:root {
    --navy: #18324a;
    --navy-dark: #102536;
    --ink: #1c2a35;
    --muted: #62717c;
    --paper: #f7f8f6;
    --white: #ffffff;
    --line: #d6dde0;
    --saffron: #c98012;
    --saffron-soft: #f6ead4;
    --seafoam: #6da999;
    --seafoam-soft: #e4f0ed;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    color: var(--ink);
    background: var(--paper);
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", Arial, Helvetica, sans-serif;
    line-height: 1.72;
}

body.menu-open {
    overflow: hidden;
}

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

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

.site-rail {
    width: min(1180px, calc(100% - 48px));
    margin: 0 auto;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 60;
    background: rgba(247, 248, 246, 0.97);
    border-bottom: 1px solid var(--line);
    backdrop-filter: blur(12px);
}

.header-inner {
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 30px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    color: var(--navy-dark);
    font-size: 20px;
    font-weight: 850;
}

.brand img {
    width: 42px;
    height: 42px;
    border-radius: 6px;
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 28px;
    font-size: 15px;
    font-weight: 700;
}

.site-nav a {
    padding: 9px 0;
    border-bottom: 2px solid transparent;
}

.site-nav a:hover,
.site-nav a.active {
    border-color: var(--saffron);
}

.site-nav .nav-download {
    min-width: 104px;
    padding: 10px 20px;
    color: #ffffff;
    text-align: center;
    background: var(--navy);
    border: 0;
    border-radius: 5px;
}

.menu-toggle {
    display: none;
    width: 44px;
    height: 44px;
    padding: 0;
    color: var(--navy);
    background: transparent;
    border: 1px solid var(--line);
    border-radius: 5px;
    font-size: 22px;
}

.hero {
    overflow: hidden;
    background: #eef2f3;
    border-bottom: 1px solid var(--line);
}

.hero-grid {
    min-height: 604px;
    display: grid;
    grid-template-columns: minmax(0, 1.08fr) minmax(410px, 0.92fr);
    align-items: center;
    gap: 72px;
    padding: 52px 0 46px;
}

.eyebrow,
.step-label {
    color: var(--saffron);
    font-size: 12px;
    font-weight: 850;
    letter-spacing: 0;
}

.hero h1,
.inner-hero h1 {
    margin: 13px 0 20px;
    color: var(--navy-dark);
    font-size: clamp(42px, 5vw, 68px);
    line-height: 1.08;
    letter-spacing: 0;
}

.hero-copy > p {
    max-width: 620px;
    margin: 0;
    color: var(--muted);
    font-size: 18px;
}

.hero-actions {
    display: flex;
    align-items: center;
    gap: 24px;
    margin-top: 30px;
}

.primary-button {
    min-width: 136px;
    min-height: 48px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 26px;
    color: #ffffff;
    background: var(--navy);
    border: 1px solid var(--navy);
    border-radius: 5px;
    font-weight: 800;
    transition: transform 180ms ease, background 180ms ease;
}

.primary-button:hover {
    background: var(--navy-dark);
    transform: translateY(-2px);
}

.inline-link {
    color: var(--navy);
    font-weight: 800;
}

.inline-link span {
    display: inline-block;
    margin-left: 5px;
    transition: transform 180ms ease;
}

.inline-link:hover span {
    transform: translateX(4px);
}

.reading-route {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 32px;
}

.reading-route span {
    padding: 7px 11px;
    color: var(--navy);
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 3px;
    font-size: 12px;
    font-weight: 750;
}

.hero-media {
    position: relative;
    min-height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 30px 96px 30px 24px;
}

.archive-sleeve {
    position: relative;
    padding: 28px 18px 18px;
    background: #e6e2d9;
    border: 1px solid #cfc9bd;
    border-radius: 4px;
    box-shadow: 0 20px 42px rgba(24, 50, 74, 0.12);
}

.archive-sleeve::before {
    content: "";
    position: absolute;
    top: -12px;
    left: 18px;
    width: 108px;
    height: 20px;
    background: #e6e2d9;
    border: 1px solid #cfc9bd;
    border-bottom: 0;
    border-radius: 4px 4px 0 0;
}

.archive-sleeve img {
    width: auto;
    max-width: 400px;
    height: 402px;
    object-fit: contain;
    background: #ffffff;
}

.sleeve-label {
    position: absolute;
    z-index: 2;
    top: 8px;
    right: 16px;
    color: var(--navy);
    font-size: 11px;
    font-weight: 850;
}

.nav-sample {
    position: absolute;
    right: 0;
    display: grid;
    gap: 0;
    width: 118px;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 4px;
    box-shadow: 0 12px 30px rgba(24, 50, 74, 0.1);
}

.nav-sample span {
    padding: 11px 14px;
    color: var(--muted);
    border-bottom: 1px solid var(--line);
    font-size: 12px;
}

.nav-sample span:last-child {
    border-bottom: 0;
}

.nav-sample .nav-title {
    color: #ffffff;
    background: var(--navy);
    font-weight: 800;
}

.route-section {
    background: var(--white);
    border-bottom: 1px solid var(--line);
}

.route-layout {
    display: grid;
    grid-template-columns: 210px minmax(0, 1fr);
    gap: 58px;
    padding: 38px 0;
}

.section {
    padding: 88px 0;
}

.section-heading {
    display: flex;
    align-items: baseline;
    gap: 14px;
    margin-bottom: 42px;
}

.section-heading span,
.section-number {
    color: var(--saffron);
    font-size: 12px;
    font-weight: 850;
}

.section-heading h2,
.learn-layout h2,
.download-inner h2,
.faq-ending h2 {
    margin: 0;
    font-size: 34px;
    line-height: 1.25;
    letter-spacing: 0;
}

.route-layout .section-heading {
    margin: 0;
}

.route-layout .section-heading h2 {
    font-size: 24px;
}

.route-rows {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.route-rows article {
    position: relative;
    min-height: 138px;
    padding: 4px 24px 4px 26px;
    border-left: 1px solid var(--line);
}

.route-rows strong {
    color: var(--navy);
}

.route-rows p {
    margin: 7px 0 22px;
    color: var(--muted);
    font-size: 14px;
}

.route-rows article > span {
    color: var(--seafoam);
    font-size: 11px;
    font-weight: 850;
}

.feature-section {
    color: #ffffff;
    background: var(--navy-dark);
}

.light-heading h2 {
    color: #ffffff;
}

.feature-list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 46px;
}

.feature-list article {
    display: grid;
    grid-template-columns: 50px 1fr;
    gap: 20px;
    padding: 26px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.18);
}

.feature-mark {
    width: 46px;
    height: 46px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--navy-dark);
    background: var(--seafoam);
    border-radius: 4px;
    font-weight: 850;
}

.feature-list h3 {
    margin: 0 0 7px;
    font-size: 20px;
}

.feature-list p {
    margin: 0;
    color: #c9d5dc;
}

.record-section {
    background: var(--paper);
}

.record-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 360px;
    gap: 100px;
    align-items: center;
}

.record-steps {
    border-top: 1px solid var(--line);
}

.record-steps div {
    display: grid;
    grid-template-columns: 190px minmax(0, 1fr);
    gap: 28px;
    padding: 22px 0;
    border-bottom: 1px solid var(--line);
}

.record-steps strong {
    color: var(--navy);
}

.record-steps p {
    margin: 0;
    color: var(--muted);
}

.record-figure {
    margin: 0;
    padding: 24px;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 5px;
}

.record-figure img {
    width: auto;
    max-width: 400px;
    height: 390px;
    margin: 0 auto;
    object-fit: contain;
}

.record-figure figcaption {
    margin-top: 18px;
    padding-top: 16px;
    color: var(--muted);
    border-top: 1px solid var(--line);
    font-size: 14px;
}

.gallery-section {
    background: var(--white);
}

.gallery-strip {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
}

.gallery-strip figure {
    margin: 0;
    padding: 18px;
    background: #f2f4f4;
    border-radius: 5px;
}

.gallery-strip img {
    width: auto;
    max-width: 400px;
    height: 380px;
    margin: 0 auto;
    object-fit: contain;
}

.gallery-strip figcaption {
    display: grid;
    gap: 4px;
    margin-top: 16px;
    padding-top: 14px;
    border-top: 1px solid var(--line);
}

.gallery-strip figcaption span {
    color: var(--saffron);
    font-size: 12px;
    font-weight: 800;
}

.learn-section {
    background: var(--seafoam-soft);
}

.learn-layout {
    display: grid;
    grid-template-columns: 0.7fr 1fr 1fr;
    gap: 24px;
}

.learn-layout > div {
    padding: 20px 24px 20px 0;
}

.learn-layout > div h2 {
    margin-top: 8px;
}

.learn-layout > a {
    min-height: 210px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: space-between;
    padding: 28px;
    background: var(--white);
    border: 1px solid #c8d9d4;
    border-radius: 5px;
}

.learn-layout > a > span:first-child {
    color: var(--navy);
    font-size: 13px;
    font-weight: 850;
}

.learn-layout > a strong {
    max-width: 310px;
    font-size: 21px;
    line-height: 1.45;
}

.faq-preview {
    background: var(--paper);
}

.faq-layout {
    display: grid;
    grid-template-columns: 280px minmax(0, 1fr);
    gap: 80px;
}

.faq-list details,
.faq-content details {
    border-top: 1px solid var(--line);
}

.faq-list details:last-of-type,
.faq-content section details:last-of-type {
    border-bottom: 1px solid var(--line);
}

summary {
    position: relative;
    padding: 21px 44px 21px 0;
    font-weight: 780;
    cursor: pointer;
    list-style: none;
}

summary::-webkit-details-marker {
    display: none;
}

summary::after {
    content: "+";
    position: absolute;
    top: 16px;
    right: 4px;
    color: var(--saffron);
    font-size: 24px;
}

details[open] summary::after {
    content: "−";
}

.faq-list details p,
.faq-content details p {
    margin: 0;
    padding: 0 42px 22px 0;
    color: var(--muted);
}

.faq-list > .inline-link {
    display: inline-block;
    margin-top: 26px;
}

.download-band {
    color: #ffffff;
    background: var(--navy);
}

.download-inner {
    min-height: 190px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 30px;
}

.download-inner > div > span {
    color: #a9c6cf;
    font-size: 13px;
}

.download-inner h2 {
    margin-top: 6px;
}

.light-button {
    color: var(--navy);
    background: #ffffff;
    border-color: #ffffff;
}

.site-footer {
    background: #e8ecec;
    border-top: 1px solid var(--line);
}

.footer-inner {
    min-height: 124px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: var(--muted);
    text-align: center;
}

.footer-inner p {
    margin: 4px 0;
    font-size: 13px;
}

.inner-main {
    background: var(--white);
}

.inner-hero {
    background: #eef2f3;
    border-bottom: 1px solid var(--line);
}

.inner-hero-content {
    min-height: 420px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    padding: 58px 0;
}

.inner-hero h1 {
    max-width: 820px;
    font-size: clamp(40px, 5vw, 64px);
}

.inner-hero p {
    max-width: 720px;
    margin: 0 0 26px;
    color: var(--muted);
    font-size: 17px;
}

.guide-ledger,
.faq-library {
    padding: 84px 0;
}

.guide-grid,
.faq-grid {
    display: grid;
    grid-template-columns: 230px minmax(0, 780px);
    justify-content: center;
    gap: 72px;
}

.guide-nav,
.faq-index {
    position: sticky;
    top: 104px;
    align-self: start;
    display: grid;
    background: var(--paper);
    border: 1px solid var(--line);
    border-radius: 5px;
}

.guide-nav strong,
.faq-index strong {
    padding: 18px 20px;
    color: #ffffff;
    background: var(--navy);
}

.guide-nav a,
.faq-index a {
    display: flex;
    gap: 10px;
    padding: 14px 20px;
    color: var(--muted);
    border-bottom: 1px solid var(--line);
    font-size: 14px;
}

.guide-nav a:last-child,
.faq-index a:last-child {
    border-bottom: 0;
}

.guide-nav a:hover,
.faq-index a:hover {
    color: var(--navy);
    background: var(--saffron-soft);
}

.guide-nav a span {
    color: var(--saffron);
    font-size: 11px;
    font-weight: 850;
}

.guide-content section,
.faq-content section {
    margin-bottom: 72px;
    scroll-margin-top: 106px;
}

.guide-content h2,
.faq-heading h2 {
    margin: 8px 0 20px;
    color: var(--navy-dark);
    font-size: 31px;
    line-height: 1.3;
}

.guide-content p {
    margin: 0 0 18px;
    color: #3e4c56;
}

.guide-content a,
.faq-ending a:not(.primary-button) {
    color: var(--navy);
    font-weight: 800;
    text-decoration: underline;
    text-underline-offset: 3px;
}

.guide-note {
    display: grid;
    gap: 4px;
    margin-top: 26px;
    padding: 21px 24px;
    background: var(--saffron-soft);
    border-left: 3px solid var(--saffron);
}

.guide-note span {
    color: var(--muted);
}

.faq-hero .inner-hero-content {
    min-height: 380px;
}

.faq-heading {
    display: flex;
    align-items: baseline;
    gap: 13px;
    margin-bottom: 22px;
}

.faq-heading span {
    color: var(--saffron);
    font-size: 12px;
    font-weight: 850;
}

.faq-heading h2 {
    margin: 0;
}

.faq-ending {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 40px;
    padding: 34px;
    background: var(--seafoam-soft);
    border: 1px solid #c8d9d4;
    border-radius: 5px;
}

.faq-ending h2 {
    margin-top: 7px;
    font-size: 26px;
}

.faq-ending p {
    max-width: 560px;
    margin: 12px 0 0;
    color: var(--muted);
}

@media (max-width: 900px) {
    .hero-grid {
        grid-template-columns: minmax(0, 1fr) 380px;
        gap: 40px;
    }

    .site-nav {
        gap: 18px;
    }

    .record-grid {
        gap: 50px;
    }

    .learn-layout {
        grid-template-columns: 1fr 1fr;
    }

    .learn-layout > div {
        grid-column: 1 / -1;
    }
}

@media (max-width: 760px) {
    .site-rail {
        width: min(100% - 32px, 620px);
    }

    .header-inner {
        min-height: 64px;
    }

    .menu-toggle {
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .site-nav {
        position: fixed;
        top: 64px;
        right: 0;
        left: 0;
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        padding: 16px 16px 22px;
        background: var(--paper);
        border-bottom: 1px solid var(--line);
        box-shadow: 0 16px 28px rgba(24, 50, 74, 0.12);
    }

    .site-nav.open {
        display: flex;
    }

    .site-nav a {
        padding: 14px 12px;
        text-align: center;
    }

    .site-nav .nav-download {
        margin-top: 8px;
    }

    .hero-grid {
        min-height: 0;
        grid-template-columns: 1fr;
        gap: 24px;
        padding: 36px 0 30px;
    }

    .hero h1,
    .inner-hero h1 {
        font-size: 36px;
    }

    .hero-copy > p,
    .inner-hero p {
        font-size: 16px;
    }

    .hero-actions {
        flex-wrap: wrap;
        gap: 14px 20px;
        margin-top: 24px;
    }

    .reading-route {
        display: none;
    }

    .hero-media {
        min-height: 282px;
        padding: 12px 72px 12px 18px;
    }

    .archive-sleeve {
        padding: 22px 12px 12px;
    }

    .archive-sleeve img {
        height: 238px;
    }

    .nav-sample {
        width: 92px;
    }

    .nav-sample span {
        padding: 8px 10px;
        font-size: 11px;
    }

    .route-layout,
    .record-grid,
    .faq-layout,
    .guide-grid,
    .faq-grid {
        grid-template-columns: 1fr;
        gap: 28px;
    }

    .route-layout {
        padding: 30px 0;
    }

    .route-rows {
        grid-template-columns: 1fr;
    }

    .route-rows article {
        min-height: 0;
        padding: 16px 0;
        border-top: 1px solid var(--line);
        border-left: 0;
    }

    .section,
    .guide-ledger,
    .faq-library {
        padding: 62px 0;
    }

    .section-heading h2,
    .learn-layout h2,
    .download-inner h2 {
        font-size: 29px;
    }

    .feature-list,
    .gallery-strip,
    .learn-layout {
        grid-template-columns: 1fr;
    }

    .feature-list {
        gap: 0;
    }

    .record-steps div {
        grid-template-columns: 1fr;
        gap: 6px;
    }

    .record-figure {
        max-width: 360px;
        margin: 0 auto;
    }

    .record-figure img,
    .gallery-strip img {
        height: 360px;
    }

    .learn-layout > div {
        grid-column: auto;
    }

    .faq-layout .section-heading {
        margin-bottom: 0;
    }

    .download-inner,
    .faq-ending {
        align-items: flex-start;
        flex-direction: column;
        justify-content: center;
        padding-top: 32px;
        padding-bottom: 32px;
    }

    .inner-hero-content,
    .faq-hero .inner-hero-content {
        min-height: 0;
        padding: 54px 0;
    }

    .guide-nav,
    .faq-index {
        position: static;
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .guide-nav strong,
    .faq-index strong {
        grid-column: 1 / -1;
    }

    .guide-content section,
    .faq-content section {
        margin-bottom: 58px;
    }

    .faq-ending {
        padding-right: 24px;
        padding-left: 24px;
    }
}

@media (max-width: 420px) {
    .site-rail {
        width: calc(100% - 28px);
    }

    .brand {
        font-size: 18px;
    }

    .hero h1,
    .inner-hero h1 {
        font-size: 33px;
    }

    .hero-media {
        min-height: 270px;
        padding-right: 66px;
    }

    .archive-sleeve img {
        height: 226px;
    }

    .gallery-strip img {
        height: 340px;
    }

    .guide-nav,
    .faq-index {
        grid-template-columns: 1fr;
    }

    .guide-nav strong,
    .faq-index strong {
        grid-column: auto;
    }

    summary {
        padding-right: 38px;
    }

    .faq-list details p,
    .faq-content details p {
        padding-right: 12px;
    }
}