/* Font stack */
@font-face {
    font-display: swap;
    font-family: "Open Sans";
    font-style: normal;
    font-weight: 400;
    src: url("../font/open-sans-v43-latin_vietnamese-regular.woff2") format("woff2");
}
@font-face {
    font-display: swap;
    font-family: "Open Sans";
    font-style: normal;
    font-weight: 600;
    src: url("../font/open-sans-v43-latin_vietnamese-600.woff2") format("woff2");
}
@font-face {
    font-display: swap;
    font-family: "Open Sans";
    font-style: normal;
    font-weight: 700;
    src: url("../font/open-sans-v43-latin_vietnamese-700.woff2") format("woff2");
}

:root {
    --brand-500: #2b44ff;
    --brand-600: #2333d7;
    --brand-100: #eef1ff;
    --accent: #ff7a45;
    --text-strong: #101428;
    --text-muted: #5c6378;
    --surface: #ffffff;
    --surface-soft: #f8f9ff;
    --border: #e4e7f4;
    --shadow-soft: 0 18px 45px rgba(16, 20, 40, 0.08);
    --radius-sm: 12px;
    --radius-md: 18px;
    --radius-lg: 28px;
    --container: clamp(320px, 92vw, 1180px);
    --transition: 200ms ease;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: "Open Sans", Arial, Helvetica, sans-serif;
    background: var(--surface-soft);
    color: var(--text-muted);
    line-height: 1.65;
    min-height: 100vh;
    padding-top: 86px;
    -webkit-font-smoothing: antialiased;
}

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

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

ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

section {
    padding: clamp(2.5rem, 6vw, 4.5rem) 0;
}

.container {
    width: var(--container);
    max-width: 100%;
    margin: 0 auto;
    padding: 0 clamp(1rem, 4vw, 2.5rem);
}

.eyebrow {
    letter-spacing: 0.28em;
    text-transform: uppercase;
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--brand-600);
    margin-bottom: 0.75rem;
}

.section-heading {
    color: var(--text-strong);
    text-align: center;
    font-weight: 700;
    font-size: clamp(1.8rem, 1rem + 1.5vw, 2.6rem);
    margin-bottom: clamp(1.3rem, 2vw, 2.2rem);
}

#main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 90;
    background: rgba(255, 255, 255, 0.92);
    border-bottom: 1px solid rgba(228, 231, 244, 0.9);
    transition: box-shadow var(--transition);
}

.header-solid {
    box-shadow: 0 10px 35px rgba(16, 20, 40, 0.08);
}

.nav {
    height: 86px;
    width: var(--container);
    max-width: 100%;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 clamp(1rem, 4vw, 2.5rem);
    gap: 1rem;
}

.nav-left,
.nav-right {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 0.7rem;
    font-weight: 700;
    font-size: 1.3rem;
    color: var(--text-strong);
}

.logo img {
    width: 42px;
    height: 42px;
    border-radius: 14px;
    box-shadow: var(--shadow-soft);
}

.nav-menu {
    display: flex;
    gap: 1.4rem;
}

.nav-menu a {
    color: var(--text-muted);
    font-weight: 600;
    font-size: 0.95rem;
    padding-bottom: 6px;
    position: relative;
}

.nav-menu a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 2px;
    background: var(--brand-500);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition);
}

.nav-menu a:hover::after,
.nav-menu a:focus-visible::after {
    transform: scaleX(1);
}

.nav-signup {
    padding: 0.55rem 1.5rem;
    border-radius: 999px;
    background: linear-gradient(120deg, var(--brand-500), #3f6cff);
    color: #fff !important;
    font-weight: 700;
    font-size: 0.95rem;
    box-shadow: 0 15px 35px rgba(43, 68, 255, 0.3);
}

header.hero {
    padding: clamp(3rem, 8vw, 5.5rem) 0;
}

.hero-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: clamp(1.8rem, 4vw, 3.8rem);
    align-items: center;
}

.hero-content {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

.hero h1 {
    margin: 0;
    color: var(--text-strong);
    font-size: clamp(2.2rem, 1.5rem + 2vw, 3.4rem);
    line-height: 1.15;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.05rem;
}

.cta-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    align-items: center;
    justify-content: center;
}

@media (min-width: 768px) {
    .cta-group {
        flex-direction: row;
        align-items: center;
    }
}

.cta-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.95rem 2.4rem;
    border-radius: var(--radius-sm);
    background: linear-gradient(120deg, var(--brand-500), var(--brand-600));
    color: #fff;
    font-weight: 700;
    font-size: 1rem;
    box-shadow: 0 18px 35px rgba(35, 51, 215, 0.3);
    transition: transform var(--transition), box-shadow var(--transition);
}

.cta-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 20px 50px rgba(35, 51, 215, 0.35);
}

.hero-meta {
    font-size: 0.92rem;
    color: var(--text-muted);
}

.hero-points {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.hero-points li {
    position: relative;
    padding-left: 1.3rem;
}

.hero-points li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.5rem;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent);
}

.hero-media {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-screen img {
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-soft);
    background: var(--surface);
}

.hero-screen.primary {
    max-width: 520px;
}

.hero-screen.floating {
    position: absolute;
    width: 180px;
    bottom: -12%;
    left: -12%;
    transform: rotate(-6deg);
}

.hero-badge {
    position: absolute;
    right: -10%;
    top: 8%;
    padding: 1rem 1.3rem;
    border-radius: var(--radius-md);
    background: #fff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow-soft);
    text-align: center;
}

.hero-badge span {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--brand-500);
}

.hero-badge p {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.card-shell {
    border-radius: var(--radius-lg);
    background: var(--surface);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-soft);
    padding: clamp(1.8rem, 4vw, 3rem);
}

.trust-strip {
    padding: 1.5rem 0 0;
}

.trust-strip .container {
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 0.9rem;
}

.trust-copy {
    font-weight: 600;
    color: var(--text-strong);
}

.trust-logos {
    display: flex;
    justify-content: center;
    gap: 1.4rem;
    flex-wrap: wrap;
}

.trust-logos img {
    width: 40px;
    height: 40px;
    opacity: 0.9;
}

.cat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: clamp(1rem, 2vw, 1.8rem);
}

.cat-card {
    border-radius: var(--radius-md);
    padding: 1.4rem 1.5rem;
    border: 1px solid var(--border);
    background: #fff;
    box-shadow: 0 12px 30px rgba(16, 20, 40, 0.06);
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.cat-head {
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.cat-head img {
    width: 42px;
    height: 42px;
}

.tag {
    text-transform: uppercase;
    font-size: 0.78rem;
    letter-spacing: 0.08em;
    color: var(--brand-500);
    margin: 0;
}

.cat-head h3 {
    margin: 0.15rem 0 0;
    color: var(--text-strong);
}

.cat-bullets {
    padding-left: 1.1rem;
    color: var(--text-muted);
}

.cat-bullets li {
    margin-bottom: 0.35rem;
}

.cat-cta {
    margin-top: auto;
    align-self: flex-start;
    padding: 0.55rem 1.2rem;
    border-radius: 999px;
    border: 1px solid transparent;
    background: var(--brand-100);
    color: var(--brand-600);
    font-weight: 600;
    transition: background var(--transition);
}

.cat-cta:hover {
    background: rgba(35, 51, 215, 0.12);
}

.pack-note {
    margin-top: 1.4rem;
    text-align: center;
    color: var(--text-muted);
}

.benefit-list,
.feature-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: clamp(1rem, 2vw, 1.6rem);
}

.benefit-item,
.feature-item {
    border-radius: var(--radius-md);
    padding: 1.4rem;
    background: var(--surface-soft);
    border: 1px solid var(--border);
}

.benefit-item h3,
.feature-item h3 {
    color: var(--text-strong);
    margin-top: 0;
}

.workflow .feature-item {
    position: relative;
    padding-top: 1.8rem;
}

.step-badge {
    position: absolute;
    top: 0;
    left: 0;
    width: 38px;
    height: 38px;
    border-radius: 50%;
    background: var(--brand-100);
    color: var(--brand-600);
    font-weight: 700;
    display: grid;
    place-items: center;
}

.review-carousel .carousel-wrapper {
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    background: #fff;
    box-shadow: var(--shadow-soft);
    overflow: hidden;
}

.carousel-track {
    display: flex;
    transition: transform 0.6s ease;
}

.review-item {
    flex: 0 0 100%;
    padding: 2rem;
    text-align: center;
}

.review-content {
    font-size: 1.05rem;
    color: var(--text-strong);
}

.review-author {
    color: var(--brand-600);
    font-weight: 600;
}

.carousel-dots {
    display: flex;
    justify-content: center;
    gap: 0.6rem;
    margin-top: 1rem;
}

.carousel-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    border: none;
    background: rgba(16, 20, 40, 0.15);
    cursor: pointer;
}

.carousel-dot.active,
.carousel-dot:hover {
    background: var(--brand-500);
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.faq-list details {
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    background: #fff;
    padding: 1.2rem 1.4rem;
    box-shadow: 0 10px 24px rgba(16, 20, 40, 0.05);
}

.faq-list summary {
    color: var(--text-strong);
    font-weight: 600;
    cursor: pointer;
    position: relative;
    padding-right: 1.5rem;
}

.faq-list summary::after {
    content: "+";
    position: absolute;
    right: 0;
    top: 0;
    color: var(--brand-500);
    font-size: 1.3rem;
    transition: transform var(--transition);
}

.faq-list details[open] summary::after {
    transform: rotate(45deg);
}

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

.bottom-cta h2 {
    color: var(--text-strong);
    margin-bottom: 0.6rem;
}

footer {
    padding: 2.5rem 0 2rem;
    text-align: center;
    color: var(--text-muted);
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 0.8rem;
    flex-wrap: wrap;
    margin-bottom: 0.6rem;
}

.footer-links a {
    color: var(--brand-600);
    font-weight: 600;
}

.footer-copy p {
    margin: 0.2rem 0;
}

/* Sticky CTA */
.sticky-cta-card {
    position: fixed;
    right: 1.5rem;
    bottom: 1.5rem;
    width: min(360px, calc(100% - 3rem));
    display: flex;
    gap: 1rem;
    align-items: center;
    padding: 1rem 1.2rem;
    border-radius: var(--radius-md);
    background: #fff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow-soft);
    color: var(--text-strong);
    z-index: 80;
}

.sticky-cta-card__title {
    font-weight: 700;
    color: var(--text-strong);
}

.sticky-cta-card__desc {
    font-size: 0.92rem;
    color: var(--text-muted);
}

.sticky-cta-card__btn {
    padding: 0.8rem 1.2rem;
    border-radius: var(--radius-sm);
    background: linear-gradient(120deg, var(--brand-500), var(--brand-600));
    color: #fff;
    font-weight: 700;
    box-shadow: 0 15px 30px rgba(35, 51, 215, 0.3);
}

.btn-text {
    letter-spacing: 0.2px;
}

.sticky-cta-card.is-hidden {
    display: none;
}

/* Modal */
.cta-modal {
    position: fixed;
    inset: 0;
    display: grid;
    place-items: center;
    background: rgba(16, 20, 40, 0.55);
    z-index: 120;
    padding: 1.5rem;
}

.cta-modal.hidden {
    display: none;
}

.cta-modal__overlay {
    position: absolute;
    inset: 0;
}

.cta-modal__content {
    position: relative;
    background: #fff;
    border-radius: var(--radius-lg);
    padding: clamp(1.5rem, 6vw, 3rem);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-soft);
    text-align: center;
    color: var(--text-strong);
}

.cta-btn-big {
    width: 100%;
    border: none;
    border-radius: var(--radius-md);
    padding: 1rem 1.2rem;
    font-weight: 700;
    color: #fff;
    background: linear-gradient(120deg, var(--brand-500), var(--brand-600));
    box-shadow: 0 15px 35px rgba(35, 51, 215, 0.3);
    cursor: pointer;
}

.cta-note {
    margin-top: 0.8rem;
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Utility */
@media (max-width: 980px) {
    .nav-menu {
        display: none;
    }

    body {
        padding-top: 72px;
    }
}

@media (max-width: 768px) {
    .nav {
        height: 72px;
    }

    .hero-screen.floating,
    .hero-badge {
        display: none;
    }

    .sticky-cta-card {
        left: 1.5rem;
        width: auto;
    }
}

@media (max-width: 520px) {
    .hero h1 {
        font-size: 1.9rem;
    }

    .cta-btn {
        width: 100%;
    }

    .footer-links {
        flex-direction: column;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
    }
}