@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Playfair+Display:ital,wght@0,600;0,700;1,600&display=swap');

/* =========================================================================
   GEN VIỆT NAM - PREMIUM MEDICAL UI/UX STYLESHEET (PRO MAX EDITION)
   Year: 2026
   Framework: Vanilla CSS3 (Custom Design System)
   Theme: High-End Genetics & Healthcare
========================================================================= */

:root {
    /* 1. Brand Color Palette (Premium Medical Theme) */
    --clr-primary-900: #004D40;
    /* Deep Medical Green - Trust & Authority */
    --clr-primary-700: #00695C;
    --clr-primary-500: #00897B;
    --clr-primary-400: #26A69A;
    --clr-primary-100: #B2DFDB;
    --clr-primary-50: #E0F2F1;

    --clr-accent-gradient: linear-gradient(135deg, #00897B 0%, #004D40 100%);
    --clr-accent-gold: linear-gradient(135deg, #BF953F, #FCF6BA, #B38728, #FBF5B7, #AA771C);
    --clr-accent-glow: 0 0 20px rgba(0, 137, 123, 0.4);

    /* 2. Neutral Palette (Clean & Minimalist) */
    --clr-neutral-900: #0F172A;
    /* Slate 900 */
    --clr-neutral-800: #1E293B;
    /* Slate 800 */
    --clr-neutral-700: #334155;
    /* Text Body */
    --clr-neutral-500: #64748B;
    /* Text Sub */
    --clr-neutral-300: #CBD5E1;
    /* Borders */
    --clr-neutral-100: #F1F5F9;
    /* Light Backgrounds */
    --clr-neutral-50: #F8FAFC;
    /* Ultra Light Bg */
    --clr-white: #FFFFFF;
    --clr-black: #000000;

    /* 3. Typography System */
    --ff-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --ff-serif: 'Playfair Display', serif;

    --fs-xs: 0.75rem;
    /* 12px */
    --fs-sm: 0.875rem;
    /* 14px */
    --fs-base: 1.0625rem;
    /* 17px - Premium readability */
    --fs-lg: 1.25rem;
    /* 20px */
    --fs-xl: 1.5rem;
    /* 24px */
    --fs-2xl: 2rem;
    /* 32px */
    --fs-3xl: 2.5rem;
    /* 40px */
    --fs-4xl: 3.5rem;
    /* 56px */
    --fs-5xl: 4.5rem;
    /* 72px */

    /* 4. Spacing System */
    --sp-1: 0.25rem;
    /* 4px */
    --sp-2: 0.5rem;
    /* 8px */
    --sp-3: 0.75rem;
    /* 12px */
    --sp-4: 1rem;
    /* 16px */
    --sp-6: 1.5rem;
    /* 24px */
    --sp-8: 2rem;
    /* 32px */
    --sp-12: 3rem;
    /* 48px */
    --sp-16: 4rem;
    /* 64px */
    --sp-24: 6rem;
    /* 96px */
    --sp-32: 8rem;
    /* 128px */

    /* 5. Border Radius */
    --rad-sm: 0.375rem;
    /* 6px */
    --rad-md: 0.75rem;
    /* 12px */
    --rad-lg: 1.5rem;
    /* 24px */
    --rad-xl: 2.5rem;
    /* 40px */
    --rad-full: 9999px;

    /* 6. Shadows (Elevation) */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.025);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.05), 0 10px 10px -5px rgba(0, 0, 0, 0.02);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.08);

    /* 7. Glassmorphism */
    --glass-bg: rgba(255, 255, 255, 0.85);
    --glass-border: rgba(255, 255, 255, 0.5);
    --glass-blur: blur(16px);

    /* 8. Layout Variables */
    --container-max: 1280px;
    --container-padding: var(--sp-6);
    --header-height: 90px;

    /* 9. Transitions */
    --trans-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --trans-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --trans-slow: 0.6s cubic-bezier(0.22, 1, 0.36, 1);
}

/* =========================================================================
   RESET & BASE STYLES
========================================================================= */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    /* Pro Max UX: Smooth anchor scrolling */
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--ff-sans);
    color: var(--clr-neutral-700);
    background-color: var(--clr-white);
    line-height: 1.7;
    overflow-x: hidden;
    padding-top: var(--header-height);
    /* Nav overlap compensation */
}

h1,
h2,
h3,
h4,
h5,
h6 {
    color: var(--clr-neutral-900);
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

p {
    margin-bottom: var(--sp-4);
}

a {
    color: var(--clr-primary-500);
    text-decoration: none;
    transition: color var(--trans-fast);
}

a:hover {
    color: var(--clr-primary-700);
}

img,
picture,
video,
canvas,
svg {
    display: block;
    max-width: 100%;
    height: auto;
}

button,
input,
textarea,
select {
    font: inherit;
    outline: none;
    border: none;
}

ul,
ol {
    list-style: none;
}

/* =========================================================================
   UTILITY CLASSES (Pro Max Layout System)
========================================================================= */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding-left: var(--container-padding);
    padding-right: var(--container-padding);
}

.section-padding {
    padding-top: var(--sp-24);
    padding-bottom: var(--sp-24);
}

@media (max-width: 768px) {
    .section-padding {
        padding-top: var(--sp-16);
        padding-bottom: var(--sp-16);
    }
}

.text-center {
    text-align: center;
}

.text-gradient {
    background: var(--clr-accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Base Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--sp-3) var(--sp-8);
    border-radius: var(--rad-full);
    font-weight: 600;
    font-size: var(--fs-base);
    cursor: pointer;
    transition: all var(--trans-normal);
    text-align: center;
    border: 2px solid transparent;
}

.btn-primary {
    background: var(--clr-accent-gradient);
    color: var(--clr-white);
    box-shadow: 0 4px 15px rgba(0, 137, 123, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 137, 123, 0.4);
    color: var(--clr-white);
}

/* =========================================================================
   HEADER & NAVIGATION (Glassmorphism & Fixed Single Line)
========================================================================= */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--glass-border);
    z-index: 1000;
    /* UX Rule: Z-Index Management */
    display: flex;
    align-items: center;
    transition: all var(--trans-normal);
    box-shadow: var(--shadow-sm);
}

.header.scrolled {
    height: 70px;
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-md);
}

.nav-container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-padding);
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

/* Logo */
.logo-box {
    display: flex;
    align-items: center;
    z-index: 1001;
}

.logo-img {
    height: 50px;
    /* Fixed height to prevent CLS */
    width: auto;
    object-fit: contain;
    transition: transform var(--trans-normal);
}

.header.scrolled .logo-img {
    height: 40px;
}

.logo-img:hover {
    transform: scale(1.05);
}

/* Main Navigation (Single Line Desktop) */
.main-menu {
    height: 100%;
}

.main-menu ul {
    display: flex;
    align-items: center;
    gap: var(--sp-6);
    height: 100%;
    margin: 0;
    padding: 0;
}

.main-menu>ul>li {
    height: 100%;
    display: flex;
    align-items: center;
    position: relative;
}

.main-menu a {
    color: var(--clr-neutral-800);
    font-weight: 600;
    font-size: 0.95rem;
    /* Slightly smaller to fit single line */
    padding: var(--sp-2) 0;
    position: relative;
    letter-spacing: 0.01em;
    white-space: nowrap;
    /* Force single line */
}

/* Active/Hover Indicator Effect */
.main-menu>ul>li>a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background: var(--clr-accent-gradient);
    border-radius: var(--rad-full);
    transition: width var(--trans-normal);
}

.main-menu>ul>li:hover>a,
.main-menu>ul>li>a.active {
    color: var(--clr-primary-700);
}

.main-menu>ul>li:hover>a::after,
.main-menu>ul>li>a.active::after {
    width: 100%;
}

/* Dropdown Submenu */
.has-submenu {
    position: relative;
}

.has-submenu>a {
    padding-right: 18px;
}

.has-submenu>a::before {
    content: '';
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
    border: solid var(--clr-neutral-500);
    border-width: 0 2px 2px 0;
    display: inline-block;
    padding: 3px;
    transform: translateY(-50%) rotate(45deg);
    transition: transform var(--trans-normal);
}

.has-submenu:hover>a::before {
    transform: translateY(-50%) rotate(-135deg);
    border-color: var(--clr-primary-500);
}

.submenu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(10px);
    background: var(--clr-white);
    min-width: 260px;
    border-radius: var(--rad-md);
    box-shadow: var(--shadow-xl);
    opacity: 0;
    visibility: hidden;
    transition: all var(--trans-normal);
    padding: var(--sp-3) 0;
    flex-direction: column !important;
    /* Override flex-row from parent */
    gap: 0 !important;
    border: 1px solid var(--clr-neutral-100);
}

.has-submenu:hover .submenu {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

.submenu li {
    width: 100%;
    height: auto !important;
}

.submenu a {
    display: block;
    padding: var(--sp-3) var(--sp-6) !important;
    color: var(--clr-neutral-700) !important;
    font-size: var(--fs-sm) !important;
    font-weight: 500 !important;
    white-space: normal !important;
}

.submenu a::after {
    display: none;
}

.submenu a:hover {
    background-color: var(--clr-primary-50);
    color: var(--clr-primary-700) !important;
    padding-left: calc(var(--sp-6) + 5px) !important;
    /* Indent effect */
}

/* Mobile Nav Toggle (Hidden on Desktop) */
.mobile-nav-toggle {
    display: none;
}/* =========================================================================
   HERO SECTION (High-End Landing)
========================================================================= */
.hero-section {
    position: relative;
    padding: var(--sp-12) var(--sp-6);
    min-height: 85vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: radial-gradient(circle at 50% 120%, var(--clr-primary-50), var(--clr-white) 70%);
    overflow: hidden;
}

/* Background Animated Gradient Overlay */
.hero-section::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at center, rgba(38, 166, 154, 0.05) 0%, transparent 50%),
                radial-gradient(circle at 80% 20%, rgba(0, 77, 64, 0.04) 0%, transparent 40%);
    animation: rotateSlow 30s linear infinite;
    z-index: 0;
    pointer-events: none;
}

@keyframes rotateSlow {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 900px;
    margin: 0 auto;
    width: 100%;
}

.hero-title {
    font-family: var(--ff-serif);
    font-size: clamp(2.5rem, 5vw + 1rem, 4.5rem);
    color: var(--clr-primary-900);
    margin-bottom: var(--sp-6);
    line-height: 1.1;
    letter-spacing: -0.02em;
    animation: fadeUp 1s ease-out forwards;
}

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

.hero-partner-notice {
    font-size: var(--fs-base);
    color: var(--clr-neutral-500);
    max-width: 700px;
    margin: 0 auto var(--sp-8);
    background: rgba(255, 255, 255, 0.7);
    padding: var(--sp-4) var(--sp-6);
    border-radius: var(--rad-lg);
    border: 1px solid var(--clr-neutral-100);
    backdrop-filter: blur(8px);
    box-shadow: var(--shadow-sm);
    animation: fadeUp 1s ease-out 0.2s forwards;
    opacity: 0;
}

/* Glassmorphism Contact Form */
.hero-form-wrapper {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--glass-border);
    border-radius: var(--rad-xl);
    padding: var(--sp-8);
    box-shadow: var(--shadow-xl), 0 0 40px rgba(0, 137, 123, 0.05);
    max-width: 600px;
    margin: 0 auto;
    position: relative;
    animation: fadeUp 1s ease-out 0.4s forwards;
    opacity: 0;
}

/* Subtle glow behind form */
.hero-form-wrapper::before {
    content: '';
    position: absolute;
    inset: -2px;
    background: linear-gradient(135deg, rgba(38, 166, 154, 0.3), rgba(0, 77, 64, 0.1));
    border-radius: inherit;
    z-index: -1;
    filter: blur(10px);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--sp-4);
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: var(--sp-4);
    border: 2px solid var(--clr-neutral-100);
    border-radius: var(--rad-md);
    background: rgba(255, 255, 255, 0.9);
    color: var(--clr-neutral-800);
    font-size: var(--fs-base);
    transition: all var(--trans-normal);
}

.contact-form input:focus,
.contact-form textarea:focus {
    border-color: var(--clr-primary-400);
    background: var(--clr-white);
    box-shadow: 0 0 0 4px rgba(38, 166, 154, 0.1);
}

.contact-form textarea {
    resize: vertical;
    min-height: 120px;
}

.submit-btn {
    background: var(--clr-accent-gradient);
    color: var(--clr-white);
    padding: var(--sp-4);
    border-radius: var(--rad-full);
    font-weight: 700;
    font-size: var(--fs-lg);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    cursor: pointer;
    border: none;
    box-shadow: 0 10px 20px rgba(0, 137, 123, 0.2);
    transition: all var(--trans-normal);
    position: relative;
    overflow: hidden;
}

.submit-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 30px rgba(0, 137, 123, 0.3);
}

.submit-btn:active {
    transform: translateY(0);
}

/* Animated shine effect on button */
.submit-btn::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(to right, transparent, rgba(255,255,255,0.3), transparent);
    transform: skewX(-20deg);
    animation: shine 4s infinite;
}

@keyframes shine {
    0% { left: -100%; }
    20% { left: 200%; }
    100% { left: 200%; }
}

/* =========================================================================
   CONTENT SECTIONS (Grid Layouts & Micro-interactions)
========================================================================= */
.intro-section,
.feature-section {
    position: relative;
    background: var(--clr-white);
}

.alternate-bg {
    background: var(--clr-neutral-50);
    border-top: 1px solid var(--clr-neutral-100);
    border-bottom: 1px solid var(--clr-neutral-100);
}

.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto var(--sp-16);
}

.section-title {
    font-family: var(--ff-serif);
    font-size: clamp(2rem, 3vw + 1rem, 3rem);
    color: var(--clr-primary-900);
    margin-bottom: var(--sp-4);
    position: relative;
    display: inline-block;
}

/* Subtle decorative line under titles */
.section-title::after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--clr-accent-gradient);
    border-radius: var(--rad-full);
}

.content-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--sp-12);
    align-items: center;
    max-width: 1000px;
    margin: 0 auto;
}

/* We added image earlier, now styles for it */
.image-wrapper {
    position: relative;
    border-radius: var(--rad-lg);
    overflow: hidden;
    /* Fancy glowing border effect using pseudo-element */
}

.image-wrapper::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    padding: 2px;
    background: linear-gradient(135deg, var(--clr-primary-100), var(--clr-primary-400), transparent);
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    pointer-events: none;
    z-index: 2;
}

.image-wrapper img {
    transition: transform 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    will-change: transform;
}

.image-wrapper:hover img {
    transform: scale(1.03);
}

.text-content {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--clr-neutral-700);
}

.text-content p {
    text-align: justify;
    hyphens: auto;
}

.text-content strong {
    color: var(--clr-primary-700);
    font-weight: 700;
}

/* Dynamic Grid on Desktop */
@media (min-width: 900px) {
    .content-grid {
        grid-template-columns: 1fr 1fr; /* Image and Text side by side */
        gap: var(--sp-16);
    }
    
    .content-grid.reversed .image-wrapper {
        order: 2; /* Reverse visual order for alternating layout */
    }
    
    .content-grid.reversed .text-content {
        order: 1;
    }
    
    .text-content p {
        font-size: 1.15rem; /* Slightly larger on desktop for premium feel */
    }
}

/* =========================================================================
   PARTNER SECTION (Glassmorphism Cards System)
========================================================================= */
.partner-section {
    background: radial-gradient(circle at top right, rgba(38, 166, 154, 0.08), transparent 50%),
                radial-gradient(circle at bottom left, rgba(0, 77, 64, 0.05), transparent 50%);
    background-color: var(--clr-white);
    position: relative;
    overflow: hidden;
}

.partner-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--sp-8);
}

.partner-card {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border: 1px solid var(--clr-neutral-100);
    border-radius: var(--rad-xl);
    padding: var(--sp-6);
    box-shadow: var(--shadow-md);
    transition: all var(--trans-normal);
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: column;
}

.partner-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-2xl), 0 10px 30px rgba(0, 137, 123, 0.1);
    border-color: var(--clr-primary-100);
}

/* Gradient accent bar top of card */
.partner-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--clr-accent-gradient);
    border-radius: var(--rad-xl) var(--rad-xl) 0 0;
    opacity: 0;
    transition: opacity var(--trans-normal);
}

.partner-card:hover::before {
    opacity: 1;
}

.partner-card img {
    width: 100%;
    height: 220px;
    object-fit: cover;
    border-radius: var(--rad-lg);
    margin-bottom: var(--sp-6);
    box-shadow: var(--shadow-sm);
    transition: transform var(--trans-normal);
}

.partner-card:hover img {
    transform: scale(1.02);
}

.partner-card .description {
    font-size: 0.95rem;
    color: var(--clr-neutral-700);
    line-height: 1.7;
    margin: 0; /* Remove bottom margin inside card */
    text-align: justify;
    flex-grow: 1; /* Stretch to fill card if content varies */
}

/* SEO Dofollow Links Styling (Premium Indicator) */
.seo-dofollow {
    color: var(--clr-primary-700);
    font-weight: 700;
    position: relative;
    white-space: nowrap;
    display: inline-block;
    padding: 0 4px;
    z-index: 1;
    background: rgba(38, 166, 154, 0.1);
    border-radius: 4px;
    transition: all var(--trans-fast);
}

.seo-dofollow:hover {
    color: var(--clr-white);
    background: var(--clr-primary-500);
    transform: translateY(-1px);
    box-shadow: 0 4px 10px rgba(0, 137, 123, 0.2);
}

/* External Link Icon */
.seo-dofollow::after {
    content: '';
    font-family: system-ui; /* Fallback for safe rendering */
    font-size: 0.8em;
    margin-left: 2px;
    display: inline-block;
    transition: transform 0.2s;
}

.seo-dofollow:hover::after {
    transform: translate(2px, -2px);
}
/* =========================================================================
   FOOTER (Dark Mode Variant for Authority)
========================================================================= */
.footer {
    background: var(--clr-neutral-900);
    color: var(--clr-neutral-300);
    padding-top: var(--sp-24);
    font-size: 0.95rem;
    position: relative;
    border-top: 5px solid var(--clr-primary-700);
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 10% 20%, rgba(38, 166, 154, 0.05) 0%, transparent 40%),
                radial-gradient(circle at 90% 80%, rgba(0, 137, 123, 0.08) 0%, transparent 40%);
    pointer-events: none;
}

.footer-top {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--sp-12);
    margin-bottom: var(--sp-16);
    position: relative;
    z-index: 1;
}

@media (min-width: 768px) {
    .footer-top {
        grid-template-columns: 2fr 1fr 1fl; /* Ratio split */
    }
}

@media (min-width: 1024px) {
    .footer-top {
        grid-template-columns: 2fr 1fr 1.5fr;
    }
}

.footer-col h4 {
    color: var(--clr-white);
    font-size: var(--fs-lg);
    margin-bottom: var(--sp-6);
    position: relative;
    display: inline-block;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 40px;
    height: 3px;
    background: var(--clr-accent-gradient);
    border-radius: var(--rad-full);
}

.brand-col .footer-logo {
    height: 60px;
    margin-bottom: var(--sp-6);
    filter: brightness(0) invert(1) drop-shadow(0 2px 4px rgba(0,0,0,0.5));
}

.brand-col p {
    line-height: 1.8;
    max-width: 400px;
    margin-bottom: 0;
}

.links-col ul {
    display: flex;
    flex-direction: column;
    gap: var(--sp-3);
}

.links-col a {
    color: var(--clr-neutral-300);
    display: inline-block;
}

.links-col a:hover {
    color: var(--clr-primary-400);
    transform: translateX(5px);
}

.contact-col p {
    margin-bottom: var(--sp-2);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: var(--sp-8) 0;
    text-align: justify;
    font-size: 0.85rem;
    line-height: 1.8;
    color: var(--clr-neutral-500);
    position: relative;
    z-index: 1;
}

/* Tool.vn Backlinks inside dark footer */
.footer-bottom .seo-dofollow {
    color: var(--clr-primary-400);
    background: transparent;
    padding: 0;
    border-bottom: 1px dashed var(--clr-primary-500);
    border-radius: 0;
}

.footer-bottom .seo-dofollow:hover {
    color: var(--clr-white);
    text-shadow: 0 0 10px rgba(38, 166, 154, 0.5);
    border-bottom-style: solid;
    transform: none;
    box-shadow: none;
    background: transparent;
}


/* =========================================================================
   ANIMATIONS & MICRO-INTERACTIONS
========================================================================= */

/* Reveal on Scroll (Optional JS integration) */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.5, 0, 0, 1);
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Image lazy load smooth blur */
img[loading] {
    transition: filter 0.5s ease;
}

img.lazyloaded {
    filter: blur(0);
}


/* =========================================================================
   MEDIA QUERIES (Mobile Responsiveness) Pro Max Standard
========================================================================= */

@media (max-width: 1024px) {
    /* Tablet & Small Desktop adjustments */
    :root {
        --fs-4xl: 2.8rem;
        --fs-3xl: 2.2rem;
        --sp-16: 3rem;
        --sp-24: 4.5rem;
    }
    
    .main-menu a {
        font-size: 0.85rem;
    }
}

@media (max-width: 900px) {
    .content-grid {
        gap: var(--sp-8);
    }
    
    .image-wrapper {
        margin-bottom: var(--sp-6);
        max-width: 100%;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
}

@media (max-width: 768px) {
    /* Mobile specific overrides */
    :root {
        --header-height: 70px;
        --fs-xl: 1.25rem;
        --fs-4xl: 2.2rem;
    }
    
    /* Mobile Navigation Hamburger (Simplified structure for this task) */
    .mobile-nav-toggle {
        display: block;
        background: none;
        padding: var(--sp-2);
        cursor: pointer;
    }
    
    .main-menu {
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100%;
        background: var(--glass-bg);
        backdrop-filter: var(--glass-blur);
        -webkit-backdrop-filter: var(--glass-blur);
        border-bottom: 1px solid var(--glass-border);
        box-shadow: var(--shadow-xl);
        padding: var(--sp-4) 0;
        transform: translateY(-150%);
        opacity: 0;
        transition: all var(--trans-normal);
        max-height: calc(100vh - var(--header-height));
        overflow-y: auto;
    }
    
    .main-menu.is-open {
        transform: translateY(0);
        opacity: 1;
    }
    
    .main-menu ul {
        flex-direction: column;
        align-items: flex-start;
        padding: 0 var(--container-padding);
        gap: 0;
    }
    
    .main-menu > ul > li {
        width: 100%;
        border-bottom: 1px solid var(--clr-neutral-100);
    }
    
    .main-menu > ul > li:last-child {
        border-bottom: none;
    }
    
    .main-menu a {
        display: block;
        width: 100%;
        padding: var(--sp-4) 0;
        font-size: var(--fs-base);
    }
    
    .main-menu > ul > li > a::after {
        display: none; /* Disable line hover on mobile */
    }
    
    .has-submenu > a::before {
        right: 0;
        top: 50%;
        transform: translateY(-50%) rotate(45deg);
    }
    
    .submenu {
        position: static;
        box-shadow: none;
        opacity: 1;
        visibility: visible;
        transform: none;
        border: none;
        background: var(--clr-primary-50);
        margin: 0;
        padding: 0;
        display: none; /* Hide default on mobile until clicked/tapped (requires JS) */
    }
    
    .has-submenu.is-expanded .submenu {
        display: block;
    }
    
    .submenu a {
        padding: var(--sp-3) var(--sp-6) !important;
        border-bottom: 1px solid rgba(0,0,0,0.05);
    }
    
    /* Hero Adjustments */
    .hero-section {
        padding-top: var(--sp-12);
        padding-bottom: var(--sp-12);
        min-height: auto;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-form-wrapper {
        padding: var(--sp-6);
        margin: 0 var(--sp-4);
    }
    
    /* Partner Cards */
    .partner-grid {
        grid-template-columns: 1fr;
    }
    
    /* Footer */
    .footer-top {
        grid-template-columns: 1fr;
        gap: var(--sp-8);
    }
}

/* =========================================================================
   ACCESSIBILITY (A11Y)
========================================================================= */
@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;
    }
}

/* Custom Scrollbar for premium feel */
::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: var(--clr-neutral-50);
}

::-webkit-scrollbar-thumb {
    background: var(--clr-primary-400);
    border-radius: 10px;
    border: 2px solid var(--clr-neutral-50);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--clr-primary-700);
}

/* Final Polish: Custom text selection */
::selection {
    background: var(--clr-primary-100);
    color: var(--clr-primary-900);
}