:root {
    --primary: #2D74B9;
    --primary-light: #528fcb;
    --primary-dark: #1e5994;
    --accent: #f59e0b; /* Orange CTA */
    --accent-hover: #d97706;
    --danger: #ef4444; /* Thêm màu đỏ cho dấu X */
    --text-dark: #111827;
    --text-main: #374151;
    --text-muted: #6b7280;
    --bg-white: #ffffff;
    --bg-light: #f8fafc;
    --bg-gray: #e5e7eb;
    
    /* Flat Design Shadows & Corners */
    --shadow-flat: 0 4px 12px rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 10px 25px rgba(0, 0, 0, 0.1);
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
    overflow-x: hidden;
}

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

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

.text-center { text-align: center; }
.text-danger { color: var(--danger); }
.text-primary { color: var(--primary); }
.text-dark { color: var(--text-dark); }
.mt-4 { margin-top: 1.5rem; }
.mt-5 { margin-top: 3rem; }
.bg-light { background-color: var(--bg-light); }

/* Typography */
h1, h2, h3, h4, h5, h6 {
    color: var(--text-dark);
    font-weight: 700;
    line-height: 1.25;
}

.section-title {
    font-size: 36px;
    margin-bottom: 24px;
}

.section-desc {
    font-size: 18px;
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto 40px;
}

.text-gradient {
    background: linear-gradient(135deg, #ffffff, #a3d1ff);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

/* Scroll Animation Classes */
.scroll-anim {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}
.scroll-anim.is-visible {
    opacity: 1;
    transform: translateY(0);
}
.anim-delay-1 {
    transition-delay: 0.2s;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 16px;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    gap: 8px;
    color: white;
}

.btn-cta {
    background-color: var(--accent);
    box-shadow: 0 4px 14px rgba(245, 158, 11, 0.4);
}

.btn-cta:hover:not(:disabled) {
    background-color: var(--accent-hover);
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 25px rgba(245, 158, 11, 0.5);
}

.btn-large {
    padding: 18px 36px;
    font-size: 18px;
    border-radius: var(--radius-lg);
}

.btn-primary {
    background-color: var(--primary);
    box-shadow: 0 4px 14px rgba(45, 116, 185, 0.3);
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.3);
}
.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.25);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    filter: grayscale(100%);
    box-shadow: none;
    transform: none;
}

.btn-glow {
    animation: glow 2s infinite alternate;
}
@keyframes glow {
    from { box-shadow: 0 0 10px rgba(245, 158, 11, 0.5); }
    to { box-shadow: 0 0 20px rgba(245, 158, 11, 0.8), 0 0 30px rgba(245, 158, 11, 0.4); }
}

/* Header */
.header {
    position: fixed;
    top: 0; left: 0; width: 100%;
    z-index: 1000;
    padding: 20px 0;
    transition: var(--transition);
}

.header.scrolled {
    padding: 12px 0;
    background-color: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-flat);
}

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

.logo {
    font-size: 28px;
    font-weight: 800;
    color: white;
    letter-spacing: -0.5px;
    transition: var(--transition);
}

.header.scrolled .logo { color: var(--primary); }

.nav {
    display: flex;
    gap: 32px;
}

.nav-link {
    font-weight: 500;
    color: rgba(255, 255, 255, 0.9);
    transition: var(--transition);
}
.nav-link:hover { color: white; }

.header.scrolled .nav-link { color: var(--text-main); }
.header.scrolled .nav-link:hover { color: var(--primary); }

.mobile-menu-btn {
    display: none;
    background: none; border: none;
    font-size: 24px; color: white;
    cursor: pointer;
}
.header.scrolled .mobile-menu-btn { color: var(--text-dark); }

/* Hero */
.hero {
    position: relative;
    padding: 160px 0 120px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: white;
    overflow: hidden;
}
.hero-container {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-title {
    font-size: 52px;
    color: white;
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: 22px;
    margin-bottom: 40px;
    color: rgba(255, 255, 255, 0.95);
    max-width: 550px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.hero-img {
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-hover);
    position: relative;
    z-index: 2;
}
.hero-illustration {
    position: relative;
}

.glass-card {
    position: absolute;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-lg);
    padding: 16px 24px;
    z-index: 3;
    display: flex;
    align-items: center;
    gap: 12px;
    color: white;
    font-weight: 600;
}
.float-card {
    bottom: -20px;
    left: -30px;
    animation: float 5s ease-in-out infinite;
}
@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}

.curve-divider {
    position: absolute;
    bottom: -1px; left: 0; width: 100%;
    overflow: hidden; line-height: 0; z-index: 2;
}
.curve-divider svg {
    display: block; width: calc(100% + 1.3px); height: 60px;
}
.curve-divider .shape-fill { fill: var(--bg-light); }

/* Section Base */
.section {
    padding: 100px 0;
}

/* Pain Section */
.pain-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
    max-width: 700px;
    margin: 40px auto 0;
    text-align: left;
}
.pain-item {
    background: white;
    padding: 24px 32px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-flat);
    font-size: 18px;
    display: flex;
    align-items: center;
    gap: 16px;
    border-left: 4px solid var(--danger);
    transition: var(--transition);
}
.pain-item i { font-size: 24px; }
.pain-item:hover { transform: translateX(10px); }

.highlight-box {
    background: #fff3cd;
    border: 2px dashed #ffeeba;
    padding: 24px;
    border-radius: var(--radius-lg);
    display: inline-block;
}
.highlight-text {
    color: #856404;
    font-size: 22px;
    font-weight: 800;
    margin: 0;
}

/* Features (Giải pháp) */
.features-wrapper {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 60px;
    align-items: center;
}
.feature-checklist {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-top: 32px;
}
.feature-checklist li {
    font-size: 18px;
    display: flex;
    align-items: flex-start;
    gap: 16px;
    background: var(--bg-light);
    padding: 16px 24px;
    border-radius: var(--radius-lg);
}
.feature-checklist i {
    color: #10b981;
    font-size: 20px;
    margin-top: 4px;
}

.future-box {
    background: var(--primary);
    border-radius: var(--radius-xl);
    padding: 40px;
    color: white;
    position: relative;
    box-shadow: var(--shadow-hover);
}
.future-desc {
    font-size: 18px;
    margin-bottom: 30px;
    opacity: 0.9;
}
.future-badge {
    background: rgba(255,255,255,0.15);
    padding: 16px 20px;
    border-radius: var(--radius-md);
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
    font-size: 16px;
    border: 1px solid rgba(255,255,255,0.1);
}
.future-badge i { font-size: 22px; color: var(--accent); }

/* Benefits 5 Cards */
.benefits-grid-5 {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 20px;
    margin-top: 48px;
}
.flat-card {
    background: white;
    padding: 32px 20px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-flat);
    text-align: center;
    transition: var(--transition);
    border: 1px solid transparent;
}
.flat-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-hover);
    border-color: rgba(45, 116, 185, 0.2);
}
.flat-card .icon-wrap {
    width: 64px; height: 64px;
    background: rgba(45, 116, 185, 0.1);
    color: var(--primary);
    border-radius: var(--radius-lg);
    display: flex; align-items: center; justify-content: center;
    font-size: 28px;
    margin: 0 auto 20px;
    transition: var(--transition);
}
.flat-card:hover .icon-wrap {
    background: var(--primary);
    color: white;
}
.flat-card h4 {
    font-size: 18px;
    margin-bottom: 12px;
}
.flat-card p {
    font-size: 14px;
    color: var(--text-muted);
}

/* Commitment Box */
.commitment-box {
    background: linear-gradient(135deg, var(--bg-white), #f0f9ff);
    border: 2px solid var(--primary-light);
    border-radius: var(--radius-xl);
    padding: 40px;
    max-width: 800px;
    margin: 60px auto 0;
}
.commitment-icon {
    font-size: 48px;
    color: var(--primary);
    margin-bottom: 20px;
}
.commitment-text {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-dark);
    margin-top: 12px;
}

/* Registration Form */
.registration-section {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    padding: 80px 0;
    position: relative;
    overflow: hidden;
}
.registration-section::before {
    content: ''; position: absolute; top:0; left:0; width:100%; height:100%;
    background-image: radial-gradient(circle, rgba(255,255,255,0.1) 2px, transparent 2px);
    background-size: 30px 30px;
    opacity: 0.3;
}
.registration-form-wrapper {
    background: white;
    max-width: 600px;
    margin: 0 auto;
    padding: 48px;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-hover);
    position: relative;
    z-index: 2;
}
.form-header h2 { color: var(--primary); }
.scarcity-badge {
    display: inline-block;
    background: #fee2e2;
    color: #b91c1c;
    padding: 8px 16px;
    border-radius: 30px;
    font-weight: bold;
    margin-top: 12px;
    margin-bottom: 32px;
}
.form-group { margin-bottom: 24px; }
.form-group label {
    display: block; font-weight: 600; margin-bottom: 8px; color: var(--text-dark);
}
.form-group input {
    width: 100%; padding: 14px 16px;
    border: 1px solid var(--bg-gray);
    border-radius: var(--radius-md);
    font-size: 16px; font-family: inherit;
    transition: var(--transition);
    background: var(--bg-light);
}
.form-group input:focus {
    outline: none; border-color: var(--primary);
    background: white; box-shadow: 0 0 0 4px rgba(45, 116, 185, 0.1);
}
.btn-submit {
    width: 100%;
    padding: 16px;
    font-size: 18px;
    background-color: var(--accent);
    box-shadow: 0 4px 14px rgba(245, 158, 11, 0.4);
    position: relative;
}
.btn-submit:hover:not(:disabled) {
    background-color: var(--accent-hover);
}

/* Loading & Popup */
.loader {
    display: none; width: 24px; height: 24px;
    border: 3px solid rgba(255,255,255,0.3); border-top-color: white;
    border-radius: 50%; position: absolute;
    animation: spin 1s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.btn-submit.loading .btn-text { opacity: 0; }
.btn-submit.loading .loader { display: block; }

.popup-overlay {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.6); backdrop-filter: blur(5px);
    display: flex; align-items: center; justify-content: center;
    z-index: 2000; opacity: 0; visibility: hidden;
    transition: var(--transition);
}
.popup-overlay.active { opacity: 1; visibility: visible; }
.popup-content {
    background: white; width: 90%; max-width: 450px; padding: 40px;
    border-radius: var(--radius-xl); text-align: center;
    transform: translateY(20px) scale(0.95); transition: var(--transition);
}
.popup-overlay.active .popup-content { transform: translateY(0) scale(1); }
.popup-icon { font-size: 64px; color: #10b981; margin-bottom: 24px; }

/* Sticky Mobile CTA */
.sticky-bottom-cta {
    position: fixed; bottom: 0; left: 0; width: 100%;
    background: rgba(255, 255, 255, 0.95); backdrop-filter: blur(10px);
    padding: 16px 0; box-shadow: 0 -4px 15px rgba(0,0,0,0.1);
    z-index: 999;
    transform: translateY(100%); transition: transform 0.3s ease;
    display: none;
}
.sticky-bottom-cta.visible { transform: translateY(0); }

/* Footer */
.footer {
    background: #111827; color: rgba(255,255,255,0.7);
    padding: 60px 0 0;
}
.footer-container {
    display: grid; grid-template-columns: 2fr 1fr; gap: 40px;
    margin-bottom: 40px;
}
.footer-contact p { margin-bottom: 12px; display: flex; align-items: center; gap: 12px; }
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: 24px 0; text-align: center; font-size: 14px;
}

/* Social Proof Notification */
.registration-notification {
    position: fixed;
    bottom: 24px;
    left: 24px;
    background: white;
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    z-index: 1000;
    transform: translateX(-150%);
    opacity: 0;
    transition: transform 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275), opacity 0.5s ease;
    border-left: 4px solid #10b981;
    max-width: 380px;
}
.registration-notification.show {
    transform: translateX(0);
    opacity: 1;
}
.reg-notif-content {
    display: flex;
    align-items: center;
    gap: 12px;
}
.reg-notif-icon i {
    font-size: 20px;
    color: #10b981;
    margin-top: 0;
}
.reg-name {
    font-weight: 700;
    color: var(--text-dark);
    font-size: 14px;
    margin-bottom: 2px;
}
.reg-phone {
    font-size: 12px;
    color: var(--text-muted);
    margin-bottom: 2px;
}
.reg-action {
    font-size: 12px;
    color: var(--text-main);
    margin-bottom: 0;
}

/* Speaker Section */
.speaker-section {
    background-color: var(--bg-light);
}
.speaker-wrapper {
    display: flex;
    align-items: center;
    gap: 40px;
    background: white;
    border-radius: var(--radius-xl);
    padding: 40px;
    box-shadow: var(--shadow-flat);
    max-width: 900px;
    margin: 0 auto;
}
.speaker-image {
    flex: 0 0 280px;
}
.speaker-img {
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-hover);
    object-fit: cover;
}
.speaker-name {
    font-size: 32px;
    color: var(--primary);
    margin-bottom: 8px;
}
.speaker-title {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 20px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--bg-gray);
}
.speaker-creds {
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.speaker-creds li {
    font-size: 16px;
    display: flex;
    align-items: flex-start;
    gap: 12px;
}
.speaker-creds i {
    color: var(--accent);
    margin-top: 4px;
}

/* Responsive */
@media (max-width: 1024px) {
    .benefits-grid-5 { grid-template-columns: repeat(3, 1fr); }
    .hero-title { font-size: 42px; }
}
@media (max-width: 768px) {
    .sticky-bottom-cta { display: block; }
    .registration-notification {
        bottom: 80px; /* Above the sticky CTA */
        right: 16px;
        left: 16px;
        max-width: calc(100% - 32px);
    }
    .speaker-wrapper { flex-direction: column; text-align: center; padding: 24px; }
    .speaker-creds li { text-align: left; }
    .hero-container, .features-wrapper, .footer-container { grid-template-columns: 1fr; }
    .hero { padding: 120px 0 60px; text-align: center; }
    .hero-actions { justify-content: center; }
    .benefits-grid-5 { grid-template-columns: repeat(2, 1fr); }
    .nav {
        position: absolute; top: 100%; left: 0; width: 100%;
        background: white; flex-direction: column; padding: 20px;
        box-shadow: var(--shadow-flat); display: none;
    }
    .nav.active { display: flex; }
    .nav-link { color: var(--text-dark); }
    .mobile-menu-btn { display: block; }
    .header .btn-cta { display: none; }
    .w-100-mobile { width: 100%; }
}
@media (max-width: 480px) {
    .hero-title { font-size: 36px; }
    .benefits-grid-5 { grid-template-columns: 1fr; }
    .pain-item { flex-direction: column; text-align: center; }
}