/* ONLYOFFICE Vietnam v3 — Pixel-perfect clone of onlyoffice.com */
@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@300;400;500;600;700;800&display=swap');

/* ── RESET ── */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{font-size:16px;scroll-behavior:smooth}
body{font-family:'Open Sans',sans-serif;color:#444;background:#fff;-webkit-font-smoothing:antialiased;line-height:1.6}
a{text-decoration:none;color:#FF6F3D}
a:hover{text-decoration:underline}
img{max-width:100%;display:block}
ul{list-style:none}

/* ── CONTAINER ── */
.oo-container{max-width:1280px;margin:0 auto;padding:0 32px}

/* ── TOPBAR ── */
.oo-topbar{background:#1a1a2e;color:rgba(255,255,255,.9);text-align:center;padding:9px 16px;font-size:13.5px;font-weight:500;line-height:1.4}
.oo-topbar a{color:#FF6F3D;font-weight:600}
.oo-topbar strong{color:#FF6F3D}

/* ── HEADER ── */
.oo-header{position:sticky;top:0;z-index:9000;background:#fff;border-bottom:1px solid #e8e8e8;box-shadow:0 1px 4px rgba(0,0,0,.06)}
.oo-header-inner{display:flex;align-items:center;height:64px;gap:0}

/* Logo */
.oo-logo{display:flex;align-items:center;gap:10px;margin-right:32px;flex-shrink:0;text-decoration:none}
.oo-logo:hover{text-decoration:none}
.oo-logo-icon{display:flex;flex-direction:column;gap:3px;position:relative;width:32px;height:32px}
.oo-logo-icon span{display:block;width:32px;height:10px;border-radius:2px;position:absolute}
.oo-logo-icon span:nth-child(1){background:#40B89A;top:0;left:0}
.oo-logo-icon span:nth-child(2){background:#F2BB3D;top:6px;left:3px}
.oo-logo-icon span:nth-child(3){background:#FF6F3D;top:12px;left:6px}
.oo-logo-text{font-size:17px;font-weight:800;color:#1a1a2e;letter-spacing:-.3px;line-height:1}

/* Nav */
.oo-nav{display:flex;align-items:stretch;height:100%;flex:1}
.oo-nav-item{position:relative;display:flex;align-items:center}
.oo-nav-item>a{color:#333;font-size:14px;font-weight:400;padding:0 14px;height:64px;display:flex;align-items:center;gap:5px;white-space:nowrap;transition:color .15s;text-decoration:none;border-bottom:2px solid transparent;cursor:pointer}
.oo-nav-item>a:hover{color:#FF6F3D;text-decoration:none;border-bottom-color:#FF6F3D}
.oo-arr{font-size:8px;color:#aaa;transition:transform .15s;display:inline-block}
.oo-nav-item.open>a .oo-arr,.oo-nav-item>a:hover .oo-arr{transform:rotate(180deg);color:#FF6F3D}

/* Dropdown shared */
.oo-dd,.oo-mega{display:none;position:absolute;top:100%;background:#fff;border:1px solid #e8e8e8;border-top:2px solid #FF6F3D;box-shadow:0 8px 32px rgba(0,0,0,.12);border-radius:0 0 6px 6px;z-index:9001;animation:ooFade .15s ease}
@keyframes ooFade{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:translateY(0)}}

/* Simple dropdown */
.oo-dd{left:0;min-width:220px;padding:8px 0}
.oo-dd a{display:block;padding:10px 20px;font-size:13.5px;color:#444;transition:background .12s;text-decoration:none;white-space:nowrap}
.oo-dd a:hover{background:#FFF4F0;color:#FF6F3D;text-decoration:none}
.oo-dd-head{padding:10px 20px 4px;font-size:11px;font-weight:700;color:#aaa;text-transform:uppercase;letter-spacing:.8px}
.oo-dd hr{border:none;border-top:1px solid #f0f0f0;margin:4px 0}

/* Mega dropdown */
.oo-mega{left:0;min-width:680px;padding:24px;display:none;grid-template-columns:repeat(3,1fr);gap:0}
.oo-mega.show,.oo-dd.show{display:block}
.oo-mega.show{display:grid}
.oo-mc{padding:0 12px}
.oo-mc:not(:last-child){border-right:1px solid #f5f5f5}
.oo-mc h5{font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.8px;color:#aaa;margin-bottom:12px;padding-bottom:8px;border-bottom:1px solid #f0f0f0}
.oo-mc a{display:flex;align-items:flex-start;gap:10px;padding:8px 10px;border-radius:4px;font-size:13px;color:#444;line-height:1.35;text-decoration:none;transition:background .12s}
.oo-mc a:hover{background:#FFF4F0;color:#FF6F3D;text-decoration:none}
.oo-mc a span.ico{font-size:18px;flex-shrink:0;margin-top:1px}
.oo-mc a div strong{display:block;font-weight:600;font-size:13px}
.oo-mc a div small{color:#999;font-size:12px}

/* Right side */
.oo-header-right{display:flex;align-items:center;gap:8px;margin-left:auto;flex-shrink:0}
.oo-btn-dl{background:#FF6F3D;color:#fff;border:none;border-radius:4px;padding:9px 20px;font-size:14px;font-weight:600;cursor:pointer;font-family:'Open Sans',sans-serif;transition:background .15s;text-decoration:none;display:inline-flex;align-items:center}
.oo-btn-dl:hover{background:#e55a28;color:#fff;text-decoration:none}
.oo-btn-text{background:none;border:none;font-size:14px;color:#333;padding:8px 12px;cursor:pointer;font-family:'Open Sans',sans-serif;text-decoration:none;display:inline-flex;align-items:center}
.oo-btn-text:hover{color:#FF6F3D;text-decoration:none}

/* Hamburger */
.oo-ham{display:none;flex-direction:column;gap:5px;background:none;border:none;padding:8px;cursor:pointer;margin-left:8px}
.oo-ham span{display:block;width:22px;height:2px;background:#333;border-radius:2px;transition:all .2s}
.oo-ham.active span:nth-child(1){transform:rotate(45deg) translate(5px,5px)}
.oo-ham.active span:nth-child(2){opacity:0}
.oo-ham.active span:nth-child(3){transform:rotate(-45deg) translate(5px,-5px)}

/* Mobile menu */
.oo-mob-menu{display:none;position:fixed;top:64px;left:0;right:0;bottom:0;background:#fff;z-index:8999;overflow-y:auto;border-top:1px solid #f0f0f0}
.oo-mob-menu.open{display:block}
.oo-mob-menu a{display:block;padding:14px 24px;font-size:15px;color:#333;border-bottom:1px solid #f5f5f5;text-decoration:none}
.oo-mob-menu a:hover{color:#FF6F3D}
.oo-mob-sec{padding:8px 24px;font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.8px;color:#aaa;background:#f8f8f8}
.oo-mob-cta{padding:16px 24px;display:flex;gap:12px}

/* ── HERO ── */
.oo-hero{background:linear-gradient(170deg,#EAF3FF 0%,#F4F9FF 50%,#fff 100%);padding:72px 0 48px;text-align:center;position:relative;overflow:hidden}
.oo-hero::before{content:'';position:absolute;width:600px;height:600px;border-radius:50%;background:radial-gradient(rgba(180,220,255,.35),transparent 70%);top:-200px;right:-100px;pointer-events:none}
.oo-hero h1{font-size:clamp(28px,4.5vw,52px);font-weight:700;color:#1a1a2e;line-height:1.18;margin-bottom:16px;position:relative;z-index:1}
.oo-hero h1 em{color:#FF6F3D;font-style:normal;font-weight:800}
.oo-hero-sub{font-size:18px;color:#555;margin-bottom:0;position:relative;z-index:1}
.oo-hero-sub em{color:#FF6F3D;font-style:normal;font-weight:600}
.oo-hero-btns{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;margin-top:32px;position:relative;z-index:1}
.oo-hero-img{max-width:960px;margin:52px auto 0;position:relative;z-index:1}
.oo-hero-video-wrap{border-radius:12px;overflow:hidden;box-shadow:0 24px 80px rgba(0,0,50,.18);animation:ooFloat 4s ease-in-out infinite}
.oo-hero-video{display:block;width:100%;height:auto;border-radius:12px}
@keyframes ooFloat{0%,100%{transform:translateY(0)}50%{transform:translateY(-8px)}}

/* ── BUTTONS ── */
.oo-btn{display:inline-flex;align-items:center;gap:8px;padding:13px 28px;border-radius:4px;font-size:15px;font-weight:600;transition:all .15s;border:2px solid transparent;cursor:pointer;text-decoration:none;font-family:'Open Sans',sans-serif}
.oo-btn:hover{text-decoration:none}
.oo-btn-primary{background:#FF6F3D;color:#fff;border-color:#FF6F3D}
.oo-btn-primary:hover{background:#e55a28;border-color:#e55a28;color:#fff}
.oo-btn-dark{background:#1a1a2e;color:#fff;border-color:#1a1a2e}
.oo-btn-dark:hover{background:#2d2d45;color:#fff}
.oo-btn-outline{background:transparent;color:#FF6F3D;border-color:#FF6F3D}
.oo-btn-outline:hover{background:#FF6F3D;color:#fff}
.oo-btn-sm{padding:9px 20px;font-size:13.5px}
.oo-btn-white{background:#fff;color:#FF6F3D;border-color:#fff}
.oo-btn-white:hover{background:transparent;color:#fff}
.oo-btn-white-ol{background:transparent;color:#fff;border-color:rgba(255,255,255,.6)}
.oo-btn-white-ol:hover{border-color:#fff}

/* ── SECTION ── */
.oo-section{padding:80px 0}
.oo-section-gray{background:#F8F9FB}
.oo-section-head{text-align:center;max-width:720px;margin:0 auto 56px}
.oo-tag{display:inline-block;color:#FF6F3D;font-size:12.5px;font-weight:700;text-transform:uppercase;letter-spacing:.9px;margin-bottom:10px}
.oo-section-head h2{font-size:clamp(24px,3.5vw,40px);font-weight:700;color:#1a1a2e;line-height:1.2;margin-bottom:14px}
.oo-section-head h2 em{color:#FF6F3D;font-style:normal}
.oo-section-head p{font-size:16px;color:#666;line-height:1.7}

/* ── STATS ── */
.oo-stats{display:flex;background:#fff;border:1px solid #e8e8e8;border-radius:8px;margin-top:48px}
.oo-stat{flex:1;text-align:center;padding:28px 16px;border-right:1px solid #e8e8e8}
.oo-stat:last-child{border-right:none}
.oo-stat strong{display:block;font-size:34px;font-weight:800;color:#FF6F3D;line-height:1}
.oo-stat span{font-size:13px;color:#777;margin-top:6px;display:block}

/* ── FEATURE SPLIT ── */
.oo-split{display:grid;grid-template-columns:1fr 1fr;gap:80px;align-items:center}
.oo-split.oo-split-rev{direction:rtl}
.oo-split.oo-split-rev>*{direction:ltr}
.oo-fc .oo-tag{display:block;margin-bottom:8px}
.oo-fc h2{font-size:clamp(22px,3vw,34px);font-weight:700;color:#1a1a2e;line-height:1.25;margin-bottom:14px}
.oo-fc p{font-size:15px;color:#666;line-height:1.75;margin-bottom:20px}
.oo-feat-list{margin-bottom:24px}
.oo-feat-list li{display:flex;align-items:flex-start;gap:10px;padding:8px 0;border-bottom:1px solid #f2f2f2;font-size:14.5px;color:#444}
.oo-feat-list li::before{content:'✓';color:#FF6F3D;font-weight:700;flex-shrink:0;margin-top:1px}
.oo-fc-btns{display:flex;gap:12px;flex-wrap:wrap;margin-top:4px}
.oo-fv{border-radius:10px;overflow:hidden;box-shadow:0 16px 56px rgba(0,0,0,.13)}
.oo-fv-placeholder{display:flex;align-items:center;justify-content:center;font-size:80px;height:360px}

/* ── PLATFORM PILLS ── */
.oo-platforms{display:flex;gap:10px;flex-wrap:wrap;margin-top:20px}
.oo-plat{display:inline-flex;align-items:center;gap:7px;border:1px solid #e0e0e0;border-radius:4px;padding:9px 14px;font-size:13px;font-weight:500;color:#333;transition:border-color .15s;text-decoration:none}
.oo-plat:hover{border-color:#FF6F3D;color:#FF6F3D;text-decoration:none}

/* ── INTEGRATION GRID ── */
.oo-int-grid{display:flex;flex-wrap:wrap;gap:10px;justify-content:center}
.oo-int{display:inline-flex;align-items:center;gap:8px;border:1px solid #e8e8e8;border-radius:6px;padding:12px 20px;font-size:13.5px;font-weight:500;color:#555;transition:all .15s;text-decoration:none}
.oo-int:hover{border-color:#FF6F3D;color:#FF6F3D;text-decoration:none}
.oo-int span{font-size:20px}

/* ── CARDS ── */
.oo-grid-3{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.oo-card{background:#fff;border:1px solid #e8e8e8;border-radius:8px;padding:28px;transition:box-shadow .2s,transform .2s}
.oo-card:hover{box-shadow:0 8px 32px rgba(0,0,0,.1);transform:translateY(-3px)}
.oo-card-icon{font-size:40px;margin-bottom:14px}
.oo-card-badge{display:inline-block;background:rgba(255,111,61,.1);color:#FF6F3D;font-size:11.5px;font-weight:600;padding:3px 10px;border-radius:100px;margin-bottom:10px}
.oo-card h3{font-size:18px;font-weight:700;color:#1a1a2e;margin-bottom:8px}
.oo-card p{font-size:13.5px;color:#666;line-height:1.65;margin-bottom:16px}
.oo-card-link{color:#FF6F3D;font-size:13.5px;font-weight:600;text-decoration:none}
.oo-card-link:hover{text-decoration:underline}

/* ── FAQ ── */
.oo-faq{max-width:800px;margin:0 auto}
.oo-faq-item{border-bottom:1px solid #e8e8e8}
.oo-faq-q{width:100%;background:none;border:none;padding:18px 0;font-size:15px;font-weight:600;color:#1a1a2e;cursor:pointer;display:flex;justify-content:space-between;align-items:center;text-align:left;font-family:'Open Sans',sans-serif;gap:12px}
.oo-faq-q .oo-faq-ico{font-size:22px;color:#FF6F3D;transition:transform .2s;flex-shrink:0;line-height:1}
.oo-faq-q.open .oo-faq-ico{transform:rotate(45deg)}
.oo-faq-a{max-height:0;overflow:hidden;transition:max-height .25s ease}
.oo-faq-a.open{max-height:400px}
.oo-faq-a-inner{padding:0 0 16px;font-size:14.5px;color:#555;line-height:1.75}

/* ── CTA BAND ── */
.oo-cta{background:#FF6F3D;padding:64px 0;text-align:center}
.oo-cta h2{font-size:clamp(22px,3.5vw,38px);font-weight:700;color:#fff;margin-bottom:12px}
.oo-cta p{font-size:17px;color:rgba(255,255,255,.87);margin-bottom:28px}
.oo-cta-btns{display:flex;gap:16px;justify-content:center;flex-wrap:wrap}

/* ── FOOTER ── */
.oo-footer{background:#F8F9FB;border-top:1px solid #e8e8e8}
.oo-footer-top{padding:52px 0 40px}
.oo-footer-apps{display:flex;gap:10px;flex-wrap:wrap;padding-bottom:36px;margin-bottom:36px;border-bottom:1px solid #e8e8e8;align-items:center}
.oo-footer-apps-label{font-size:13px;font-weight:600;color:#666;margin-right:6px;white-space:nowrap}
.oo-app-btn{display:inline-flex;align-items:center;gap:8px;border:1px solid #ddd;border-radius:4px;padding:8px 16px;font-size:13px;font-weight:500;color:#444;background:#fff;transition:border-color .15s;text-decoration:none}
.oo-app-btn:hover{border-color:#FF6F3D;color:#FF6F3D;text-decoration:none}
.oo-footer-grid{display:grid;grid-template-columns:repeat(5,1fr);gap:24px}
.oo-footer-col h4{font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.9px;color:#999;margin-bottom:14px}
.oo-footer-col ul li{margin-bottom:9px}
.oo-footer-col ul a,.oo-footer-col a{font-size:13.5px;color:#555;text-decoration:none;transition:color .12s}
.oo-footer-col ul a:hover,.oo-footer-col a:hover{color:#FF6F3D;text-decoration:none}
.oo-contact-email{color:#FF6F3D !important;font-size:13.5px}
.oo-contact-label{font-size:13px;color:#444;margin-bottom:3px;display:block}
.oo-footer-bottom{border-top:1px solid #e8e8e8;padding:20px 0;display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:14px}
.oo-socials{display:flex;gap:6px;align-items:center}
.oo-socials a{width:32px;height:32px;border:1px solid #ddd;border-radius:4px;display:flex;align-items:center;justify-content:center;color:#666;font-size:13px;text-decoration:none;transition:all .15s}
.oo-socials a:hover{border-color:#FF6F3D;color:#FF6F3D}
.oo-footer-copy{font-size:12.5px;color:#999}
.oo-footer-copy a{color:#999}
.oo-footer-lang{display:flex;align-items:center;gap:6px;font-size:13px;color:#555;border:1px solid #ddd;border-radius:4px;padding:6px 12px;background:#fff;cursor:pointer}

/* ── ZALO ── */
.oo-zalo{position:fixed;bottom:24px;right:24px;z-index:10000;width:52px;height:52px;border-radius:50%;background:#0068FF;display:flex;align-items:center;justify-content:center;box-shadow:0 4px 16px rgba(0,104,255,.45);animation:ooZpulse 2.2s infinite;text-decoration:none}
.oo-zalo:hover{transform:scale(1.08);text-decoration:none}
@keyframes ooZpulse{0%,100%{box-shadow:0 4px 16px rgba(0,104,255,.45)}50%{box-shadow:0 4px 28px rgba(0,104,255,.7)}}
.oo-zalo svg{width:28px;height:28px}

/* ── COOKIE ── */
.oo-cookie{position:fixed;bottom:0;left:0;right:0;z-index:9999;background:#1a1a2e;color:rgba(255,255,255,.85);padding:14px 24px;display:flex;align-items:center;justify-content:space-between;gap:16px;transform:translateY(100%);transition:transform .4s ease}
.oo-cookie.show{transform:translateY(0)}
.oo-cookie p{font-size:13.5px}
.oo-cookie a{color:#FF6F3D}
.oo-cookie-btns{display:flex;gap:10px;flex-shrink:0}

/* ── PAGE CONTENT ── */
.oo-page-title{font-size:2rem;font-weight:800;color:#1a1a2e;margin-bottom:24px}
.oo-page-content{font-size:15px;line-height:1.8;color:#444}
.oo-page-content h2,.oo-page-content h3{color:#1a1a2e;margin:24px 0 12px}

/* ── RESPONSIVE ── */
@media(max-width:1060px){
  .oo-split,.oo-split.oo-split-rev{grid-template-columns:1fr;direction:ltr;gap:40px}
  .oo-footer-grid{grid-template-columns:repeat(3,1fr)}
  .oo-mega{min-width:500px;grid-template-columns:repeat(2,1fr)}
}
@media(max-width:768px){
  .oo-nav{display:none}
  .oo-ham{display:flex}
  .oo-btn-text{display:none}
  .oo-stats{flex-direction:column}
  .oo-stat{border-right:none;border-bottom:1px solid #e8e8e8}
  .oo-stat:last-child{border-bottom:none}
  .oo-grid-3{grid-template-columns:1fr}
  .oo-footer-grid{grid-template-columns:repeat(2,1fr)}
  .oo-hero{padding:48px 0 32px}
}
@media(max-width:480px){
  .oo-footer-grid{grid-template-columns:1fr}
  .oo-container{padding:0 16px}
  .oo-hero-btns{flex-direction:column;align-items:center}
}