:root {
    /* Light Mode */
    --bg-color: #f4f7fc;
    --text-color: #333;
    --text-muted-color: #6c757d;
    --card-bg: #ffffff;
    --border-color: #e9ecef;
    --navbar-bg: rgba(255, 255, 255, 0.85);
    --shadow-color: rgba(0, 0, 0, 0.05);
    --accent-color-1: #0d6efd;
    --accent-color-2: #0a58ca;
    --accent-gradient: linear-gradient(45deg, #0d6efd, #0a58ca);
    --accent-shadow: rgba(13, 110, 253, 0.3);
    --section-bg-darker: #ffffff;
}

body.dark-mode {
    /* Dark Mode */
    --bg-color: #0c0f14;
    --text-color: #e0e0e0;
    --text-muted-color: #888;
    --card-bg: #1a1e25;
    --border-color: #2a2e35;
    --navbar-bg: rgba(12, 15, 20, 0.85);
    --shadow-color: rgba(0, 0, 0, 0.2);
    --accent-color-1: #00f2fe;
    --accent-color-2: #4facfe;
    --accent-gradient: linear-gradient(45deg, #00f2fe, #4facfe);
    --accent-shadow: rgba(0, 242, 254, 0.25);
    --section-bg-darker: #12151a;
}

/* 1. GLOBAL & TYPOGRAPHY */
html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Be Vietnam Pro', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
    font-size: 20px; /* Compact font size */
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    color: var(--text-color);
}

p {
    color: var(--text-muted-color);
    font-size: 0.95rem;
    line-height: 1.7;
}

section {
    padding: 5rem 0;
    overflow: hidden;
}

.section-title {
    text-align: center;
    margin-bottom: 3.5rem;
    position: relative;
}

.section-title h2 {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.section-title p {
    font-size: 1rem;
    max-width: 600px;
    margin: 0 auto;
    color: var(--text-muted-color);
}

/* 2. CUSTOM PARALLELOGRAM BUTTON */
.btn-skew {
    display: inline-block;
    text-decoration: none;
    color: #fff;
    background: var(--accent-gradient);
    padding: 10px 30px;
    margin: 5px;
    border-radius: 8px;
    transform: skewX(-15deg);
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.3s;
    font-weight: 600;
    font-size: 0.9rem;
    border: none;
    box-shadow: 0 4px 15px var(--accent-shadow);
    position: relative;
}

.btn-skew span {
    display: inline-block;
    transform: skewX(15deg); /* Un-skew the text */
    position: relative;
    z-index: 2;
}

.btn-skew:hover {
    transform: skewX(-15deg) scale(1.05);
    box-shadow: 0 8px 25px var(--accent-shadow);
    color: #fff;
}

/* Secondary Button Style */
.btn-skew.btn-secondary {
    background: var(--card-bg);
    color: var(--accent-color-1);
    border: 2px solid var(--accent-color-1);
    box-shadow: none;
}

.btn-skew.btn-secondary:hover {
     background: var(--accent-gradient);
     color: #fff;
     border-color: transparent;
}

.btn-skew.btn-sm {
    padding: 5px 15px;
    font-size: 0.8rem;
}

/* 3. NAVBAR */
.navbar {
    background-color: var(--navbar-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px var(--shadow-color);
    padding: 0.75rem 0;
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--text-color);
}

.nav-link {
    color: var(--text-color);
    font-weight: 500;
    font-size: 0.9rem;
    margin: 0 0.5rem;
    transition: color 0.2s;
}

.nav-link:hover, .nav-link.active {
    color: var(--accent-color-1) !important;
}

.form-check-label {
    color: var(--text-color);
    cursor: pointer;
}

/* 4. HERO SECTION */
.hero-section {
    min-height: 100vh;
    padding-top: 80px; /* Navbar height */
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    background-color: var(--section-bg-darker);
}

.hero-content h1 {
    font-size: 2.8rem;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 1rem;
}

.hero-content h2 {
    font-size: 1.5rem;
    font-weight: 400;
    margin-bottom: 1.5rem;
    color: var(--text-muted-color);
}

/* Animated Text */
.animated-text-wrapper {
    display: inline-block;
    position: relative;
    height: 40px; /* Giữ nguyên chiều cao này cho animation */
    width: 280px; /* <-- THÊM CÁI NÀY (Bạn có thể chỉnh 280px to/nhỏ cho vừa ý) */
    vertical-align: top;
}

.animated-text {
    color: var(--accent-color-1);
    font-weight: 600;
    position: absolute;
    left: 0;
    top: 0;
    opacity: 0;
    transform: translateY(100%);
    transition: opacity 0.4s ease, transform 0.4s ease;
}

.animated-text.active {
    opacity: 1;
    transform: translateY(0);
}

.animated-text.exit {
    opacity: 0;
    transform: translateY(-100%);
}

.hero-content .trust-badges {
    list-style: none;
    padding: 0;
    margin-top: 2rem;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.hero-content .trust-badges li {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-muted-color);
}

.hero-content .trust-badges li i {
    color: #28a745; /* Green check */
    margin-right: 5px;
}

/* ==== NEW 3D HERO ILLUSTRATION ==== */
.hero-3d-container {
    perspective: 1500px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 500px;
    position: relative;
}

/* Khối bao bọc nội dung 3D */
.iso-content {
    position: relative;
    width: 300px;
    height: 500px;
    transform-style: preserve-3d;
    transform: rotateX(55deg) rotateZ(-35deg) rotateY(10deg);
    transition: transform 0.5s ease;
    animation: iso-float 6s ease-in-out infinite;
}

/* Animation cho cả khối bay nhẹ */
@keyframes iso-float {
    0%, 100% { transform: rotateX(55deg) rotateZ(-35deg) rotateY(10deg) translateZ(0px); }
    50% { transform: rotateX(55deg) rotateZ(-35deg) rotateY(10deg) translateZ(20px); }
}

/* 1. Bóng đổ dưới cùng */
.iso-shadow {
    position: absolute;
    top: 20px;
    left: 20px;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.3);
    filter: blur(30px);
    border-radius: 40px;
    transform: translateZ(-50px);
}

/* 2. Khối Điện thoại / Panel Base */
.iso-phone-base {
    position: absolute;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #ffffff 0%, #f0f4ff 100%);
    border-radius: 40px;
    box-shadow: 
        -10px 10px 20px rgba(0,0,0,0.05),
        inset 0 0 0 2px rgba(255,255,255,0.5);
    padding: 20px;
    transform-style: preserve-3d;
}

/* Tạo độ dày giả (3D thickness) cho khối */
.iso-phone-base::after {
    content: '';
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    border-radius: 40px;
    background: #e0e5ec;
    transform: translateZ(-15px);
}
.iso-phone-base::before {
    content: '';
    position: absolute;
    bottom: -15px; left: 0; width: 100%; height: 15px;
    background: #cfd6e0;
    border-radius: 0 0 40px 40px;
    transform: rotateX(-90deg);
    transform-origin: bottom;
}

/* Nội dung màn hình giả lập */
.screen-content {
    background: #fff;
    width: 100%;
    height: 100%;
    border-radius: 30px;
    padding: 20px;
    box-shadow: inset 0 0 20px rgba(0,0,0,0.02);
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.header-bar {
    height: 10px;
    width: 50%;
    background: #e9ecef;
    border-radius: 5px;
}

.chart-line {
    height: 8px;
    width: 100%;
    background: #f1f3f5;
    border-radius: 4px;
}

.chart-bars {
    margin-top: auto;
    display: flex;
    justify-content: space-around;
    align-items: flex-end;
    height: 100px;
}

.bar {
    width: 15px;
    background: #e9ecef;
    border-radius: 4px 4px 0 0;
}
.bar.active {
    background: var(--accent-gradient);
    box-shadow: 0 0 15px var(--accent-shadow);
}

/* Dark Mode Adjustment cho Base */
body.dark-mode .iso-phone-base {
    background: linear-gradient(135deg, #1a1e25 0%, #2a2e35 100%);
}
body.dark-mode .iso-phone-base::after { background: #12151a; }
body.dark-mode .iso-phone-base::before { background: #0c0f14; }
body.dark-mode .screen-content { background: #212529; }
body.dark-mode .bar, body.dark-mode .header-bar, body.dark-mode .chart-line { background: #343a40; }

/* 3. Floating Cards (Thông báo nổi) */
.float-card {
    position: absolute;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 12px 20px;
    border-radius: 15px;
    display: flex;
    align-items: center;
    gap: 15px;
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
    transform-style: preserve-3d;
    transition: transform 0.3s;
    border: 1px solid rgba(255,255,255,0.5);
}

body.dark-mode .float-card {
    background: rgba(33, 37, 41, 0.85);
    border-color: rgba(255,255,255,0.1);
}

.float-card .icon-box {
    width: 40px; height: 40px;
    background: #fff;
    border-radius: 10px;
    display: flex; justify-content: center; align-items: center;
    font-size: 1.2rem;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}
body.dark-mode .float-card .icon-box { background: #2c3036; }

.float-card .text-box { display: flex; flex-direction: column; }
.float-card .text-box span { font-size: 0.75rem; color: var(--text-muted-color); }
.float-card .text-box strong { font-size: 1rem; color: var(--text-color); }

/* Vị trí Card Like */
.card-like {
    top: 10%; right: -40px;
    transform: translateZ(60px);
    animation: float-card 5s ease-in-out infinite;
}
/* Vị trí Card Follow */
.card-follow {
    bottom: 20%; left: -50px;
    transform: translateZ(80px);
    animation: float-card 5s ease-in-out infinite reverse;
}

@keyframes float-card {
    0%, 100% { transform: translateZ(60px) translateY(0); }
    50% { transform: translateZ(60px) translateY(-15px); }
}

/* 4. Social Orbs (Icon cầu tròn 3D) */
.social-orb {
    position: absolute;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex; justify-content: center; align-items: center;
    font-size: 1.5rem;
    color: #fff;
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
    transform-style: preserve-3d;
}

/* Màu sắc từng thương hiệu */
.orb-fb { 
    background: linear-gradient(45deg, #1877f2, #0d5bb3); 
    top: -30px; left: 20px; transform: translateZ(100px);
    animation: orbit-1 6s ease-in-out infinite;
}
.orb-tk { 
    background: linear-gradient(45deg, #000000, #25f4ee); 
    top: 40%; right: -60px; transform: translateZ(90px);
    animation: orbit-2 7s ease-in-out infinite;
}
.orb-yt { 
    background: linear-gradient(45deg, #ff0000, #c40000); 
    bottom: -20px; right: 20px; transform: translateZ(110px);
    animation: orbit-1 5s ease-in-out infinite reverse;
}
.orb-ig { 
    background: linear-gradient(45deg, #f09433, #e6683c, #dc2743, #cc2366, #bc1888); 
    bottom: 40%; left: -60px; transform: translateZ(70px);
    animation: orbit-2 8s ease-in-out infinite reverse;
}

@keyframes orbit-1 {
    0%, 100% { transform: translateZ(100px) translateY(0); }
    50% { transform: translateZ(100px) translateY(-20px); }
}
@keyframes orbit-2 {
    0%, 100% { transform: translateZ(90px) translateY(0); }
    50% { transform: translateZ(90px) translateY(20px); }
}

/* Mobile responsive */
@media (max-width: 991.98px) {
    .iso-content {
        transform: rotateX(55deg) rotateZ(-35deg) rotateY(10deg) scale(0.8);
    }
}
@media (max-width: 576px) {
    .iso-content {
        transform: rotateX(55deg) rotateZ(-35deg) rotateY(10deg) scale(0.6);
        left: -10px; /* Căn chỉnh lại cho màn hình nhỏ */
    }
}
/* END */

/* --- SỬA CSS NAVBAR THÀNH DẠNG HỘP NỔI --- */

/* 1. Reset khung ngoài cùng của Navbar */
.navbar.navbar-floating {
    background-color: transparent !important; /* Xóa màu nền full màn hình */
    box-shadow: none !important;              /* Xóa bóng full màn hình */
    padding-top: 20px;                        /* Cách lề trên một chút cho đẹp */
    padding-bottom: 0;
    transition: all 0.3s ease;
}

/* 2. Tạo khung "Hộp" (Wrapper) bên trong */
.desktop-navbar-wrapper {
    background-color: var(--navbar-bg);       /* Dùng lại biến màu nền cũ (đục mờ) */
    backdrop-filter: blur(12px);              /* Hiệu ứng kính mờ */
    -webkit-backdrop-filter: blur(12px);
    
    border-radius: 16px;                      /* Bo góc nhẹ (theo yêu cầu bo 1 xíu tròn) */
    border: 1px solid rgba(255, 255, 255, 0.4); /* Viền kính mỏng */
    
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08); /* Đổ bóng nổi */
    
    padding: 0.5rem 1.5rem !important;        /* Khoảng cách nội dung bên trong hộp */
    width: 100%;
    margin: 0 auto;                           /* Căn giữa */
}

/* Xử lý Dark Mode cho khung hộp */
body.dark-mode .desktop-navbar-wrapper {
    border-color: rgba(255, 255, 255, 0.08);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

/* 3. Tinh chỉnh lại Logo và Link cho cân đối trong hộp */
.navbar-brand {
    font-size: 1.4rem;
    margin-right: 1rem;
}

/* Khi cuộn trang (nếu muốn hộp dính sát lên trên thì chỉnh ở JS, 
   nhưng CSS này sẽ giữ nó luôn nổi cách top 20px đẹp hơn) */

/* Responsive: Trên mobile, giảm padding và bo góc để đỡ tốn diện tích */
@media (max-width: 991.98px) {
    .navbar.navbar-floating {
        padding-top: 10px;
    }
    .desktop-navbar-wrapper {
        border-radius: 12px;
        padding: 0.5rem 1rem !important;
    }
    /* Sửa menu xổ xuống trên mobile nằm gọn trong hộp */
    .navbar-collapse {
        margin-top: 10px;
        border-top: 1px solid var(--border-color);
        padding-top: 10px;
    }
}

/* 5. SERVICES SECTION */
.services-section {
    background-color: var(--section-bg-darker);
}

/* Custom Bootstrap Tabs */
.services-section .nav-tabs {
    border-bottom: 2px solid var(--border-color);
    justify-content: center;
    margin-bottom: 2rem;
}

.services-section .nav-tabs .nav-link {
    border: none;
    border-bottom: 3px solid transparent;
    color: var(--text-muted-color);
    font-weight: 600;
    font-size: 1rem;
    padding: 0.75rem 1.5rem;
    margin: 0 0.25rem;
}

.services-section .nav-tabs .nav-link.active {
    color: var(--accent-color-1);
    border-bottom-color: var(--accent-color-1);
    background-color: transparent;
}

.service-table {
    background-color: var(--card-bg);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 5px 20px var(--shadow-color);
}

.service-table .table {
    margin-bottom: 0;
    color: var(--text-color);
    font-size: 0.9rem;
}

.service-table th {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-weight: 600;
    padding: 1rem;
}

.service-table td {
    vertical-align: middle;
    padding: 1rem;
    border-top: 1px solid var(--border-color);
}

.service-table td:first-child {
    font-weight: 600;
}

/* 6. TIERS SECTION (ƯU ĐÃI) */
.tier-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2.5rem 2rem;
    text-align: center;
    height: 100%;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    box-shadow: 0 5px 20px var(--shadow-color);
}

.tier-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px var(--shadow-color);
}

.tier-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--accent-color-1);
}

.tier-card .description {
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
    min-height: 40px;
}

.tier-card .benefits-list {
    list-style: none;
    padding: 0;
    margin: 2rem 0;
    text-align: left;
}

.tier-card .benefits-list li {
    margin-bottom: 0.75rem;
    font-size: 0.9rem;
}

.tier-card .benefits-list li i {
    color: var(--accent-color-1);
    margin-right: 10px;
    font-weight: bold;
}

.tier-card .discount {
    font-size: 1.75rem;
    font-weight: 700;
    margin: 1.5rem 0;
}
.tier-card .discount span {
    font-size: 1rem;
    font-weight: 400;
    color: var(--text-muted-color);
}

/* Highlight popular card */
.tier-card.popular {
    border: 2px solid var(--accent-color-1);
    transform: scale(1.05);
    position: relative;
    z-index: 2;
}

.tier-card.popular .badge {
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent-gradient);
    font-size: 0.8rem;
    padding: 0.5em 1em;
    border-radius: 20px;
}

@media (max-width: 991.98px) {
    .tier-card.popular {
        transform: scale(1); /* No scale on tablet/mobile */
    }
}

/* 7. TESTIMONIALS SECTION */
.testimonials-section {
    background-color: var(--section-bg-darker);
}

.testimonial-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2.5rem;
    text-align: center;
    box-shadow: 0 5px 20px var(--shadow-color);
    margin: 1rem; /* Margin for carousel spacing */
}

.testimonial-card .stars {
    color: #ffc107; /* Yellow stars */
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
}

.testimonial-card .review-text {
    font-style: italic;
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-color);
    margin-bottom: 2rem;
}

.testimonial-card .author-name {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.testimonial-card .author-role {
    font-size: 0.85rem;
    color: var(--text-muted-color);
}

.testimonials-section .carousel-indicators [data-bs-target] {
    background-color: var(--accent-color-1);
    opacity: 0.5;
}
.testimonials-section .carousel-indicators .active {
    opacity: 1;
}

.testimonials-section .carousel-control-prev-icon,
.testimonials-section .carousel-control-next-icon {
    filter: invert(1);
    /* A bit of a hack for dark mode, but Bootstrap's icons are tricky */
}

body.dark-mode .testimonials-section .carousel-control-prev-icon,
body.dark-mode .testimonials-section .carousel-control-next-icon {
     filter: none;
}


/* 8. FINAL CTA SECTION */
.cta-section {
    background: var(--accent-gradient);
    color: #fff;
    padding: 6rem 0;
}

.cta-section h2, .cta-section p {
    color: #fff;
}

.cta-section h2 {
    font-size: 2.5rem;
}

.cta-section p {
    font-size: 1.1rem;
    opacity: 0.9;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.cta-section .btn-skew {
    transform: skewX(-15deg); /* Re-apply base skew */
    background: #fff;
    color: var(--accent-color-2);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}
.cta-section .btn-skew:hover {
    transform: skewX(-15deg) scale(1.05);
    background: #fff;
    color: var(--accent-color-1);
}

.cta-section .btn-secondary {
    background: transparent;
    border: 2px solid #fff;
    color: #fff;
    box-shadow: none;
}
.cta-section .btn-secondary:hover {
    background: #fff;
    color: var(--accent-color-2);
}

.trust-elements {
    margin-top: 3rem;
}

.trust-element {
    text-align: center;
    color: #fff;
}

.trust-element i {
    font-size: 2.5rem;
    display: block;
    margin-bottom: 1rem;
    opacity: 0.9;
}

.trust-element h5 {
    font-size: 1rem;
    font-weight: 600;
    color: #fff;
}

/* 9. FOOTER */
.footer {
    background-color: var(--section-bg-darker);
    padding: 2rem 0;
    border-top: 1px solid var(--border-color);
}

.footer .footer-links {
    margin-bottom: 1rem;
}

.footer .footer-links a {
    text-decoration: none;
    color: var(--text-muted-color);
    margin: 0 1rem;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.footer .footer-links a:hover {
    color: var(--accent-color-1);
}

.footer .copyright {
    font-size: 0.85rem;
    color: var(--text-muted-color);
    margin: 0;
}

/* 10. SCROLL ANIMATION */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

/* 11. RESPONSIVE ADJUSTMENTS */
@media (max-width: 991.98px) {
    .hero-section {
        min-height: auto;
        padding-top: 120px;
        text-align: center;
    }
    .hero-illustration {
        margin-top: 4rem;
        min-height: 300px;
    }
    .server-unit {
        width: 200px;
    }
    .hero-content .trust-badges {
        justify-content: center;
    }
}

@media (max-width: 767.98px) {
    body { font-size: 14px; }
    h1 { font-size: 2.2rem; }
    .hero-content h1 { font-size: 2.2rem; }
    .hero-content h2 { font-size: 1.2rem; }
    
    .section-title h2 { font-size: 1.8rem; }
    
    .services-section .nav-tabs .nav-link {
        padding: 0.5rem 0.75rem;
        font-size: 0.85rem;
    }
    
    .tier-card {
        margin-bottom: 2rem;
    }
    
    .cta-section h2 { font-size: 1.8rem; }
    
    .trust-element {
        margin-bottom: 2rem;
    }
    
    .footer .footer-links a {
        display: block;
        margin: 0.5rem 0;
    }
}
/* 4.5. FLOW SECTION - REDESIGNED PRO */
.flow-section {
    position: relative;
    padding: 6rem 0;
    overflow: hidden;
    /* Thêm hình nền mờ nhẹ hoặc gradient nền để làm nổi bật thẻ kính */
    background: radial-gradient(circle at 50% 50%, rgba(13, 110, 253, 0.05) 0%, transparent 70%);
}

.sub-badge {
    display: inline-block;
    background: rgba(13, 110, 253, 0.1);
    color: var(--accent-color-1);
    padding: 6px 16px;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.flow-timeline {
    position: relative;
    max-width: 1000px;
    margin: 3rem auto 0;
    padding-bottom: 2rem;
}

/* Đường kẻ dọc trung tâm */
.timeline-line {
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 4px;
    background: var(--border-color);
    transform: translateX(-50%);
    border-radius: 4px;
    z-index: 0;
}

/* Thanh tiến trình chạy dọc (Animation Gradient) */
.timeline-line .line-progress {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 0%; /* JS sẽ thay đổi cái này hoặc để auto animation */
    background: var(--accent-gradient);
    box-shadow: 0 0 15px var(--accent-color-1);
    border-radius: 4px;
    transition: height 1.5s ease-out;
}

/* Layout từng hàng (Item) */
.flow-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 4rem;
    position: relative;
    z-index: 1;
}

.flow-content, .flow-space {
    width: 45%;
}

.flow-icon {
    width: 10%;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

/* Vòng tròn Icon ở giữa */
.icon-circle {
    width: 60px;
    height: 60px;
    background: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--text-muted-color);
    box-shadow: 0 0 0 5px var(--bg-color); /* Tạo khoảng cách với đường kẻ */
    transition: all 0.4s ease;
    z-index: 2;
}

/* Thẻ nội dung (Glassmorphism) */
.glass-card {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.5);
    border-radius: 20px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
}

/* Dark mode adjustment cho thẻ */
body.dark-mode .glass-card {
    background: rgba(30, 34, 45, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

/* Số thứ tự mờ trong thẻ */
.step-number {
    position: absolute;
    top: -10px;
    right: 15px;
    font-size: 4rem;
    font-weight: 900;
    color: var(--accent-color-1);
    opacity: 0.07;
    line-height: 1;
    z-index: 0;
}

.flow-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    position: relative;
    z-index: 1;
}

.flow-card p {
    font-size: 0.95rem;
    margin: 0;
    position: relative;
    z-index: 1;
}

/* --- TRẠNG THÁI ACTIVE (Khi cuộn tới) --- */

/* Khi active thì line chạy full */
.flow-section.active-animation .timeline-line .line-progress {
    height: 100%;
}

.flow-item.active .icon-circle {
    background: var(--accent-gradient);
    color: #fff;
    border-color: transparent;
    box-shadow: 0 0 0 5px var(--bg-color), 0 0 20px var(--accent-shadow);
    transform: scale(1.1);
}

.flow-item.active .glass-card {
    transform: translateY(-10px);
    border-color: var(--accent-color-1);
    box-shadow: 0 15px 40px var(--accent-shadow);
}

/* Animation xuất hiện từ 2 bên */
.flow-content.left {
    transform: translateX(-50px);
    opacity: 0;
    transition: all 0.8s ease;
}
.flow-content.right {
    transform: translateX(50px);
    opacity: 0;
    transition: all 0.8s ease;
}

.flow-item.active .flow-content.left,
.flow-item.active .flow-content.right {
    transform: translateX(0);
    opacity: 1;
}

/* --- RESPONSIVE MOBILE --- */
@media (max-width: 768px) {
    .timeline-line {
        left: 30px; /* Dời đường kẻ sang trái */
    }
    
    .flow-item {
        flex-direction: column; /* Xếp chồng */
        align-items: flex-start;
        margin-bottom: 3rem;
    }
    
    .flow-icon {
        width: 60px;
        order: 1;
        margin-bottom: 1rem;
        justify-content: flex-start;
    }
    
    .icon-circle {
        margin-left: 0; /* Căn chỉnh icon khớp line */
    }
    
    .flow-content, .flow-space {
        width: 100%;
        padding-left: 70px; /* Chừa chỗ cho icon bên trái */
        order: 2;
    }
    
    .flow-content.left, .flow-content.right {
        text-align: left; /* Mobile căn trái hết */
    }

    /* Tắt animation bay trái phải trên mobile cho đỡ lag */
    .flow-content.left, .flow-content.right {
        transform: translateY(20px);
    }
}