:root {
    --ink: #08245f;
    --muted: #53647d;
    --line: #d9e2ef;
    --paper: #f4f8fc;
    --card: #ffffff;
    --brand: #0758b8;
    --brand-deep: #062d73;
    --brand-soft: #e7f5ff;
    --accent: #27c9ff;
    --accent-soft: #fff0f1;
    --tg: #0758b8;
    --radius: 10px;
}

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

body {
    font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
    background: var(--paper);
    color: var(--ink);
    display: flex;
    justify-content: center;
    min-height: 100dvh;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

.shell {
    position: relative;
    width: 100%;
    max-width: 430px;
    min-height: 100dvh;
    height: 100dvh;
    background: var(--card);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    border-inline: 1px solid var(--line);
}

nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    padding: 10px 12px;
    background: var(--card);
    border-bottom: 1px solid var(--line);
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    color: inherit;
    min-width: 0;
}

.logo img {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    flex-shrink: 0;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
}

.home-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 34px;
    padding: 6px 14px;
    background: var(--brand);
    color: var(--ink);
    font-size: 0.8rem;
    font-weight: 750;
    text-decoration: none;
    border-radius: 8px;
    white-space: nowrap;
}

.home-btn:hover,
.home-btn:focus-visible {
    filter: brightness(0.96);
    outline: none;
}

.logo-name {
    font-weight: 700;
    font-size: 0.95rem;
}

.hamburger {
    display: flex;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.hamburger span {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--ink);
    border-radius: 2px;
}

.dropdown {
    display: none;
    position: absolute;
    top: calc(100% + 4px);
    right: 12px;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    width: 200px;
    max-height: 70dvh;
    overflow-y: auto;
    z-index: 99;
}

.dropdown.open {
    display: block;
}

.dropdown a {
    display: block;
    padding: 10px 14px;
    font-size: 0.84rem;
    font-weight: 500;
    color: var(--ink);
    text-decoration: none;
    border-bottom: 1px solid var(--line);
}

.dropdown a:last-child {
    border-bottom: none;
}

.dropdown a:hover {
    background: var(--brand-soft);
}

.scroll {
    flex: 1;
    overflow-y: auto;
    scrollbar-width: none;
    padding-bottom: 16px;
}

.scroll::-webkit-scrollbar {
    display: none;
}

.hero {
    padding: 24px 16px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    background: linear-gradient(180deg, var(--brand-soft) 0%, var(--card) 100%);
    border-bottom: 1px solid var(--line);
}

.hero-logo {
    width: 80px;
    height: 80px;
    border-radius: 16px;
    margin-bottom: 12px;
}

.hero h1 {
    font-size: 1.4rem;
    font-weight: 750;
    margin-bottom: 6px;
}

.hero p {
    font-size: 0.86rem;
    color: var(--muted);
    max-width: 310px;
    margin-bottom: 14px;
}

.facts {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    width: 100%;
    margin-bottom: 14px;
}

.fact {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 9px 8px;
    text-align: center;
}

.fact b {
    display: block;
    font-size: 0.9rem;
    color: var(--brand-deep);
    font-weight: 750;
}

.fact span {
    font-size: 0.7rem;
    color: var(--muted);
}

.btn-row {
    display: flex;
    gap: 8px;
    width: 100%;
    margin-bottom: 8px;
}

.btn {
    flex: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 11px 12px;
    border-radius: var(--radius);
    font-size: 0.84rem;
    font-weight: 650;
    text-decoration: none;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background: var(--brand);
    color: #fff;
}

.btn-primary:hover {
    background: var(--brand-deep);
}

.btn-outline {
    background: var(--card);
    color: var(--brand);
    border: 1.5px solid var(--brand);
}

.btn-outline:hover {
    background: var(--brand-soft);
}

.btn-blue {
    background: var(--tg);
    color: #fff;
}

.btn-blue:hover {
    filter: brightness(0.92);
}

.btn-orange {
    background: #16b9f2;
    color: #fff;
}

.btn-orange:hover {
    filter: brightness(0.95);
}

.vivipay-card {
    margin: 12px 12px 0;
    padding: 16px;
    border-radius: var(--radius);
    background: linear-gradient(160deg, #062d73 0%, #0758b8 52%, #16b9f2 100%);
    color: #fff;
    text-align: center;
}

.vivipay-card h2,
.vivipay-card p,
.vivipay-card a {
    color: #fff;
}

.vivipay-card h2 {
    font-size: 1.02rem;
    font-weight: 750;
    margin-bottom: 8px;
    border: none;
    padding: 0;
}

.vivipay-card p {
    font-size: 0.84rem;
    margin-bottom: 10px;
    opacity: 0.95;
}

.vivipay-card .vivipay-pct {
    font-size: 2rem;
    font-weight: 800;
    line-height: 1;
    margin: 6px 0 2px;
}

.vivipay-card .vivipay-label {
    font-size: 0.72rem;
    letter-spacing: 0.12em;
    font-weight: 700;
    opacity: 0.85;
    margin-bottom: 12px;
}

.vivipay-card .btn {
    background: #16b9f2;
    color: #fff;
}

.sec {
    margin: 12px 12px 0;
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 16px;
    content-visibility: auto;
    contain-intrinsic-size: auto 360px;
}

.sec h2 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 10px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--brand-soft);
}

.sec h3 {
    font-size: 0.88rem;
    font-weight: 700;
    margin: 12px 0 4px;
}

.sec p {
    font-size: 0.84rem;
    color: var(--muted);
    margin-bottom: 8px;
    line-height: 1.62;
}

.sec ul,
.sec ol {
    padding-left: 18px;
    margin-top: 4px;
}

.sec li {
    font-size: 0.84rem;
    color: var(--muted);
    margin-bottom: 4px;
}

.sec a {
    color: var(--brand);
    text-decoration: none;
    font-weight: 650;
}

.sec a:hover {
    text-decoration: underline;
}

.sec img {
    display: block;
    width: 100%;
    max-width: 340px;
    height: auto;
    margin: 10px auto 0;
    border-radius: 8px;
}

.sec figure {
    margin: 12px auto 4px;
    max-width: 340px;
}

.sec figure img {
    margin: 0;
    aspect-ratio: 350 / 200;
    object-fit: cover;
    background: var(--paper);
}

.sec figcaption {
    font-size: 0.78rem;
    color: var(--muted);
    text-align: center;
    margin-top: 6px;
    line-height: 1.4;
}

.toc-list {
    list-style: none;
    padding: 0;
    counter-reset: toc;
}

.toc-list li {
    counter-increment: toc;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 0;
    border-bottom: 1px solid var(--line);
    font-size: 0.84rem;
}

.toc-list li:last-child {
    border-bottom: none;
}

.toc-list li::before {
    content: counter(toc);
    width: 22px;
    height: 22px;
    background: var(--brand);
    color: #fff;
    border-radius: 6px;
    display: grid;
    place-items: center;
    font-size: 0.72rem;
    font-weight: 700;
    flex-shrink: 0;
}

.toc-list a {
    color: var(--ink);
    text-decoration: none;
    font-weight: 550;
}

.toc-list a:hover {
    color: var(--brand);
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
    font-size: 0.8rem;
}

.data-table th {
    background: var(--brand);
    color: #fff;
    padding: 8px;
    text-align: left;
    font-weight: 650;
}

.data-table td {
    padding: 8px;
    border-bottom: 1px solid var(--line);
    color: var(--muted);
}

.data-table tr:nth-child(even) td {
    background: var(--brand-soft);
}

.note {
    background: var(--accent-soft);
    border-left: 3px solid var(--accent);
    padding: 10px 12px;
    border-radius: 0 8px 8px 0;
    font-size: 0.8rem;
    color: var(--muted);
    margin-top: 10px;
}

.badge-list {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 8px;
}

.badge {
    background: var(--brand-soft);
    color: var(--brand-deep);
    padding: 4px 9px;
    border-radius: 6px;
    font-size: 0.74rem;
    font-weight: 650;
}

.steps {
    list-style: none;
    padding: 0;
    margin-top: 8px;
    counter-reset: step;
}

.steps li {
    counter-increment: step;
    display: flex;
    gap: 10px;
    align-items: flex-start;
    padding: 8px 0;
    border-bottom: 1px solid var(--line);
    font-size: 0.84rem;
    color: var(--muted);
}

.steps li:last-child {
    border-bottom: none;
}

.steps li::before {
    content: counter(step);
    flex-shrink: 0;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--brand-soft);
    color: var(--brand-deep);
    font-weight: 750;
    font-size: 0.75rem;
    display: grid;
    place-items: center;
}

.tip {
    margin-top: 10px;
    padding: 10px 12px;
    background: var(--brand-soft);
    border-radius: 8px;
    font-size: 0.8rem;
    color: var(--muted);
}

footer {
    width: 100%;
    background: var(--card);
    border-top: 1px solid var(--line);
    text-align: center;
    padding: 16px 12px 20px;
    font-size: 0.72rem;
    color: var(--muted);
    margin-top: 12px;
}

.footer-menu {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 6px 10px;
    margin-bottom: 8px;
}

.footer-menu a {
    color: var(--muted);
    text-decoration: none;
    font-weight: 550;
}

.footer-menu a:hover {
    color: var(--brand);
    text-decoration: underline;
}

footer .copy {
    margin: 0;
}

footer .copy a {
    color: var(--brand);
    text-decoration: none;
    font-weight: 650;
}

.pay-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
    margin: 10px 0 12px;
}

.pay-card {
    border: 1px solid var(--line);
    border-radius: 8px;
    padding: 10px 8px;
    text-align: center;
    background: var(--paper);
}

.pay-card b {
    display: block;
    font-size: 0.82rem;
    color: var(--ink);
}

.pay-card span {
    font-size: 0.7rem;
    color: var(--muted);
}

.calc-box {
    margin-top: 10px;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--paper);
}

.calc-box label {
    display: block;
    font-size: 0.78rem;
    font-weight: 650;
    margin-bottom: 6px;
}

.calc-box input {
    width: 100%;
    padding: 10px;
    border: 1px solid var(--line);
    border-radius: 8px;
    font-size: 0.9rem;
}

.calc-out {
    margin-top: 8px;
    font-size: 0.86rem;
    font-weight: 700;
    color: var(--brand-deep);
}

.alias-wrap {
    font-size: 0.78rem;
    color: var(--muted);
    line-height: 1.7;
}

.page-hero {
    padding: 20px 16px 14px;
    text-align: center;
    background: linear-gradient(180deg, var(--brand-soft), var(--card));
    border-bottom: 1px solid var(--line);
}

.page-hero h1 {
    font-size: 1.28rem;
    font-weight: 750;
    margin-bottom: 4px;
}

.page-hero p {
    font-size: 0.84rem;
    color: var(--muted);
}

.faq-item {
    border-bottom: 1px solid var(--line);
    padding: 4px 0;
}

.faq-item:last-child {
    border-bottom: none;
}

.faq-item summary {
    cursor: pointer;
    font-size: 0.86rem;
    font-weight: 700;
    color: var(--ink);
    padding: 8px 0;
    list-style: none;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary::after {
    content: "+";
    float: right;
    color: var(--brand);
    font-weight: 700;
}

.faq-item[open] summary::after {
    content: "–";
}

.split-list {
    display: grid;
    gap: 8px;
}

@media (min-width: 400px) {
    .split-list {
        grid-template-columns: 1fr 1fr;
    }
}

.breadcrumb {
    font-size: 0.76rem;
    color: var(--muted);
    margin-bottom: 8px;
}

.breadcrumb a {
    color: var(--brand);
    text-decoration: none;
    font-weight: 650;
}

@media (max-width: 480px) {
    body {
        background: var(--card);
    }

    .shell {
        border-inline: none;
    }
}

.invite-code {
    display: inline-block;
    padding: 8px 16px;
    background: #16b9f2;
    color: #ffffff;
    font-size: 18px;
    font-weight: 700;
    text-decoration: none;
    border-radius: 8px;
    cursor: pointer;
    transition: 0.3s ease;
}

.invite-code:hover {
    background: #062d73;
}

.invite-code:active {
    transform: scale(0.96);
}