/*
Theme Name: Boxin Yang — Signal
Theme URI: https://boxinyang.me/
Author: Boxin Yang
Description: A dark editorial WordPress theme for Boxin Yang's field notes.
Version: 1.0.1
Text Domain: boxinyang-signal
*/

@font-face {
  font-family: "Boxin Display";
  src: url("assets/fonts/space-grotesk-latin.woff2") format("woff2");
  font-display: swap;
  font-weight: 300 700;
}

@font-face {
  font-family: "Boxin Sans";
  src: url("assets/fonts/dm-sans-latin.woff2") format("woff2");
  font-display: swap;
  font-weight: 300 800;
}

:root {
  --ink: #090b0f;
  --surface: #11161c;
  --surface-raised: #171e26;
  --line: #28323a;
  --paper: #f4f2ea;
  --muted: #98a3ad;
  --lime: #c8ff5a;
  --aqua: #8bf5e2;
  --violet: #8b6cff;
  --coral: #ff8364;
  --display: "Boxin Display", "Noto Sans SC", "PingFang SC", sans-serif;
  --sans: "Boxin Sans", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --content: min(100% - 48px, 1296px);
  --reading: min(100% - 48px, 760px);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  color: var(--paper);
  background: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body::selection { background: var(--lime); color: var(--ink); }
a { color: inherit; text-decoration: none; }
a:focus-visible, button:focus-visible, input:focus-visible { outline: 2px solid var(--lime); outline-offset: 4px; }
img { display: block; max-width: 100%; height: auto; }
button, input { font: inherit; }

.screen-reader-text { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(1px, 1px, 1px, 1px); white-space: nowrap; }
.screen-reader-text:focus { clip: auto; width: auto; height: auto; z-index: 100; padding: 10px 14px; background: var(--lime); color: var(--ink); }

.site-header { border-bottom: 1px solid var(--line); background: color-mix(in srgb, var(--ink) 90%, transparent); }
.site-header__inner { width: var(--content); min-height: 88px; margin: auto; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: baseline; gap: 11px; white-space: nowrap; }
.brand__name { font: 700 16px/1 var(--display); letter-spacing: -.04em; }
.brand__slash { color: var(--lime); font: 400 14px/1 var(--sans); }
.brand__type { color: var(--muted); font: 400 11px/1 var(--sans); letter-spacing: .13em; }
.site-nav { display: flex; align-items: center; gap: 28px; color: var(--muted); font-size: 14px; }
.site-nav a { transition: color .2s ease; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--paper); }
.site-nav__external::after { content: " ↗"; font-size: .8em; }

.site-main { overflow: hidden; }
.hero, .topics, .feature-section, .notes, .article-hero, .article-body, .site-footer__cta { padding-inline: max(24px, calc((100vw - 1296px) / 2)); }
.hero { padding-top: clamp(78px, 11vw, 164px); padding-bottom: clamp(70px, 9vw, 132px); }
.eyebrow { display: flex; align-items: center; gap: 12px; color: var(--muted); font: 400 12px/1.35 var(--sans); letter-spacing: .1em; text-transform: uppercase; }
.eyebrow__accent { color: var(--lime); }
.hero h1 { max-width: 930px; margin: 28px 0 23px; font: 700 clamp(45px, 6.15vw, 88px)/1.22 var(--display); letter-spacing: -.075em; }
.hero__intro { max-width: 565px; margin: 0; color: var(--muted); font-size: 19px; line-height: 1.75; }
.reading-signal { display: inline-flex; align-items: center; gap: 12px; margin-top: 42px; color: var(--muted); font-size: 12px; letter-spacing: .03em; }
.reading-signal::before { content: ""; width: 72px; height: 2px; background: var(--lime); }

.topics { padding-top: 42px; padding-bottom: 42px; background: var(--surface); }
.section-head { display: flex; justify-content: space-between; align-items: baseline; gap: 20px; margin-bottom: 25px; }
.section-head h2 { margin: 0; font: 500 17px/1.4 var(--sans); }
.section-head__link { color: var(--muted); font-size: 14px; transition: color .2s ease; }
.section-head__link:hover { color: var(--paper); }
.topic-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 0; }
.topic { min-height: 120px; padding: 17px 22px 15px 0; border-right: 1px solid var(--line); }
.topic + .topic { padding-left: 22px; }
.topic:last-child { border-right: 0; }
.topic__index { display: block; margin-bottom: 8px; color: var(--topic-color, var(--lime)); font: 400 11px/1.2 var(--sans); letter-spacing: .08em; }
.topic__name { display: block; font-size: 17px; font-weight: 500; }
.topic__detail { display: block; margin-top: 6px; color: var(--muted); font-size: 12px; }

.feature-section { padding-top: clamp(72px, 8vw, 105px); padding-bottom: clamp(78px, 9vw, 116px); }
.feature-label, .notes__meta, .footer-kicker { color: var(--lime); font: 400 12px/1.35 var(--sans); letter-spacing: .08em; text-transform: uppercase; }
.feature { display: grid; grid-template-columns: minmax(0, 1.68fr) minmax(310px, .9fr); min-height: 520px; margin-top: 28px; overflow: hidden; border: 1px solid var(--line); border-radius: 24px; background: var(--surface-raised); }
.feature__content { display: flex; flex-direction: column; align-items: flex-start; justify-content: center; padding: clamp(34px, 4vw, 56px); }
.post-meta { display: flex; flex-wrap: wrap; gap: 9px; color: var(--muted); font: 400 12px/1.35 var(--sans); letter-spacing: .04em; }
.post-meta__category { color: var(--lime); }
.feature__title { max-width: 680px; margin: 18px 0; font: 700 clamp(30px, 3.1vw, 45px)/1.35 var(--display); letter-spacing: -.055em; }
.feature__excerpt { max-width: 575px; margin: 0; color: var(--muted); font-size: 16px; line-height: 1.8; }
.text-link { display: inline-flex; align-items: center; gap: 8px; margin-top: 27px; font-size: 15px; transition: color .2s ease, transform .2s ease; }
.text-link:hover { color: var(--lime); transform: translateX(3px); }
.feature__visual { position: relative; display: flex; flex-direction: column; justify-content: flex-end; align-items: flex-end; min-height: 260px; padding: 38px; overflow: hidden; background: var(--surface); isolation: isolate; }
.feature__visual::before { content: ""; position: absolute; inset: 0; background: radial-gradient(circle at 80% 22%, color-mix(in srgb, var(--lime) 11%, transparent), transparent 35%), linear-gradient(145deg, transparent 35%, rgba(255,255,255,.025) 36%, transparent 37%); }
.feature__number { position: relative; color: var(--lime); font: 700 clamp(104px, 12vw, 180px)/.72 var(--display); letter-spacing: -.12em; }
.feature__stamp { position: relative; margin-top: 24px; color: var(--muted); font: 400 10px/1.4 var(--sans); letter-spacing: .08em; }

.notes { padding-top: clamp(70px, 8vw, 100px); padding-bottom: clamp(72px, 8vw, 100px); background: var(--surface); }
.notes .section-head h2 { font: 500 clamp(25px, 2.2vw, 32px)/1.3 var(--sans); }
.notes__meta { color: var(--aqua); }
.post-list { border-top: 1px solid var(--line); }
.post-row { display: grid; grid-template-columns: 54px minmax(0, 1fr) 185px; gap: 22px; padding: 28px 0 30px; border-bottom: 1px solid var(--line); transition: background .2s ease, padding .2s ease; }
.post-row:hover { padding-inline: 14px; background: rgba(255,255,255,.018); }
.post-row__index { color: var(--lime); font: 400 12px/1.4 var(--sans); }
.post-row__title { display: block; font: 500 20px/1.48 var(--sans); letter-spacing: -.025em; }
.post-row__title:hover { color: var(--lime); }
.post-row__excerpt { margin: 7px 0 0; color: var(--muted); font-size: 14px; line-height: 1.7; }
.post-row__right { align-self: center; text-align: right; font-size: 13px; }
.post-row__category { display: block; color: var(--paper); }
.post-row__date { display: block; margin-top: 6px; color: var(--muted); font: 400 11px/1.4 var(--sans); }
.empty-state { padding: 60px 0; color: var(--muted); }

.site-footer { background: var(--ink); }
.site-footer__cta { padding-top: clamp(75px, 8vw, 108px); padding-bottom: 46px; border-top: 1px solid var(--line); }
.site-footer h2 { max-width: 680px; margin: 16px 0 26px; font: 700 clamp(35px, 4.2vw, 58px)/1.28 var(--display); letter-spacing: -.065em; }
.footer-links { display: flex; flex-wrap: wrap; gap: 26px; color: var(--muted); font-size: 15px; }
.footer-links a:hover { color: var(--paper); }
.site-footer__bottom { width: var(--content); margin: auto; padding: 21px 0 38px; border-top: 1px solid var(--line); color: var(--muted); font: 400 11px/1.4 var(--sans); letter-spacing: .06em; }

.article-hero { display: grid; grid-template-columns: minmax(0, 1fr) 240px; align-items: end; gap: 74px; padding-top: clamp(78px, 9vw, 132px); padding-bottom: clamp(78px, 9vw, 116px); }
.article-hero__back { color: var(--muted); font-size: 14px; }
.article-hero__back:hover { color: var(--paper); }
.article-hero__meta { margin-top: 22px; color: var(--lime); font: 400 12px/1.4 var(--sans); letter-spacing: .07em; text-transform: uppercase; }
.article-hero h1 { max-width: 820px; margin: 20px 0; font: 700 clamp(40px, 5vw, 70px)/1.25 var(--display); letter-spacing: -.075em; }
.article-hero__deck { max-width: 650px; margin: 0; color: var(--muted); font-size: 18px; line-height: 1.75; }
.article-hero__byline { margin-top: 22px; color: var(--muted); font: 400 11px/1.4 var(--sans); letter-spacing: .07em; }
.article-stamp { display: flex; min-height: 236px; padding: 26px; flex-direction: column; justify-content: flex-end; align-items: flex-end; border: 1px solid var(--line); background: var(--surface); }
.article-stamp__number { color: var(--lime); font: 700 96px/.75 var(--display); letter-spacing: -.12em; }
.article-stamp__label { margin-top: 22px; color: var(--muted); font: 400 10px/1.4 var(--sans); letter-spacing: .07em; }
.article-body { display: grid; grid-template-columns: minmax(0, 760px) 200px; justify-content: center; gap: clamp(45px, 10vw, 130px); padding-top: clamp(65px, 8vw, 100px); padding-bottom: clamp(80px, 10vw, 145px); border-top: 1px solid var(--line); background: var(--surface); }
.entry-content { min-width: 0; color: var(--muted); font-size: 18px; line-height: 1.88; }
.entry-content > :first-child { margin-top: 0; }
.entry-content p { margin: 0 0 1.55em; }
.entry-content h2, .entry-content h3, .entry-content h4 { color: var(--paper); font-family: var(--display); letter-spacing: -.045em; line-height: 1.32; }
.entry-content h2 { margin: 2.1em 0 .72em; font-size: clamp(28px, 3vw, 40px); }
.entry-content h3 { margin: 1.9em 0 .62em; font-size: 25px; }
.entry-content a { color: var(--aqua); text-decoration: underline; text-decoration-color: color-mix(in srgb, var(--aqua) 40%, transparent); text-underline-offset: 4px; }
.entry-content a:hover { color: var(--lime); }
.entry-content strong { color: var(--paper); font-weight: 600; }
.entry-content blockquote { margin: 2em 0; padding: 6px 0 6px 26px; border-left: 2px solid var(--lime); color: var(--paper); font-size: 1.22em; line-height: 1.7; }
.entry-content ul, .entry-content ol { padding-left: 1.3em; margin: 0 0 1.6em; }
.entry-content li + li { margin-top: .55em; }
.entry-content code { padding: .15em .38em; border: 1px solid var(--line); border-radius: 4px; background: var(--ink); color: var(--aqua); font: .84em/1.4 ui-monospace, SFMono-Regular, Menlo, monospace; }
.entry-content pre { overflow-x: auto; padding: 20px; border: 1px solid var(--line); border-radius: 12px; background: var(--ink); }
.entry-content pre code { padding: 0; border: 0; background: none; }
.entry-content img, .entry-content figure { margin: 2em 0; border-radius: 16px; }
.entry-content figcaption { margin-top: 10px; color: var(--muted); font-size: 13px; text-align: center; }
.entry-content hr { margin: 2.5em 0; border: 0; border-top: 1px solid var(--line); }
.article-side { padding-top: 8px; }
.article-side__label { margin: 0 0 15px; color: var(--aqua); font: 400 11px/1.4 var(--sans); letter-spacing: .08em; }
.article-side__item { display: block; margin-bottom: 11px; color: var(--muted); font-size: 14px; }
.article-side__item:first-of-type { color: var(--paper); }
.article-side__item:hover { color: var(--lime); }
.article-after { width: var(--reading); margin: 0 auto; padding-bottom: clamp(75px, 8vw, 110px); background: var(--surface); }
.article-after__rule { border: 0; border-top: 1px solid var(--line); margin: 0 0 35px; }
.article-after__label { color: var(--aqua); font: 400 11px/1.4 var(--sans); letter-spacing: .08em; }
.article-after__title { margin: 12px 0 0; font: 600 25px/1.45 var(--display); }

.archive-hero { padding: clamp(76px, 9vw, 130px) max(24px, calc((100vw - 1296px) / 2)) 66px; }
.archive-hero h1 { max-width: 900px; margin: 18px 0 0; font: 700 clamp(42px, 5.3vw, 72px)/1.25 var(--display); letter-spacing: -.07em; }
.search-form { display: flex; gap: 10px; margin-top: 28px; }
.search-form label { flex: 1; }
.search-field { width: 100%; padding: 13px 15px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); color: var(--paper); }
.search-submit { padding: 13px 18px; border: 1px solid var(--lime); border-radius: 8px; background: var(--lime); color: var(--ink); cursor: pointer; }

@media (max-width: 760px) {
  :root { --content: min(100% - 40px, 1296px); --reading: min(100% - 40px, 760px); }
  .site-header__inner { min-height: 64px; gap: 12px; }
  .brand__type { display: none; }
  .site-nav { gap: 15px; font-size: 12px; }
  .site-nav a:nth-child(1), .site-nav a:nth-child(3) { display: none; }
  .site-nav a:nth-child(2)::after { content: "目录 +"; font-size: 13px; }
  .site-nav a:nth-child(2) { font-size: 0; color: var(--paper); }
  .hero, .topics, .feature-section, .notes, .article-hero, .article-body, .site-footer__cta { padding-inline: 20px; }
  .hero { padding-top: 68px; padding-bottom: 58px; }
  .hero h1 { margin-top: 24px; font-size: 43px; line-height: 1.38; letter-spacing: -.07em; }
  .hero__intro { font-size: 15px; line-height: 1.76; }
  .reading-signal { margin-top: 18px; }
  .reading-signal::before { width: 42px; }
  .topics { padding-top: 32px; padding-bottom: 30px; }
  .topic-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .topic { min-height: 96px; padding: 14px 14px 14px 0; border-bottom: 1px solid var(--line); }
  .topic:nth-child(2n) { padding-left: 14px; border-right: 0; }
  .topic:nth-child(n+3) { border-bottom: 0; }
  .feature-section { padding-top: 42px; padding-bottom: 48px; }
  .feature { grid-template-columns: 1fr; min-height: 0; border-radius: 24px; }
  .feature__visual { order: -1; min-height: 145px; padding: 20px 24px; }
  .feature__number { font-size: 92px; }
  .feature__stamp { display: none; }
  .feature__content { padding: 24px 22px 27px; }
  .feature__title { margin: 13px 0; font-size: 24px; line-height: 1.5; }
  .feature__excerpt { display: none; }
  .text-link { margin-top: 18px; }
  .notes { padding-top: 44px; padding-bottom: 48px; }
  .notes .section-head h2 { font-size: 24px; }
  .notes__meta { font-size: 0; }
  .notes__meta::after { content: "查看全部 →"; font-size: 13px; letter-spacing: 0; text-transform: none; }
  .post-row { grid-template-columns: 1fr; gap: 7px; padding: 20px 0 22px; }
  .post-row:hover { padding-inline: 0; background: transparent; }
  .post-row__index { order: -2; }
  .post-row__title { font-size: 17px; line-height: 1.58; }
  .post-row__excerpt { display: none; }
  .post-row__right { display: none; }
  .site-footer__cta { padding-top: 60px; padding-bottom: 34px; }
  .site-footer h2 { margin: 14px 0 20px; font-size: 32px; line-height: 1.43; }
  .footer-links { gap: 14px; font-size: 13px; }
  .site-footer__bottom { padding: 20px 0 30px; font-size: 10px; }
  .article-hero { grid-template-columns: 1fr; gap: 34px; padding-top: 65px; padding-bottom: 60px; }
  .article-hero h1 { font-size: 42px; line-height: 1.36; }
  .article-hero__deck { font-size: 16px; }
  .article-stamp { display: none; }
  .article-body { grid-template-columns: 1fr; gap: 42px; padding-top: 54px; padding-bottom: 65px; }
  .entry-content { font-size: 16px; line-height: 1.88; }
  .entry-content h2 { font-size: 29px; }
  .article-side { order: -1; padding: 0; display: flex; flex-wrap: wrap; gap: 12px 16px; }
  .article-side__label { width: 100%; margin-bottom: 0; }
  .article-side__item { margin: 0; font-size: 13px; }
  .article-after { width: var(--reading); padding-bottom: 70px; }
  .archive-hero { padding: 65px 20px 48px; }
  .archive-hero h1 { font-size: 40px; }
}