/* Research theme: an academic measurement-project shell on top of public.css. */
[data-public-theme="research"] {
  --page: #f6f6f2; --surface: #fffefa; --surface-sunk: #ecede7; --text: #1c2433; --muted: #5b6472;
  --line: #d8dbd3; --accent: #274c77; --accent-strong: #1c3a5e; --on-accent: #fffefa; --beam: #e0a326;
  --soft: #e4ebf3; --note: #eef1e6; --saffron: #c88d1d; --paprika: #b5432b; --pandan: #2f9c95;
}
@media (prefers-color-scheme: dark) {
  [data-public-theme="research"] {
    color-scheme: dark;
    --page: #12161f; --surface: #1a2030; --surface-sunk: #171c29; --text: #e8eaf0; --muted: #a6aebc;
    --line: #2d3546; --accent: #9dbbe3; --accent-strong: #bcd2ee; --on-accent: #10192a;
    --soft: #22304a; --note: #1f2a3a; --saffron: #e0a326; --paprika: #e2795c;
  }
}
[data-public-theme="research"] { scroll-padding-top: 6rem; }
@media (prefers-reduced-motion: no-preference) { [data-public-theme="research"] { scroll-behavior: smooth; } }
[data-public-theme="research"] body { background: var(--page); color: var(--text); }
[data-public-theme="research"] .masthead { background: var(--page); }
[data-public-theme="research"] .wordmark { color: var(--text); font-weight: 600; letter-spacing: -.02em; }
[data-public-theme="research"] .wordmark__mark { height: 1.75rem; width: 1.75rem; border-radius: .5rem; }
[data-public-theme="research"] .masthead__link, [data-public-theme="research"] .masthead__lang { color: var(--muted); }
[data-public-theme="research"] .masthead__link { display: inline-flex; align-items: center; min-height: 44px; white-space: nowrap; }
[data-public-theme="research"] .masthead__link:hover, [data-public-theme="research"] .masthead__lang:hover, [data-public-theme="research"] .masthead__link[aria-current="page"] { color: var(--text); }
[data-public-theme="research"] .masthead__lang { min-height: 44px; white-space: nowrap; }
[data-public-theme="research"] .masthead__nav { gap: .25rem 1.4rem; }
[data-public-theme="research"] .rs-signin { min-height: 44px; padding: .5rem 1.1rem; border: 1px solid var(--accent); border-radius: .5rem; color: var(--accent); white-space: nowrap; }
[data-public-theme="research"] .rs-signin:hover { background: var(--soft); border-color: var(--accent-strong); color: var(--accent-strong); }
[data-public-theme="research"] .flashes li { border-left-color: var(--accent); }
[data-public-theme="research"] :focus-visible { outline: 3px solid var(--accent); outline-offset: 4px; }

.rs-site { overflow-wrap: anywhere; }
.rs-eyebrow { color: var(--accent); font-family: var(--mono); font-size: .7rem; font-weight: 500; letter-spacing: .16em; line-height: 1.6; text-transform: uppercase; }
.rs-site h1 { font-family: var(--display); font-size: clamp(2.3rem, 1.4rem + 3.4vw, 4.1rem); font-weight: 600; letter-spacing: -.02em; line-height: 1.12; margin: 1.2rem 0 1.3rem; }
/* Chinese lines carry more meaning per glyph; keep two lines at every width. */
html[lang="zh-hans"] .rs-site h1 { font-size: clamp(2rem, 1rem + 2.8vw, 3.3rem); letter-spacing: 0; }
.rs-site h1 span { display: block; }
.rs-site h1 span:last-child { color: var(--accent); }
.rs-site h2 { font-family: var(--display); font-size: clamp(1.6rem, 1.2rem + 1.6vw, 2.4rem); font-weight: 600; letter-spacing: -.02em; line-height: 1.25; }
.rs-site h3 { font-family: var(--display); font-size: 1.22rem; font-weight: 600; line-height: 1.4; margin: 1rem 0 .6rem; }
.rs-intro { color: var(--muted); font-size: 1.05rem; line-height: 1.85; max-width: 36rem; }
.rs-footnote { color: var(--muted); font-family: var(--mono); font-size: .72rem; letter-spacing: .06em; line-height: 1.8; margin-top: 1.4rem; }

.rs-hero { display: grid; grid-template-columns: 1.05fr 1fr; align-items: center; gap: clamp(2rem, 5vw, 4rem); padding-block: clamp(3rem, 6vw, 5rem) clamp(2rem, 4vw, 3rem); }
.rs-actions { display: flex; flex-wrap: wrap; gap: 1.1rem 1.5rem; align-items: center; margin-top: 1.9rem; }
.rs-button { background: var(--accent); border: 1px solid var(--accent); border-radius: .5rem; color: var(--on-accent); font-weight: 600; padding: .85rem 1.3rem; }
.rs-button:hover { background: var(--accent-strong); border-color: var(--accent-strong); }
.rs-button span { margin-left: .8rem; }
.rs-text-link { border-bottom: 1px solid var(--line); color: var(--accent); font-size: .92rem; padding-block: .3rem; text-decoration: none; }
.rs-text-link:hover { border-bottom-color: var(--accent); }
.rs-hero__art { background: var(--soft); border-radius: 1.25rem; margin: 0; position: relative; }
.rs-hero__art img { display: block; height: auto; width: 100%; }
.rs-hero__art figcaption { color: var(--muted); display: flex; font-family: var(--mono); font-size: .68rem; justify-content: space-between; letter-spacing: .08em; padding: 0 1.6rem 1.3rem; text-transform: uppercase; }

.rs-principles { border-block: 1px solid var(--line); display: flex; flex-wrap: wrap; gap: .8rem 2.5rem; list-style: none; margin: 0 auto; padding-block: 1.1rem; }
.rs-principles li { align-items: center; color: var(--muted); display: flex; font-size: .9rem; gap: .7rem; }
.rs-principles li::before { background: var(--beam); border-radius: 2px; content: ""; flex: 0 0 1.1rem; height: 3px; }

.rs-section { padding-block: clamp(2.5rem, 5vw, 4rem); }
.rs-section + .rs-section { border-top: 1px solid var(--line); }
.rs-section-heading { margin-bottom: clamp(1.6rem, 3vw, 2.4rem); }
.rs-section-heading h2 { margin-top: .6rem; max-width: 30em; }
.rs-feature-grid { display: grid; gap: clamp(1.5rem, 3vw, 2.5rem); grid-template-columns: repeat(3, 1fr); }
.rs-feature-grid article p { color: var(--muted); font-size: .95rem; line-height: 1.85; }
.rs-feature-icon { background: var(--soft); border-radius: 50%; color: var(--accent); display: inline-grid; font-size: 1.4rem; height: 3rem; place-items: center; width: 3rem; }

.rs-steps { --rs-step-gap: clamp(1.5rem, 3vw, 2.5rem); display: grid; gap: var(--rs-step-gap); grid-template-columns: repeat(3, 1fr); list-style: none; margin: 0; padding: 0; }
.rs-steps li { position: relative; }
.rs-step__marker { background: var(--surface); border: 2px solid var(--accent); border-radius: 50%; display: grid; height: 1.6rem; place-items: center; position: relative; width: 1.6rem; z-index: 1; }
.rs-step__marker::after { background: var(--accent); border-radius: 50%; content: ""; height: .5rem; width: .5rem; }
.rs-steps li::before { background: var(--line); content: ""; height: 2px; left: 1.6rem; position: absolute; right: calc(-1 * var(--rs-step-gap)); top: .75rem; }
.rs-steps li:last-child::before { display: none; }
.rs-steps p { color: var(--muted); font-size: .95rem; line-height: 1.85; }

.rs-note { background: var(--note); border-left: 4px solid var(--beam); border-radius: .75rem; padding: clamp(1.4rem, 3vw, 2.2rem) clamp(1.4rem, 3vw, 2.6rem); }
.rs-note p { font-family: var(--display); font-size: clamp(1.1rem, 1rem + .6vw, 1.45rem); line-height: 1.7; max-width: 46em; }
.rs-about__intro { margin-top: 1.8rem; max-width: 48rem; }

.rs-questions { display: grid; gap: clamp(2rem, 4vw, 4rem); grid-template-columns: .8fr 1.2fr; padding-block: clamp(2rem, 4vw, 3rem) clamp(2.5rem, 5vw, 4rem); }
.rs-questions h2 { margin-top: .6rem; }
.rs-questions__list details { border-bottom: 1px solid var(--line); padding: 1.1rem 0; }
.rs-questions__list details:first-child { border-top: 1px solid var(--line); }
.rs-questions summary { align-items: center; cursor: pointer; display: flex; font-weight: 600; gap: 1rem; justify-content: space-between; line-height: 1.55; list-style: none; }
.rs-questions summary::-webkit-details-marker { display: none; }
.rs-questions summary span { color: var(--accent); flex-shrink: 0; font-size: 1.4rem; transition: transform .16s ease; }
.rs-questions details[open] summary span { transform: rotate(45deg); }
.rs-questions details p { color: var(--muted); font-size: .94rem; line-height: 1.85; margin-top: .6rem; padding-right: 1.5rem; }

.rs-closing { border-top: 1px solid var(--line); padding-block: clamp(2.5rem, 5vw, 4rem) clamp(3rem, 6vw, 5rem); }
.rs-closing .rs-intro { margin-top: .8rem; }

[data-public-theme="research"] .colophon { background: var(--surface-sunk); border-top: 1px solid var(--line); color: var(--text); padding-block: 2rem 1.5rem; }
[data-public-theme="research"] .colophon a, [data-public-theme="research"] .colophon .wordmark { color: var(--text); }
[data-public-theme="research"] .colophon a:hover { color: var(--accent); }
[data-public-theme="research"] .colophon__fine { border-top-color: var(--line); color: var(--muted); margin-top: 1.2rem; padding-top: 1rem; }
.rs-footer { align-items: center; display: flex; flex-wrap: wrap; gap: 1rem 2rem; justify-content: space-between; }
.rs-footer .wordmark { font-size: 1.2rem; }
.rs-footer .colophon__blurb { margin-top: .5rem; max-width: 33rem; }
.rs-footer__links { align-items: center; display: flex; gap: 1.5rem; }
.rs-footer__links a { align-items: center; display: inline-flex; min-height: 44px; }

[data-public-theme="research"] .auth-card { background: var(--surface); border-color: var(--line); }
[data-public-theme="research"] .auth-card::before { background: linear-gradient(90deg, var(--beam), #d9663d 50%, var(--pandan)); }
[data-public-theme="research"] .auth-submit { background: var(--accent); color: var(--on-accent); }
[data-public-theme="research"] .auth-submit:hover { background: var(--accent-strong); }
[data-public-theme="research"] .auth-field input:focus { border-color: var(--accent); }
.rs-auth-brand { align-items: center; display: flex; font: 600 1.35rem/1.2 var(--display); gap: .6rem; letter-spacing: -.02em; margin-bottom: 1.3rem; }
.rs-auth-brand img { border-radius: .5rem; display: block; flex: 0 0 34px; }

@media (max-width: 850px) {
  .rs-hero { gap: 2rem; grid-template-columns: 1fr; padding-block: 2.5rem 2rem; }
  .rs-hero__art { justify-self: center; max-width: 520px; width: 100%; }
  .rs-steps { grid-template-columns: 1fr; gap: 1.5rem; }
  .rs-steps li::before { display: none; }
  .rs-questions { gap: 1rem; grid-template-columns: 1fr; }
  .rs-feature-grid { gap: 1.5rem; grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  [data-public-theme="research"] .masthead__inner:not(.masthead__inner--language-only) { display: grid; gap: .15rem; grid-template-columns: 1fr; }
  [data-public-theme="research"] .masthead__inner > .wordmark { justify-self: start; }
  [data-public-theme="research"] .masthead__nav { flex-wrap: nowrap; gap: .6rem; justify-content: space-between; }
  [data-public-theme="research"] .masthead__inner--language-only .masthead__nav { justify-content: flex-end; }
  html[lang="zh-hans"] .rs-site h1 { font-size: clamp(1.6rem, 8.2vw, 2.2rem); }
  .rs-principles { gap: .6rem 1.5rem; }
  .rs-footer { display: grid; gap: .6rem; }
  .rs-hero__art figcaption { font-size: .7rem; padding-inline: 1.1rem; }
  .rs-actions { gap: 1rem; }
  .rs-button { font-size: .9rem; }
}