/* Hallmark · v1.1.0 · pre-emit critique: P5 H5 E5 S5 R5 V5
 * genre: editorial · macrostructure: Narrative Workflow + Pain Points Grid · theme: Newsprint
 * enrichment: interactive bilingual spread & dropzone (typography + CSS demo plates)
 * nav: N9 Edge-aligned minimal with section jumps · footer: Ft4 Dense colophon
 * motion: static (Newsprint 0×) — functional state changes only
 * type: Newsreader (display) + IBM Plex Sans (body) · palette: warm paper, cinnabar accent
 * contrast: pass (40–41) ink/paper 15.66, muted/paper 6.73, accent/paper 6.95, paper/ink 15.66
 * slop: pass (42–45) · honest: pass (46) · chrome: pass (47) · tokens: pass (48) · icons: pass (30)
 * responsive: pass (49) · mobile: pass (34, 49, 50–57) — verified 320/375/414/768
 */

:root {
  /* Paper & ink — warm, tinted toward the cinnabar anchor */
  --color-paper:       oklch(96.5% 0.012 75);
  --color-paper-2:     oklch(93.5% 0.014 75);
  --color-paper-3:     oklch(90%   0.016 75);
  --color-paper-dim:   oklch(82%   0.018 75);
  --color-rule:        oklch(85%   0.012 75);
  --color-line-input:  oklch(52%   0.012 62);
  --color-neutral:     oklch(58%   0.010 65);
  --color-muted:       oklch(45%   0.010 60);
  --color-ink:         oklch(22%   0.014 55);
  --color-muted-on-ink: oklch(78%  0.014 75);
  --color-neutral-on-ink: oklch(62% 0.012 75);

  --color-accent:      oklch(46%   0.155 32);
  --color-accent-quiet: oklch(94%  0.035 32);
  --color-accent-ink:  oklch(96.5% 0.012 75);
  --color-focus:       oklch(46%   0.155 32);

  /* Type */
  --font-display: "Newsreader", "Iowan Old Style", "Times New Roman", serif;
  --font-body: "IBM Plex Sans", "Helvetica Neue", Arial, sans-serif;

  --text-sm:      0.8rem;
  --text-base:    1rem;
  --text-lg:      1.5625rem;
  --text-2xl:     clamp(1.85rem, 1.6vw + 1.4rem, 2.6rem);
  --text-display: clamp(2.4rem, 6.2vw + 0.6rem, 5.1rem);

  /* Space — 4 pt scale */
  --space-3xs: 0.125rem;
  --space-2xs: 0.25rem;
  --space-xs:  0.5rem;
  --space-sm:  0.75rem;
  --space-md:  1rem;
  --space-lg:  1.5rem;
  --space-xl:  2.5rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;
  --space-4xl: 8rem;

  --page-max: 74rem;
  --page-gutter: clamp(1.25rem, 4vw, 3.5rem);

  --dur-micro: 120ms;
  --dur-short: 220ms;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --ease-in: cubic-bezier(0.7, 0, 0.84, 0);
}

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

[hidden] {
  display: none !important;
}

html {
  overflow-x: clip;
  scroll-behavior: smooth;
  scroll-padding-top: var(--space-lg);
}

body {
  margin: 0;
  overflow-x: clip;
  background-color: var(--color-paper);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.8' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)' opacity='.05'/%3E%3C/svg%3E");
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection {
  background: var(--color-accent-quiet);
  color: var(--color-ink);
}

h1,
h2,
h3,
p {
  margin: 0;
}

h1,
h2,
h3 {
  font-family: var(--font-display);
  font-weight: 300;
  font-style: normal;
  overflow-wrap: anywhere;
  min-width: 0;
  text-wrap: balance;
}

p {
  text-wrap: pretty;
}

a {
  color: inherit;
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 0.12em;
  text-decoration-color: var(--color-rule);
  transition: color var(--dur-micro) var(--ease-out),
              text-decoration-color var(--dur-micro) var(--ease-out);
}

a:hover {
  color: var(--color-accent);
  text-decoration-color: var(--color-accent);
}

a:active {
  color: var(--color-accent);
  text-decoration-color: var(--color-accent);
  text-underline-offset: 0.1em;
}

:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 3px;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.nowrap {
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  top: var(--space-md);
  left: var(--space-md);
  z-index: 10;
  padding: var(--space-sm) var(--space-md);
  background: var(--color-ink);
  color: var(--color-paper);
  font-size: var(--text-sm);
  text-decoration: none;
  transform: translateY(-200%);
}

.skip-link:focus-visible {
  transform: none;
  color: var(--color-paper);
}

/* Shared type details */
.label {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  line-height: 1.4;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-muted);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  border: 1px solid transparent;
  border-radius: 0;
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: 0.005em;
  text-decoration: none;
  white-space: nowrap;
  cursor: pointer;
  transition: background-color var(--dur-micro) var(--ease-out),
              color var(--dur-micro) var(--ease-out),
              border-color var(--dur-micro) var(--ease-out),
              transform 100ms var(--ease-out);
}

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

.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  transform: none;
}

.btn--primary {
  background: var(--color-ink);
  border-color: var(--color-ink);
  color: var(--color-paper);
}

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

.btn--inverse {
  background: var(--color-paper);
  border-color: var(--color-paper);
  color: var(--color-ink);
}

.btn--inverse:hover {
  background: var(--color-paper-dim);
  border-color: var(--color-paper-dim);
  color: var(--color-ink);
}

/* ── Navigation — N9 edge-aligned ─────────────────────────────── */
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-lg);
  max-width: var(--page-max);
  margin-inline: auto;
  padding: var(--space-lg) var(--page-gutter);
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 500;
  line-height: 1;
  letter-spacing: -0.02em;
  text-decoration: none;
}

.wordmark:hover {
  color: var(--color-ink);
}

.nav__links {
  display: none;
  align-items: center;
  gap: var(--space-lg);
  font-size: var(--text-sm);
  font-weight: 500;
}

.nav__links a {
  text-decoration: none;
  color: var(--color-ink);
  padding-bottom: var(--space-3xs);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-micro) var(--ease-out), color var(--dur-micro) var(--ease-out);
}

.nav__links a:hover {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

@media (min-width: 48rem) {
  .nav__links {
    display: flex;
  }
}

.seal {
  display: inline-grid;
  place-items: center;
  flex: none;
  width: 1.5rem;
  height: 1.5rem;
  background: var(--color-accent);
  color: var(--color-accent-ink);
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 500;
  line-height: 1;
  letter-spacing: 0;
}

.nav__cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  min-height: 2.75rem;
  padding-block: var(--space-2xs);
  border-bottom: 1px solid var(--color-ink);
  font-size: var(--text-base);
  font-weight: 500;
  line-height: 1.2;
  white-space: nowrap;
  text-decoration: none;
}

.nav__cta span {
  transition: transform var(--dur-micro) var(--ease-out);
}

.nav__cta:hover {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

.nav__cta:hover span {
  transform: translateX(3px);
}

/* ── Opening ─────────────────────────────────────────────────── */
.opening {
  max-width: var(--page-max);
  margin-inline: auto;
  padding: clamp(2.75rem, 6vw, 5.5rem) var(--page-gutter) clamp(4.5rem, 9vw, 8rem);
}

.opening__grid {
  display: grid;
  gap: var(--space-xl);
}

.opening__eyebrow {
  margin-bottom: var(--space-md);
}

.opening__head h1 {
  max-width: 18ch;
  font-size: var(--text-display);
  font-weight: 300;
  line-height: 1.05;
  letter-spacing: -0.028em;
}

.lede {
  max-width: 46ch;
  margin-top: var(--space-lg);
  font-size: var(--text-lg);
  line-height: 1.45;
  letter-spacing: -0.005em;
}

.opening__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-md) var(--space-lg);
  margin-top: var(--space-xl);
}

.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  font-size: var(--text-base);
  font-weight: 500;
  white-space: nowrap;
  text-decoration: none;
}

.link-arrow span {
  transition: transform var(--dur-micro) var(--ease-out);
}

.link-arrow:hover span {
  transform: translateY(3px);
}

.opening__meta {
  max-width: 52ch;
  margin-top: var(--space-xl);
  padding-top: var(--space-sm);
  border-top: 1px solid var(--color-rule);
  color: var(--color-muted);
  font-size: var(--text-sm);
  letter-spacing: 0.01em;
}

.sample {
  align-self: start;
  max-width: 46ch;
  padding-top: var(--space-sm);
  border-top: 1px solid var(--color-ink);
}

.sample .label {
  margin-bottom: var(--space-sm);
}

.sample__en,
.sample__vi {
  font-family: var(--font-display);
  font-size: var(--text-base);
  line-height: 1.55;
  color: var(--color-ink);
}

.sample__en {
  font-style: italic;
  font-weight: 400;
}

.sample__vi {
  margin-top: var(--space-sm);
  font-weight: 400;
}

.sample__cite {
  margin-top: var(--space-md);
  padding-top: var(--space-xs);
  border-top: 1px solid var(--color-rule);
  color: var(--color-muted);
  font-size: var(--text-sm);
  letter-spacing: 0.01em;
}

/* ── Problems Section (Thực trạng) ─────────────────────────── */
.problems {
  max-width: var(--page-max);
  margin-inline: auto;
  padding: 0 var(--page-gutter) clamp(3.5rem, 7vw, 6rem);
}

.problems__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

.problem-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: var(--space-lg);
  border: 1px solid var(--color-rule);
  background: var(--color-paper-2);
  transition: border-color var(--dur-micro) var(--ease-out),
              background-color var(--dur-micro) var(--ease-out);
}

.problem-card:hover {
  border-color: var(--color-ink);
  background: var(--color-paper);
}

.problem-card__num {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-accent);
  letter-spacing: 0.08em;
  margin-bottom: var(--space-xs);
  font-variant-numeric: tabular-nums;
}

.problem-card h3 {
  margin: 0 0 var(--space-3xs);
  font-size: var(--text-lg);
  font-weight: 400;
  line-height: 1.25;
  letter-spacing: -0.015em;
  color: var(--color-ink);
}

.problem-card__term {
  margin: 0 0 var(--space-sm);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-muted);
}

.problem-card p:not(.problem-card__term) {
  margin: 0;
  color: var(--color-ink);
  font-size: var(--text-base);
  line-height: 1.6;
}

@media (min-width: 44rem) {
  .problems__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 68rem) {
  .problems__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ── Workflow ────────────────────────────────────────────────── */
.workflow {
  max-width: var(--page-max);
  margin-inline: auto;
  padding: 0 var(--page-gutter) clamp(3.5rem, 7vw, 6rem);
}

.section-head {
  display: grid;
  gap: var(--space-xs);
  padding-block: var(--space-lg) var(--space-xl);
  border-top: 1px solid var(--color-rule);
}

.section-head h2 {
  max-width: 24ch;
  font-size: var(--text-2xl);
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.section-head__note {
  max-width: 46ch;
  color: var(--color-muted);
  font-size: var(--text-base);
}

.stages {
  margin: 0;
  padding: 0;
  list-style: none;
}

.stage {
  display: grid;
  gap: var(--space-xl);
  padding-block: var(--space-2xl);
  border-top: 1px solid var(--color-rule);
}

.stage:last-child {
  padding-bottom: 0;
}

.stage__num {
  color: var(--color-accent);
  font-size: var(--text-lg);
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: 0.04em;
  font-variant-numeric: tabular-nums;
}

.stage h3 {
  margin: var(--space-xs) 0 var(--space-md);
  font-size: var(--text-lg);
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: -0.015em;
}

.stage__text p:not(.stage__num) {
  max-width: 46ch;
  color: var(--color-ink);
}

.plate {
  margin: 0;
  min-width: 0;
}

.plate__cap {
  margin-top: var(--space-sm);
  color: var(--color-muted);
  font-size: var(--text-sm);
  line-height: 1.55;
  letter-spacing: 0.01em;
}

#upload,
#cach-lam,
#nguyen-tac,
#van-de,
#loi-ich,
#dat-ban-thao {
  scroll-margin-top: var(--space-lg);
}

/* Stage 01 — dropzone */
.drop {
  padding: var(--space-xl) var(--space-lg);
  border: 1px solid var(--color-line-input);
  background: var(--color-paper-2);
  text-align: center;
  transition: border-color var(--dur-micro) var(--ease-out),
              background-color var(--dur-micro) var(--ease-out);
}

.drop:hover {
  border-color: var(--color-ink);
}

.drop:focus-within {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.drop.is-dragover {
  border-color: var(--color-accent);
  background: var(--color-paper-3);
}

.drop.is-error {
  border-color: var(--color-accent);
}

.drop__label {
  display: grid;
  justify-items: center;
  gap: var(--space-2xs);
  cursor: pointer;
}

.drop__title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.drop__hint {
  color: var(--color-muted);
  font-size: var(--text-base);
}

.drop__browse {
  text-decoration: underline;
  text-underline-offset: 0.12em;
  text-decoration-color: var(--color-rule);
}

.drop:hover .drop__browse {
  color: var(--color-accent);
  text-decoration-color: currentColor;
}

.file {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: var(--space-2xs) var(--space-md);
  align-items: baseline;
  padding-block: var(--space-sm);
  border-bottom: 1px solid var(--color-rule);
  animation: file-in 150ms var(--ease-out) both;
}

@keyframes file-in {
  from {
    opacity: 0;
    transform: translateY(4px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.file__name {
  grid-column: 1;
  font-weight: 500;
  font-size: var(--text-base);
  overflow-wrap: anywhere;
}

.file__meta {
  grid-column: 1;
  color: var(--color-muted);
  font-size: var(--text-sm);
  font-variant-numeric: tabular-nums;
}

.file__state {
  grid-column: 2;
  grid-row: 1 / span 2;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  color: var(--color-ink);
  font-size: var(--text-sm);
  white-space: nowrap;
}

.file__state::before {
  content: "";
  width: 0.4rem;
  height: 0.4rem;
  background: var(--color-accent);
}

.plate__error {
  min-height: 1.45em;
  margin-top: var(--space-2xs);
  color: var(--color-accent);
  font-size: var(--text-sm);
  line-height: 1.45;
}

/* Stage 02 — register picker */
.registers {
  margin: 0;
  padding: 0;
  border: 0;
}

.registers legend {
  padding: 0;
  margin-bottom: var(--space-sm);
}

.reg {
  display: grid;
  grid-template-columns: 1.15rem minmax(0, 1fr);
  gap: var(--space-md);
  align-items: start;
  padding-block: var(--space-sm);
  border-top: 1px solid var(--color-rule);
  cursor: pointer;
}

.reg:last-of-type {
  border-bottom: 1px solid var(--color-rule);
}

.reg__dot {
  display: grid;
  place-items: center;
  width: 1.05rem;
  height: 1.05rem;
  margin-top: var(--space-2xs);
  border: 1px solid var(--color-line-input);
  border-radius: 50%;
  transition: border-color var(--dur-micro) var(--ease-out);
}

.reg__dot::after {
  content: "";
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: var(--color-accent);
  opacity: 0;
  transition: opacity var(--dur-micro) var(--ease-out);
}

.reg__body {
  display: grid;
  gap: var(--space-3xs);
}

.reg__name {
  font-weight: 500;
  line-height: 1.35;
  transition: color var(--dur-micro) var(--ease-out);
}

.reg__desc {
  color: var(--color-muted);
  font-size: var(--text-base);
  line-height: 1.45;
}

.reg:hover .reg__name {
  color: var(--color-accent);
}

.reg:hover .reg__dot,
.reg input:checked + .reg__dot {
  border-color: var(--color-accent);
}

.reg input:checked + .reg__dot::after {
  opacity: 1;
}

.reg input:checked ~ .reg__body .reg__name {
  font-weight: 600;
}

.reg input:focus-visible + .reg__dot {
  outline: 2px solid var(--color-focus);
  outline-offset: 3px;
}

/* Stage 03 — bilingual spread */
.spread {
  display: grid;
  gap: 0;
}

.spread__col {
  min-width: 0;
}

.spread__col + .spread__col {
  margin-top: var(--space-lg);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-rule);
}

.spread__label {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-xs);
  margin-bottom: var(--space-sm);
  color: var(--color-muted);
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.spread__reg {
  color: var(--color-ink);
  font-weight: 500;
  letter-spacing: 0.01em;
  text-transform: none;
}

.spread__text {
  font-family: var(--font-display);
  font-size: var(--text-base);
  line-height: 1.7;
  color: var(--color-ink);
}

.spread__text--en {
  font-style: italic;
}

.spread__text--vi {
  transition: opacity var(--dur-micro) var(--ease-out);
}

.spread__text--vi::first-letter {
  float: left;
  margin-top: 0.06em;
  padding-right: 0.02em;
  font-family: var(--font-display);
  font-size: 3.1em;
  font-weight: 300;
  line-height: 0.8;
  color: var(--color-ink);
}

.note {
  display: flex;
  gap: var(--space-sm);
  margin-top: var(--space-lg);
  padding-top: var(--space-sm);
  border-top: 1px solid var(--color-rule);
}

.note__num {
  flex: none;
  color: var(--color-accent);
  font-size: var(--text-sm);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.note__body {
  max-width: 52ch;
  color: var(--color-muted);
  font-size: var(--text-sm);
  line-height: 1.55;
}

.note__body em {
  color: var(--color-ink);
  font-style: italic;
}

/* Stage 04 — print proof */
.proof-wrap {
  position: relative;
  max-width: 22rem;
  margin-inline: auto;
}

.proof-wrap::before {
  content: "";
  position: absolute;
  inset: 0;
  transform: translate(0.45rem, 0.45rem);
  border: 1px solid var(--color-rule);
  background: var(--color-paper-2);
}

.proof {
  position: relative;
  display: flex;
  flex-direction: column;
  aspect-ratio: 148 / 210;
  padding: var(--space-lg);
  border: 1px solid var(--color-rule);
  background: var(--color-paper);
}

.proof__head {
  padding-bottom: var(--space-xs);
  border-bottom: 1px solid var(--color-ink);
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-ink);
}

.proof__chapter {
  margin-top: var(--space-xs);
  color: var(--color-muted);
  font-size: var(--text-sm);
  letter-spacing: 0.01em;
}

.proof__text {
  margin-top: var(--space-sm);
  font-family: var(--font-display);
  font-size: var(--text-base);
  line-height: 1.65;
  color: var(--color-ink);
}

.proof__num {
  margin-top: auto;
  padding-top: var(--space-sm);
  color: var(--color-muted);
  font-size: var(--text-sm);
  text-align: center;
  font-variant-numeric: tabular-nums;
}

.formats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  margin-top: var(--space-md);
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.formats span {
  color: var(--color-muted);
  letter-spacing: 0;
}

/* ── Mid-page Interlude (Nghỉ chân / Kêu gọi giữa trang) ────── */
.interlude {
  max-width: var(--page-max);
  margin-inline: auto;
  padding: 0 var(--page-gutter) clamp(3.5rem, 7vw, 6rem);
}

.interlude__inner {
  display: grid;
  gap: var(--space-md);
  padding: clamp(2rem, 5vw, 3.5rem);
  border: 1px solid var(--color-ink);
  background: var(--color-paper-2);
  text-align: left;
}

.interlude h2 {
  max-width: 28ch;
  font-size: var(--text-2xl);
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin: 0;
}

.interlude__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-md) var(--space-lg);
  margin-top: var(--space-xs);
}

.interlude__meta {
  color: var(--color-muted);
  font-size: var(--text-sm);
}

/* ── Principles ──────────────────────────────────────────────── */
.principles {
  max-width: var(--page-max);
  margin-inline: auto;
  padding: 0 var(--page-gutter) clamp(4rem, 8vw, 7rem);
}

.promises {
  margin: 0;
  padding: 0;
  list-style: none;
}

.promise {
  display: grid;
  gap: var(--space-xs);
  padding-block: var(--space-xl);
  border-top: 1px solid var(--color-rule);
}

.promise:last-child {
  border-bottom: 1px solid var(--color-rule);
}

.promise__line {
  position: relative;
  max-width: 24ch;
  padding-left: 1.1em;
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 300;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.promise__line::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 0.4em;
  height: 0.4em;
  background: var(--color-accent);
}

.promise__note {
  max-width: 46ch;
  color: var(--color-muted);
}

/* ── Closing ─────────────────────────────────────────────────── */
.close {
  background: var(--color-ink);
  color: var(--color-paper);
}

.close__inner {
  position: relative;
  display: grid;
  justify-items: start;
  gap: var(--space-lg);
  max-width: var(--page-max);
  margin-inline: auto;
  padding: clamp(4rem, 9vw, 7rem) var(--page-gutter);
}

.close h2 {
  max-width: 14ch;
  font-size: var(--text-display);
  line-height: 1.02;
  letter-spacing: -0.028em;
  color: var(--color-paper);
}

.close__lede {
  max-width: 46ch;
  color: var(--color-paper-dim);
  font-size: var(--text-lg);
  line-height: 1.45;
}

.close__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-md) var(--space-lg);
}

.close__note {
  color: var(--color-muted-on-ink);
  font-size: var(--text-sm);
}

.close__note a {
  color: var(--color-paper);
  text-decoration-color: var(--color-neutral-on-ink);
}

.close__note a:hover {
  color: var(--color-paper);
  text-decoration-color: var(--color-paper);
}

/* Paper ring on the ink surface — accent/ink is only 2.25:1. */
.close :focus-visible {
  outline-color: var(--color-paper);
}

.close .seal--lg {
  position: absolute;
  top: clamp(4rem, 9vw, 7rem);
  right: var(--page-gutter);
  display: none;
  width: 3rem;
  height: 3rem;
  font-size: var(--text-lg);
}

/* ── Colophon — Ft4 ──────────────────────────────────────────── */
.colophon {
  border-top: 3px double var(--color-ink);
}

.colophon__inner {
  display: grid;
  gap: var(--space-lg);
  max-width: var(--page-max);
  margin-inline: auto;
  padding: var(--space-xl) var(--page-gutter) var(--space-2xl);
}

.colophon__nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-xs) var(--space-lg);
  font-size: var(--text-sm);
  font-weight: 500;
}

.colophon__nav a {
  white-space: nowrap;
  text-decoration: none;
  border-bottom: 1px solid var(--color-rule);
  padding-bottom: var(--space-3xs);
}

.colophon__nav a:hover {
  border-bottom-color: var(--color-accent);
}

.colophon p {
  max-width: 72ch;
  color: var(--color-muted);
  font-size: var(--text-sm);
  line-height: 1.75;
  letter-spacing: 0.005em;
}

.colophon cite {
  color: var(--color-ink);
  font-style: normal;
}

/* ── Desktop composition ─────────────────────────────────────── */
@media (min-width: 60rem) {
  .nav {
    padding-block: var(--space-xl) var(--space-lg);
  }

  .opening__grid {
    grid-template-columns: minmax(0, 7.4fr) minmax(0, 4fr);
    column-gap: clamp(2.5rem, 5vw, 5rem);
    align-items: start;
  }

  .opening__head {
    padding-top: 0;
  }

  .sample {
    margin-top: var(--space-xs);
    justify-self: end;
  }

  .stage {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    column-gap: var(--space-xl);
    align-items: start;
    padding-block: var(--space-3xl);
  }

  .stage__text {
    grid-column: 1 / span 5;
    grid-row: 1;
  }

  .stage > .plate {
    grid-column: 7 / span 6;
    grid-row: 1;
  }

  .stage#upload.stage--has-manuscript {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    column-gap: var(--space-xl);
  }

  .stage#upload.stage--has-manuscript .manuscript-dossier {
    grid-column: 1 / span 4;
    grid-row: 1;
  }

  .stage#upload.stage--has-manuscript .plate--studio {
    grid-column: 5 / span 8;
    grid-row: 1;
  }

  .stage:nth-child(even) .stage__text {
    grid-column: 8 / span 5;
  }

  .stage:nth-child(even) .plate {
    grid-column: 1 / span 6;
  }

  .spread {
    position: relative;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    column-gap: clamp(2rem, 4vw, 3.25rem);
  }

  .spread::before {
    content: "";
    position: absolute;
    inset-block: 0;
    left: 50%;
    width: 1px;
    background: var(--color-rule);
  }

  .spread__col + .spread__col {
    margin-top: 0;
    padding-top: 0;
    border-top: 0;
  }

  .promise {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    column-gap: clamp(2rem, 5vw, 4rem);
    align-items: start;
  }

  .close .seal--lg {
    display: grid;
  }
}

/* ── Reduced motion ──────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}


/* ── Navigation Auth ─────────────────────────────────────────── */
.nav__auth {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.btn--sm {
  padding: var(--space-2xs) var(--space-sm);
  font-size: var(--text-sm);
}

.nav__user-pill {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  font-size: var(--text-sm);
  color: var(--color-ink);
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  padding: var(--space-2xs) var(--space-sm);
}

.nav__user-logout {
  color: var(--color-accent);
  text-decoration: underline;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
  font-size: var(--text-sm);
  font-family: inherit;
}

/* ── Manuscript Dossier (Editorial Book Card) ────────────────── */
.manuscript-dossier {
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  text-align: left;
}

.dossier__tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.dossier__tag-dot {
  width: 6px;
  height: 6px;
  background: var(--color-accent);
  border-radius: 50%;
}

.dossier__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 500;
  line-height: 1.25;
  color: var(--color-ink);
  margin: 0;
  word-break: break-word;
}

.dossier__author {
  font-size: var(--text-sm);
  color: var(--color-muted);
  margin: 0;
  line-height: 1.4;
}

.dossier__stats {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  border-top: 1px solid var(--color-rule);
  border-bottom: 1px solid var(--color-rule);
  padding-block: var(--space-sm);
}

.dossier__stat-box {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: var(--text-sm);
}

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

.dossier__stat-num {
  font-weight: 600;
  color: var(--color-ink);
  font-variant-numeric: tabular-nums;
}

.dossier__stat-box--highlight .dossier__stat-num {
  color: var(--color-accent);
  font-size: var(--text-base);
}

.dossier__footer {
  margin-top: auto;
  padding-top: var(--space-xs);
}

.dossier__switch-file {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2xs);
  font-size: var(--text-sm);
  color: var(--color-muted);
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--dur-micro) var(--ease-out);
}

.dossier__switch-file:hover {
  color: var(--color-ink);
}

/* ── Studio Funnel Workspace ─────────────────────────────────── */
.plate--studio {
  width: 100%;
}

.studio-funnel {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
  width: 100%;
}

.dual-funnel {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
  width: 100%;
}

@media (min-width: 48rem) {
  .dual-funnel {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.funnel-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: var(--space-lg);
  background: var(--color-paper);
  border: 1px solid var(--color-rule);
  transition: border-color var(--dur-micro) var(--ease-out), box-shadow var(--dur-micro) var(--ease-out);
  text-align: left;
}

.funnel-card:hover {
  border-color: var(--color-ink);
}

.funnel-card--express {
  border-color: var(--color-accent);
  background: var(--color-paper-2);
}

.funnel-card__badge {
  display: inline-block;
  align-self: flex-start;
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.2rem 0.5rem;
  margin-bottom: var(--space-xs);
}

.funnel-card__badge--express {
  background: var(--color-accent);
  color: #fff;
}

.funnel-card__badge--free {
  background: var(--color-ink);
  color: var(--color-paper);
}

.funnel-card__title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 500;
  margin: 0 0 var(--space-2xs);
  color: var(--color-ink);
  line-height: 1.3;
}

.funnel-card__desc {
  font-size: var(--text-sm);
  color: var(--color-ink);
  line-height: 1.55;
  margin: 0 0 var(--space-md);
}

.funnel-card__action {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.input-label {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.input-text {
  width: 100%;
  padding: 0.65rem 0.85rem;
  background: var(--color-paper);
  border: 1px solid var(--color-line-input);
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-ink);
  border-radius: 0;
  outline: none;
  transition: border-color var(--dur-micro) var(--ease-out);
  box-sizing: border-box;
}

.input-text:focus {
  border-color: var(--color-ink);
  outline: 2px solid var(--color-focus);
}

.funnel-card__meta {
  font-size: var(--text-xs);
  color: var(--color-muted);
  margin-bottom: var(--space-2xs);
  display: flex;
  align-items: center;
  gap: var(--space-3xs);
}

/* ── Funnel Action Buttons (Anti-overflow, Hallmark compliant) ── */
.btn--funnel {
  width: 100%;
  white-space: normal;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-xs);
  padding: 0.75rem 1rem;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  line-height: 1.3;
  text-decoration: none;
  cursor: pointer;
  border-radius: 0;
  transition: all var(--dur-micro) var(--ease-out);
  box-sizing: border-box;
}

.btn--funnel .btn__text {
  font-weight: 500;
  letter-spacing: 0.01em;
}

.btn--funnel .btn__badge {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.5rem;
  background: var(--color-accent);
  color: #fff;
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.02em;
  border-radius: 2px;
  white-space: nowrap;
}

.btn--funnel:hover .btn__badge {
  background: #000;
  color: #fff;
}

.btn--funnel .btn__arrow {
  font-size: 1.1em;
  line-height: 1;
}

.btn--inverse-outline {
  background: transparent;
  border: 1px solid var(--color-ink);
  color: var(--color-ink);
}

.btn--inverse-outline:hover {
  background: var(--color-ink);
  color: var(--color-paper);
}

/* ── Live Translation Progress ───────────────────────────────── */
.translate-progress {
  padding: var(--space-lg);
  background: var(--color-paper-2);
  border: 1px solid var(--color-ink);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  text-align: left;
}

.translate-progress__header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--space-md);
}

.translate-progress__status {
  font-size: var(--text-sm);
  color: var(--color-ink);
  font-weight: 500;
}

.translate-progress__percent {
  font-size: var(--text-base);
  color: var(--color-accent);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
}

.translate-progress__bar-bg {
  width: 100%;
  height: 0.5rem;
  background: var(--color-paper-dim);
  border: 1px solid var(--color-rule);
  overflow: hidden;
}

.translate-progress__bar-fill {
  width: 0%;
  height: 100%;
  background: var(--color-accent);
  transition: width 300ms ease-out;
}

.translate-progress__hint {
  font-size: var(--text-sm);
  color: var(--color-muted);
  margin-top: var(--space-3xs);
  line-height: 1.45;
}

.translate-progress__action {
  margin-top: var(--space-sm);
}

.btn--download {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.85rem 1.25rem;
  font-size: var(--text-base);
}

/* ── Bookshelf Section ───────────────────────────────────────── */
.bookshelf-section {
  max-width: var(--page-max);
  margin-inline: auto;
  padding: 0 var(--page-gutter) clamp(3.5rem, 7vw, 6rem);
}

.bookshelf-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  margin-top: var(--space-xl);
}

@media (min-width: 48rem) {
  .bookshelf-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 68rem) {
  .bookshelf-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.book-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: var(--space-lg);
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  transition: border-color var(--dur-micro) var(--ease-out);
}

.book-card:hover {
  border-color: var(--color-ink);
}

.book-card__header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-xs);
}

.book-card__title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 500;
  margin: 0;
  color: var(--color-ink);
}

.book-card__badge {
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: var(--space-3xs) var(--space-2xs);
  white-space: nowrap;
}

.book-card__badge--done {
  background: oklch(90% 0.1 140);
  color: oklch(25% 0.08 140);
}

.book-card__badge--running {
  background: var(--color-accent-quiet);
  color: var(--color-accent);
}

.book-card__meta {
  margin: var(--space-xs) 0 var(--space-md);
  font-size: var(--text-sm);
  color: var(--color-muted);
}

.book-card__actions {
  display: flex;
  gap: var(--space-xs);
}

/* ── Modals (Auth & VietQR) ──────────────────────────────────── */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(26, 26, 26, 0.65);
  backdrop-filter: blur(2px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: var(--space-md);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur-short) var(--ease-out);
}

.modal-backdrop.is-open {
  opacity: 1;
  pointer-events: auto;
}

.modal-dialog {
  position: relative;
  width: 100%;
  max-width: 32rem;
  max-height: 90vh;
  overflow-y: auto;
  background: var(--color-paper);
  border: 2px solid var(--color-ink);
  box-shadow: 8px 8px 0px var(--color-ink);
  padding: clamp(1.5rem, 4vw, 2.5rem);
  text-align: left;
}

.modal-close {
  position: absolute;
  top: var(--space-md);
  right: var(--space-md);
  background: none;
  border: none;
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
  color: var(--color-ink);
}

.modal-close:hover {
  color: var(--color-accent);
}

.modal-tabs {
  display: flex;
  border-bottom: 2px solid var(--color-ink);
  margin-bottom: var(--space-lg);
}

.modal-tab-btn {
  flex: 1;
  padding: var(--space-xs) var(--space-sm);
  background: none;
  border: none;
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-muted);
  cursor: pointer;
  text-align: center;
}

.modal-tab-btn.is-active {
  color: var(--color-ink);
  border-bottom: 3px solid var(--color-accent);
}

.modal-field {
  margin-bottom: var(--space-md);
}

.modal-field label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: var(--space-3xs);
}

.modal-device-box {
  padding: var(--space-sm);
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
  font-size: var(--text-sm);
  color: var(--color-muted);
  margin-bottom: var(--space-md);
  line-height: 1.45;
}

.modal-error {
  color: var(--color-accent);
  font-size: var(--text-sm);
  margin-bottom: var(--space-sm);
}

.vietqr-card {
  text-align: center;
  display: grid;
  gap: var(--space-sm);
}

.vietqr-card img {
  max-width: 16rem;
  margin-inline: auto;
  border: 1px solid var(--color-ink);
  background: #fff;
  padding: var(--space-2xs);
}

.vietqr-details {
  text-align: left;
  font-size: var(--text-sm);
  padding: var(--space-sm);
  background: var(--color-paper-2);
  border: 1px solid var(--color-rule);
}