/* ===== RESET & VARIABLES ===== */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
:root{
  --primary:#52a7e0;--primary-dark:#2c81ba;--primary-light:#89c5eb;
  --dark:#0a0f1a;--dark-2:#121a2d;--dark-3:#1a2440;
  --white:#ffffff;--gray-100:#f4f5f7;--gray-200:#e2e4e8;--gray-400:#8b92a5;--gray-600:#4a5068;--gray-800:#1e2235;
  --font-heading:'Playfair Display',Georgia,serif;
  --font-body:'Inter',system-ui,sans-serif;
  --radius:12px;--radius-lg:20px;
  --shadow:0 4px 30px rgba(0,0,0,.12);--shadow-lg:0 20px 60px rgba(0,0,0,.2);
  --transition:all .3s cubic-bezier(.4,0,.2,1);
}
html{scroll-behavior:smooth;scroll-padding-top:80px}
body{font-family:var(--font-body);color:var(--gray-600);background:var(--white);line-height:1.7;overflow-x:hidden}
img{max-width:100%;display:block}
a{text-decoration:none;color:inherit;transition:var(--transition)}
.container{max-width:1200px;margin:0 auto;padding:0 24px}

/* ===== HEADER ===== */
.header{position:fixed;top:0;left:0;width:100%;z-index:1000;padding:16px 0;transition:var(--transition)}
.header.scrolled{background:rgba(10,15,26,.95);backdrop-filter:blur(20px);padding:10px 0;box-shadow:0 2px 30px rgba(0,0,0,.3)}
.header-inner{display:flex;align-items:center;justify-content:space-between}
.logo{display:flex;align-items:center;gap:10px}
.logo-icon{font-size:1.8rem;color:var(--primary);filter:drop-shadow(0 0 8px rgba(82,167,224,.4))}
.logo-main{display:block;font-family:var(--font-heading);font-size:1.1rem;font-weight:700;color:var(--white);letter-spacing:2px}
.logo-sub{display:block;font-size:.6rem;letter-spacing:4px;color:var(--primary);text-transform:uppercase}
.nav{display:flex;gap:32px}
.nav-link{color:rgba(255,255,255,.7);font-size:.9rem;font-weight:500;position:relative;padding:4px 0}
.nav-link::after{content:'';position:absolute;bottom:0;left:0;width:0;height:2px;background:var(--primary);transition:var(--transition)}
.nav-link:hover,.nav-link.active{color:var(--white)}
.nav-link:hover::after,.nav-link.active::after{width:100%}
.header-phone{display:flex;align-items:center;gap:6px;color:var(--primary);font-weight:600;font-size:.9rem}
.header-phone:hover{color:var(--primary-light)}
.hamburger{display:none;flex-direction:column;gap:5px;background:none;border:none;cursor:pointer;padding:4px}
.hamburger span{width:24px;height:2px;background:var(--white);transition:var(--transition)}

/* ===== HERO ===== */
.hero{position:relative;min-height:100vh;display:flex;align-items:center;justify-content:center;background:var(--dark);overflow:hidden;background-size:cover;background-position:center;background-repeat:no-repeat}
.hero-overlay{position:absolute;inset:0;background:linear-gradient(135deg,rgba(10,15,26,.92),rgba(18,26,45,.85),rgba(26,36,64,.78));z-index:1}
.hero-particles{position:absolute;inset:0;z-index:0}
.hero-content{position:relative;z-index:2;text-align:center;max-width:800px}
.hero-badge{display:inline-block;padding:8px 24px;border:1px solid var(--primary);color:var(--primary);font-size:.8rem;letter-spacing:4px;border-radius:50px;margin-bottom:32px;font-weight:500}
.hero-title{font-family:var(--font-heading);color:var(--white);margin-bottom:24px}
.hero-title-line{display:block;font-size:clamp(2rem,5vw,3.5rem);font-weight:600;line-height:1.2}
.hero-title-accent{display:block;font-size:clamp(3rem,8vw,5.5rem);font-weight:800;background:linear-gradient(135deg,var(--primary),var(--primary-light));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;line-height:1.1;margin:8px 0}
.hero-desc{color:rgba(255,255,255,.6);font-size:1.1rem;max-width:600px;margin:0 auto 40px;line-height:1.8}
.hero-cta{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}
.hero-scroll{position:absolute;bottom:32px;left:50%;transform:translateX(-50%);z-index:2;text-align:center;color:rgba(255,255,255,.4);font-size:.75rem;letter-spacing:2px}
.scroll-indicator{width:2px;height:40px;background:rgba(255,255,255,.15);margin:8px auto 0;position:relative;overflow:hidden;border-radius:2px}
.scroll-indicator::after{content:'';position:absolute;top:-100%;left:0;width:100%;height:50%;background:var(--primary);animation:scrollDown 2s infinite}
@keyframes scrollDown{0%{top:-50%}100%{top:150%}}

/* ===== BUTTONS ===== */
.btn{display:inline-flex;align-items:center;gap:8px;padding:14px 32px;border-radius:8px;font-weight:600;font-size:.95rem;cursor:pointer;transition:var(--transition);border:2px solid transparent}
.btn-primary{background:linear-gradient(135deg,var(--primary),var(--primary-dark));color:var(--dark);border-color:var(--primary)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 30px rgba(82,167,224,.4)}
.btn-outline{border-color:rgba(255,255,255,.3);color:var(--white);background:transparent}
.btn-outline:hover{border-color:var(--primary);color:var(--primary);transform:translateY(-2px)}
.btn-full{width:100%;justify-content:center}

/* ===== STATS ===== */
.stats{background:linear-gradient(135deg,var(--dark-2),var(--dark-3));padding:60px 0;border-top:1px solid rgba(82,167,224,.15)}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:32px;text-align:center}
.stat-item{padding:20px}
.stat-number{font-family:var(--font-heading);font-size:3rem;font-weight:800;color:var(--primary);line-height:1}
.stat-plus{font-family:var(--font-heading);font-size:1.8rem;color:var(--primary)}
.stat-label{display:block;margin-top:8px;color:rgba(255,255,255,.5);font-size:.85rem;letter-spacing:1px}

/* ===== SECTION COMMON ===== */
.section-header{text-align:center;margin-bottom:60px}
.section-tag{display:inline-block;color:var(--primary);font-size:.8rem;font-weight:600;letter-spacing:3px;text-transform:uppercase;margin-bottom:12px}
.section-title{font-family:var(--font-heading);font-size:clamp(1.8rem,4vw,2.8rem);font-weight:700;color:var(--dark);line-height:1.3}
.text-accent{color:var(--primary)}

/* ===== SERVICES ===== */
.services{padding:100px 0;background:var(--gray-100)}
.services-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
.service-card{background:var(--white);border-radius:var(--radius-lg);padding:40px 28px;transition:var(--transition);border:1px solid var(--gray-200);position:relative;overflow:hidden}
.service-card::before{content:'';position:absolute;top:0;left:0;width:100%;height:3px;background:linear-gradient(90deg,var(--primary),var(--primary-light));transform:scaleX(0);transition:var(--transition);transform-origin:left}
.service-card:hover{transform:translateY(-8px);box-shadow:var(--shadow-lg);border-color:transparent}
.service-card:hover::before{transform:scaleX(1)}
.service-icon{font-size:2.5rem;margin-bottom:20px}
.service-card h3{font-family:var(--font-heading);font-size:1.2rem;color:var(--dark);margin-bottom:12px}
.service-card p{font-size:.9rem;color:var(--gray-400);line-height:1.7;margin-bottom:16px}
.service-link{color:var(--primary);font-weight:600;font-size:.85rem}
.service-link:hover{color:var(--primary-dark)}

/* ===== PROJECTS ===== */
.projects{padding:100px 0;background:var(--white)}
.projects-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}
.project-card{border-radius:var(--radius-lg);overflow:hidden;background:var(--white);border:1px solid var(--gray-200);transition:var(--transition)}
.project-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg)}
.project-card-large{grid-row:span 2}
.project-card-large .project-img{height:300px}
.project-img{height:220px;display:flex;align-items:center;justify-content:center;position:relative;overflow:hidden}
.project-img img{width:100%;height:100%;object-fit:cover;transition:transform .5s ease}
.project-card:hover .project-img img{transform:scale(1.08)}
.project-info{padding:24px}
.project-tag{display:inline-block;padding:4px 12px;background:rgba(82,167,224,.1);color:var(--primary);font-size:.75rem;font-weight:600;border-radius:20px;margin-bottom:8px}
.project-info h3{font-family:var(--font-heading);font-size:1.15rem;color:var(--dark);margin-bottom:8px}
.project-info p{font-size:.85rem;color:var(--gray-400);margin-bottom:12px}
.project-meta{display:flex;gap:16px;font-size:.8rem;color:var(--gray-400)}

/* ===== ABOUT ===== */
.about{padding:100px 0;background:var(--gray-100)}
.about-grid{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center}
.about-content .section-title{text-align:left}
.about-content p{margin-bottom:16px}
.about-features{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:24px}
.about-feature{display:flex;align-items:center;gap:10px;font-weight:500;color:var(--dark)}
.feature-icon{width:24px;height:24px;background:rgba(82,167,224,.15);color:var(--primary);border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.75rem;flex-shrink:0}
.about-visual{position:relative}
.about-img-wrapper{position:relative}
.about-img{height:450px;border-radius:var(--radius-lg);overflow:hidden}
.about-img img{width:100%;height:100%;object-fit:cover}
.about-experience-badge{position:absolute;bottom:-20px;right:-20px;background:linear-gradient(135deg,var(--primary),var(--primary-dark));color:var(--dark);padding:24px;border-radius:var(--radius);text-align:center;box-shadow:var(--shadow-lg)}
.badge-number{display:block;font-family:var(--font-heading);font-size:2.5rem;font-weight:800;line-height:1}
.badge-text{font-size:.75rem;font-weight:600;letter-spacing:1px;text-transform:uppercase}

/* ===== TESTIMONIALS ===== */
.testimonials{padding:100px 0;background:var(--dark);color:var(--white)}
.testimonials .section-title{color:var(--white)}
.testimonials-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.testimonial-card{background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.08);border-radius:var(--radius-lg);padding:32px;transition:var(--transition)}
.testimonial-card:hover{background:rgba(255,255,255,.08);transform:translateY(-4px)}
.testimonial-stars{color:var(--primary);font-size:1.1rem;margin-bottom:16px;letter-spacing:2px}
.testimonial-card p{color:rgba(255,255,255,.7);font-size:.95rem;line-height:1.8;margin-bottom:20px;font-style:italic}
.testimonial-author{display:flex;align-items:center;gap:12px}
.author-avatar{width:44px;height:44px;border-radius:50%;background:linear-gradient(135deg,var(--primary),var(--primary-dark));display:flex;align-items:center;justify-content:center;color:var(--dark);font-weight:700;font-size:.85rem;flex-shrink:0}
.testimonial-author strong{color:var(--white);font-size:.9rem}
.testimonial-author small{color:var(--gray-400);font-size:.8rem}

/* ===== CONTACT ===== */
.contact{padding:100px 0;background:var(--gray-100)}
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:start}
.contact-info .section-title{text-align:left}
.contact-details{margin-top:32px;display:flex;flex-direction:column;gap:20px}
.contact-item{display:flex;gap:16px;align-items:flex-start}
.contact-icon{font-size:1.3rem;flex-shrink:0;margin-top:2px}
.contact-item a{color:var(--primary);font-weight:500}
.contact-item a:hover{color:var(--primary-dark)}
.contact-form-wrapper{background:var(--white);border-radius:var(--radius-lg);padding:40px;box-shadow:var(--shadow);border:1px solid var(--gray-200)}
.contact-form h3{font-family:var(--font-heading);font-size:1.3rem;color:var(--dark);margin-bottom:24px}
.form-group{margin-bottom:16px}
.form-row{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.contact-form input,.contact-form select,.contact-form textarea{width:100%;padding:14px 16px;border:1px solid var(--gray-200);border-radius:8px;font-family:var(--font-body);font-size:.9rem;transition:var(--transition);background:var(--gray-100);color:var(--dark)}
.contact-form input:focus,.contact-form select:focus,.contact-form textarea:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px rgba(82,167,224,.15);background:var(--white)}
.contact-form textarea{resize:vertical}

/* ===== FOOTER ===== */
.footer{background:var(--dark);color:rgba(255,255,255,.6);padding:60px 0 0}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px}
.footer-brand p{margin-top:16px;font-size:.9rem;line-height:1.7}
.footer-links h4,.footer-contact h4{color:var(--white);font-size:.95rem;margin-bottom:16px;font-weight:600}
.footer-links a{display:block;padding:4px 0;font-size:.9rem;transition:var(--transition)}
.footer-links a:hover{color:var(--primary);padding-left:4px}
.footer-contact p{font-size:.85rem;margin-bottom:8px}
.footer-bottom{margin-top:40px;padding:20px 0;border-top:1px solid rgba(255,255,255,.08);text-align:center;font-size:.8rem}

/* ===== FLOATING BUTTONS ===== */
.zalo-float{position:fixed;bottom:24px;right:24px;width:56px;height:56px;background:linear-gradient(135deg,#0068ff,#0052cc);border-radius:50%;display:flex;align-items:center;justify-content:center;z-index:999;box-shadow:0 4px 20px rgba(0,104,255,.4);transition:var(--transition)}
.zalo-float:hover{transform:scale(1.1);box-shadow:0 6px 30px rgba(0,104,255,.6)}
.zalo-pulse{position:absolute;inset:-4px;border-radius:50%;border:2px solid #0068ff;animation:pulse 2s infinite}
@keyframes pulse{0%{transform:scale(1);opacity:.6}100%{transform:scale(1.4);opacity:0}}
.back-to-top{position:fixed;bottom:24px;right:90px;width:44px;height:44px;background:var(--dark);color:var(--white);border:1px solid rgba(255,255,255,.15);border-radius:50%;font-size:1.2rem;cursor:pointer;opacity:0;visibility:hidden;transition:var(--transition);z-index:999}
.back-to-top.visible{opacity:1;visibility:visible}
.back-to-top:hover{background:var(--primary);color:var(--dark);border-color:var(--primary)}

/* ===== ANIMATIONS ===== */
[data-reveal]{opacity:0;transform:translateY(30px);transition:opacity .8s ease,transform .8s ease}
[data-reveal].revealed{opacity:1;transform:translateY(0)}

/* ===== MOBILE ===== */
@media(max-width:1024px){
  .services-grid{grid-template-columns:repeat(2,1fr)}
  .testimonials-grid{grid-template-columns:repeat(2,1fr)}
  .footer-grid{grid-template-columns:1fr 1fr}
}
@media(max-width:768px){
  .nav{display:none;position:fixed;top:0;left:0;width:100%;height:100vh;background:rgba(10,15,26,.98);flex-direction:column;align-items:center;justify-content:center;gap:24px;z-index:998}
  .nav.open{display:flex}
  .nav-link{font-size:1.2rem}
  .hamburger{display:flex;z-index:999}
  .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(5px,-5px)}
  .header-phone{display:none}
  .hero-title-accent{font-size:clamp(2.5rem,10vw,4rem)}
  .stats-grid{grid-template-columns:repeat(2,1fr);gap:16px}
  .services-grid{grid-template-columns:1fr}
  .projects-grid{grid-template-columns:1fr}
  .project-card-large{grid-row:span 1}
  .about-grid{grid-template-columns:1fr;gap:40px}
  .about-features{grid-template-columns:1fr}
  .testimonials-grid{grid-template-columns:1fr}
  .contact-grid{grid-template-columns:1fr;gap:40px}
  .form-row{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr;gap:24px;text-align:center}
}