/* 
  VIETBAR ACADEMY v6.0 - Modern Vocational Style
  Philosophy: Trusted, Dynamic, Practical, Vocational Startup.
*/

@import url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;600;700;800;900&family=Inter:wght@300;400;500;600&display=swap');

:root {
    /* Primary Colors - Light Neon Concept */
    --primary: #2b3991;
    --primary-glow: rgba(43, 57, 145, 0.4);
    --accent: #ff9b09;
    --accent-glow: rgba(255, 155, 9, 0.5);
    
    /* Light Neon Palette */
    --bg-main: #fcfdfe;        /* Glacial White */
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.4);
    
    /* Semantic Colors */
    --text-dark: #121926;
    --text-muted: #4b5563;
    --white: #ffffff;
    
    /* Animation & Shadows */
    --shadow-soft: 0 10px 40px -10px rgba(0, 0, 0, 0.08);
    --neon-blue: 0 0 20px var(--primary-glow);
    --neon-orange: 0 0 20px var(--accent-glow);
    --transition: all 0.5s cubic-bezier(0.23, 1, 0.32, 1);
}

@keyframes float {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(5deg); }
}

@keyframes glow-pulse {
    0%, 100% { opacity: 0.5; filter: blur(50px); }
    50% { opacity: 0.8; filter: blur(70px); }
}

@keyframes logo-drift {
    from { transform: translate(0, 0); }
    to { transform: translate(30px, 30px); }
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-dark);
    background-color: var(--white);
    line-height: 1.6;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    line-height: 1.2;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Logo Watermark Background */
.bg-logo-watermark {
    position: absolute;
    top: -10%;
    left: -5%;
    width: 600px;
    height: 600px;
    background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" fill="%232b3991"><path d="M400 0H112C94.3 0 80 14.3 80 32v16c0 17.7 14.3 32 32 32h288c17.7 0 32-14.3 32-32V32c0-17.7-14.3-32-32-32zm32 128H80c-26.5 0-48 21.5-48 48s21.5 48 48 48h3c.1 127.2 28.5 242.4 81.3 288H349.7c52.8-45.6 81.2-160.8 81.3-288h3c26.5 0 48-21.5 48-48s-21.5-48-48-48zm-114.7 320H194.7c-32.9-28.5-56-118-58.5-224h183.6c-2.5 106-25.6 195.5-58.5 224z"/></svg>');
    background-repeat: no-repeat;
    background-size: contain;
    opacity: 0.03;
    pointer-events: none;
    transform: rotate(-15deg);
    z-index: 0;
}

/* Sections */
section {
    position: relative;
    overflow: hidden;
    padding: 6rem 0;
}

.section-head {
    text-align: center;
    margin-bottom: 4rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.section-head h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--primary);
}

.section-head p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.8rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    font-family: 'Montserrat', sans-serif;
    gap: 0.5rem;
}

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

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(255, 155, 9, 0.3);
}

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

.btn-outline:hover {
    background-color: var(--primary);
    color: var(--white);
}

/* Decorative Blobs & Particles */
.neon-blobs {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    pointer-events: none;
    overflow: hidden;
}

.blob {
    position: absolute;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.15;
    animation: glow-pulse 10s infinite alternate;
}

.blob-1 {
    top: -100px;
    right: -100px;
    background: radial-gradient(circle, var(--accent), transparent 70%);
}

.blob-2 {
    bottom: -100px;
    left: -100px;
    background: radial-gradient(circle, var(--primary), transparent 70%);
    animation-delay: -5s;
}

/* Animations Utility */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 1s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.floating-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1; /* Đảm bảo nằm dưới nội dung */
    pointer-events: none;
}

.float-item {
    position: absolute;
    width: 40px;
    height: 40px;
    background-image: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" fill="%232b3991"><path d="M400 0H112C94.3 0 80 14.3 80 32v16c0 17.7 14.3 32 32 32h288c17.7 0 32-14.3 32-32V32c0-17.7-14.3-32-32-32zm32 128H80c-26.5 0-48 21.5-48 48s21.5 48 48 48h3c.1 127.2 28.5 242.4 81.3 288H349.7c52.8-45.6 81.2-160.8 81.3-288h3c26.5 0 48-21.5 48-48s-21.5-48-48-48z"/></svg>');
    background-size: contain;
    background-repeat: no-repeat;
    opacity: 0.1;
    animation: float 15s infinite ease-in-out;
}

.particle-1 { top: 15%; left: 10%; animation-delay: 0s; width: 60px; height: 60px; }
.particle-2 { top: 60%; right: 15%; animation-delay: -4s; width: 80px; height: 80px; }
.particle-3 { bottom: 20%; left: 20%; animation-delay: -8s; width: 50px; height: 50px; }

/* Glassmorphism Classes */
.glass {
    background: var(--glass-bg);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border-bottom: 1px solid var(--glass-border);
}

/* Navbar Upgrade */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 0.8rem 0;
    transition: var(--transition);
}

.navbar.scrolled {
    padding: 0.5rem 0;
    box-shadow: var(--neon-blue);
}

.nav-flex {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    font-weight: 900;
    font-size: 1.5rem;
    color: var(--primary);
    text-decoration: none;
}

.logo span {
    color: var(--accent);
    margin-left: 2px;
}

.nav-links {
    display: flex;
    gap: 2.5rem;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition);
}

.nav-links a:hover {
    color: var(--accent);
}

/* Hero Section Upgrade */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 10rem 0 6rem;
    background: radial-gradient(circle at 80% 20%, #ffe4e6, transparent 40%),
                radial-gradient(circle at 10% 80%, #fff7ed, transparent 40%),
                var(--bg-main);
    color: var(--text-dark);
    position: relative;
    overflow: hidden;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    align-items: center;
    gap: 4rem;
}

.hero-content h1 {
    font-size: 4.8rem;
    line-height: 1.1;
    margin-bottom: 2rem;
    font-weight: 800;
    color: var(--text-dark);
}

.hero-content h1 span {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    position: relative;
}

.hero-content p {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 550px;
    margin-bottom: 3rem;
    line-height: 1.6;
}

.hero-btns {
    display: flex;
    align-items: center;
    gap: 2rem;
    margin-bottom: 4rem;
}

.hero-store-icons {
    display: flex;
    gap: 1.2rem;
    font-size: 1.8rem;
    color: #cbd5e1;
}

/* Social Proof Styles */
.hero-social {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 1rem;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border-radius: 50px;
    width: fit-content;
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow-soft);
}

.student-avatars {
    display: flex;
    padding-left: 10px;
}

.avatar {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    border: 3px solid var(--white);
    background-size: cover;
    margin-left: -12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.social-text {
    font-size: 0.95rem;
}

.social-text strong {
    display: block;
    font-weight: 700;
}

.rating {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Visual Mockup Styles */
.hero-visual {
    position: relative;
}

.mockup-wrapper {
    position: relative;
    z-index: 2;
    transition: var(--transition);
}

.mockup-wrapper:hover {
    transform: translateY(-10px) scale(1.02);
}

.hero-signature-img {
    width: 100%;
    max-width: 550px;
    filter: drop-shadow(0 30px 60px rgba(0,0,0,0.15));
    border-radius: 32px;
    object-fit: cover;
}

.glow-orb {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 120%;
    height: 120%;
    background: radial-gradient(circle, var(--accent-glow), transparent 70%);
    z-index: -1;
    filter: blur(40px);
    opacity: 0.6;
}

/* Glassmorphism Mission Box */
.mission-box {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    padding: 3rem;
    border-radius: 24px;
    box-shadow: var(--shadow-soft);
    display: flex;
    align-items: center;
    gap: 3rem;
    transition: var(--transition);
}

.mission-box:hover {
    box-shadow: var(--neon-blue);
    transform: scale(1.02);
}

/* Service Cards Upgrade */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2.5rem;
}

.service-card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    padding: 3.5rem;
    border-radius: 24px;
    transition: var(--transition);
    text-align: center;
}

.service-card:hover {
    border-color: var(--accent);
    transform: translateY(-10px) scale(1.05);
    box-shadow: var(--neon-orange);
}

.service-card i {
    font-size: 3rem;
    color: var(--primary);
    margin-bottom: 2rem;
}

/* Why Us Grid */
.why-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.5rem;
}

/* Why Us Upgrade */
.why-item {
    display: flex;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--glass-bg);
    backdrop-filter: blur(5px);
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05);
    transition: var(--transition);
}

.why-item:hover {
    box-shadow: var(--neon-blue);
    transform: translateX(10px);
}

.why-item i {
    font-size: 1.5rem;
    color: var(--accent);
    flex-shrink: 0;
}

/* Course Cards */
.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.course-card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow-soft);
    transition: var(--transition);
}

.course-card:hover {
    box-shadow: var(--neon-orange);
    transform: translateY(-10px);
}

.course-img {
    height: 200px;
    background-size: cover;
    background-position: center;
}

.course-body {
    padding: 2rem;
}

.course-tag {
    font-size: 0.75rem;
    background: var(--bg-light);
    color: var(--primary);
    padding: 0.3rem 0.8rem;
    border-radius: 50px;
    font-weight: 700;
}

/* Gallery Grid */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.gallery-item {
    position: relative;
    height: 300px;
    border-radius: 12px;
    overflow: hidden;
    cursor: pointer;
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.gallery-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to top, rgba(43, 57, 145, 0.8), transparent);
    display: flex;
    align-items: flex-end;
    padding: 2rem;
    opacity: 0;
    transition: var(--transition);
}

.gallery-overlay span {
    color: var(--white);
    font-weight: 700;
    font-family: 'Montserrat', sans-serif;
    font-size: 1.2rem;
    transform: translateY(20px);
    transition: var(--transition);
}

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

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

.gallery-item:hover .gallery-overlay span {
    transform: translateY(0);
}

/* Footer */
/* Footer Upgrade to Light Neon */
.footer {
    background: var(--bg-main);
    color: var(--text-dark);
    border-top: 1px solid var(--glass-border);
    padding: 6rem 0 3rem;
    position: relative;
    z-index: 1;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 10% 90%, var(--primary-glow), transparent 30%);
    z-index: -1;
}

.footer .logo img {
    filter: none;
}

.footer a {
    color: var(--text-dark);
    transition: var(--transition);
    text-decoration: none;
}

.footer a:hover {
    color: var(--accent);
    text-shadow: 0 0 5px var(--accent-glow);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr;
    gap: 4rem;
}

/* Responsive UI Tweak */
@media (max-width: 900px) {
    .hero h1 { font-size: 3rem; }
    .mission-box { flex-direction: column; text-align: center; }
    .footer-grid { grid-template-columns: 1fr; gap: 3rem; }
}