/* ============================================
   MOBILE FIRST CSS - SỬA MÁY THÀNH NHÂN
   Base styles target mobile (< 576px)
   Then scale up: 576px → 768px → 992px → 1200px
   ============================================ */

/* ---------- CSS Variables ---------- */
:root {
    --primary: #FF6B00;
    --primary-dark: #E55A00;
    --primary-light: #FF8533;
    --secondary: #1A1A2E;
    --dark: #0F0F1E;
    --light: #F5F5F7;
    --white: #FFFFFF;
    --gray: #6B7280;
    --gray-light: #E5E7EB;
    --success: #10B981;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.15);
    --shadow-orange: 0 8px 25px rgba(255, 107, 0, 0.35);
    --transition: all 0.3s ease;
    --radius: 12px;
    --radius-lg: 20px;
}

/* ---------- Reset & Base ---------- */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: 'Be Vietnam Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 15px;
    line-height: 1.6;
    color: var(--secondary);
    background: var(--white);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Be Vietnam Pro', sans-serif;
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }

.highlight { color: var(--primary); }

.container {
    width: 100%;
    padding: 0 16px;
    margin: 0 auto;
}

/* ============================================
   HEADER & NAVIGATION (Mobile)
   ============================================ */
#header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(15, 15, 30, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    transition: var(--transition);
}

#header.scrolled {
    background: rgba(15, 15, 30, 0.98);
    box-shadow: var(--shadow);
}

.navbar { padding: 12px 0; }

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    position: relative;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--white);
    font-family: 'Be Vietnam Pro', sans-serif;
    font-size: 18px;
    font-weight: 900;
    letter-spacing: 0.5px;
    z-index: 101;
}

.logo i {
    color: var(--primary);
    font-size: 24px;
}

.logo-fi {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--primary);
    color: var(--white);
    font-size: 11px;
    font-weight: 900;
    padding: 2px 8px;
    border-radius: 4px;
    letter-spacing: 0.5px;
    line-height: 1;
    height: 20px;
    box-shadow: 0 2px 8px rgba(255, 107, 0, 0.4);
}

.hero-fi {
    display: inline-block;
    background: var(--primary);
    color: var(--white);
    font-size: 0.55em;
    font-weight: 900;
    padding: 0.15em 0.4em;
    border-radius: 8px;
    letter-spacing: 0.05em;
    vertical-align: middle;
    margin-left: 0.15em;
    transform: translateY(-0.15em);
    box-shadow: 0 6px 20px rgba(255, 107, 0, 0.5);
}

/* Mobile menu - hidden by default, slides in */
.nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 320px;
    height: 100vh;
    background: var(--dark);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 24px;
    display: flex;
    transition: right 0.4s ease;
    z-index: 100;
    box-shadow: -10px 0 40px rgba(0, 0, 0, 0.3);
}

.nav-menu.active { right: 0; }

.nav-link {
    color: var(--white);
    font-weight: 500;
    font-size: 18px;
    padding: 8px 0;
    position: relative;
    transition: var(--transition);
}

.nav-link:hover, .nav-link.active { color: var(--primary); }

.nav-cta {
    display: none; /* Hidden on mobile - replaced by floating call button */
}

/* Hamburger Menu */
.hamburger {
    display: flex;
    flex-direction: column;
    gap: 5px;
    z-index: 101;
    padding: 8px;
}

.hamburger span {
    display: block;
    width: 26px;
    height: 3px;
    background: var(--white);
    border-radius: 3px;
    transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* ============================================
   HERO SECTION (Mobile)
   ============================================ */
.hero {
    position: relative;
    min-height: 100vh;
    min-height: 100dvh;
    display: flex;
    align-items: center;
    justify-content: center;
    background:
        linear-gradient(135deg, rgba(15, 15, 30, 0.92), rgba(255, 107, 0, 0.5)),
        url('https://images.unsplash.com/photo-1558981806-ec527fa84c39?w=1600&auto=format&fit=crop') center/cover;
    color: var(--white);
    text-align: center;
    padding: 100px 16px 60px;
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 50% 50%, transparent 0%, rgba(0,0,0,0.4) 100%);
}

.hero-content {
    position: relative;
    z-index: 2;
    width: 100%;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 107, 0, 0.15);
    border: 1px solid var(--primary);
    color: var(--primary-light);
    padding: 8px 16px;
    border-radius: 50px;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.5px;
    margin-bottom: 20px;
    animation: fadeInDown 0.8s ease;
}

.hero-title {
    font-family: 'Be Vietnam Pro', sans-serif;
    font-size: clamp(36px, 10vw, 64px);
    font-weight: 900;
    line-height: 1.05;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
    text-transform: uppercase;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-subtitle {
    font-size: clamp(16px, 4.5vw, 22px);
    font-weight: 500;
    margin-bottom: 12px;
    color: var(--primary-light);
    animation: fadeInUp 0.8s ease 0.4s both;
}

.hero-description {
    font-size: 14px;
    margin-bottom: 28px;
    opacity: 0.9;
    max-width: 90%;
    margin-left: auto;
    margin-right: auto;
    animation: fadeInUp 0.8s ease 0.6s both;
}

.hero-buttons {
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-items: center;
    margin-bottom: 36px;
    animation: fadeInUp 0.8s ease 0.8s both;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: 50px;
    font-weight: 700;
    font-size: 14px;
    letter-spacing: 0.5px;
    transition: var(--transition);
    cursor: pointer;
    text-align: center;
    width: 100%;
    max-width: 280px;
}

.btn-primary {
    background: var(--primary);
    color: var(--white);
    box-shadow: var(--shadow-orange);
}

.btn-primary:hover, .btn-primary:active {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.btn-secondary {
    background: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}

.btn-secondary:hover, .btn-secondary:active {
    background: var(--white);
    color: var(--secondary);
}

.btn-large {
    padding: 16px 32px;
    font-size: 15px;
}

.hero-features {
    display: flex;
    flex-direction: column;
    gap: 10px;
    align-items: center;
    animation: fadeInUp 0.8s ease 1s both;
}

.hero-feature {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    font-weight: 500;
}

.hero-feature i { color: var(--primary-light); font-size: 16px; }

.hero-scroll {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
}

.hero-scroll a {
    color: var(--white);
    font-size: 22px;
    animation: bounce 2s infinite;
    display: block;
    padding: 10px;
}

/* ============================================
   SECTION COMMON (Mobile)
   ============================================ */
section { padding: 60px 0; }

.section-header {
    text-align: center;
    margin-bottom: 40px;
}

.section-tag {
    display: inline-block;
    color: var(--primary);
    font-weight: 700;
    font-size: 12px;
    letter-spacing: 2px;
    margin-bottom: 12px;
    text-transform: uppercase;
}

.section-title {
    font-family: 'Be Vietnam Pro', sans-serif;
    font-size: clamp(26px, 6.5vw, 40px);
    font-weight: 900;
    line-height: 1.15;
    letter-spacing: -0.02em;
    margin-bottom: 16px;
    text-transform: uppercase;
}

.section-line {
    width: 60px;
    height: 4px;
    background: var(--primary);
    border-radius: 2px;
    margin: 0 auto 16px;
}

.section-subtitle {
    color: var(--gray);
    font-size: 14px;
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   ABOUT SECTION (Mobile)
   ============================================ */
.about { background: var(--light); }

.about-content {
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.about-text { order: 2; }
.about-image { order: 1; }

.about-intro {
    font-size: 16px;
    color: var(--secondary);
    margin-bottom: 14px;
    line-height: 1.7;
}

.about-text p { margin-bottom: 14px; color: var(--gray); }

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-top: 28px;
}

.stat-item {
    text-align: center;
    padding: 16px 8px;
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.stat-number {
    font-family: 'Be Vietnam Pro', sans-serif;
    font-size: clamp(24px, 6vw, 36px);
    font-weight: 900;
    color: var(--primary);
    line-height: 1;
    letter-spacing: -0.02em;
}

.stat-label {
    font-size: 11px;
    color: var(--gray);
    margin-top: 6px;
    font-weight: 500;
}

.about-image-wrapper {
    position: relative;
    background: linear-gradient(135deg, var(--secondary), var(--primary));
    border-radius: var(--radius-lg);
    padding: 40px 20px;
    text-align: center;
    box-shadow: var(--shadow-lg);
    min-height: 240px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.about-icon {
    font-size: 100px;
    color: rgba(255, 255, 255, 0.95);
}

.about-badge {
    position: absolute;
    bottom: -16px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--white);
    padding: 12px 18px;
    border-radius: 50px;
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 10px;
    white-space: nowrap;
}

.about-badge i {
    color: var(--primary);
    font-size: 22px;
}

.about-badge strong {
    display: block;
    font-size: 13px;
    color: var(--secondary);
}

.about-badge span {
    font-size: 10px;
    color: var(--gray);
}

/* ============================================
   SERVICES SECTION (Mobile)
   ============================================ */
.services { background: var(--white); }

.services-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

.service-card {
    position: relative;
    background: var(--white);
    padding: 28px 20px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--gray-light);
    text-align: center;
}

.service-card:hover, .service-card:active {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.service-card-featured {
    background: linear-gradient(135deg, #FFF5EE 0%, #FFE4D0 100%);
    border: 2px solid var(--primary);
    box-shadow: 0 10px 30px rgba(255, 107, 0, 0.2);
}

.service-card-featured:hover, .service-card-featured:active {
    box-shadow: 0 15px 40px rgba(255, 107, 0, 0.3);
}

.service-badge {
    position: absolute;
    top: -10px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: var(--white);
    font-size: 10px;
    font-weight: 900;
    letter-spacing: 1px;
    padding: 5px 14px;
    border-radius: 50px;
    box-shadow: 0 4px 12px rgba(255, 107, 0, 0.4);
    white-space: nowrap;
}

.service-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 16px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 28px;
    box-shadow: var(--shadow-orange);
}

.service-card h3 {
    font-family: 'Be Vietnam Pro', sans-serif;
    font-size: 20px;
    font-weight: 800;
    letter-spacing: -0.01em;
    margin-bottom: 10px;
    color: var(--secondary);
}

.service-card p {
    color: var(--gray);
    font-size: 13px;
    line-height: 1.6;
}

/* ============================================
   WHY CHOOSE US (Mobile)
   ============================================ */
.why-us {
    background: linear-gradient(135deg, var(--secondary) 0%, var(--dark) 100%);
    color: var(--white);
}

.why-us .section-title { color: var(--white); }
.why-us .section-subtitle { color: rgba(255, 255, 255, 0.7); }

.why-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
}

.why-card {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: 28px 20px;
    border-radius: var(--radius);
    position: relative;
    transition: var(--transition);
    overflow: hidden;
}

.why-card:hover, .why-card:active {
    background: rgba(255, 107, 0, 0.1);
    border-color: var(--primary);
    transform: translateY(-4px);
}

.why-number {
    position: absolute;
    top: 12px;
    right: 16px;
    font-family: 'Be Vietnam Pro', sans-serif;
    font-size: 50px;
    font-weight: 900;
    color: rgba(255, 107, 0, 0.2);
    line-height: 1;
    letter-spacing: -0.04em;
}

.why-icon {
    font-size: 36px;
    color: var(--primary);
    margin-bottom: 14px;
}

.why-card h3 {
    font-size: 17px;
    margin-bottom: 10px;
    font-weight: 700;
}

.why-card p {
    color: rgba(255, 255, 255, 0.75);
    font-size: 13px;
    line-height: 1.6;
}

/* ============================================
   GALLERY SECTION (Mobile)
   ============================================ */
.gallery {
    background: var(--light);
}

.gallery-grid {
    column-count: 2;
    column-gap: 8px;
}

.gallery-item {
    position: relative;
    overflow: hidden;
    border-radius: 8px;
    cursor: pointer;
    background: var(--gray-light);
    box-shadow: var(--shadow);
    transition: var(--transition);
    break-inside: avoid;
    -webkit-column-break-inside: avoid;
    page-break-inside: avoid;
    margin-bottom: 8px;
    display: block;
    width: 100%;
}

.gallery-item img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.5s ease;
}

.gallery-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255, 107, 0, 0.85), rgba(15, 15, 30, 0.85));
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 28px;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.gallery-item:hover .gallery-overlay,
.gallery-item:active .gallery-overlay {
    opacity: 1;
}

.gallery-item:hover img,
.gallery-item:active img {
    transform: scale(1.1);
}

.gallery-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

/* ---------- Lightbox ---------- */
.lightbox {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.95);
    z-index: 9999;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 16px;
    -webkit-tap-highlight-color: transparent;
}

.lightbox.active {
    display: flex;
    animation: lightboxFadeIn 0.25s ease;
}

@keyframes lightboxFadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.lightbox-content {
    position: relative;
    max-width: 100%;
    max-height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
}

#lightbox-img {
    max-width: 100%;
    max-height: calc(100vh - 80px);
    max-height: calc(100dvh - 80px);
    object-fit: contain;
    border-radius: 4px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    user-select: none;
    -webkit-user-drag: none;
}

.lightbox-counter {
    color: var(--white);
    margin-top: 12px;
    font-size: 13px;
    font-weight: 500;
    background: rgba(0, 0, 0, 0.5);
    padding: 6px 14px;
    border-radius: 50px;
}

.lightbox-close,
.lightbox-prev,
.lightbox-next {
    position: absolute;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    z-index: 10;
    -webkit-tap-highlight-color: transparent;
}

.lightbox-close {
    top: 16px;
    right: 16px;
    width: 44px;
    height: 44px;
    font-size: 18px;
}

.lightbox-prev,
.lightbox-next {
    top: 50%;
    transform: translateY(-50%);
    width: 44px;
    height: 44px;
    font-size: 18px;
}

.lightbox-prev { left: 8px; }
.lightbox-next { right: 8px; }

.lightbox-close:hover,
.lightbox-close:active,
.lightbox-prev:hover,
.lightbox-prev:active,
.lightbox-next:hover,
.lightbox-next:active {
    background: var(--primary);
    transform: scale(1.1);
}

.lightbox-prev:hover, .lightbox-prev:active,
.lightbox-next:hover, .lightbox-next:active {
    transform: translateY(-50%) scale(1.1);
}

body.lightbox-open {
    overflow: hidden;
}

/* ============================================
   CTA BANNER (Mobile)
   ============================================ */
.cta-banner {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    padding: 50px 0;
    color: var(--white);
}

.cta-content {
    display: flex;
    flex-direction: column;
    gap: 24px;
    align-items: center;
    text-align: center;
}

.cta-text h2 {
    font-family: 'Be Vietnam Pro', sans-serif;
    font-size: clamp(24px, 6.5vw, 36px);
    font-weight: 900;
    letter-spacing: -0.02em;
    margin-bottom: 8px;
    line-height: 1.15;
    text-transform: uppercase;
}

.cta-text p {
    font-size: 15px;
    opacity: 0.95;
}

.cta-banner .btn-primary {
    background: var(--white);
    color: var(--primary);
}

.cta-banner .btn-primary:hover, .cta-banner .btn-primary:active {
    background: var(--secondary);
    color: var(--white);
}

/* ============================================
   CONTACT SECTION (Mobile)
   ============================================ */
.contact { background: var(--light); }

.contact-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 28px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.contact-item {
    display: flex;
    gap: 14px;
    background: var(--white);
    padding: 18px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: var(--transition);
    align-items: flex-start;
}

.contact-item:hover, .contact-item:active {
    transform: translateX(4px);
    box-shadow: var(--shadow-lg);
}

.contact-icon {
    width: 48px;
    height: 48px;
    min-width: 48px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 18px;
}

.contact-icon-zalo {
    background: linear-gradient(135deg, #0068FF, #004FCC);
}

.footer-social a.social-zalo:hover,
.footer-social a.social-zalo:active {
    background: #0068FF;
}

.contact-detail h3 {
    font-size: 15px;
    margin-bottom: 4px;
    color: var(--secondary);
}

.contact-detail p, .contact-detail a {
    color: var(--gray);
    font-size: 14px;
    word-break: break-word;
    line-height: 1.5;
}

.address-note {
    font-size: 12px;
    color: var(--primary);
    font-style: italic;
}

.contact-detail a:hover { color: var(--primary); }

.contact-map {
    position: relative;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    min-height: 280px;
    height: 280px;
}

.map-link {
    position: absolute;
    bottom: 12px;
    left: 50%;
    transform: translateX(-50%);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--primary);
    color: var(--white);
    padding: 10px 18px;
    border-radius: 50px;
    font-size: 13px;
    font-weight: 700;
    box-shadow: var(--shadow-orange);
    transition: var(--transition);
    z-index: 2;
    white-space: nowrap;
}

.map-link:hover, .map-link:active {
    background: var(--primary-dark);
    transform: translateX(-50%) translateY(-2px);
}

/* ============================================
   FOOTER (Mobile)
   ============================================ */
.footer {
    background: var(--dark);
    color: var(--white);
    padding: 50px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 32px;
    margin-bottom: 32px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: 'Be Vietnam Pro', sans-serif;
    font-size: 20px;
    font-weight: 900;
    color: var(--white);
    margin-bottom: 14px;
    letter-spacing: 0.5px;
}

.footer-logo i { color: var(--primary); }

.footer-desc {
    color: rgba(255, 255, 255, 0.7);
    font-size: 13px;
    margin-bottom: 16px;
    line-height: 1.7;
}

.footer-social {
    display: flex;
    gap: 10px;
}

.footer-social a {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    transition: var(--transition);
    font-size: 15px;
}

.footer-social a:hover, .footer-social a:active {
    background: var(--primary);
    transform: translateY(-3px);
}

.footer-col h4 {
    font-size: 16px;
    margin-bottom: 16px;
    color: var(--white);
    position: relative;
    padding-bottom: 8px;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 2px;
    background: var(--primary);
}

.footer-col ul li {
    margin-bottom: 10px;
}

.footer-col ul li a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 13px;
    transition: var(--transition);
    display: inline-block;
}

.footer-col ul li a:hover, .footer-col ul li a:active {
    color: var(--primary);
    transform: translateX(4px);
}

.footer-contact li {
    color: rgba(255, 255, 255, 0.7);
    font-size: 13px;
    display: flex;
    gap: 8px;
    align-items: flex-start;
    margin-bottom: 10px;
    line-height: 1.6;
}

.footer-contact i {
    color: var(--primary);
    margin-top: 4px;
    flex-shrink: 0;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 20px 0;
    text-align: center;
    color: rgba(255, 255, 255, 0.5);
    font-size: 11px;
    line-height: 1.6;
}

.footer-copyright { margin-bottom: 8px; }

.footer-credit {
    display: inline-flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 8px 16px;
    background: rgba(255, 107, 0, 0.08);
    border: 1px solid rgba(255, 107, 0, 0.25);
    border-radius: 50px;
    color: rgba(255, 255, 255, 0.7);
    font-size: 12px;
    margin-top: 4px;
}

.footer-credit i.fa-code { color: var(--primary); }

.credit-name {
    color: var(--primary);
    font-weight: 700;
    transition: var(--transition);
}

.credit-name:hover { color: var(--primary-light); }

.credit-divider {
    color: rgba(255, 255, 255, 0.3);
    margin: 0 2px;
}

.credit-phone {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    color: rgba(255, 255, 255, 0.85);
    font-weight: 600;
    transition: var(--transition);
}

.credit-phone:hover { color: var(--primary); }
.credit-phone i { font-size: 10px; }

/* ============================================
   FLOATING BUTTONS (Mobile - prominent)
   ============================================ */
.floating-buttons {
    position: fixed;
    bottom: 16px;
    right: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    z-index: 999;
}

.float-btn {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 22px;
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
    position: relative;
}

.float-btn:active { transform: scale(0.95); }
.float-btn:hover { transform: scale(1.1); }

.float-call { background: var(--primary); }
.float-zalo { background: #0068FF; }
.float-messenger {
    background: linear-gradient(135deg, #00C6FF, #0078FF);
}

.float-pulse {
    position: absolute;
    inset: 0;
    border-radius: 50%;
    background: var(--primary);
    animation: pulse 1.5s infinite;
    z-index: -1;
}

/* ============================================
   BACK TO TOP (Mobile)
   ============================================ */
.back-to-top {
    position: fixed;
    bottom: 16px;
    left: 16px;
    width: 44px;
    height: 44px;
    background: var(--secondary);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 998;
    box-shadow: var(--shadow-lg);
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover, .back-to-top:active {
    background: var(--primary);
    transform: translateY(-3px);
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeInDown {
    from { opacity: 0; transform: translateY(-30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-10px); }
    60% { transform: translateY(-5px); }
}

@keyframes pulse {
    0% { transform: scale(1); opacity: 1; }
    100% { transform: scale(1.5); opacity: 0; }
}

/* ============================================
   📱 BREAKPOINT: Small phones+ (≥ 576px)
   ============================================ */
@media (min-width: 576px) {
    .container { padding: 0 24px; max-width: 540px; }

    body { font-size: 16px; }

    section { padding: 70px 0; }

    .hero { padding: 110px 24px 70px; }
    .hero-description { font-size: 15px; }

    .hero-buttons {
        flex-direction: row;
        justify-content: center;
        gap: 16px;
    }

    .btn { width: auto; max-width: none; }

    .hero-features {
        flex-direction: row;
        flex-wrap: wrap;
        justify-content: center;
        gap: 16px 24px;
    }

    .services-grid, .why-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .service-card, .why-card { padding: 32px 24px; }
    .service-card h3 { font-size: 24px; }
    .service-card p, .why-card p { font-size: 14px; }

    .gallery-grid { column-gap: 12px; }
    .gallery-item { margin-bottom: 12px; }

    .lightbox-close { width: 48px; height: 48px; font-size: 20px; top: 20px; right: 20px; }
    .lightbox-prev, .lightbox-next { width: 52px; height: 52px; font-size: 20px; }
    .lightbox-prev { left: 16px; }
    .lightbox-next { right: 16px; }

    .floating-buttons { bottom: 24px; right: 24px; gap: 14px; }
    .float-btn { width: 56px; height: 56px; font-size: 24px; }
    .back-to-top { bottom: 24px; left: 24px; width: 48px; height: 48px; }
}

/* ============================================
   📱 BREAKPOINT: Tablets (≥ 768px)
   ============================================ */
@media (min-width: 768px) {
    .container { max-width: 720px; padding: 0 32px; }

    section { padding: 90px 0; }

    .section-header { margin-bottom: 56px; }

    /* Hero scales up */
    .hero { padding: 120px 32px 80px; }
    .hero-description { font-size: 16px; max-width: 600px; }

    /* About: 2-column layout */
    .about-content {
        grid-template-columns: 1fr 1fr;
        display: grid;
        gap: 48px;
        align-items: center;
    }

    .about-text { order: 1; }
    .about-image { order: 2; }

    .about-intro { font-size: 17px; }

    .about-image-wrapper {
        padding: 60px 30px;
        min-height: 320px;
    }

    .about-icon { font-size: 140px; }

    /* Services & Why grids */
    .services-grid, .why-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }

    /* Gallery: 3 columns on tablet (masonry) */
    .gallery-grid {
        column-count: 3;
        column-gap: 14px;
    }
    .gallery-item { margin-bottom: 14px; }

    /* CTA banner: horizontal */
    .cta-content {
        flex-direction: row;
        justify-content: space-between;
        text-align: left;
        gap: 32px;
    }

    /* Contact: 2-column */
    .contact-grid {
        grid-template-columns: 1fr 1fr;
        gap: 32px;
    }

    .contact-map { min-height: 100%; height: auto; }

    /* Footer 2x2 grid */
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 40px;
    }
}

/* ============================================
   💻 BREAKPOINT: Small desktops (≥ 992px)
   ============================================ */
@media (min-width: 992px) {
    .container { max-width: 960px; }

    /* Show desktop nav menu */
    .nav-menu {
        position: static;
        width: auto;
        max-width: none;
        height: auto;
        background: transparent;
        flex-direction: row;
        gap: 32px;
        box-shadow: none;
        right: auto;
    }

    .nav-link {
        font-size: 14px;
        padding: 6px 0;
    }

    .nav-link::after {
        content: '';
        position: absolute;
        bottom: -4px;
        left: 0;
        width: 0;
        height: 2px;
        background: var(--primary);
        transition: var(--transition);
    }

    .nav-link:hover::after, .nav-link.active::after { width: 100%; }

    .nav-cta {
        display: inline-flex;
        align-items: center;
        gap: 8px;
        background: var(--primary);
        color: var(--white);
        padding: 10px 20px;
        border-radius: 50px;
        font-weight: 700;
        font-size: 14px;
        transition: var(--transition);
        box-shadow: var(--shadow-orange);
    }

    .nav-cta:hover {
        background: var(--primary-dark);
        transform: translateY(-2px);
    }

    .hamburger { display: none; }

    .logo { font-size: 26px; }
    .logo i { font-size: 28px; }

    section { padding: 100px 0; }

    /* 3-column grids */
    .services-grid, .why-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 28px;
    }

    /* Gallery: 4 columns on desktop (masonry) */
    .gallery-grid {
        column-count: 4;
        column-gap: 16px;
    }
    .gallery-item { margin-bottom: 16px; }

    .lightbox-prev, .lightbox-next { width: 56px; height: 56px; font-size: 22px; }
    .lightbox-prev { left: 32px; }
    .lightbox-next { right: 32px; }
    .lightbox-close { top: 32px; right: 32px; }

    .service-card { padding: 40px 28px; }
    .service-icon { width: 80px; height: 80px; font-size: 32px; }

    /* Footer 4-column */
    .footer-grid {
        grid-template-columns: 2fr 1fr 1fr 1.5fr;
        gap: 40px;
    }

    /* Larger floating call */
    .float-btn { width: 60px; height: 60px; font-size: 26px; }
}

/* ============================================
   🖥️  BREAKPOINT: Large desktops (≥ 1200px)
   ============================================ */
@media (min-width: 1200px) {
    .container { max-width: 1200px; }

    body { font-size: 17px; }

    .hero { padding: 140px 40px 100px; }

    .section-title { letter-spacing: -0.02em; }

    .hero-features { gap: 20px 40px; }
    .hero-feature { font-size: 15px; }

    .about-image-wrapper { min-height: 400px; padding: 80px 40px; }
    .about-icon { font-size: 180px; }

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

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

/* ============================================
   🖥️  BREAKPOINT: XL (≥ 1400px)
   ============================================ */
@media (min-width: 1400px) {
    .container { max-width: 1320px; }
}

/* ============================================
   ACCESSIBILITY & PRINT
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

@media print {
    .floating-buttons, .back-to-top, #header, .hero-scroll { display: none; }
    body { color: #000; background: #fff; }
}