:root {
    --cadet: #5f9ea0;
    --cadet-dark: #376f72;
    --cadet-deep: #214f53;
    --cadet-soft: #dcebec;
    --ink: #172326;
    --muted: #627276;
    --line: #d7e1e2;
    --paper: #fff;
    --canvas: #f5f8f8;
    --amber-soft: #fff3de;
    --green-soft: #e4f3eb;
    color-scheme: light;
}

* { box-sizing: border-box; }
html { min-width: 320px; background: var(--canvas); }
body { margin: 0; color: var(--ink); background: var(--canvas); font: 15px/1.6 Lato, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; letter-spacing: 0; }
button, input { font: inherit; letter-spacing: 0; }
a { color: var(--cadet-deep); }
button { cursor: pointer; }

.doi-topbar { position: sticky; top: 0; z-index: 20; min-height: 64px; display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 8px clamp(18px, 4vw, 64px); border-bottom: 1px solid var(--line); background: rgba(255,255,255,.97); }
.doi-brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; }
.doi-brand img { width: 46px; height: 46px; object-fit: contain; }
.doi-brand span { display: grid; line-height: 1.1; }
.doi-brand strong { font-size: 18px; }
.doi-brand small { margin-top: 4px; color: var(--cadet-dark); font-size: 9px; font-weight: 800; text-transform: uppercase; }
.doi-topbar nav { display: flex; align-items: center; gap: 4px; }
.doi-topbar nav a { min-height: 38px; display: inline-flex; align-items: center; gap: 7px; padding: 0 11px; border: 1px solid transparent; border-radius: 5px; color: #4c5c60; font-size: 12px; font-weight: 750; text-decoration: none; }
.doi-topbar nav a:hover { border-color: var(--line); background: var(--canvas); color: var(--cadet-deep); }
.doi-topbar nav .doi-app-link { border-color: var(--cadet-dark); color: white; background: var(--cadet-dark); }
.doi-topbar nav .doi-app-link:hover { background: var(--cadet-deep); color: white; }

.doi-work-head { padding: clamp(34px, 6vw, 74px) clamp(18px, 6vw, 92px) 34px; border-bottom: 1px solid #bad5d6; background: #edf7f7; }
.doi-head-inner { max-width: 1180px; margin: auto; }
.doi-eyebrow { margin: 0 0 8px; color: var(--cadet-dark); font-size: 11px; font-weight: 850; text-transform: uppercase; }
.doi-work-head h1 { max-width: 1050px; margin: 0; font-size: 48px; line-height: 1.08; overflow-wrap: anywhere; }
.doi-work-head h2 { margin: 18px 0 0; color: #46585c; font-size: 16px; font-weight: 650; }
.doi-publication-line { margin: 7px 0 0; color: var(--muted); }
.doi-identifier-row { display: flex; align-items: center; gap: 7px; margin-top: 20px; }
.doi-identifier { max-width: calc(100% - 44px); overflow: hidden; text-overflow: ellipsis; padding: 7px 10px; border: 1px solid #b8d6d7; border-radius: 4px; background: white; font-size: 13px; font-weight: 750; white-space: nowrap; text-decoration: none; }
.doi-icon-button { width: 37px; height: 37px; display: grid; place-items: center; flex: 0 0 auto; border: 1px solid #b8d6d7; border-radius: 4px; background: white; color: var(--cadet-deep); }

.doi-alert { max-width: 1360px; display: grid; grid-template-columns: 30px minmax(0,1fr); gap: 12px; margin: 18px auto 0; padding: 13px 16px; border: 1px solid #e9c985; border-radius: 5px; background: var(--amber-soft); }
.doi-alert i { color: #9a641b; font-size: 20px; }
.doi-alert div { display: grid; }
.doi-alert span { color: #6f5b3b; font-size: 13px; }
.doi-layout { max-width: 1360px; display: grid; grid-template-columns: minmax(0, 1fr) 320px; align-items: start; gap: 0; margin: 22px auto 60px; border: 1px solid var(--line); background: white; }
.doi-article { min-width: 0; }
.doi-section { padding: 34px clamp(20px, 4vw, 54px); border-bottom: 1px solid var(--line); }
.doi-section:last-child { border-bottom: 0; }
.doi-section h2, .doi-action-panel h2, .doi-resolve-panel h2 { margin: 0 0 18px; font-size: 23px; line-height: 1.2; }
.doi-abstract-section { border-left: 5px solid var(--cadet); }
.doi-abstract { margin: 0; color: #27383c; font-size: 17px; line-height: 1.82; white-space: pre-line; }
.doi-abstract-source { display: flex; align-items: center; gap: 5px; margin: 15px 0 0; color: var(--muted); font-size: 10px; font-weight: 750; }
.doi-abstract-source i { color: var(--cadet-dark); }
.doi-missing { display: grid; grid-template-columns: 24px minmax(0,1fr); gap: 10px; padding: 15px; border: 1px solid #e8cd95; background: var(--amber-soft); color: #6d5a3b; }
.doi-missing p { margin: 0; }
.doi-facts { display: grid; grid-template-columns: 1fr 1fr; gap: 0; margin: 0; border-top: 1px solid var(--line); }
.doi-facts div { min-width: 0; padding: 13px 15px; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.doi-facts div:nth-child(even) { border-right: 0; }
.doi-facts dt { color: var(--muted); font-size: 10px; font-weight: 850; text-transform: uppercase; }
.doi-facts dd { margin: 3px 0 0; overflow-wrap: anywhere; font-weight: 650; }
.doi-section blockquote { margin: 0; padding: 17px 19px; border-left: 4px solid var(--cadet); background: var(--canvas); color: #2d3d41; }
.doi-button-row { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 13px; }
.doi-button, .doi-primary-button, .doi-secondary-button { min-height: 40px; display: inline-flex; align-items: center; justify-content: center; gap: 7px; padding: 0 13px; border: 1px solid var(--line); border-radius: 5px; background: white; color: var(--cadet-deep); font-size: 12px; font-weight: 800; text-decoration: none; }
button.doi-button { cursor: pointer; }
.doi-button:hover, .doi-secondary-button:hover { border-color: var(--cadet); background: #eef7f7; }
.doi-tags { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 16px; }
.doi-tags span { padding: 4px 7px; border: 1px solid #bfd6d7; border-radius: 3px; color: var(--cadet-deep); background: #f3fafa; font-size: 11px; font-weight: 700; }
.doi-side { position: sticky; top: 64px; border-left: 1px solid var(--line); }
.doi-action-panel, .doi-resolve-panel { padding: 25px 22px; border-bottom: 1px solid var(--line); }
.doi-action-panel { display: grid; gap: 8px; }
.doi-action-panel .doi-eyebrow { margin-bottom: 0; }
.doi-primary-button { border-color: var(--cadet-dark); background: var(--cadet-dark); color: white; }
.doi-primary-button:hover { background: var(--cadet-deep); }
.doi-search-form label { display: block; margin-bottom: 6px; color: var(--muted); font-size: 11px; font-weight: 750; }
.doi-search-form > div { display: grid; grid-template-columns: minmax(0,1fr) 40px; }
.doi-search-form input { min-width: 0; height: 40px; padding: 0 10px; border: 1px solid var(--line); border-right: 0; border-radius: 4px 0 0 4px; }
.doi-search-form button { border: 1px solid var(--cadet-dark); border-radius: 0 4px 4px 0; background: var(--cadet-dark); color: white; }
.doi-provenance { margin: 0; padding: 20px 22px; color: var(--muted); font-size: 11px; }

.doi-resolver-main { min-height: calc(100vh - 190px); }
.doi-resolver-hero { padding: clamp(52px, 9vw, 118px) clamp(18px, 8vw, 130px) 66px; border-bottom: 1px solid #bad5d6; background: #edf7f7; }
.doi-resolver-hero > div, .doi-main-search { max-width: 1080px; margin-inline: auto; }
.doi-resolver-hero h1 { max-width: 900px; margin: 0; font-size: 64px; line-height: 1.04; }
.doi-resolver-hero > div > p:last-child { max-width: 740px; margin: 20px 0 30px; color: #4c6064; font-size: 18px; }
.doi-main-search { display: block; }
.doi-main-search > label { display: block; margin-bottom: 7px; font-size: 12px; font-weight: 800; }
.doi-main-search > div { min-height: 68px; display: grid; grid-template-columns: 50px minmax(0,1fr) auto; align-items: center; border: 1px solid #a8cbcd; background: white; box-shadow: 0 16px 36px rgba(33,79,83,.12); }
.doi-main-search > div > i { text-align: center; color: var(--cadet-dark); font-size: 23px; }
.doi-main-search input { min-width: 0; height: 66px; padding: 0 10px; border: 0; outline: 0; font-size: 18px; }
.doi-main-search button { height: 48px; display: inline-flex; align-items: center; gap: 9px; margin-right: 9px; padding: 0 19px; border: 0; border-radius: 5px; background: var(--cadet-dark); color: white; font-weight: 800; }
.doi-main-search small { display: block; margin-top: 8px; color: var(--muted); }
.doi-benefit-band { max-width: 1260px; display: grid; grid-template-columns: repeat(4,1fr); margin: 0 auto; border-inline: 1px solid var(--line); background: white; }
.doi-benefit-band > div { display: grid; grid-template-columns: 34px minmax(0,1fr); column-gap: 10px; padding: 25px 20px; border-right: 1px solid var(--line); }
.doi-benefit-band > div:last-child { border-right: 0; }
.doi-benefit-band i { grid-row: 1 / 3; color: var(--cadet-dark); font-size: 22px; }
.doi-benefit-band strong { font-size: 13px; }
.doi-benefit-band span { color: var(--muted); font-size: 11px; }
.doi-explain { max-width: 1260px; display: grid; grid-template-columns: minmax(0,1fr) auto; align-items: center; gap: 40px; margin: 55px auto 75px; padding: 0 20px; }
.doi-explain h2 { max-width: 680px; margin: 0; font-size: 36px; line-height: 1.15; }
.doi-explain p:last-child { max-width: 760px; color: var(--muted); }
.doi-explain-actions { display: grid; gap: 8px; min-width: 250px; }

.doi-browse-main { max-width: 1180px; min-height: calc(100vh - 168px); margin: 0 auto; padding: 48px 18px 70px; }
.doi-browse-head { display: grid; grid-template-columns: minmax(0,1fr) 310px; align-items: end; gap: 55px; padding-bottom: 28px; border-bottom: 2px solid var(--cadet-dark); }
.doi-browse-head h1 { margin: 0; font-size: 52px; line-height: 1.05; }
.doi-browse-head > div > p:last-child { max-width: 730px; margin-bottom: 0; color: var(--muted); }
.doi-topic-browser { padding: 26px 24px 20px; border-bottom: 1px solid var(--line); background: #edf7f7; }
.doi-topic-title { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 16px; }
.doi-topic-title h2 { margin: 0; font-size: 23px; line-height: 1.2; }
.doi-topic-title form { display: flex; align-items: center; gap: 9px; }
.doi-topic-title label { color: var(--muted); font-size: 11px; font-weight: 750; }
.doi-topic-title select { min-width: 180px; height: 38px; padding: 0 32px 0 10px; border: 1px solid #afcdce; border-radius: 4px; color: var(--ink); background: white; }
.doi-topic-grid { display: grid; grid-template-columns: repeat(5,minmax(0,1fr)); gap: 7px; }
.doi-topic-grid a { min-width: 0; min-height: 58px; display: flex; align-items: center; gap: 9px; padding: 9px 11px; border: 1px solid #c3d9da; border-radius: 5px; color: #36565a; background: rgba(255,255,255,.78); font-size: 12px; font-weight: 750; line-height: 1.2; text-decoration: none; }
.doi-topic-grid a:hover { border-color: var(--cadet); background: white; }
.doi-topic-grid a.active { border-color: var(--cadet-dark); color: white; background: var(--cadet-dark); }
.doi-topic-grid i { flex: 0 0 auto; font-size: 18px; }
.doi-feed-status { display: flex; flex-wrap: wrap; gap: 7px 18px; margin-top: 16px; color: #53686c; font-size: 10px; font-weight: 700; }
.doi-feed-status span { display: inline-flex; align-items: center; gap: 5px; }
.doi-feed-status i { color: var(--cadet-dark); }
.doi-browse-list { background: white; }
.doi-browse-item { display: grid; grid-template-columns: 100px minmax(0,1fr); gap: 24px; padding: 30px 24px; border-bottom: 1px solid var(--line); }
.doi-browse-item:hover { background: #fbfdfd; }
.doi-browse-date { display: grid; align-content: start; gap: 2px; padding-top: 4px; }
.doi-browse-date strong { color: var(--cadet-deep); font-size: 22px; }
.doi-browse-date span, .doi-browse-source { color: var(--muted); font-size: 10px; font-weight: 800; text-transform: uppercase; }
.doi-browse-source { margin: 0 0 5px; }
.doi-browse-item h2 { margin: 0; font-size: 21px; line-height: 1.28; }
.doi-browse-item h2 a { color: var(--ink); text-decoration: none; }
.doi-browse-item h2 a:hover { color: var(--cadet-deep); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 3px; }
.doi-browse-authors { margin: 7px 0; color: #506267; font-size: 12px; font-weight: 650; }
.doi-browse-abstract { margin: 10px 0 13px; color: #42555a; }
.doi-browse-meta { display: flex; flex-wrap: wrap; gap: 5px; margin: -2px 0 13px; }
.doi-browse-meta span { display: inline-flex; align-items: center; gap: 4px; padding: 3px 6px; border: 1px solid #d3e1e2; border-radius: 3px; color: #53686c; background: #f7fafa; font-size: 9px; font-weight: 700; }
.doi-browse-item footer { display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.doi-browse-item footer a { display: inline-flex; align-items: center; gap: 6px; font-size: 12px; font-weight: 800; text-decoration: none; }
.doi-browse-item footer span { overflow: hidden; color: #7a898c; font-size: 10px; text-overflow: ellipsis; white-space: nowrap; }
.doi-browse-empty { padding: 80px 20px; border-bottom: 1px solid var(--line); background: white; text-align: center; }
.doi-browse-empty i { color: var(--cadet); font-size: 38px; }
.doi-browse-empty h2 { margin-bottom: 3px; }
.doi-browse-empty p { margin-top: 0; color: var(--muted); }
.doi-pagination { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 15px; padding: 22px 0; }
.doi-pagination a { display: inline-flex; align-items: center; gap: 7px; font-size: 12px; font-weight: 800; text-decoration: none; }
.doi-pagination a:last-child { justify-self: end; }
.doi-pagination strong { color: var(--muted); font-size: 11px; }

.doi-footer { min-height: 104px; display: flex; align-items: center; justify-content: space-between; gap: 24px; padding: 24px clamp(18px, 5vw, 72px); border-top: 1px solid var(--line); background: white; }
.doi-footer > div { display: grid; }
.doi-footer span { color: var(--muted); font-size: 11px; }
.doi-footer nav { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 18px; }
.doi-footer a { color: var(--muted); font-size: 12px; text-decoration: none; }
.doi-toast { position: fixed; right: 18px; bottom: 18px; z-index: 50; max-width: calc(100vw - 36px); padding: 11px 14px; border: 1px solid #a8cfc0; border-radius: 5px; background: var(--green-soft); color: #285f46; font-size: 12px; font-weight: 750; opacity: 0; transform: translateY(14px); pointer-events: none; transition: .18s ease; }
.doi-toast.visible { opacity: 1; transform: translateY(0); }

@media (max-width: 900px) {
    .doi-resolver-hero h1, .doi-browse-head h1 { font-size: 46px; }
    .doi-explain h2 { font-size: 32px; }
    .doi-topbar { align-items: flex-start; flex-direction: column; gap: 5px; padding: 8px 16px; }
    .doi-topbar nav { width: 100%; overflow-x: auto; }
    .doi-topbar nav a { flex: 0 0 auto; }
    .doi-layout { grid-template-columns: 1fr; margin: 15px 12px 45px; }
    .doi-side { position: static; border-top: 1px solid var(--line); border-left: 0; }
    .doi-benefit-band { grid-template-columns: 1fr 1fr; margin-inline: 12px; }
    .doi-benefit-band > div:nth-child(2) { border-right: 0; }
    .doi-benefit-band > div:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
    .doi-explain { grid-template-columns: 1fr; }
    .doi-explain-actions { min-width: 0; }
    .doi-browse-head { grid-template-columns: 1fr; gap: 20px; }
    .doi-browse-head .doi-search-form { max-width: 420px; }
    .doi-topic-grid { grid-template-columns: repeat(3,minmax(0,1fr)); }
}

@media (max-width: 620px) {
    .doi-brand img { width: 39px; height: 39px; }
    .doi-topbar nav a { padding-inline: 8px; font-size: 11px; }
    .doi-work-head { padding: 28px 16px 24px; }
    .doi-work-head h1 { font-size: 28px; }
    .doi-layout { margin-inline: 0; border-inline: 0; }
    .doi-section { padding: 25px 16px; }
    .doi-section h2 { font-size: 20px; }
    .doi-abstract { font-size: 15px; line-height: 1.72; }
    .doi-facts { grid-template-columns: 1fr; }
    .doi-facts div, .doi-facts div:nth-child(even) { border-right: 0; }
    .doi-button { flex: 1 1 calc(50% - 7px); }
    .doi-resolver-hero { padding: 43px 14px 46px; }
    .doi-resolver-hero h1 { font-size: 38px; }
    .doi-browse-head h1 { font-size: 34px; }
    .doi-resolver-hero > div > p:last-child { font-size: 16px; }
    .doi-main-search > div { grid-template-columns: 40px minmax(0,1fr); }
    .doi-main-search input { height: 56px; font-size: 15px; }
    .doi-main-search button { grid-column: 1 / -1; width: calc(100% - 16px); justify-content: center; margin: 0 8px 8px; }
    .doi-benefit-band { grid-template-columns: 1fr; margin-inline: 0; border-inline: 0; }
    .doi-benefit-band > div { border-right: 0; border-bottom: 1px solid var(--line); }
    .doi-benefit-band > div:last-child { border-bottom: 0; }
    .doi-browse-main { padding: 34px 0 50px; }
    .doi-browse-head { padding-inline: 15px; }
    .doi-topic-browser { padding: 21px 15px 17px; }
    .doi-topic-title { align-items: stretch; flex-direction: column; gap: 12px; }
    .doi-topic-title form { align-items: stretch; flex-direction: column; gap: 4px; }
    .doi-topic-title select { width: 100%; }
    .doi-topic-grid { grid-template-columns: 1fr 1fr; }
    .doi-topic-grid a { min-height: 54px; }
    .doi-feed-status { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
    .doi-browse-item { grid-template-columns: 1fr; gap: 4px; padding: 24px 15px; }
    .doi-browse-date { display: flex; align-items: baseline; gap: 8px; }
    .doi-browse-date strong { font-size: 16px; }
    .doi-browse-item h2 { font-size: 18px; }
    .doi-browse-item footer { align-items: flex-start; flex-direction: column; gap: 5px; }
    .doi-browse-item footer span { max-width: 100%; }
    .doi-pagination { padding-inline: 15px; }
    .doi-pagination strong { display: none; }
    .doi-pagination { grid-template-columns: 1fr 1fr; }
    .doi-footer { align-items: flex-start; flex-direction: column; }
    .doi-footer nav { justify-content: flex-start; }
}