:root {
    --bg: #FAF9F6;
    --bg-soft: #F1EFE9;
    --ink: #1D2321;
    --ink-soft: #5B615E;
    --primary: #234E4B;
    --primary-light: #2F6B66;
    --accent: #F4A93A;
    --line: #E3E0D8;
    --card: #FFFFFF;
    --radius: 14px;
    --shadow: 0 1px 2px rgba(29, 35, 33, .04), 0 8px 24px -12px rgba(29, 35, 33, .10);
    --maxw: 1180px;
    --focus: #1E63FF;
}
* {
    box-sizing: border-box;
}
html {
    scroll-behavior: smooth;
}
body {
    margin: 0;
    background: var(--bg);
    color: var(--ink);
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    font-size: 16px;
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
}
h1,
h2,
h3 {
    font-family: 'Fraunces', Georgia, serif;
    font-weight: 600;
    line-height: 1.15;
    margin: 0;
    letter-spacing: -0.01em;
}
a {
    color: inherit;
    text-decoration: none;
}
img,
svg {
    display: block;
    max-width: 100%;
}
ul {
    list-style: none;
    margin: 0;
    padding: 0;
}
button {
    font: inherit;
    background: none;
    border: none;
    cursor: pointer;
    color: inherit;
}
:focus-visible {
    outline: 2.5px solid var(--focus);
    outline-offset: 3px;
    border-radius: 6px;
}
.skip-link {
    position: absolute;
    left: -999px;
    top: 0;
    background: var(--primary);
    color: #fff;
    padding: 10px 16px;
    border-radius: 0 0 8px 0;
    z-index: 200;
}
.skip-link:focus {
    left: 0;
}
.wrap {
    max-width: var(--maxw);
    margin: 0 auto;
    padding: 0 24px;
}
/* ===== Header ===== */
/* Nền mờ được đặt ở ::before (không phải trực tiếp trên header) để header
     không tạo "containing block" làm kẹt menu mobile position:fixed bên trong nó. */
header.site {
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--line);
}
header.site::before {
    content: "";
    position: absolute;
    inset: 0;
    background: rgba(250, 249, 246, .9);
    backdrop-filter: blur(10px);
    z-index: -1;
}
.nav-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 68px;
    gap: 20px;
}
.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-family: 'Fraunces', serif;
    font-weight: 700;
    font-size: 19px;
    color: var(--primary);
    flex: none;
}
.logo-mark {
    width: 34px;
    height: 34px;
    border-radius: 9px;
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    flex: none;
}
.logo-mark svg {
    width: 18px;
    height: 18px;
}
/* ---- Main menu (desktop) ---- */
nav.main-menu {
    flex: 1;
    display: flex;
    justify-content: center;
}
nav.main-menu>ul {
    display: flex;
    gap: 2px;
}
nav.main-menu>ul>li {
    position: relative;
}
nav.main-menu>ul>li>a,
.menu-parent {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 9px 13px;
    border-radius: 8px;
    font-size: 14.5px;
    font-weight: 500;
    color: var(--ink-soft);
    transition: background .15s ease, color .15s ease;
    white-space: nowrap;
}
nav.main-menu>ul>li>a:hover,
.menu-parent:hover {
    background: var(--bg-soft);
    color: var(--ink);
}
.caret {
    width: 11px;
    height: 11px;
    transition: transform .15s ease;
    flex: none;
}
.has-sub.open>.menu-parent .caret,
.has-sub:hover>.menu-parent .caret,
.has-sub:focus-within>.menu-parent .caret {
    transform: rotate(180deg);
}
.has-sub {
    position: relative;
}
/* Vùng đệm vô hình lấp khoảng cách giữa nút cha và submenu, giữ vùng hover liền mạch */
.has-sub::before {
    content: "";
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    height: 10px;
}
.submenu {
    position: absolute;
    top: calc(100% + 6px);
    left: 0;
    min-width: 270px;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 12px;
    box-shadow: var(--shadow);
    padding: 8px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-6px);
    transition: opacity .15s ease, transform .15s ease, visibility .15s;
    z-index: 50;
}
.has-sub:hover>.submenu,
.has-sub:focus-within>.submenu,
.has-sub.open>.submenu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.submenu li a {
    display: block;
    padding: 9px 12px;
    border-radius: 8px;
    font-size: 14px;
    color: var(--ink);
    white-space: normal;
}
.submenu li a:hover {
    background: var(--bg-soft);
    color: var(--primary);
}
.nav-actions {
    display: flex;
    align-items: center;
    gap: 10px;
    flex: none;
}
.mobile-auth {
    display: none;
}
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    border-radius: 9px;
    font-size: 14.5px;
    font-weight: 600;
    border: 1px solid transparent;
    cursor: pointer;
    transition: transform .12s ease, background .15s ease;
    white-space: nowrap;
}
.btn-primary {
    background: var(--primary);
    color: #fff;
}
.btn-primary:hover {
    background: var(--primary-light);
}
.btn-ghost {
    background: transparent;
    border-color: var(--line);
    color: var(--ink);
}
.btn-ghost:hover {
    background: var(--bg-soft);
}
.menu-toggle {
    display: none;
    width: 40px;
    height: 40px;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: 1px solid var(--line);
    border-radius: 9px;
}
.menu-toggle svg {
    width: 20px;
    height: 20px;
}
/* ===== Hero ===== */
.hero {
    padding: 76px 0 56px;
    border-bottom: 1px solid var(--line);
    position: relative;
    overflow: hidden;
}
.hero::before {
    content: "";
    position: absolute;
    top: -140px;
    right: -120px;
    width: 420px;
    height: 420px;
    border-radius: 50%;
    background: radial-gradient(circle at 30% 30%, #F4A93A22, transparent 70%);
    pointer-events: none;
}
.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-family: 'IBM Plex Mono', monospace;
    font-size: 12.5px;
    letter-spacing: .03em;
    color: var(--primary);
    background: #234E4B12;
    padding: 6px 12px;
    border-radius: 999px;
    margin-bottom: 20px;
}
.eyebrow .dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--accent);
}
.hero h1 {
    font-size: clamp(32px, 4.6vw, 52px);
    max-width: 16ch;
    margin-bottom: 18px;
}
.hero p.lead {
    font-size: 18px;
    color: var(--ink-soft);
    max-width: 54ch;
    margin-bottom: 34px;
}
/* ===== About / Welcome (persuasive content) ===== */
.about {
    padding: 64px 0;
    border-top: 1px solid var(--line);
    background: var(--bg-soft);
}
.about-inner {
    max-width: 760px;
}
.about h2 {
    font-size: 30px;
    margin-bottom: 18px;
}
.about p {
    color: var(--ink-soft);
    font-size: 16.5px;
    margin: 0 0 16px;
}
.about p:last-of-type {
    margin-bottom: 0;
}
.about strong {
    color: var(--ink);
}
.reason-row {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 14px;
    margin-top: 36px;
}
.reason {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 18px;
}
.reason .r-icon {
    width: 34px;
    height: 34px;
    border-radius: 9px;
    background: #234E4B12;
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 12px;
}
.reason .r-icon svg {
    width: 18px;
    height: 18px;
}
.reason b {
    display: block;
    font-size: 14.5px;
    margin-bottom: 4px;
}
.reason span {
    font-size: 13px;
    color: var(--ink-soft);
}
/* ===== FAQ ===== */
.faq {
    padding: 64px 0;
    border-top: 1px solid var(--line);
}
.faq .section-head {
    margin-bottom: 28px;
}
.faq h2 {
    font-size: 28px;
}
.faq-list {
    max-width: 820px;
}
.faq-item {
    border-bottom: 1px solid var(--line);
}
.faq-item summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 18px 4px;
    cursor: pointer;
    list-style: none;
    font-weight: 600;
    font-size: 15.5px;
    color: var(--ink);
}
.faq-item summary::-webkit-details-marker {
    display: none;
}
.faq-plus {
    flex: none;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    border: 1px solid var(--line);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform .15s ease, background .15s ease;
}
.faq-plus svg {
    width: 11px;
    height: 11px;
}
.faq-item[open] .faq-plus {
    transform: rotate(45deg);
    background: var(--bg-soft);
}
.faq-item p {
    margin: 0 4px 18px;
    color: var(--ink-soft);
    font-size: 14.5px;
    max-width: 68ch;
}
/* ===== Footer ===== */
footer.site {
    border-top: 1px solid var(--line);
    padding: 40px 0 28px;
}
.footer-row {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 28px;
}
.footer-cols {
    display: flex;
    gap: 48px;
    flex-wrap: wrap;
}
.footer-col h4 {
    font-size: 12.5px;
    text-transform: uppercase;
    letter-spacing: .04em;
    color: var(--ink-soft);
    margin-bottom: 12px;
    font-family: 'Inter', sans-serif;
    font-weight: 600;
}
.footer-col a {
    display: block;
    font-size: 13.5px;
    color: var(--ink-soft);
    padding: 4px 0;
}
.footer-col a:hover {
    color: var(--primary);
}
.copyright {
    font-size: 13px;
    color: #9AA09D;
    margin-top: 32px;
}
/* ===== Responsive ===== */
@media (max-width: 980px) {
    .reason-row {
        grid-template-columns: 1fr 1fr;
    }
}
@media (max-width: 860px) {
    nav.main-menu {
        display: none;
    }
    nav.main-menu.open {
        display: block;
        position: fixed;
        top: 68px;
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--bg);
        overflow-y: auto;
        -webkit-overflow-scrolling: touch;
        border-bottom: 1px solid var(--line);
        box-shadow: var(--shadow);
        padding: 10px 24px 28px;
        z-index: 150;
    }
    nav.main-menu>ul {
        flex-direction: column;
        gap: 2px;
    }
    nav.main-menu>ul>li>a,
    .menu-parent {
        padding: 13px 10px;
        font-size: 15.5px;
        width: 100%;
        justify-content: space-between;
    }
    .submenu {
        position: static;
        box-shadow: none;
        border: none;
        background: transparent;
        padding: 0 0 0 12px;
        max-height: 0;
        overflow: hidden;
        opacity: 1;
        visibility: visible;
        transform: none;
        transition: max-height .2s ease;
    }
    .has-sub.open>.submenu {
        max-height: 600px;
    }
    .submenu li a {
        padding: 10px 12px;
        font-size: 14.5px;
    }
    .menu-toggle {
        display: flex;
    }
    .nav-actions .auth-btn {
        display: none;
    }
    .mobile-auth {
        display: flex;
        gap: 10px;
        margin-top: 14px;
        padding-top: 14px;
        border-top: 1px solid var(--line);
    }
    .mobile-auth .btn {
        flex: 1;
        justify-content: center;
        padding: 10px 18px;
        font-size: 14.5px;
        font-weight: 600;
        white-space: nowrap;
    }
    .mobile-auth .btn-primary {
        color: #fff;
    }
    .mobile-auth .btn-ghost {
        color: var(--ink);
    }
    .hero {
        padding: 48px 0 40px;
    }
    .hero p.lead {
        font-size: 16.5px;
    }
}
@media (max-width: 480px) {
    .wrap {
        padding: 0 16px;
    }
    .reason-row {
        grid-template-columns: 1fr;
    }
}
@media (prefers-reduced-motion: reduce) {
    * {
        animation: none !important;
        transition: none !important;
        scroll-behavior: auto !important;
    }
}
.content-k h2 {
    font-size: 23px;
    margin: 11px 0px;
    padding-top: 11px;
    border-top: 1px solid #176abc;
    font-weight: bold;
    color: #176abc;
}
.content-k h3 {
    font-size: 21px;
    font-weight: bold;
    margin: 9px 0px 5px 0px;
}
.content-k ul {
    list-style: circle !important;
    margin: revert !important;
    padding: revert !important;
}