:root {
    --color-brand: #2f8f83;
    --color-brand-deep: #256f67;
    --color-brand-soft: #dceee9;
    --color-accent: #e96b4c;
    --color-accent-deep: #c9543a;
    --color-warm: #f2b36f;
    --color-ink: #243331;
    --color-text: #2e3836;
    --color-muted: #71807c;
    --color-bg: #fafcfa;
    --color-surface: #ffffff;
    --color-subtle: #eef5f2;
    --color-line: #d9e5e1;
    --shadow-sm: 0 10px 28px rgba(36, 51, 49, 0.08);
    --shadow-md: 0 18px 48px rgba(36, 51, 49, 0.12);
    --shadow-lg: 0 28px 72px rgba(36, 51, 49, 0.16);
    --radius-sm: 12px;
    --radius-md: 20px;
    --radius-lg: 30px;
    --radius-pill: 999px;
    --shell: 1180px;
    --shell-wide: 1320px;
    --content: 760px;
    --header-height: 76px;
    --transition: 180ms ease;
}

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

html {
    min-width: 320px;
    scroll-behavior: smooth;
    background: var(--color-bg);
    color: var(--color-text);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
}

body {
    margin: 0;
    min-height: 100vh;
    overflow-x: hidden;
    background:
        radial-gradient(circle at 12% -10%, rgba(47, 143, 131, 0.08), transparent 28rem),
        radial-gradient(circle at 92% 10%, rgba(242, 179, 111, 0.1), transparent 24rem),
        var(--color-bg);
    color: var(--color-text);
    line-height: 1.72;
}

body.menu-open {
    overflow: hidden;
}

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

a {
    color: inherit;
    text-decoration-thickness: 1px;
    text-underline-offset: 0.18em;
}

a:hover {
    text-decoration-thickness: 2px;
}

button,
input,
select,
textarea {
    font: inherit;
}

button {
    color: inherit;
}

h1,
h2,
h3,
p,
figure,
ul,
ol {
    margin-top: 0;
}

h1,
h2,
h3 {
    color: var(--color-ink);
    font-weight: 760;
    line-height: 1.18;
    letter-spacing: -0.025em;
}

h1 {
    font-size: clamp(2.35rem, 5.6vw, 5.35rem);
}

h2 {
    font-size: clamp(1.85rem, 3.5vw, 3.25rem);
}

h3 {
    font-size: clamp(1.2rem, 2vw, 1.55rem);
}

p {
    margin-bottom: 1.1rem;
}

::selection {
    background: rgba(47, 143, 131, 0.2);
    color: var(--color-ink);
}

:focus-visible {
    outline: 3px solid var(--color-accent);
    outline-offset: 4px;
    border-radius: 4px;
}

.shell {
    width: min(calc(100% - 40px), var(--shell));
    margin-inline: auto;
}

.shell--wide {
    width: min(calc(100% - 40px), var(--shell-wide));
}

.skip-link {
    position: fixed;
    top: 10px;
    left: 10px;
    z-index: 1000;
    padding: 0.7rem 1rem;
    border-radius: 8px;
    background: var(--color-ink);
    color: #fff;
    transform: translateY(-150%);
    transition: transform var(--transition);
}

.skip-link:focus {
    transform: translateY(0);
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    min-height: var(--header-height);
    border-bottom: 1px solid rgba(217, 229, 225, 0.82);
    background: rgba(250, 252, 250, 0.9);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
}

.site-header.is-scrolled {
    box-shadow: 0 8px 30px rgba(36, 51, 49, 0.06);
}

.site-header__inner {
    min-height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 0.8rem;
    min-width: 0;
    text-decoration: none;
}

.brand:hover {
    text-decoration: none;
}

.brand__logo {
    width: 48px;
    height: 48px;
    flex: 0 0 auto;
    border-radius: 14px;
    object-fit: cover;
    background: var(--color-subtle);
    box-shadow: inset 0 0 0 1px rgba(47, 143, 131, 0.12);
}

.brand__text {
    display: grid;
    min-width: 0;
}

.brand__text strong {
    color: var(--color-ink);
    font-size: 1.12rem;
    line-height: 1.25;
}

.brand__text small {
    margin-top: 0.16rem;
    color: var(--color-muted);
    font-size: 0.78rem;
    white-space: nowrap;
}

.primary-nav ul {
    display: flex;
    align-items: center;
    gap: 0.28rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

.primary-nav a {
    position: relative;
    display: inline-flex;
    align-items: center;
    min-height: 42px;
    padding: 0.5rem 0.9rem;
    border-radius: var(--radius-pill);
    color: var(--color-text);
    font-size: 0.95rem;
    font-weight: 650;
    text-decoration: none;
    transition: color var(--transition), background var(--transition), transform var(--transition);
}

.primary-nav a:hover {
    background: var(--color-subtle);
    color: var(--color-brand-deep);
    transform: translateY(-1px);
}

.primary-nav a[aria-current="page"] {
    background: var(--color-ink);
    color: #fff;
}

.menu-toggle {
    display: none;
    width: 48px;
    height: 48px;
    padding: 0;
    border: 1px solid var(--color-line);
    border-radius: 14px;
    background: var(--color-surface);
    cursor: pointer;
}

.menu-toggle__line {
    display: block;
    width: 20px;
    height: 2px;
    margin: 5px auto;
    border-radius: 2px;
    background: var(--color-ink);
    transition: transform var(--transition), opacity var(--transition);
}

.menu-toggle__label {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0 0 0 0);
    white-space: nowrap;
}

.menu-toggle[aria-expanded="true"] .menu-toggle__line:first-child {
    transform: translateY(3.5px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-toggle__line:nth-child(2) {
    transform: translateY(-3.5px) rotate(-45deg);
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    margin-bottom: 1rem;
    color: var(--color-brand-deep);
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.13em;
    text-transform: uppercase;
}

.eyebrow::before {
    content: "";
    width: 22px;
    height: 2px;
    border-radius: 2px;
    background: currentColor;
}

.eyebrow--accent {
    color: var(--color-accent-deep);
}

.eyebrow--light {
    color: #dff5ef;
}

.hero {
    position: relative;
    padding: clamp(4.2rem, 8vw, 8rem) 0 clamp(4rem, 7vw, 7rem);
}

.hero::before {
    content: "";
    position: absolute;
    inset: 10% auto auto 4%;
    width: 150px;
    height: 150px;
    border: 1px solid rgba(47, 143, 131, 0.18);
    border-radius: 50%;
    pointer-events: none;
}

.hero__grid {
    display: grid;
    grid-template-columns: minmax(0, 1.06fr) minmax(340px, 0.94fr);
    align-items: center;
    gap: clamp(2.5rem, 5vw, 6rem);
}

.hero__copy {
    position: relative;
    z-index: 1;
}

.hero__copy h1 {
    max-width: 13ch;
    margin-bottom: 1.4rem;
}

.hero__lead {
    max-width: 42rem;
    margin-bottom: 1.8rem;
    color: #4c5d59;
    font-size: clamp(1.05rem, 1.5vw, 1.24rem);
}

.hero__actions,
.page-hero__actions,
.not-found__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
    margin-top: 1.65rem;
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0.75rem 1.2rem;
    border: 1px solid transparent;
    border-radius: var(--radius-pill);
    font-weight: 750;
    line-height: 1.2;
    text-decoration: none;
    transition: transform var(--transition), box-shadow var(--transition), background var(--transition), color var(--transition), border-color var(--transition);
}

.button:hover {
    text-decoration: none;
    transform: translateY(-2px);
}

.button--primary {
    background: var(--color-brand);
    color: #fff;
    box-shadow: 0 12px 28px rgba(47, 143, 131, 0.22);
}

.button--primary:hover {
    background: var(--color-brand-deep);
    box-shadow: 0 16px 36px rgba(47, 143, 131, 0.28);
}

.button--quiet {
    border-color: var(--color-line);
    background: rgba(255, 255, 255, 0.82);
    color: var(--color-ink);
}

.button--quiet:hover {
    border-color: rgba(47, 143, 131, 0.38);
    background: var(--color-surface);
    color: var(--color-brand-deep);
}

.hero__notes {
    display: flex;
    flex-wrap: wrap;
    gap: 0.55rem;
    margin-top: 1.8rem;
}

.hero__notes span {
    display: inline-flex;
    align-items: center;
    min-height: 32px;
    padding: 0.35rem 0.7rem;
    border: 1px solid rgba(47, 143, 131, 0.18);
    border-radius: var(--radius-pill);
    background: rgba(238, 245, 242, 0.68);
    color: var(--color-brand-deep);
    font-size: 0.82rem;
    font-weight: 700;
}

.hero__media {
    position: relative;
    margin: 0;
}

.hero__media::before {
    content: "";
    position: absolute;
    inset: -18px 18px 18px -18px;
    z-index: -1;
    border-radius: calc(var(--radius-lg) + 10px);
    background: linear-gradient(145deg, rgba(47, 143, 131, 0.16), rgba(242, 179, 111, 0.2));
}

.hero__media img {
    width: 100%;
    aspect-ratio: 4 / 4.6;
    border-radius: var(--radius-lg);
    object-fit: cover;
    box-shadow: var(--shadow-lg);
}

.hero__media figcaption,
.page-hero__media figcaption,
.feature-layout__visual figcaption,
.desktop-layout__media figcaption,
.portrait-layout__media figcaption {
    margin-top: 0.8rem;
    color: var(--color-muted);
    font-size: 0.86rem;
}

.section {
    position: relative;
    padding: clamp(4.5rem, 8vw, 8rem) 0;
}

.section--content,
.section--guide,
.section--desktop-guide,
.section--app-guide {
    background: var(--color-surface);
}

.section--rhythm,
.section--browser-map,
.section--desktop-layout,
.section--portrait,
.section--device-compare {
    background: var(--color-subtle);
}

.section-heading {
    max-width: 780px;
    margin-bottom: clamp(2rem, 4vw, 3.6rem);
}

.section-heading h2 {
    margin-bottom: 1rem;
}

.section-heading > p:last-child {
    color: var(--color-muted);
    font-size: 1.02rem;
}

.section-heading--split {
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.9fr);
    align-items: end;
    gap: 3rem;
    max-width: none;
}

.section-heading--split > p {
    margin-bottom: 0.4rem;
}

.section-heading--compact {
    margin-bottom: 2rem;
}

.feature-layout {
    display: grid;
    grid-template-columns: minmax(260px, 0.72fr) minmax(0, 1.28fr);
    gap: clamp(2rem, 4vw, 4.5rem);
    align-items: start;
}

.feature-layout__visual {
    position: sticky;
    top: calc(var(--header-height) + 24px);
    margin: 0;
}

.feature-layout__visual img {
    width: 100%;
    aspect-ratio: 4 / 5.1;
    border-radius: var(--radius-lg);
    object-fit: cover;
    box-shadow: var(--shadow-md);
}

.topic-grid {
    display: grid;
    gap: 1rem;
}

.topic-grid--home {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.topic-grid--guide,
.topic-grid--desktop {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.topic-grid--app {
    grid-template-columns: repeat(3, minmax(0, 1fr));
}

.topic-card {
    position: relative;
    min-width: 0;
    padding: 1.5rem;
    overflow: hidden;
    border: 1px solid var(--color-line);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    box-shadow: 0 8px 28px rgba(36, 51, 49, 0.035);
    transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.topic-card::after {
    content: "";
    position: absolute;
    right: -36px;
    bottom: -36px;
    width: 90px;
    height: 90px;
    border-radius: 50%;
    background: rgba(47, 143, 131, 0.055);
    transition: transform var(--transition);
}

.topic-card:hover {
    transform: translateY(-3px);
    border-color: rgba(47, 143, 131, 0.28);
    box-shadow: var(--shadow-sm);
}

.topic-card:hover::after {
    transform: scale(1.3);
}

.topic-card h3 {
    margin-bottom: 0.75rem;
}

.topic-card p {
    color: #52615e;
}

.topic-card .eyebrow {
    margin-bottom: 0.7rem;
    font-size: 0.68rem;
}

.plain-list,
.check-list {
    margin: 1rem 0 0;
    padding: 0;
    list-style: none;
}

.plain-list li,
.check-list li {
    position: relative;
    margin: 0.48rem 0;
    padding-left: 1.2rem;
    color: #4c5c58;
    font-size: 0.9rem;
}

.plain-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0.72em;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--color-warm);
}

.check-list li {
    padding-left: 1.65rem;
}

.check-list li::before {
    content: "✓";
    position: absolute;
    left: 0;
    top: 0;
    color: var(--color-brand);
    font-weight: 900;
}

.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 0.45rem;
    margin: 1.1rem 0 0;
    padding: 0;
    list-style: none;
}

.tag-list li {
    padding: 0.28rem 0.6rem;
    border-radius: var(--radius-pill);
    background: var(--color-subtle);
    color: var(--color-brand-deep);
    font-size: 0.76rem;
    font-weight: 700;
}

.rhythm-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1rem;
}

.rhythm-card {
    min-height: 280px;
    padding: 1.55rem;
    border-radius: var(--radius-md);
    background: var(--color-surface);
    box-shadow: 0 10px 28px rgba(36, 51, 49, 0.05);
}

.rhythm-card__index {
    display: block;
    margin-bottom: 2.5rem;
    color: var(--color-brand);
    font-size: 2.2rem;
    font-weight: 800;
    line-height: 1;
    letter-spacing: -0.05em;
}

.rhythm-card h3 {
    margin-bottom: 0.8rem;
}

.rhythm-card p {
    margin-bottom: 0;
    color: var(--color-muted);
    font-size: 0.94rem;
}

.split-panel {
    display: grid;
    grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
    align-items: center;
    gap: clamp(2.5rem, 6vw, 6rem);
}

.split-panel__media {
    position: relative;
}

.split-panel__media::after {
    content: "";
    position: absolute;
    inset: auto -20px -20px auto;
    width: 42%;
    aspect-ratio: 1;
    z-index: -1;
    border-radius: 50%;
    background: rgba(242, 179, 111, 0.22);
}

.split-panel__media img {
    width: 100%;
    aspect-ratio: 1.13 / 1;
    border-radius: var(--radius-lg);
    object-fit: cover;
}

.split-panel__copy h2 {
    margin-bottom: 1.2rem;
}

.split-panel__copy > p {
    color: #4b5c58;
}

.text-link {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    margin-top: 1.1rem;
    color: var(--color-brand-deep);
    font-weight: 800;
    text-decoration: none;
}

.text-link span {
    transition: transform var(--transition);
}

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

.text-link--light {
    color: #f4fffc;
}

.section--device-bridge {
    padding-top: 2rem;
}

.device-bridge {
    padding: clamp(2rem, 4vw, 4rem);
    border-radius: var(--radius-lg);
    background: var(--color-ink);
    color: #e7f1ee;
}

.device-bridge__intro {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(280px, 0.8fr);
    align-items: end;
    gap: 2.5rem;
    margin-bottom: 2.5rem;
}

.device-bridge__intro h2 {
    max-width: 14ch;
    margin-bottom: 0;
    color: #fff;
}

.device-bridge__intro p:last-child {
    margin-bottom: 0.3rem;
    color: #bed0cb;
}

.device-bridge__cards {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
}

.device-card {
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    background: rgba(255, 255, 255, 0.06);
    text-decoration: none;
    transition: transform var(--transition), background var(--transition), border-color var(--transition);
}

.device-card:hover {
    transform: translateY(-4px);
    border-color: rgba(255, 255, 255, 0.22);
    background: rgba(255, 255, 255, 0.09);
}

.device-card img {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
}

.device-card__body {
    display: grid;
    gap: 0.55rem;
    padding: 1.35rem;
}

.device-card__label {
    color: #b8e1d8;
    font-size: 0.78rem;
    font-weight: 800;
    letter-spacing: 0.08em;
}

.device-card strong {
    color: #fff;
    font-size: 1.22rem;
}

.device-card__body > span:last-child {
    color: #c2d2ce;
    font-size: 0.92rem;
}

.faq-layout {
    display: grid;
    grid-template-columns: minmax(260px, 0.78fr) minmax(0, 1.22fr);
    gap: clamp(2rem, 5vw, 5rem);
    align-items: start;
}

.faq-layout--reverse {
    grid-template-columns: minmax(0, 1.22fr) minmax(260px, 0.78fr);
}

.faq-layout--reverse .faq-layout__intro {
    grid-column: 2;
    grid-row: 1;
}

.faq-layout--reverse .faq-layout__list {
    grid-column: 1;
    grid-row: 1;
}

.faq-layout__intro {
    position: sticky;
    top: calc(var(--header-height) + 28px);
}

.faq-layout__intro h2 {
    margin-bottom: 1rem;
}

.faq-layout__intro > p {
    color: var(--color-muted);
}

.faq-layout__intro img {
    width: min(100%, 520px);
    margin-top: 1.8rem;
    aspect-ratio: 1.24 / 1;
    border-radius: var(--radius-md);
    object-fit: cover;
}

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

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

.faq-item summary {
    position: relative;
    padding: 1.4rem 3rem 1.4rem 0;
    color: var(--color-ink);
    font-size: 1.05rem;
    font-weight: 750;
    cursor: pointer;
    list-style: none;
}

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

.faq-item summary::before,
.faq-item summary::after {
    content: "";
    position: absolute;
    right: 0.4rem;
    top: 50%;
    width: 16px;
    height: 2px;
    background: var(--color-brand);
    transform: translateY(-50%);
    transition: transform var(--transition);
}

.faq-item summary::after {
    transform: translateY(-50%) rotate(90deg);
}

.faq-item[open] summary::after {
    transform: translateY(-50%) rotate(0deg);
}

.faq-answer {
    max-width: 680px;
    padding: 0 2.5rem 1.35rem 0;
}

.faq-answer p {
    margin-bottom: 0;
    color: var(--color-muted);
}

.related-links {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1rem;
}

.related-link {
    position: relative;
    display: grid;
    gap: 0.45rem;
    min-height: 180px;
    padding: 1.4rem 3.2rem 1.4rem 1.4rem;
    border: 1px solid var(--color-line);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    text-decoration: none;
    transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.related-link:hover {
    transform: translateY(-3px);
    border-color: rgba(47, 143, 131, 0.28);
    box-shadow: var(--shadow-sm);
}

.related-link__title {
    color: var(--color-ink);
    font-size: 1.15rem;
    font-weight: 780;
}

.related-link__text {
    color: var(--color-muted);
    font-size: 0.92rem;
}

.related-link__arrow {
    position: absolute;
    right: 1.2rem;
    bottom: 1.2rem;
    display: grid;
    place-items: center;
    width: 34px;
    height: 34px;
    border-radius: 50%;
    background: var(--color-subtle);
    color: var(--color-brand-deep);
    font-weight: 900;
    transition: transform var(--transition), background var(--transition);
}

.related-link:hover .related-link__arrow {
    transform: translateX(3px);
    background: var(--color-brand);
    color: #fff;
}

.page-hero {
    padding: 2rem 0 clamp(4rem, 7vw, 7rem);
}

.breadcrumbs {
    padding: 1rem 0 2rem;
}

.breadcrumbs ol {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 0.45rem;
    margin: 0;
    padding: 0;
    list-style: none;
    color: var(--color-muted);
    font-size: 0.84rem;
}

.breadcrumbs li {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
}

.breadcrumbs li:not(:last-child)::after {
    content: "/";
    color: #a6b3b0;
}

.breadcrumbs a {
    color: var(--color-brand-deep);
}

.page-hero__grid {
    display: grid;
    grid-template-columns: minmax(0, 1.03fr) minmax(340px, 0.97fr);
    align-items: center;
    gap: clamp(2.6rem, 5vw, 5.5rem);
}

.page-hero__copy h1 {
    max-width: 14ch;
    margin-bottom: 1.35rem;
    font-size: clamp(2.3rem, 5vw, 4.75rem);
}

.page-hero__lead {
    max-width: 44rem;
    color: #4d5d59;
    font-size: clamp(1.03rem, 1.45vw, 1.2rem);
}

.page-hero__media {
    margin: 0;
}

.page-hero__media img {
    width: 100%;
    border-radius: var(--radius-lg);
    object-fit: cover;
    box-shadow: var(--shadow-md);
}

.page-hero__media--contained img {
    aspect-ratio: 1.12 / 1;
}

.page-hero__media--wide img {
    aspect-ratio: 1.34 / 1;
}

.page-hero__media--phone {
    width: min(100%, 520px);
    justify-self: end;
}

.page-hero__media--phone img {
    aspect-ratio: 0.82 / 1;
}

.page-hero--web .page-hero__media img {
    background: linear-gradient(180deg, #e3f1ed, #f7efe3);
}

.page-hero--desktop .page-hero__media img {
    background: linear-gradient(150deg, #e8f4f0, #f7ead9);
}

.page-hero--app .page-hero__media img {
    background: linear-gradient(180deg, #e8f3ef, #fff7ec);
}

.browser-map {
    display: grid;
    grid-template-columns: minmax(280px, 0.8fr) minmax(0, 1.2fr);
    align-items: center;
    gap: clamp(2.5rem, 5vw, 5rem);
}

.browser-map__visual img {
    width: 100%;
    aspect-ratio: 0.95 / 1;
    border-radius: var(--radius-lg);
    object-fit: cover;
}

.browser-map__content h2 {
    margin-bottom: 1rem;
}

.step-list {
    display: grid;
    gap: 1rem;
    margin: 1.8rem 0 0;
    padding: 0;
    list-style: none;
}

.step-list li {
    display: grid;
    grid-template-columns: 46px minmax(0, 1fr);
    gap: 1rem;
    align-items: start;
    padding: 1rem 0;
    border-top: 1px solid rgba(47, 143, 131, 0.15);
}

.step-list__number {
    display: grid;
    place-items: center;
    width: 42px;
    height: 42px;
    border-radius: 14px;
    background: var(--color-surface);
    color: var(--color-brand-deep);
    font-weight: 850;
    box-shadow: 0 6px 18px rgba(36, 51, 49, 0.06);
}

.step-list strong {
    color: var(--color-ink);
    font-size: 1.02rem;
}

.step-list p {
    margin: 0.35rem 0 0;
    color: var(--color-muted);
}

.section--web-notes,
.section--keyboard {
    padding-block: 2rem;
}

.note-strip,
.keyboard-panel {
    display: grid;
    grid-template-columns: minmax(0, 1.1fr) minmax(280px, 0.9fr);
    align-items: center;
    gap: 2.5rem;
    padding: clamp(2rem, 4vw, 3.6rem);
    border-radius: var(--radius-lg);
    background: linear-gradient(135deg, #285d57, var(--color-ink));
    color: #dce9e6;
}

.note-strip h2,
.keyboard-panel h2 {
    color: #fff;
}

.note-strip p,
.keyboard-panel p {
    margin-bottom: 0;
    color: #bed0cb;
}

.note-strip__facts {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.7rem;
}

.note-strip__facts span {
    display: grid;
    place-items: center;
    min-height: 86px;
    padding: 1rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.05);
    color: #eff8f6;
    font-weight: 750;
    text-align: center;
}

.desktop-layout {
    display: grid;
    grid-template-columns: minmax(0, 1.12fr) minmax(300px, 0.88fr);
    align-items: center;
    gap: clamp(2.5rem, 5vw, 5rem);
}

.desktop-layout__content h2 {
    margin-bottom: 1rem;
}

.desktop-layout__content > p {
    color: var(--color-muted);
}

.desktop-layout__media {
    margin: 0;
}

.desktop-layout__media img {
    width: 100%;
    aspect-ratio: 0.92 / 1;
    border-radius: var(--radius-lg);
    object-fit: cover;
}

.metric-list {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.8rem;
    margin-top: 1.8rem;
}

.metric-item {
    padding: 1rem;
    border: 1px solid rgba(47, 143, 131, 0.16);
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.7);
}

.metric-item strong,
.metric-item span {
    display: block;
}

.metric-item strong {
    margin-bottom: 0.35rem;
    color: var(--color-brand-deep);
}

.metric-item span {
    color: #61706d;
    font-size: 0.88rem;
}

.keyboard-panel {
    grid-template-columns: minmax(260px, 0.75fr) minmax(0, 1.25fr);
}

.keyboard-panel__visual {
    display: grid;
    grid-template-columns: repeat(2, minmax(80px, 1fr));
    gap: 0.8rem;
}

.key {
    display: grid;
    place-items: center;
    min-height: 76px;
    border: 1px solid rgba(255, 255, 255, 0.14);
    border-bottom-width: 4px;
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.07);
    color: #fff;
    font-weight: 820;
    box-shadow: inset 0 -3px 0 rgba(0, 0, 0, 0.12);
}

.portrait-layout {
    display: grid;
    grid-template-columns: minmax(280px, 0.82fr) minmax(0, 1.18fr);
    align-items: center;
    gap: clamp(2.6rem, 6vw, 6rem);
}

.portrait-layout__media {
    margin: 0;
}

.portrait-layout__media img {
    width: 100%;
    aspect-ratio: 0.76 / 1;
    border-radius: var(--radius-lg);
    object-fit: cover;
}

.portrait-layout__copy > p {
    color: var(--color-muted);
}

.portrait-points {
    display: grid;
    gap: 0.9rem;
    margin-top: 1.8rem;
}

.portrait-points article {
    padding: 1.05rem 1.1rem;
    border-left: 3px solid var(--color-brand);
    background: rgba(255, 255, 255, 0.68);
}

.portrait-points strong {
    color: var(--color-ink);
}

.portrait-points p {
    margin: 0.32rem 0 0;
    color: var(--color-muted);
    font-size: 0.9rem;
}

.compare-table-wrap {
    overflow-x: auto;
    border: 1px solid var(--color-line);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    box-shadow: 0 10px 30px rgba(36, 51, 49, 0.04);
}

.compare-table {
    width: 100%;
    min-width: 760px;
    border-collapse: collapse;
    color: var(--color-text);
}

.compare-table th,
.compare-table td {
    padding: 1rem 1.1rem;
    border-bottom: 1px solid var(--color-line);
    text-align: left;
    vertical-align: top;
}

.compare-table thead th {
    background: #e7f2ee;
    color: var(--color-ink);
    font-size: 0.9rem;
}

.compare-table tbody th {
    width: 18%;
    color: var(--color-brand-deep);
    font-size: 0.9rem;
}

.compare-table td {
    color: #586864;
    font-size: 0.92rem;
}

.compare-table tbody tr:last-child th,
.compare-table tbody tr:last-child td {
    border-bottom: 0;
}

.not-found {
    min-height: calc(100vh - var(--header-height) - 260px);
    display: grid;
    align-items: center;
    padding: 4rem 0 6rem;
}

.not-found__inner {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(280px, 0.8fr);
    align-items: center;
    gap: clamp(2rem, 5vw, 5rem);
}

.not-found__copy h1 {
    max-width: 9ch;
    margin-bottom: 1rem;
}

.not-found__copy p {
    max-width: 42rem;
    color: var(--color-muted);
    font-size: 1.04rem;
}

.not-found__inner img {
    width: 100%;
    border-radius: var(--radius-lg);
    object-fit: cover;
}

.site-footer {
    border-top: 1px solid var(--color-line);
    background: #f3f7f5;
}

.site-footer__grid {
    display: grid;
    grid-template-columns: minmax(0, 1.3fr) minmax(180px, 0.7fr) minmax(220px, 0.8fr);
    gap: 2rem;
    padding-block: 3.5rem;
}

.site-footer__title {
    margin-bottom: 0.6rem;
    color: var(--color-ink);
    font-size: 1.22rem;
    font-weight: 820;
}

.site-footer__brand p:last-child,
.site-footer__meta p {
    color: var(--color-muted);
    font-size: 0.9rem;
}

.site-footer__nav {
    display: grid;
    align-content: start;
    gap: 0.52rem;
}

.site-footer__nav a {
    width: fit-content;
    color: var(--color-brand-deep);
    font-weight: 700;
}

.site-footer__meta p {
    margin-bottom: 0.45rem;
}

[data-reveal] {
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 500ms ease, transform 500ms ease;
}

[data-reveal].is-visible {
    opacity: 1;
    transform: translateY(0);
}

.no-js [data-reveal] {
    opacity: 1;
    transform: none;
}

@media (max-width: 1120px) {
    .hero__grid,
    .page-hero__grid {
        grid-template-columns: minmax(0, 1.08fr) minmax(300px, 0.92fr);
        gap: 3rem;
    }

    .rhythm-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .topic-grid--app {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .device-bridge__intro {
        grid-template-columns: 1fr;
        gap: 1.2rem;
    }

    .device-bridge__intro h2 {
        max-width: 18ch;
    }
}

@media (max-width: 920px) {
    :root {
        --header-height: 70px;
    }

    .shell,
    .shell--wide {
        width: min(calc(100% - 30px), var(--shell));
    }

    .brand__text small {
        display: none;
    }

    .menu-toggle {
        display: inline-block;
        position: relative;
        z-index: 102;
        flex: 0 0 auto;
    }

    .primary-nav {
        position: fixed;
        inset: var(--header-height) 0 auto 0;
        z-index: 101;
        padding: 1rem 15px 1.2rem;
        border-bottom: 1px solid var(--color-line);
        background: rgba(250, 252, 250, 0.98);
        box-shadow: 0 18px 42px rgba(36, 51, 49, 0.12);
        transform: translateY(-130%);
        opacity: 0;
        visibility: hidden;
        transition: transform 220ms ease, opacity 180ms ease, visibility 180ms ease;
    }

    .primary-nav.is-open {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .primary-nav ul {
        display: grid;
        width: min(100%, 760px);
        margin-inline: auto;
    }

    .primary-nav a {
        width: 100%;
        justify-content: space-between;
        border-radius: 12px;
    }

    .hero__grid,
    .page-hero__grid,
    .feature-layout,
    .split-panel,
    .browser-map,
    .desktop-layout,
    .portrait-layout,
    .not-found__inner {
        grid-template-columns: 1fr;
    }

    .hero__copy h1,
    .page-hero__copy h1 {
        max-width: 16ch;
    }

    .hero__media,
    .page-hero__media,
    .page-hero__media--phone {
        width: min(100%, 680px);
        justify-self: center;
    }

    .feature-layout__visual,
    .faq-layout__intro {
        position: static;
    }

    .feature-layout__visual {
        width: min(100%, 520px);
    }

    .feature-layout__visual img {
        aspect-ratio: 1.06 / 1;
    }

    .section-heading--split {
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }

    .faq-layout,
    .faq-layout--reverse {
        grid-template-columns: 1fr;
    }

    .faq-layout--reverse .faq-layout__intro,
    .faq-layout--reverse .faq-layout__list {
        grid-column: auto;
        grid-row: auto;
    }

    .faq-layout--reverse .faq-layout__intro {
        order: -1;
    }

    .faq-layout__intro img {
        max-width: 420px;
    }

    .related-links {
        grid-template-columns: 1fr;
    }

    .related-link {
        min-height: 140px;
    }

    .note-strip,
    .keyboard-panel {
        grid-template-columns: 1fr;
    }

    .page-hero__media--wide img {
        aspect-ratio: 1.2 / 1;
    }

    .desktop-layout__media,
    .portrait-layout__media {
        width: min(100%, 600px);
    }

    .portrait-layout__media {
        justify-self: center;
    }

    .site-footer__grid {
        grid-template-columns: 1fr 1fr;
    }

    .site-footer__brand {
        grid-column: 1 / -1;
    }
}

@media (max-width: 680px) {
    .shell,
    .shell--wide {
        width: min(calc(100% - 24px), var(--shell));
    }

    .brand__logo {
        width: 42px;
        height: 42px;
        border-radius: 12px;
    }

    .brand__text strong {
        font-size: 1rem;
    }

    .hero,
    .section {
        padding-block: 4.5rem;
    }

    .hero {
        padding-top: 3.2rem;
    }

    .hero__grid,
    .page-hero__grid {
        gap: 2.2rem;
    }

    .hero__copy h1,
    .page-hero__copy h1 {
        margin-bottom: 1rem;
    }

    .hero__actions,
    .page-hero__actions,
    .not-found__actions {
        display: grid;
        grid-template-columns: 1fr;
    }

    .button {
        width: 100%;
    }

    .hero__notes {
        margin-top: 1.3rem;
    }

    .hero__media::before {
        inset: -10px 10px 10px -10px;
    }

    .hero__media img {
        aspect-ratio: 1 / 1.08;
    }

    .topic-grid--home,
    .topic-grid--guide,
    .topic-grid--desktop,
    .topic-grid--app,
    .rhythm-grid,
    .device-bridge__cards,
    .metric-list,
    .site-footer__grid {
        grid-template-columns: 1fr;
    }

    .topic-card,
    .rhythm-card {
        padding: 1.2rem;
    }

    .rhythm-card {
        min-height: 0;
    }

    .rhythm-card__index {
        margin-bottom: 1.4rem;
    }

    .device-bridge {
        padding: 1.35rem;
        border-radius: var(--radius-md);
    }

    .device-bridge__intro {
        margin-bottom: 1.4rem;
    }

    .faq-item summary {
        padding-right: 2.4rem;
        font-size: 1rem;
    }

    .faq-answer {
        padding-right: 0.4rem;
    }

    .page-hero {
        padding-bottom: 4.5rem;
    }

    .breadcrumbs {
        padding-bottom: 1.3rem;
    }

    .step-list li {
        grid-template-columns: 38px minmax(0, 1fr);
        gap: 0.8rem;
    }

    .step-list__number {
        width: 36px;
        height: 36px;
        border-radius: 11px;
        font-size: 0.9rem;
    }

    .note-strip,
    .keyboard-panel {
        padding: 1.4rem;
        border-radius: var(--radius-md);
    }

    .note-strip__facts,
    .keyboard-panel__visual {
        grid-template-columns: 1fr 1fr;
    }

    .note-strip__facts span,
    .key {
        min-height: 66px;
    }

    .compare-table-wrap {
        margin-inline: -12px;
        border-radius: 0;
        border-left: 0;
        border-right: 0;
    }

    .site-footer__brand {
        grid-column: auto;
    }

    .site-footer__grid {
        padding-block: 2.6rem;
    }
}

@media (max-width: 420px) {
    .hero__notes span {
        flex: 1 1 auto;
        justify-content: center;
    }

    .topic-card {
        border-radius: 16px;
    }

    .note-strip__facts,
    .keyboard-panel__visual {
        grid-template-columns: 1fr;
    }

    .page-hero__media--phone img,
    .portrait-layout__media img {
        border-radius: 22px;
    }
}

@media (hover: none) {
    .topic-card:hover,
    .related-link:hover,
    .device-card:hover,
    .button:hover,
    .primary-nav a:hover {
        transform: none;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
    }

    [data-reveal] {
        opacity: 1;
        transform: none;
    }
}

@media print {
    .site-header,
    .site-footer,
    .hero__actions,
    .page-hero__actions,
    .skip-link {
        display: none !important;
    }

    body {
        background: #fff;
        color: #000;
    }

    .section,
    .hero,
    .page-hero {
        padding: 1.5rem 0;
    }

    .shell,
    .shell--wide {
        width: 100%;
    }

    .topic-card,
    .rhythm-card,
    .related-link,
    .device-bridge,
    .note-strip,
    .keyboard-panel {
        break-inside: avoid;
        box-shadow: none;
    }

    a[href]::after {
        content: " (" attr(href) ")";
        font-size: 0.8em;
        color: #555;
    }
}

/* Progressive enhancement states used by the local interaction script. */
.compact-target {
    position: relative;
}

.compact-target::before {
    content: "";
    position: absolute;
    inset: -6px;
}

.compare-table-wrap.is-scrollable {
    position: relative;
    scrollbar-width: thin;
    scrollbar-color: var(--color-brand) var(--color-subtle);
}

.compare-table-wrap.is-scrollable::-webkit-scrollbar {
    height: 10px;
}

.compare-table-wrap.is-scrollable::-webkit-scrollbar-track {
    background: var(--color-subtle);
}

.compare-table-wrap.is-scrollable::-webkit-scrollbar-thumb {
    border: 2px solid var(--color-subtle);
    border-radius: 999px;
    background: var(--color-brand);
}

figure.has-missing-image {
    min-height: 180px;
    display: grid;
    align-content: start;
}

figure.has-missing-image img.is-missing {
    min-height: 180px;
    opacity: 0;
    background: linear-gradient(135deg, var(--color-subtle), #f8efe4);
}

img.is-loaded {
    opacity: 1;
    transition: opacity 220ms ease;
}

.page--home .hero__copy::after {
    content: "";
    position: absolute;
    left: -32px;
    bottom: -40px;
    width: 92px;
    height: 92px;
    z-index: -1;
    border: 1px dashed rgba(233, 107, 76, 0.28);
    border-radius: 50%;
}

.page--web .section--guide .topic-card:nth-child(2n),
.page--desktop .section--desktop-guide .topic-card:nth-child(2n),
.page--app .section--app-guide .topic-card:nth-child(2n) {
    background: linear-gradient(180deg, #fff, #fbfdfc);
}

.page--web .section--guide .topic-card:nth-child(1) .eyebrow,
.page--desktop .section--desktop-guide .topic-card:nth-child(1) .eyebrow,
.page--app .section--app-guide .topic-card:nth-child(1) .eyebrow {
    color: var(--color-accent-deep);
}

.primary-nav a[data-current-path="true"]::after {
    content: "";
    position: absolute;
    right: 10px;
    bottom: 4px;
    left: 10px;
    height: 2px;
    border-radius: 2px;
    background: currentColor;
    opacity: 0.28;
}

.primary-nav a[aria-current="page"][data-current-path="true"]::after {
    background: rgba(255, 255, 255, 0.9);
}

html[data-visible-section="content-index"] .site-header,
html[data-visible-section="web-guide"] .site-header,
html[data-visible-section="desktop-guide"] .site-header,
html[data-visible-section="app-guide"] .site-header {
    border-bottom-color: rgba(47, 143, 131, 0.28);
}

@media (min-width: 1280px) {
    .topic-grid--home .topic-card:nth-child(3n + 1) {
        transform-origin: left center;
    }

    .topic-grid--home .topic-card:nth-child(3n + 2) {
        transform-origin: right center;
    }

    .section--related .related-link:first-child {
        border-color: rgba(47, 143, 131, 0.24);
    }
}

@media (max-width: 920px) {
    .primary-nav a[data-current-path="true"]::after {
        right: auto;
        bottom: 8px;
        left: 14px;
        width: 28px;
    }

    .page--home .hero__copy::after {
        display: none;
    }
}

@media (max-width: 680px) {
    .compare-table th,
    .compare-table td {
        padding: 0.85rem 0.9rem;
    }

    figure.has-missing-image,
    figure.has-missing-image img.is-missing {
        min-height: 140px;
    }
}

@media (prefers-contrast: more) {
    :root {
        --color-muted: #4f5e5a;
        --color-line: #aebfba;
    }

    .button--quiet,
    .topic-card,
    .related-link,
    .compare-table-wrap {
        border-width: 2px;
    }

    .eyebrow,
    .text-link,
    .primary-nav a {
        text-decoration-thickness: 2px;
    }
}