:root {
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --font-display: 'Plus Jakarta Sans', 'Inter', system-ui, sans-serif;
    --primary: #0ea5e9;
    --violet: #7c3aed;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
    font-family: var(--font-sans);
    font-size: 1.0625rem;
    line-height: 1.6;
    background: #fafafa;
    color: #0f172a;
    -webkit-font-smoothing: antialiased;
}
html { scroll-behavior: smooth; }
h1, h2, h3, h4 { font-family: var(--font-display); letter-spacing: -0.025em; }

.btn-primary {
    background: linear-gradient(135deg, #0ea5e9, #8b5cf6);
    transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    box-shadow: 0 4px 20px rgba(14, 165, 233, 0.25);
    position: relative;
    overflow: hidden;
    border: none;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-weight: 600;
    font-size: 0.9375rem;
    border-radius: 9999px;
    padding: 0.75rem 1.75rem;
    color: white;
    text-decoration: none;
}
.btn-primary::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, #8b5cf6, #0ea5e9);
    opacity: 0;
    transition: opacity 0.4s ease;
    border-radius: inherit;
}
.btn-primary:hover::after { opacity: 1; }
.btn-primary:hover {
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 12px 40px rgba(14, 165, 233, 0.35);
}
.btn-primary span { position: relative; z-index: 1; }
.btn-primary.btn-sm { padding: 0.625rem 1.25rem; font-size: 0.875rem; }

.btn-secondary {
    background: white;
    color: #0f172a;
    border: 1.5px solid #e5e7eb;
    transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-weight: 600;
    font-size: 0.9375rem;
    border-radius: 9999px;
    padding: 0.75rem 1.75rem;
    text-decoration: none;
}
.btn-secondary:hover { border-color: #0ea5e9; color: #0ea5e9; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(14, 165, 233, 0.1); }

/* ===== HEADER ===== */
.header {
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(226,232,240,0.7);
}

/* ===== DROPDOWN ===== */
.nav-dropdown { position: relative; }
.nav-dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}
.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(8px);
    background: white;
    border-radius: 16px;
    padding: 16px 20px;
    min-width: 240px;
    box-shadow: 0 20px 48px rgba(0,0,0,0.08);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    border: 1px solid #f1f5f9;
    z-index: 100;
}
.dropdown-menu a {
    display: block;
    padding: 8px 12px;
    border-radius: 8px;
    font-size: 14px;
    color: #475569;
    transition: all 0.2s ease;
    text-decoration: none;
}
.dropdown-menu a:hover { background: #f8fafc; color: #0ea5e9; }
.dropdown-menu .menu-title {
    font-weight: 700;
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: #94a3b8;
    padding: 4px 12px 8px;
    border-bottom: 1px solid #f1f5f9;
    margin-bottom: 4px;
}

/* ===== TECH LOGOS ===== */
.tech-logos {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 1.5rem 2.5rem;
    padding: 1.5rem 0;
}
.tech-logos .logo-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #64748b;
    font-size: 0.875rem;
    font-weight: 500;
    opacity: 0.6;
    transition: all 0.3s ease;
}
.tech-logos .logo-item:hover {
    opacity: 1;
    transform: translateY(-2px);
}
.tech-logos .logo-item svg,
.tech-logos .logo-item i {
    font-size: 1.75rem;
}
.tech-logos .logo-item .text {
    font-size: 0.875rem;
    font-weight: 600;
}

/* ===== DASHBOARD ===== */
.dashboard {
    background: #0f172a;
    border-radius: 20px;
    padding: 1.75rem;
    color: white;
    position: relative;
    overflow: hidden;
    border: 1px solid rgba(255,255,255,0.06);
    box-shadow: 0 20px 25px -5px rgba(0,0,0,0.08);
}
.dashboard::before {
    content: '';
    position: absolute;
    top: -40%;
    right: -20%;
    width: 70%;
    height: 180%;
    background: radial-gradient(ellipse, rgba(14,165,233,0.08) 0%, transparent 65%);
    pointer-events: none;
}
.stat-card {
    background: rgba(255,255,255,0.04);
    border: 1px solid rgba(255,255,255,0.06);
    border-radius: 12px;
    padding: 0.875rem 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
}
.stat-card:hover {
    background: rgba(255,255,255,0.08);
    border-color: rgba(14,165,233,0.35);
    transform: translateY(-2px);
}

/* ===== FLOATING ===== */
.floating {
    position: fixed;
    left: 1.25rem;
    bottom: 1.5rem;
    z-index: 999;
    display: flex;
    flex-direction: column;
    gap: 0.625rem;
}
.floating a {
    width: 3.5rem;
    height: 3.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: white;
    box-shadow: 0 8px 28px rgba(0,0,0,0.1);
    border: 1px solid #f1f5f9;
    transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    color: #0f172a;
    text-decoration: none;
    font-size: 1.25rem;
    position: relative;
}
.floating a:hover { transform: scale(1.12); }
.floating .hotline { background: linear-gradient(135deg, #0ea5e9, #8b5cf6); color: white; border: none; }
.floating .zalo { background: #0188e0; color: white; border: none; }

.floating .tooltip {
    position: absolute;
    left: 68px;
    background: #0f172a;
    color: white;
    padding: 4px 14px;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 500;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: all 0.3s ease;
}
.floating a:hover .tooltip { opacity: 1; }
.floating .tooltip::before {
    content: '';
    position: absolute;
    left: -6px;
    top: 50%;
    transform: translateY(-50%);
    border: 6px solid transparent;
    border-right-color: #0f172a;
}

/* ===== MOBILE BAR ===== */
.mobile-bar {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: white;
    border-top: 1px solid #f1f5f9;
    padding: 0.75rem 1rem;
    z-index: 100;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 -4px 20px rgba(0,0,0,0.04);
}
@media (max-width: 768px) { .mobile-bar { display: flex; } .floating { display: none; } }

/* ===== PRICING ===== */
.pricing-card {
    background: white;
    border: 1px solid #e5e7eb;
    border-radius: 20px;
    padding: 2rem 1.75rem;
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
    position: relative;
}
.pricing-card:hover {
    transform: translateY(-6px);
    border-color: #0ea5e9;
    box-shadow: 0 20px 48px rgba(14, 165, 233, 0.08);
}
.pricing-card.featured {
    border: 2px solid #8b5cf6;
    background: linear-gradient(180deg, #faf5ff, #ffffff);
    box-shadow: 0 20px 40px -12px rgba(139,92,246,0.15);
}
.popular-badge {
    position: absolute;
    top: -11px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(135deg, #8b5cf6, #0ea5e9);
    color: white;
    font-size: 11px;
    font-weight: 700;
    padding: 4px 18px;
    border-radius: 9999px;
}

/* ===== MODULE ===== */
.module-card {
    background: white;
    border: 1px solid #e5e7eb;
    border-radius: 16px;
    padding: 1.25rem 1rem;
    text-align: center;
    transition: all 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    cursor: pointer;
    text-decoration: none;
    color: inherit;
    display: block;
}
.module-card:hover {
    transform: translateY(-4px);
    border-color: #0ea5e9;
    box-shadow: 0 12px 32px rgba(14, 165, 233, 0.08);
}
.module-card .icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 0.75rem;
    font-size: 1.25rem;
}
.module-card .name { font-weight: 700; font-size: 0.875rem; color: #0f172a; }
.module-card .desc { font-size: 0.75rem; color: #64748b; margin-top: 0.25rem; }

/* ===== FAQ ===== */
.faq-item {
    background: white;
    border: 1px solid #e5e7eb;
    border-radius: 12px;
    padding: 1.125rem 1.25rem;
    margin-bottom: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
}
.faq-item:hover { border-color: #cbd5e1; }
.faq-item .answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.3s ease;
    color: #64748b;
    font-size: 0.9375rem;
    line-height: 1.625;
}
.faq-item.open .answer { max-height: 200px; padding-top: 0.75rem; }
.faq-item.open .chevron { transform: rotate(180deg); }

/* ===== TOAST ===== */
.toast {
    position: fixed;
    bottom: 6rem;
    right: 1.5rem;
    background: #0f172a;
    color: white;
    padding: 0.875rem 1.25rem;
    border-radius: 12px;
    box-shadow: 0 12px 40px rgba(0,0,0,0.15);
    z-index: 1000;
    transform: translateY(80px);
    opacity: 0;
    transition: all 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
    font-size: 0.9375rem;
    max-width: 340px;
}
.toast.show { transform: translateY(0); opacity: 1; }

/* ===== FORM ===== */
.form-input {
    width: 100%;
    padding: 0.8125rem 1rem;
    border: 1.5px solid #e5e7eb;
    border-radius: 12px;
    font-size: 0.9375rem;
    transition: all 0.3s ease;
    background: white;
    color: #0f172a;
    font-family: inherit;
}
.form-input:focus {
    outline: none;
    border-color: #0ea5e9;
    box-shadow: 0 0 0 4px rgba(14,165,233,0.1);
}
.form-input::placeholder { color: #94a3b8; }

/* ===== SCROLL REVEAL ===== */
.reveal { opacity: 0; transform: translateY(24px); transition: all 0.7s cubic-bezier(0.34, 1.56, 0.64, 1); }
.reveal.visible { opacity: 1; transform: translateY(0); }
.delay-1 { transition-delay: 0.06s; }
.delay-2 { transition-delay: 0.12s; }
.delay-3 { transition-delay: 0.18s; }
.delay-4 { transition-delay: 0.24s; }
.delay-5 { transition-delay: 0.30s; }

/* ===== GOOGLE TRANSLATE ===== */
.goog-te-banner-frame, .goog-te-balloon-frame, #goog-gt-tt { display: none !important; }
body { top: 0 !important; }
.goog-te-gadget { font-size: 0 !important; display: inline-flex !important; align-items: center; }
.goog-te-gadget .goog-te-combo {
    font-size: 13px !important;
    padding: 6px 12px;
    border-radius: 20px;
    border: 1px solid #e5e7eb;
    background: #f8fafc;
    color: #0f172a;
    font-family: Inter, sans-serif;
    font-weight: 500;
    cursor: pointer;
    outline: none;
    min-width: 110px;
}
.goog-te-gadget .goog-te-combo:hover { border-color: #0ea5e9; }

/* Language switcher buttons */
.lang-switcher {
    display: flex;
    align-items: center;
    gap: 2px;
    background: #f1f5f9;
    border-radius: 30px;
    padding: 3px;
    border: 1px solid #e2e8f0;
}
.lang-btn {
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    background: transparent;
    color: #94a3b8;
    font-family: 'Inter', sans-serif;
}
.lang-btn:hover { color: #0a0a0a; }
.lang-btn.active {
    background: white;
    color: #0ea5e9;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.section-label {
    font-size: 0.8125rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: #0ea5e9;
}

@media (max-width: 640px) {
    .hero-title { font-size: 2.25rem !important; }
    .tech-logos { gap: 1rem 1.5rem; }
    .tech-logos .logo-item { font-size: 0.75rem; }
    .tech-logos .logo-item i { font-size: 1.25rem; }
}

/* ===== HEADER & MENU MOBILE ===== */

/* ---------- HEADER ---------- */
#header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(241, 245, 249, 0.8);
    transition: box-shadow 0.3s ease;
}

#header.shadow-sm {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

/* ---------- HAMBURGER BUTTON ---------- */
.hamburger-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 8px;
    border: 1px solid #e2e8f0;
    border-radius: 10px;
    background: white;
    transition: all 0.3s ease;
    position: relative;
    z-index: 1001;
    width: 44px;
    height: 44px;
    align-items: center;
    justify-content: center;
}

.hamburger-btn:hover {
    border-color: #8b5cf6;
}

.hamburger-btn span {
    display: block;
    width: 22px;
    height: 2.5px;
    background: #475569;
    border-radius: 4px;
    transition: all 0.3s ease;
    transform-origin: center;
}

/* Khi checkbox được check - biến thành X */
#menu-toggle:checked ~ .hamburger-btn span:nth-child(1) {
    transform: translateY(7.5px) rotate(45deg);
}

#menu-toggle:checked ~ .hamburger-btn span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}

#menu-toggle:checked ~ .hamburger-btn span:nth-child(3) {
    transform: translateY(-7.5px) rotate(-45deg);
}

#menu-toggle:checked ~ .hamburger-btn {
    border-color: #8b5cf6;
}

/* ---------- MENU OVERLAY ---------- */
.menu-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 998;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    backdrop-filter: blur(2px);
    -webkit-backdrop-filter: blur(2px);
}

body:has(#menu-toggle:checked) .menu-overlay {
    opacity: 1;
    visibility: visible;
}

/* ---------- MENU MOBILE ---------- */
.menu-mobile {
    position: fixed;
    top: 0;
    right: -100%;
    width: 85%;
    max-width: 360px;
    height: 100vh;
    background: white;
    z-index: 999;
    padding: 20px 16px 30px;
    overflow-y: auto;
    transition: right 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
    box-shadow: -4px 0 30px rgba(0, 0, 0, 0.08);
}

body:has(#menu-toggle:checked) .menu-mobile {
    right: 0;
}

/* Menu header */
.menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 16px;
    border-bottom: 1px solid #f1f5f9;
    margin-bottom: 16px;
}

.menu-header .brand {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
}

.menu-header .brand-icon {
    width: 36px;
    height: 36px;
    border-radius: 12px;
    background: linear-gradient(135deg, #0ea5e9, #8b5cf6);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 18px;
    color: white;
    flex-shrink: 0;
}

.menu-header .brand-name {
    font-size: 20px;
    font-weight: 700;
    color: #0a0a0a;
}

.menu-header .brand-name span {
    color: #0ea5e9;
}

/* Nút đóng menu */
.menu-close-label {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: #f1f5f9;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 18px;
    color: #64748b;
    transition: all 0.3s ease;
}

.menu-close-label:hover {
    background: #e2e8f0;
    color: #0a0a0a;
}

/* ---------- MENU ITEMS ---------- */
.menu-section {
    margin-bottom: 20px;
}

.menu-section-title {
    font-size: 10px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: #94a3b8;
    padding: 4px 0 8px;
    border-bottom: 1px solid #f1f5f9;
    margin-bottom: 6px;
}

/* Item chính */
.menu-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 12px;
    border-radius: 10px;
    color: #475569;
    font-size: 15px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s ease;
    cursor: pointer;
}

.menu-item:hover {
    background: #f8fafc;
    color: #8b5cf6;
}

.menu-item i {
    width: 20px;
    font-size: 15px;
    color: #94a3b8;
}

.menu-item:hover i {
    color: #8b5cf6;
}

/* Item có sub menu */
.menu-item.has-sub {
    position: relative;
    justify-content: space-between;
}

.menu-item.has-sub .arrow {
    font-size: 12px;
    color: #cbd5e1;
    transition: transform 0.3s ease;
}

/* Checkbox toggle sub menu */
.menu-sub-toggle {
    display: none;
}

.menu-sub-toggle:checked ~ .menu-item.has-sub .arrow {
    transform: rotate(180deg);
}

/* Sub menu */
.menu-sub {
    padding-left: 44px;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease;
}

.menu-sub-toggle:checked ~ .menu-sub {
    max-height: 600px;
}

.menu-sub .sub-item {
    display: block;
    padding: 8px 12px;
    border-radius: 8px;
    color: #64748b;
    font-size: 14px;
    text-decoration: none;
    transition: all 0.2s ease;
}

.menu-sub .sub-item:hover {
    background: #f8fafc;
    color: #8b5cf6;
}

/* ---------- MENU CTA ---------- */
.menu-cta {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px;
    background: linear-gradient(135deg, #0ea5e9, #8b5cf6);
    color: white;
    border-radius: 12px;
    font-weight: 600;
    font-size: 15px;
    text-decoration: none;
    margin-top: 12px;
    transition: all 0.3s ease;
}

.menu-cta:active {
    transform: scale(0.96);
}

/* ---------- LANGUAGE SWITCHER MOBILE ---------- */
.menu-lang {
    display: flex;
    gap: 4px;
    background: #f1f5f9;
    border-radius: 30px;
    padding: 4px;
    margin-top: 12px;
    border: 1px solid #e2e8f0;
}

.menu-lang label {
    flex: 1;
    padding: 6px 8px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    color: #94a3b8;
    font-family: 'Inter', sans-serif;
}

.menu-lang input[type="radio"] {
    display: none;
}

.menu-lang input[type="radio"]:checked + label {
    background: white;
    color: #8b5cf6;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.menu-lang label:hover {
    color: #0a0a0a;
}

/* ---------- RESPONSIVE ---------- */
@media (max-width: 1023px) {
    .hamburger-btn {
        display: flex;
    }
}

@media (min-width: 1024px) {
    #menu-toggle,
    .hamburger-btn,
    .menu-overlay,
    .menu-mobile {
        display: none !important;
    }
}

/* Ngăn cuộn body khi menu mở */
body:has(#menu-toggle:checked) {
    overflow: hidden;
}