/* ==========================================================================
   路过集 · Field Journal - Stylesheet
   Zero external dependencies, WCAG AA+ contrast, single-accent editorial tokens
   ========================================================================== */

:root {
  color-scheme: light;
  --bg-paper: #F7F6F1;
  --bg-surface: #EFECE4;
  --bg-elevated: #FFFFFF;
  --bg-code: #1A1D1B;
  --text-code: #F2F0E8;
  --ink-primary: #181A18;
  --ink-secondary: #484C49;
  --ink-muted: #666B67;
  --rule-hairline: #D6D2C7;
  --rule-strong: #181A18;
  --accent: #C83218;
  --accent-hover: #A8250E;
  --accent-tint: rgba(200, 50, 24, 0.08);
  --radius-sm: 4px;

  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", "Source Han Sans SC", system-ui, -apple-system, sans-serif;
  --font-serif: "Songti SC", "Noto Serif CJK SC", "Source Han Serif SC", "STSong", Georgia, serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;

  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  --z-header: 20;
  --z-skip: 40;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg-paper: #141615;
    --bg-surface: #1D201E;
    --bg-elevated: #242826;
    --bg-code: #0E100F;
    --text-code: #ECEAE2;
    --ink-primary: #ECEAE2;
    --ink-secondary: #B8B5AA;
    --ink-muted: #8E8B80;
    --rule-hairline: #2F3431;
    --rule-strong: #ECEAE2;
    --accent: #F05438;
    --accent-hover: #FF6B50;
    --accent-tint: rgba(240, 84, 56, 0.14);
  }
}

:root[data-theme="dark"],
body[data-theme="dark"] {
  color-scheme: dark;
  --bg-paper: #141615;
  --bg-surface: #1D201E;
  --bg-elevated: #242826;
  --bg-code: #0E100F;
  --text-code: #ECEAE2;
  --ink-primary: #ECEAE2;
  --ink-secondary: #B8B5AA;
  --ink-muted: #8E8B80;
  --rule-hairline: #2F3431;
  --rule-strong: #ECEAE2;
  --accent: #F05438;
  --accent-hover: #FF6B50;
  --accent-tint: rgba(240, 84, 56, 0.14);
}

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

html {
  background-color: var(--bg-paper);
  color: var(--ink-primary);
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100dvh;
  background-color: var(--bg-paper);
  color: var(--ink-primary);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  /* Subtle technical graph paper micro-dots */
  background-image: radial-gradient(var(--rule-hairline) 0.75px, transparent 0.75px);
  background-size: 24px 24px;
}

:root[data-theme="dark"] body,
body[data-theme="dark"] {
  background-color: #141615;
  color: #ECEAE2;
  background-image: radial-gradient(#2F3431 0.75px, transparent 0.75px);
}

:root[data-theme="dark"] .btn-secondary {
  background: #242826;
  color: #ECEAE2;
  border-color: #3E4541;
}

:root[data-theme="dark"] .preset-chip,
:root[data-theme="dark"] .calc-preset {
  background: #1D201E;
  color: #B8B5AA;
  border-color: #3E4541;
}

:root[data-theme="dark"] .preset-chip.is-active,
:root[data-theme="dark"] .calc-preset.is-active {
  background: #ECEAE2;
  color: #141615;
  border-color: #ECEAE2;
}

:root[data-theme="dark"] .nav-link {
  color: #B8B5AA;
}

:root[data-theme="dark"] .nav-link:hover {
  color: #ECEAE2;
}

/* Screen-reader only utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Skip link for keyboard users */
.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: var(--z-skip);
  background: var(--accent);
  color: #FFFFFF;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  text-decoration: none;
  transition: top 0.2s var(--ease-out-expo);
}

.skip-link:focus {
  top: 12px;
  outline: 2px solid var(--ink-primary);
  outline-offset: 2px;
}

/* Universal visible keyboard focus */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

/* ==========================================================================
   Header & Navigation (Single-line desktop <= 72px)
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-header);
  height: 68px;
  background-color: var(--bg-paper);
  border-bottom: 1px solid var(--rule-hairline);
}

.header-inner {
  max-width: 1240px;
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--ink-primary);
}

.brand-stamp {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  background: var(--ink-primary);
  color: var(--bg-paper);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  position: relative;
}

.brand-stamp::after {
  content: "";
  position: absolute;
  top: 5px;
  right: 5px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent);
}

.brand-titles {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.brand-cn {
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand-en {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-muted);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-link {
  color: var(--ink-secondary);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  padding: 6px 2px;
  border-bottom: 2px solid transparent;
  transition: color 0.2s var(--ease-out-expo), border-color 0.2s var(--ease-out-expo);
}

.nav-link:hover {
  color: var(--ink-primary);
  border-bottom-color: var(--accent);
}

.theme-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-surface);
  color: var(--ink-primary);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
  padding: 7px 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  cursor: pointer;
  transition: border-color 0.2s var(--ease-out-expo), transform 0.15s var(--ease-out-expo);
}

.theme-btn:hover {
  border-color: var(--ink-secondary);
}

.theme-btn:active {
  transform: translateY(1px);
}

.theme-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
}

/* ==========================================================================
   Section 1: Hero & Interactive Curl Timing Waterfall
   ========================================================================== */

.hero-section {
  max-width: 1240px;
  margin: 0 auto;
  padding: 56px 24px 64px;
  border-bottom: 1px solid var(--rule-hairline);
}

.hero-grid {
  display: grid;
  grid-template-columns: 5fr 7fr;
  gap: 48px;
  align-items: center;
}

.eyebrow-tag {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

.hero-title {
  margin: 0 0 18px;
  font-family: var(--font-serif);
  font-size: clamp(2rem, 3.4vw, 2.85rem);
  line-height: 1.18;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink-primary);
}

.hero-lead {
  margin: 0 0 28px;
  font-size: 16px;
  line-height: 1.65;
  color: var(--ink-secondary);
  max-width: 46ch;
}

.hero-cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn-primary,
.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 11px 20px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  white-space: nowrap;
  transition: transform 0.15s var(--ease-out-expo), background-color 0.2s var(--ease-out-expo), border-color 0.2s var(--ease-out-expo);
}

.btn-primary {
  background: var(--accent);
  color: #FFFFFF;
  border: 1px solid var(--accent);
}

.btn-primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.btn-secondary {
  background: var(--bg-elevated);
  color: var(--ink-primary);
  border: 1px solid var(--rule-hairline);
}

.btn-secondary:hover {
  border-color: var(--ink-primary);
}

.btn-primary:active,
.btn-secondary:active {
  transform: translateY(1px);
}

/* Interactive Waterfall Specimen */
.hero-specimen {
  background: var(--bg-elevated);
  border: 1px solid var(--rule-hairline);
  border-top: 3px solid var(--ink-primary);
  border-radius: var(--radius-sm);
  padding: 24px;
}

.specimen-header {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--rule-hairline);
  margin-bottom: 18px;
}

.specimen-code {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-muted);
  margin-bottom: 4px;
}

.specimen-heading {
  margin: 0;
  font-size: 16px;
  font-weight: 700;
}

.preset-group {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.preset-chip,
.calc-preset {
  background: var(--bg-surface);
  color: var(--ink-secondary);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  cursor: pointer;
  transition: background-color 0.2s var(--ease-out-expo), color 0.2s var(--ease-out-expo), border-color 0.2s var(--ease-out-expo);
}

.preset-chip:hover,
.calc-preset:hover {
  color: var(--ink-primary);
  border-color: var(--ink-secondary);
}

.preset-chip.is-active,
.calc-preset.is-active {
  background: var(--ink-primary);
  color: var(--bg-paper);
  border-color: var(--ink-primary);
  font-weight: 600;
}

.waterfall-total-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 8px 12px;
  background: var(--bg-surface);
  border-radius: var(--radius-sm);
  margin-bottom: 14px;
}

.wf-controls-inline {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

.wf-inline-field {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-secondary);
}

.wf-inline-field input {
  width: 66px;
  height: 28px;
  padding: 0 6px;
  background: var(--bg-paper);
  color: var(--ink-primary);
  border: 1px solid var(--rule-hairline);
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 12px;
}

.wf-total-readout {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
}

.total-label {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-secondary);
}

.total-value {
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--accent);
}

.wf-rows {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.wf-row {
  display: grid;
  grid-template-columns: 185px 1fr 72px;
  align-items: center;
  gap: 12px;
}

.wf-meta {
  display: flex;
  flex-direction: column;
}

.wf-name {
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-primary);
}

.wf-var {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-muted);
}

.wf-track {
  position: relative;
  height: 14px;
  background: var(--bg-surface);
  border-radius: 2px;
  overflow: hidden;
}

.wf-bar {
  position: absolute;
  top: 2px;
  bottom: 2px;
  background: var(--ink-primary);
  border-radius: 2px;
  min-width: 2px;
  transition: left 0.3s var(--ease-out-expo), width 0.3s var(--ease-out-expo);
}

.wf-bar.is-accent {
  background: var(--accent);
}

.wf-num {
  text-align: right;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-primary);
}

.specimen-diagnosis {
  margin: 16px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--rule-hairline);
  font-size: 13px;
  color: var(--ink-secondary);
}

/* ==========================================================================
   Shared Section Typography
   ========================================================================== */

.essays-section,
.workbench-section,
.cheatsheet-section {
  max-width: 1240px;
  margin: 0 auto;
  padding: 64px 24px;
  border-bottom: 1px solid var(--rule-hairline);
}

.section-intro {
  margin-bottom: 36px;
  max-width: 68ch;
}

.section-title {
  margin: 0 0 10px;
  font-family: var(--font-serif);
  font-size: clamp(1.65rem, 2.4vw, 2.15rem);
  line-height: 1.25;
}

.section-sub {
  margin: 0;
  color: var(--ink-secondary);
  font-size: 15px;
}

/* ==========================================================================
   Section 2: Editorial Reader + Margin Directory
   ========================================================================== */

.editorial-workspace {
  display: grid;
  grid-template-columns: 360px 1fr;
  gap: 40px;
  align-items: start;
}

.essay-index {
  position: sticky;
  top: 92px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.index-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--ink-primary);
}

.index-caption {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--ink-secondary);
}

.view-mode-btn {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.2s var(--ease-out-expo), color 0.2s var(--ease-out-expo);
}

.view-mode-btn:hover,
.view-mode-btn[aria-pressed="true"] {
  background: var(--accent);
  color: #FFFFFF;
}

.essay-tab-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.essay-tab {
  text-align: left;
  background: var(--bg-elevated);
  color: var(--ink-primary);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
  padding: 16px;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: border-color 0.2s var(--ease-out-expo), background-color 0.2s var(--ease-out-expo), transform 0.15s var(--ease-out-expo);
}

.essay-tab:hover {
  border-color: var(--ink-secondary);
}

.essay-tab.is-active {
  border-color: var(--ink-primary);
  background: var(--bg-surface);
  box-shadow: inset 0 2px 0 0 var(--accent);
}

.tab-kicker {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  color: var(--accent);
}

.tab-title {
  font-size: 15px;
  font-weight: 700;
  line-height: 1.4;
}

.tab-meta {
  font-size: 12px;
  color: var(--ink-muted);
}

.tab-meta code {
  font-family: var(--font-mono);
  color: var(--ink-secondary);
}

.margin-note-box {
  padding: 14px 16px;
  background: var(--bg-surface);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
}

.margin-note-title {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-primary);
}

.margin-note-body {
  margin: 0;
  font-size: 13px;
  color: var(--ink-secondary);
  line-height: 1.55;
}

/* Essay Article Stage */
.essay-stage {
  display: flex;
  flex-direction: column;
  gap: 36px;
  min-width: 0;
}

.essay-article {
  background: var(--bg-elevated);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
  padding: 36px 40px;
  min-width: 0;
}

.essay-article[hidden] {
  display: none;
}

.article-header {
  padding-bottom: 24px;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--rule-hairline);
}

.article-meta-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
}

.article-id {
  background: var(--ink-primary);
  color: var(--bg-paper);
  padding: 2px 8px;
  border-radius: 2px;
  font-weight: 700;
}

.article-topic {
  color: var(--ink-muted);
}

.article-title {
  margin: 0 0 14px;
  font-family: var(--font-serif);
  font-size: clamp(1.35rem, 2vw, 1.75rem);
  line-height: 1.3;
}

.article-deck {
  margin: 0;
  color: var(--ink-secondary);
  font-size: 15px;
  line-height: 1.65;
}

.article-body h4 {
  margin: 28px 0 12px;
  font-size: 17px;
  font-weight: 700;
  color: var(--ink-primary);
}

.article-body h4:first-child {
  margin-top: 0;
}

.article-body p {
  margin: 0 0 16px;
  color: var(--ink-primary);
}

.editorial-list {
  margin: 0 0 18px;
  padding-left: 20px;
}

.editorial-list li {
  margin-bottom: 8px;
}

.article-body code,
.section-sub code,
.panel-note code,
.overhead-desc code,
.empty-state code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--bg-surface);
  padding: 2px 5px;
  border-radius: 3px;
}

/* Code blocks with copy button */
.code-frame,
.sysctl-snippet {
  margin: 16px 0 20px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--rule-hairline);
  background: var(--bg-code);
  color: var(--text-code);
}

.code-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 8px 14px;
  background: rgba(255, 255, 255, 0.06);
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
}

.code-lang {
  font-family: var(--font-mono);
  font-size: 12px;
  color: #C7C4B8;
}

.copy-btn {
  background: rgba(255, 255, 255, 0.1);
  color: #FFFFFF;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 3px;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  cursor: pointer;
  white-space: nowrap;
  transition: background-color 0.15s var(--ease-out-expo), border-color 0.15s var(--ease-out-expo);
}

.copy-btn:hover {
  background: var(--accent);
  border-color: var(--accent);
}

.cmd-item .copy-btn {
  background: var(--bg-surface);
  color: var(--ink-primary);
  border: 1px solid var(--rule-hairline);
}

.cmd-item .copy-btn:hover {
  background: var(--accent);
  color: #FFFFFF;
  border-color: var(--accent);
}

.code-frame pre,
.sysctl-snippet pre,
.output-sample,
.cmd-item pre {
  margin: 0;
  padding: 14px 16px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.55;
}

.code-frame pre code,
.sysctl-snippet pre code,
.output-sample code,
.cmd-item pre code {
  background: transparent;
  padding: 0;
  color: inherit;
}

.output-sample {
  background: var(--bg-surface);
  color: var(--ink-primary);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
  margin-bottom: 18px;
}

/* Specification tables (no border-t + border-b on every row; clean header border + subtle zebra) */
.spec-table-wrap,
.matrix-table-wrap {
  overflow-x: auto;
  margin: 16px 0 20px;
}

.spec-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  text-align: left;
}

.spec-table th {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-secondary);
  padding: 10px 12px;
  border-bottom: 2px solid var(--ink-primary);
  white-space: nowrap;
}

.spec-table td {
  padding: 11px 12px;
  vertical-align: top;
}

.spec-table tbody tr:nth-child(even) {
  background: var(--bg-surface);
}

/* ==========================================================================
   Section 3: Interactive Workbench (BDP & Byte Base Converter)
   ========================================================================== */

.workbench-grid {
  display: grid;
  grid-template-columns: 7fr 5fr;
  gap: 32px;
  align-items: start;
}

.tool-panel {
  background: var(--bg-elevated);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
  padding: 28px;
  min-width: 0;
}

.panel-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 16px;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--rule-hairline);
}

.panel-title {
  margin: 0;
  font-size: 17px;
  font-weight: 700;
}

.panel-badge {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--accent);
  background: var(--accent-tint);
  padding: 4px 8px;
  border-radius: 2px;
  font-weight: 600;
}

.calc-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 22px;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.field-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field-group label {
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-primary);
}

.label-hint {
  font-weight: 400;
  color: var(--ink-muted);
  font-size: 12px;
}

.combo-input {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 6px;
}

.calc-form input,
.calc-form select,
.search-box input {
  width: 100%;
  min-width: 0;
  height: 40px;
  padding: 0 12px;
  background: var(--bg-paper);
  color: var(--ink-primary);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 14px;
}

.calc-form input:hover,
.calc-form select:hover,
.search-box input:hover {
  border-color: var(--ink-secondary);
}

.form-error {
  margin: 0 0 16px;
  padding: 10px 12px;
  background: var(--accent-tint);
  border: 1px solid var(--accent);
  border-radius: var(--radius-sm);
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
}

.result-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.result-cell {
  padding: 14px 16px;
  background: var(--bg-surface);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.result-cell.is-highlighted {
  border-color: var(--ink-primary);
  background: var(--bg-paper);
}

.result-label {
  font-size: 12px;
  color: var(--ink-secondary);
}

.result-val {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  color: var(--ink-primary);
}

.result-cell.is-highlighted .result-val {
  color: var(--accent);
}

.result-sub {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-muted);
}

.panel-note {
  margin: 0 0 14px;
  font-size: 13.5px;
  color: var(--ink-secondary);
}

.matrix-table td {
  font-family: var(--font-mono);
  font-size: 13px;
  white-space: nowrap;
}

.matrix-table td:first-child {
  font-family: var(--font-sans);
  font-weight: 600;
  white-space: nowrap;
}

.overhead-card {
  margin-top: 20px;
  padding: 16px;
  background: var(--bg-surface);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
}

.overhead-title {
  margin: 0 0 8px;
  font-size: 14px;
  font-weight: 700;
}

.overhead-desc {
  margin: 0 0 10px;
  font-size: 13px;
  color: var(--ink-secondary);
}

.overhead-desc:last-child {
  margin-bottom: 0;
}

.formula-strip {
  padding: 8px 12px;
  margin-bottom: 10px;
  background: var(--bg-elevated);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
}

/* ==========================================================================
   Section 4: Filterable One-Liner Diagnostic Cheatsheet
   ========================================================================== */

.cheatsheet-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 28px;
}

.search-box {
  min-width: 280px;
  flex: 0 1 340px;
}

.search-box input {
  width: 100%;
  font-family: var(--font-sans);
}

.cmd-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.cmd-item {
  background: var(--bg-elevated);
  border: 1px solid var(--rule-hairline);
  border-radius: var(--radius-sm);
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 0;
}

.cmd-item[hidden] {
  display: none;
}

.cmd-item-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.cmd-tag {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--accent);
}

.cmd-purpose {
  margin: 0;
  font-size: 13.5px;
  color: var(--ink-secondary);
}

.cmd-item pre {
  background: var(--bg-code);
  color: var(--text-code);
  border-radius: var(--radius-sm);
}

.empty-state {
  padding: 28px;
  text-align: center;
  background: var(--bg-surface);
  border: 1px dashed var(--rule-hairline);
  border-radius: var(--radius-sm);
  color: var(--ink-secondary);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.site-footer {
  max-width: 1240px;
  margin: 0 auto;
  padding: 40px 24px 56px;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  justify-content: space-between;
  gap: 24px;
}

.footer-brand {
  margin: 0 0 6px;
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 700;
}

.footer-desc {
  margin: 0;
  font-size: 13px;
  color: var(--ink-muted);
  max-width: 56ch;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

.footer-links a {
  color: var(--ink-secondary);
  text-decoration: none;
  font-size: 13px;
}

.footer-links a:hover {
  color: var(--accent);
}

/* ==========================================================================
   Explicit Mobile Collapse (< 768px) & Reduced Motion
   ========================================================================== */

@media (max-width: 960px) {
  .hero-grid,
  .editorial-workspace,
  .workbench-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }

  .essay-index {
    position: static;
  }
}

@media (max-width: 767px) {
  html {
    scroll-padding-top: 104px;
  }

  .site-header {
    height: auto;
    min-height: 60px;
    padding: 8px 0;
  }

  .header-inner {
    padding: 0 16px;
    flex-wrap: wrap;
    gap: 10px;
  }

  .brand-en {
    display: none;
  }

  .site-nav {
    order: 3;
    width: 100%;
    justify-content: space-between;
    gap: 8px;
    padding-top: 6px;
    border-top: 1px solid var(--rule-hairline);
  }

  .nav-link {
    font-size: 13px;
  }

  .hero-section,
  .essays-section,
  .workbench-section,
  .cheatsheet-section {
    padding: 32px 16px;
  }

  .hero-specimen,
  .essay-article,
  .tool-panel {
    padding: 20px 16px;
  }

  .wf-row {
    grid-template-columns: 1fr auto;
    gap: 6px;
  }

  .wf-track {
    grid-column: 1 / -1;
    order: 3;
  }

  .field-row,
  .cmd-grid {
    grid-template-columns: 1fr;
  }

  .search-box {
    flex: 1 1 100%;
    min-width: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}