section-title h2{
    font-size:44px;
    margin-bottom:25px;
    color:#0f172a;
}

.section-title p{
    font-size:18px;
    line-height:1.8;
    color:#64748b;
}

.service-process{
    padding:120px 10%;
    background:#f8fafc;
    text-align:center;
}

.service-process h2{
    font-size:42px;
    margin-bottom:70px;
}

.cta-section{
    padding:110px 10%;
    background:#0f172a;
    color:white;
    text-align:center;
}

.cta-section h2{
    font-size:42px;
    margin-bottom:20px;
    color:white;
}

.cta-section p{
    font-size:19px;
    margin-bottom:35px;
    color:#cbd5e1;
}.services-hero{
    background-image: url("servicios-fondo.png");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;

    min-height: 80vh;
    padding: 40px 10%;
    position: relative;
}
.services-hero::before{
    content:"";
    position:absolute;
    inset:0;
    background:rgba(255,255,255,.65);
}
.services-content{
    position:relative;
    z-index:2;
}
.services-hero{
    background-image:url("servicios-fondo.png");
    background-size:cover;
    background-position:center;
    background-repeat:no-repeat;

    min-height:80vh;
    padding:40px 10%;
    position:relative;
}

.services-hero::before{
    content:"";
    position:absolute;
    inset:0;
    background:rgba(255,255,255,.65);
}

.services-content{
    position:relative;
    z-index:2;
}
.services-content{
    position:relative;
    z-index:2;
}
.services-hero{
    background-image:url("servicios-fondo.png") !important;
    background-size:cover !important;
    background-position:center !important;
    background-repeat:no-repeat !important;
    min-height:80vh;
    padding:40px 10%;
    position:relative;
}

.services-hero::before{
    content:"";
    position:absolute;
    inset:0;
    background:rgba(255,255,255,.65);
    z-index:1;
}

.services-content{
    position:relative !important;
    z-index:2 !important;
    max-width:850px;
    margin:90px auto 0;
    text-align:center;
}
.service-process{
    padding:120px 10%;
    background:#f8fafc;
}

.service-process h2{
    text-align:center;
    font-size:42px;
    margin-bottom:70px;
    color:#0f172a;
}
.contact-hero{
    background-image:url("contacto-fondo.png");
    background-size:100% auto;
    background-position:center center;
    background-repeat:no-repeat;
    padding:40px 10%;
    min-height:75vh;
    position:relative;
    color:#0f172a;
    .contact-hero::before{
    content:"";
    position:absolute;
    inset:0;
    background:rgba(255,255,255,.65);
    z-index:1;
}

.contact-hero-content,
.contact-hero .menu-button,
.contact-hero .side-menu{
    position:relative;
    z-index:2;
}
}

.contact-hero-content{
    max-width:850px;
    margin:90px auto 0;
    text-align:center;
}

.contact-premium{
    padding:120px 10%;
    background:white;
    display:grid;
    grid-template-columns:1fr 1fr;
    gap:60px;
    align-items:start;
}

.contact-info h2{
    font-size:44px;
    margin-bottom:25px;
    color:#0f172a;
}

.contact-info p{
    font-size:18px;
    line-height:1.8;
    color:#64748b;
}

.contact-details{
    margin-top:40px;
    display:grid;
    gap:20px;
}

.contact-details div{
    background:#f8fafc;
    padding:25px;
    border-radius:20px;
    border:1px solid #e2e8f0;
}

.contact-details h3{
    margin-bottom:10px;
    color:#0f172a;
}

.contact-form{
    background:#f8fafc;
    padding:45px;
    border-radius:28px;
    box-shadow:0 15px 40px rgba(15,23,42,.08);
    display:flex;
    flex-direction:column;
    gap:18px;
}

.contact-form input,
.contact-form textarea{
    width:100%;
    padding:18px 20px;
    border:1px solid #cbd5e1;
    border-radius:14px;
    font-size:16px;
    font-family:Arial, sans-serif;
}

.contact-form textarea{
    min-height:150px;
    resize:none;
}

.contact-form button{
    border:none;
    cursor:pointer;
}
.contact-details a{
    text-decoration:none;
    color:#0f172a;
}

.contact-details a:hover{
    color:#2563eb;
}
.footer{
    background:#0f172a;
    color:white;
    padding:70px 10%;
    text-align:center;
}

.footer h3{
    font-size:30px;
    margin-bottom:20px;
}

.footer p{
    color:#cbd5e1;
    line-height:1.8;
}

.footer-info{
    margin:30px 0;
}

.footer-links{
    margin:35px 0;
    display:flex;
    justify-content:center;
    gap:30px;
    flex-wrap:wrap;
}

.footer-links a{
    color:white;
    text-decoration:none;
}

.footer-links a:hover{
    color:#93c5fd;
}

.copyright{
    margin-top:40px;
    font-size:14px;
}
.about-text-box{
    max-width:1000px;
    margin:0 auto;
    background:white;
    padding:60px;
    border-radius:28px;
    box-shadow:0 15px 40px rgba(15,23,42,.08);
}

.about-text-box h2{
    font-size:30px;
    margin-top:45px;
    margin-bottom:20px;
    color:#0f172a;
}

.about-text-box h2:first-child{
    margin-top:0;
}

.about-text-box p{
    font-size:18px;
    line-height:1.9;
    color:#475569;
    margin-bottom:18px;
}

.about-text-box strong{
    color:#0f172a;
}

.about-section{
    padding:120px 10%;
    background:#f8fafc;
}
.about-text-box{
    max-width:1000px;
    margin:0 auto;
    background:white;
    padding:70px;
    border-radius:30px;
    box-shadow:0 20px 50px rgba(15,23,42,.08);
}

.about-text-box h2{
    font-size:28px;
    color:#0f172a;
    margin-top:55px;
    margin-bottom:25px;
    padding-bottom:12px;
    border-bottom:1px solid #e2e8f0;
}

.about-text-box h2:first-of-type{
    margin-top:40px;
}

.about-text-box p{
    font-size:17px;
    line-height:2;
    color:#475569;
    margin-bottom:20px;
    text-align:justify;
}

.about-text-box strong{
    color:#0f172a;
}

.about-section{
    background:#f8fafc;
    padding:120px 10%;
}
.privacy-check{
    display:flex;
    align-items:flex-start;
    gap:12px;
    margin-top:10px;
    margin-bottom:15px;
}

.privacy-check label{
    color:#64748b;
    font-size:15px;
    line-height:1.6;
}

.privacy-check a{
    color:#2563eb;
    text-decoration:none;
}

.privacy-check a:hover{
    text-decoration:underline;
}
.cookie-banner{
    position:fixed;
    bottom:20px;
    left:50%;
    transform:translateX(-50%);
    width:90%;
    max-width:900px;
    background:#0f172a;
    color:white;
    padding:25px 30px;
    border-radius:20px;
    box-shadow:0 10px 40px rgba(0,0,0,.25);
    display:flex;
    justify-content:space-between;
    align-items:center;
    gap:25px;
    z-index:99999;
}

.cookie-banner p{
    margin:0;
    line-height:1.7;
    color:#e2e8f0;
}

.cookie-buttons{
    display:flex;
    align-items:center;
    gap:15px;
}

.cookie-buttons button{
    border:none;
    padding:12px 22px;
    border-radius:12px;
    cursor:pointer;
    font-weight:bold;
}

#acceptCookies{
    background:#2563eb;
    color:white;
}

#rejectCookies{
    background:white;
    color:#0f172a;
}

.cookie-buttons a{
    color:#93c5fd;
    text-decoration:none;
}
.service-card{
    text-decoration:none;
    color:inherit;
}

.service-card:hover{
    color:inherit;
}
.service-card,
.service-card:visited,
.service-card:hover,
.service-card:active{
    text-decoration:none;
    color:inherit;
}
.nacionalidad-hero{
    background-image: url("nacionalidad-fondo.png");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    height: 80vh;
    padding: 40px 10%;
    position: relative;
}

.nacionalidad-hero::before{
    content:"";
    position:absolute;
    inset:0;
    background:rgba(255,255,255,.75);
}

.nacionalidad-hero .services-content{
    position:relative;
    z-index:2;
}
.nie-hero{
    background-image: url("nie-fondo.png");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    height: 80vh;
    padding: 40px 10%;
    position: relative;
}

.nie-hero::before{
    content:"";
    position:absolute;
    inset:0;
    background:rgba(255,255,255,.75);
}

.nie-hero .services-content{
    position:relative;
    z-index:2;
}
.nie-hero,
.arraigo-hero,
.nacionalidad-hero,
.renovaciones-hero,
.reagrupacion-hero,
.estudios-hero{
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    height: 80vh;
    padding: 40px 10%;
    position: relative;
}

.nie-hero{
    background-image: url("nie-fondo.png");
}

.nacionalidad-hero{
    background-image: url("nacionalidad-fondo.png");
}
.nie-hero{
    background-image: url("nie-fondo.png");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    height: 80vh;
    padding: 40px 10%;
    position: relative;
}

.nie-hero::before{
    content:"";
    position:absolute;
    inset:0;
    background:rgba(255,255,255,.75);
}

.nie-hero .services-content{
    position:relative;
    z-index:2;
}
.nie-hero .services-content,
.nacionalidad-hero .services-content,
.arraigo-hero .services-content,
.renovaciones-hero .services-content,
.reagrupacion-hero .services-content,
.estudios-hero .services-content,
.residencia-hero .services-content{
    position:relative !important;
    z-index:10 !important;
    max-width:850px;
    margin:90px auto 0;
    text-align:center;
}
.nie-hero::before,
.nacionalidad-hero::before{
    z-index:1 !important;
}
.nacionalidad-hero{
    background-image: url("nacionalidad-fondo.png");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    height: 80vh;
    padding: 40px 10%;
    position: relative;
}
.arraigo-hero{
    background-image: url("arraigo-fondo.png");
}
.arraigo-hero::before{
    content: "";
    position: absolute;
    inset: 0;
    background: rgba(255,255,255,.85);
    backdrop-filter: blur(3px);
}
.renovaciones-hero{
    background-image: url("renovaciones-fondo.png");
}
.renovaciones-hero::before{
    content: "";
    position: absolute;
    inset: 0;
    background: rgba(255,255,255,.85);
    backdrop-filter: blur(3px);
}
.reagrupacion-hero{
    background-image: url("reagrupacion-fondo.png");
}
.estudios-hero{
    background-image: url("estudios-fondo.png");
}

.estudios-hero::before{
    content: "";
    position: absolute;
    inset: 0;
    background: rgba(255,255,255,.85);
    backdrop-filter: blur(3px);
}
.reagrupacion-hero::before{
    content: "";
    position: absolute;
    inset: 0;
    background: rgba(255,255,255,.85);
    backdrop-filter: blur(3px);
}
.services h2{
    text-align: center;
    margin-bottom: 50px;
    margin-top: -20px;
}
.estudios-hero{
    background-image: url("estudios-fondo.png");
}

.estudios-hero::before{
    content: "";
    position: absolute;
    inset: 0;
    background: rgba(255,255,255,.85);
    backdrop-filter: blur(3px);
}

.estudios-hero .services-content{
    position: relative !important;
    z-index: 10 !important;
    max-width: 850px;
    margin: 90px auto 0;
    text-align: center;
}
.estudios-hero{
    background-image: url("estudios-fondo.png");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    height: 80vh;
    padding: 40px 10%;
    position: relative;
}

.estudios-hero::before{
    content:"";
    position:absolute;
    inset:0;
    background:rgba(255,255,255,.75);
    z-index:1;
}
.estudios-hero{
    background-image: url("estudios-fondo.png");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    height: 80vh;
    padding: 40px 10%;
    position: relative;
}

.estudios-hero::before{
    content:"";
    position:absolute;
    inset:0;
    background:rgba(255,255,255,.85);
    backdrop-filter: blur(3px);
}

.estudios-hero .services-content{
    position:relative;
    z-index:10;
    max-width:850px;
    margin:90px auto 0;
    text-align:center;
}
 .legal-content p{
    font-size: 15px;
    line-height: 1.8;
}

.legal-content li{
    font-size: 15px;
    line-height: 1.8;
}
.legal-content p,
.legal-content li{
    font-size: 14px;
    line-height: 1.7;
}
.about-text-box p,
.about-text-box li{
    font-size: 14px;
    line-height: 1.8;
}

.about-text-box h2{
    font-size: 26px;
}
/* Ajuste para evitar desplazamiento horizontal en móvil */

html,
body {
    margin: 0;
    padding: 0;
    width: 100%;
    max-width: 100%;
    overflow-x: hidden;
}

* {
    box-sizing: border-box;
}

img {
    max-width: 100%;
    height: auto;
}
/* =========================
   VERSIÓN MÓVIL
   ========================= */

@media (max-width: 768px) {

    html,
    body {
        width: 100%;
        max-width: 100%;
        overflow-x: hidden;
    }

    /* INICIO */

    .hero {
        width: 100%;
        min-height: 100vh;
        padding: 30px 20px 60px;
    }

    .hero-content {
        width: calc(100% - 20px);
        max-width: 380px;
        margin: 80px auto 0;
        padding: 0;
        text-align: center;
    }

    .hero-logo {
        margin-bottom: 25px;
    }
.hero-logo img {
    width: 220px;
    max-width: 100%;
    height: auto;
}
    

    .hero-content h1 {
        font-size: 32px;
        line-height: 1.2;
        margin: 20px 0;
    }

    .hero-content .intro {
        font-size: 16px;
        line-height: 1.6;
        margin-bottom: 25px;
    }

    /* SECCIONES */

    .services,
    .process,
    .why-us,
    .faq,
    .contact {
        width: 100%;
        padding: 70px 20px;
    }

    .services h2,
    .process h2,
    .why-us h2,
    .faq h2 {
        font-size: 30px;
        line-height: 1.25;
        margin-bottom: 40px;
    }

    /* TARJETAS */

    .cards {
        display: grid;
        grid-template-columns: 1fr;
        gap: 20px;
        width: 100%;
    }

    .card {
        width: 100%;
        padding: 30px 24px;
    }

    .card h3 {
        font-size: 21px;
    }

    .card p {
        font-size: 16px;
        line-height: 1.7;
    }

    /* CONTACTO */

    .contact form {
        width: 100%;
        max-width: 100%;
    }

    /* WHATSAPP */

    .whatsapp-box {
        left: 15px;
        right: 15px;
        bottom: 15px;
        width: auto;
        max-width: none;
    }

    /* MENÚ */

    .menu-button {
        top: 20px;
        left: 20px;
    }

}