/* F.F Magazine — dual theme, borderless slices
   Spec: DESIGN.md / ff-homepage-mockup-v22-final.png */

@import url("https://fonts.googleapis.com/css2?family=M+PLUS+Rounded+1c:wght@400;500;700&family=Libre+Baskerville:ital,wght@0,400;0,700;1,400&display=swap");

:root,
[data-theme="light"] {
  /* 浅色：对齐浅色 Hero 背景取样 #EEEBE8 */
  --bg: #eeebe8;
  --ink: #1c1c1c;
  --muted: #7a7e84;
  --accent: #1c1c1c;
  --surface-art: #e5e2de;
  --hero-overlay: rgba(238, 235, 232, 0.72);
  --prose-link: #1c1c1c;
}

[data-theme="dark"] {
  /* 深色：对齐深色 Hero #000000 */
  --bg: #000000;
  --ink: #f2f0ec;
  --muted: #8a8a8a;
  --accent: #f2f0ec;
  --surface-art: #0a0a0a;
  --hero-overlay: rgba(0, 0, 0, 0.55);
  --prose-link: #f2f0ec;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #000000;
    --ink: #f2f0ec;
    --muted: #8a8a8a;
    --accent: #f2f0ec;
    --surface-art: #0a0a0a;
    --hero-overlay: rgba(0, 0, 0, 0.55);
    --prose-link: #f2f0ec;
  }
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #eeebe8;
    --ink: #1c1c1c;
    --muted: #7a7e84;
    --accent: #1c1c1c;
    --surface-art: #e5e2de;
    --hero-overlay: rgba(238, 235, 232, 0.72);
    --prose-link: #1c1c1c;
  }
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Libre Baskerville", "Source Serif 4", Georgia, serif;
  line-height: 1.6;
  min-height: 100vh;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
  border: 0;
}

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

a:hover {
  opacity: 0.75;
}

/* —— Utilities —— */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.label {
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
}

.muted {
  color: var(--muted);
}

/* —— Site header (article / inner pages) —— */
.site-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

.site-bar__brand {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.site-bar__nav {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-family: system-ui, sans-serif;
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}

.site-bar__nav a[aria-current="page"],
.site-bar__nav a.is-active {
  color: var(--accent);
}

.view-switch {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  margin-left: 0.2rem;
  padding-left: 1rem;
  border-left: 1px solid currentColor;
  white-space: nowrap;
}

.view-switch a {
  color: var(--muted);
}

.view-switch a[aria-current="page"] {
  color: var(--accent);
  font-weight: 700;
}

.view-switch__slash {
  color: var(--muted);
  opacity: 0.55;
}

.theme-toggle {
  width: 1.35rem;
  height: 1.35rem;
  margin: 0 0 0 0.125rem;
  padding: 0;
  display: inline-grid;
  place-items: center;
  flex: 0 0 auto;
  border: 1px solid currentColor;
  border-radius: 50%;
  background: transparent;
  color: var(--muted);
  font: inherit;
  line-height: 1;
  cursor: pointer;
}

.theme-toggle::before {
  content: "◐";
  font-size: 0.8125rem;
  transform: translateY(-0.015rem);
}

[data-theme="dark"] .theme-toggle::before {
  content: "◑";
}

.theme-toggle:hover {
  color: var(--accent);
}

.theme-toggle:focus-visible {
  outline: 1px solid var(--accent);
  outline-offset: 3px;
}

@media (max-width: 640px) {
  .site-bar {
    align-items: flex-start;
    gap: 1rem;
  }

  .site-bar__nav {
    justify-content: flex-end;
    flex-wrap: wrap;
    gap: 0.55rem 0.7rem;
  }

  .view-switch {
    width: 100%;
    justify-content: flex-end;
    margin-left: 0;
    padding-left: 0;
    border-left: 0;
  }
}

/* —— Home Hero (centered Mac + stacked masthead, matching v22 mockup) —— */
.home-hero {
  width: 100%;
  background: var(--bg);
  color: var(--ink);
  text-align: center;
  padding: 3.5rem 1.5rem 2.25rem;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.home-hero__stage {
  width: min(520px, 78vw);
  margin: 0 auto 1.25rem;
  line-height: 0;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  transition: transform 0.25s ease, opacity 0.25s ease;
}

.home-hero__stage:hover {
  transform: translateY(-2px);
  opacity: 0.92;
}

.home-hero__stage:focus-visible {
  outline: 1px solid var(--ink);
  outline-offset: 8px;
}

.home-hero__media {
  width: 100%;
  height: auto;
  display: block;
  object-fit: contain;
  border: 0;
  background: transparent;
}

.home-hero__media--light {
  display: none;
}

[data-theme="light"] .home-hero__media--dark {
  display: none;
}

[data-theme="light"] .home-hero__media--light {
  display: block;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .home-hero__media--dark {
    display: none;
  }
  :root:not([data-theme="dark"]) .home-hero__media--light {
    display: block;
  }
}

.home-hero__content {
  width: 100%;
  max-width: 720px;
  margin: 0 auto;
  padding: 0;
  text-align: center;
  color: var(--ink);
}

.home-hero__avatar {
  width: 64px;
  height: 64px;
  object-fit: contain;
  margin: 0 auto 0.85rem;
  border: 0;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  outline: none;
}

.home-hero__brand {
  margin: 0;
  font-size: clamp(2.75rem, 7vw, 3.75rem);
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--ink);
}

.home-hero__tagline {
  margin: 0.15rem 0 1.1rem;
  font-family: "M PLUS Rounded 1c", "Hiragino Maru Gothic ProN", "Yu Gothic", system-ui, sans-serif;
  font-style: normal;
  font-weight: 500;
  font-size: clamp(1.05rem, 2.4vw, 1.35rem);
  color: var(--ink);
  letter-spacing: 0.04em;
}

.home-hero__social {
  display: flex;
  justify-content: center;
  gap: 1.35rem;
  margin-bottom: 1.35rem;
}

.home-hero__social a {
  color: var(--muted);
  display: inline-flex;
}

.home-hero__social a:hover {
  color: var(--ink);
  opacity: 1;
}

.home-hero__social svg {
  width: 18px;
  height: 18px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.5;
}

.home-hero__nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 0.35rem 0.55rem;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.home-hero__nav button,
.home-hero__nav a {
  background: none;
  border: 0;
  color: var(--muted);
  cursor: pointer;
  font: inherit;
  letter-spacing: inherit;
  text-transform: inherit;
  padding: 0.25rem 0.1rem;
}

.home-hero__nav .dot {
  color: var(--muted);
  opacity: 0.55;
  pointer-events: none;
}

.home-hero__nav [aria-pressed="true"],
.home-hero__nav .is-active {
  color: var(--ink);
}

/* —— Magazine feed (borderless, flush, 50/50) —— */
.magazine-feed {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
}

.magazine-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: stretch;
  margin: 0;
  /* zero gap between rows */
}

.magazine-row.is-flip .magazine-row__media {
  order: 2;
}

.magazine-row.is-flip .magazine-row__body {
  order: 1;
}

.magazine-row__media {
  margin: 0;
  min-height: 240px;
  background: var(--bg);
  overflow: hidden;
  border: 0;
}

.magazine-row__media img {
  width: 100%;
  height: 100%;
  min-height: 240px;
  object-fit: cover;
  border: 0;
  box-shadow: none;
  outline: none;
}

/* Dual banner assets: light paper #EEEBE8 / dark pure #000 — no CSS invert */
.magazine-row__media {
  position: relative;
}

.magazine-row__media img.banner-sketch {
  background: var(--bg);
  filter: none;
}

.magazine-row__media img.banner-sketch--dark,
.article-hero__cover.banner-sketch--dark {
  display: none;
}

[data-theme="dark"] .magazine-row__media img.banner-sketch--light,
[data-theme="dark"] .article-hero__cover.banner-sketch--light {
  display: none;
}

[data-theme="dark"] .magazine-row__media img.banner-sketch--dark,
[data-theme="dark"] .article-hero__cover.banner-sketch--dark {
  display: block;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .magazine-row__media img.banner-sketch--light,
  :root:not([data-theme="light"]) .article-hero__cover.banner-sketch--light {
    display: none;
  }
  :root:not([data-theme="light"]) .magazine-row__media img.banner-sketch--dark,
  :root:not([data-theme="light"]) .article-hero__cover.banner-sketch--dark {
    display: block;
  }
}

.magazine-row__body {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 2rem 2.25rem;
  border: 0;
}

.magazine-row__body .label {
  margin-bottom: 0.65rem;
}

.magazine-row__title {
  margin: 0 0 0.75rem;
  font-size: clamp(1.35rem, 2.4vw, 1.85rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

.magazine-row__excerpt {
  margin: 0 0 1rem;
  font-size: 0.95rem;
  line-height: 1.55;
  color: var(--muted);
}

.magazine-row__meta {
  margin: 0;
  font-size: 0.8125rem;
  font-style: italic;
  color: var(--muted);
}

.magazine-row[hidden] {
  display: none;
}

@media (max-width: 800px) {
  .magazine-row,
  .magazine-row.is-flip {
    grid-template-columns: 1fr;
  }

  .magazine-row.is-flip .magazine-row__media,
  .magazine-row.is-flip .magazine-row__body {
    order: unset;
  }

  .magazine-row__media img {
    min-height: 180px;
    max-height: 240px;
  }

  .magazine-row__body {
    padding: 1.5rem 1.25rem 2rem;
  }
}

/* —— Article page —— */
.article-hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 0 2rem;
}

.article-hero__cover {
  width: 100%;
  height: min(66.6667vw, 480px);
  max-height: none;
  object-fit: contain;
  background: var(--bg);
  margin-bottom: 2rem;
  border: 0;
}

.article-hero__inner {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.article-hero__title {
  margin: 0.5rem 0 0.75rem;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  line-height: 1.2;
}

.article-hero__meta {
  font-size: 0.875rem;
  font-style: italic;
  color: var(--muted);
}

.article-body,
.prose {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
}

.prose h1,
.prose h2,
.prose h3,
.prose h4 {
  line-height: 1.25;
  margin: 2rem 0 0.75rem;
}

.prose p,
.prose ul,
.prose ol,
.prose blockquote {
  margin: 0 0 1.15rem;
  line-height: 1.7;
}

.prose img {
  margin: 1.5rem 0;
  width: 100%;
  border: 0;
}

/* Dual-theme in-article sketches (same language as banners) */
.figure-sketch {
  margin: 1.5rem 0;
  position: relative;
}

.figure-sketch img {
  margin: 0;
  width: 100%;
  display: block;
  background: var(--bg);
}

.figure-sketch .sketch--dark {
  display: none;
}

[data-theme="dark"] .figure-sketch .sketch--light {
  display: none;
}

[data-theme="dark"] .figure-sketch .sketch--dark {
  display: block;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .figure-sketch .sketch--light {
    display: none;
  }
  :root:not([data-theme="light"]) .figure-sketch .sketch--dark {
    display: block;
  }
}

.prose .figure-caption {
  margin: 0.35rem 0 1.75rem;
  font-size: 0.9rem;
  color: var(--muted);
  line-height: 1.5;
}

.prose .figure-placeholder {
  margin: 1.5rem 0 0.35rem;
  padding: 1.25rem 1rem;
  text-align: center;
  color: var(--muted);
  background: var(--surface-art);
  font-size: 0.9rem;
}

.prose a {
  color: var(--prose-link);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.prose blockquote {
  padding-left: 1rem;
  border-left: 2px solid var(--muted);
  color: var(--muted);
}

.prose code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.875em;
}

.prose pre {
  overflow-x: auto;
  padding: 1rem;
  background: var(--surface-art);
  font-size: 0.875rem;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.9rem;
}

.prose th,
.prose td {
  padding: 0.5rem;
  border-bottom: 1px solid var(--muted);
  text-align: left;
}

/* —— Topics / About / 404 —— */
.page-wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
}

.page-wrap h1 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  margin: 0 0 1rem;
}

.footer-mini {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1.5rem 3rem;
  font-size: 0.75rem;
  color: var(--muted);
  font-style: italic;
}