@font-face {
  font-family: 'Barlow Condensed';
  src: url('/fonts/barlow-condensed-latin-500-normal.woff2') format('woff2');
  font-weight: 500;
  font-display: swap;
}
@font-face {
  font-family: 'Barlow Condensed';
  src: url('/fonts/barlow-condensed-latin-700-normal.woff2') format('woff2');
  font-weight: 700;
  font-display: swap;
}
@font-face {
  font-family: 'Source Sans 3';
  src: url('/fonts/source-sans-3-latin-400-normal.woff2') format('woff2');
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: 'Source Sans 3';
  src: url('/fonts/source-sans-3-latin-600-normal.woff2') format('woff2');
  font-weight: 600;
  font-display: swap;
}
@font-face {
  font-family: 'IBM Plex Mono';
  src: url('/fonts/ibm-plex-mono-latin-400-normal.woff2') format('woff2');
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: 'IBM Plex Mono';
  src: url('/fonts/ibm-plex-mono-latin-500-normal.woff2') format('woff2');
  font-weight: 500;
  font-display: swap;
}

:root {
  --paper: #eceef0;
  --sheet: #fafbfb;
  --ink: #1a1d21;
  --ink-soft: #4a5058;
  --rule: #c9ced4;
  --stamp: #2f3db5;
  --stamp-deep: #232d8c;
  --alert: #a3262a;

  --display: 'Barlow Condensed', 'Arial Narrow', sans-serif;
  --body: 'Source Sans 3', system-ui, sans-serif;
  --mono: 'IBM Plex Mono', ui-monospace, monospace;
}

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

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

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--paper);
  color: var(--ink);
  font: 400 1.0625rem/1.55 var(--body);
}

h1,
h2,
p,
ul,
dl,
dd {
  margin: 0;
}

.mono {
  font-family: var(--mono);
}

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

/* Masthead */

.masthead {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem clamp(1.25rem, 4vw, 3rem);
  border-bottom: 1px solid var(--rule);
}

.wordmark {
  font: 700 1.375rem/1 var(--display);
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.lang {
  display: flex;
  border: 1px solid var(--ink);
}

.lang button {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--ink);
  font: 500 0.8125rem/1 var(--mono);
  letter-spacing: 0.06em;
  padding: 0.5rem 0.75rem;
  cursor: pointer;
}

.lang button[aria-pressed='true'] {
  background: var(--ink);
  color: var(--sheet);
}

/* Layout */

.page {
  flex: 1;
  width: 100%;
  max-width: 72rem;
  margin: 0 auto;
  padding: clamp(2.5rem, 7vw, 5.5rem) clamp(1.25rem, 4vw, 3rem) 3rem;
  display: grid;
  gap: 2.5rem;
  grid-template-columns: minmax(0, 1fr);
  grid-template-areas:
    'intro'
    'action'
    'receive';
}

@media (min-width: 60rem) {
  .page {
    grid-template-columns: minmax(0, 1fr) minmax(0, 30rem);
    grid-template-rows: auto 1fr;
    grid-template-areas:
      'intro action'
      'receive action';
    column-gap: clamp(3rem, 6vw, 6rem);
    row-gap: 0;
    align-items: start;
  }
}

/* Intro */

.intro,
.receive-block {
  max-width: 34rem;
}

.intro {
  grid-area: intro;
}

.receive-block {
  grid-area: receive;
}

.eyebrow {
  font: 500 0.8125rem/1.4 var(--mono);
  letter-spacing: 0.04em;
  color: var(--ink-soft);
  margin-bottom: 1.25rem;
}

h1 {
  font: 500 clamp(2.75rem, 6.5vw, 4.75rem)/0.95 var(--display);
  letter-spacing: -0.01em;
  margin-bottom: 1.75rem;
  text-wrap: balance;
}

.lede {
  font-size: 1.1875rem;
  color: var(--ink-soft);
}

@media (min-width: 60rem) {
  .lede {
    margin-bottom: 2.5rem;
  }
}

.receive-title {
  font: 600 0.9375rem/1.4 var(--body);
  margin-bottom: 0.75rem;
}

.receive {
  list-style: none;
  padding: 0;
  border-top: 1px solid var(--rule);
}

.receive li {
  padding: 0.6rem 0;
  border-bottom: 1px solid var(--rule);
}

/* Handover protocol: the document the subscriber signs */

.action {
  grid-area: action;
}

.protocol {
  position: relative;
  background: var(--sheet);
  border: 1px solid var(--rule);
  box-shadow: 0 1px 0 var(--rule), 0 18px 40px -24px rgba(26, 29, 33, 0.35);
}

.protocol-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem 1.5rem 1rem;
  border-bottom: 2px solid var(--ink);
}

.protocol-head h2 {
  font: 700 1.125rem/1.2 var(--display);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.protocol-date {
  font-size: 0.8125rem;
  color: var(--ink-soft);
  white-space: nowrap;
}

.protocol-rows > div {
  display: grid;
  grid-template-columns: 8.5rem minmax(0, 1fr);
  gap: 1rem;
  padding: 0.8rem 1.5rem;
  border-bottom: 1px solid var(--rule);
}

.protocol-rows dt {
  font: 500 0.75rem/1.9 var(--mono);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.protocol-rows dd {
  font-weight: 600;
  overflow-wrap: anywhere;
}

.protocol-rows dd.mono {
  font-weight: 500;
  font-size: 0.9375rem;
  line-height: 1.75;
}

.powered {
  font-weight: 400;
  color: var(--ink-soft);
}

@media (max-width: 30rem) {
  .protocol-rows > div {
    grid-template-columns: minmax(0, 1fr);
    gap: 0.15rem;
  }
}

.sign {
  position: relative;
  padding: 1.5rem;
}

.consent {
  font-size: 0.9375rem;
  margin-bottom: 1.5rem;
}

.confirm {
  appearance: none;
  width: 100%;
  border: 0;
  background: var(--stamp);
  color: #fff;
  font: 600 1.0625rem/1 var(--body);
  padding: 1.1rem 1.5rem;
  cursor: pointer;
  transition: background-color 150ms ease;
}

.confirm:hover {
  background: var(--stamp-deep);
}

.confirm:disabled {
  cursor: progress;
  background: var(--stamp-deep);
}

.note {
  margin-top: 0.85rem;
  font-size: 0.8125rem;
  color: var(--ink-soft);
}

/* The stamp lands on the document once the confirmation is logged. */

.stamp {
  display: none;
  width: max-content;
  margin: 0.25rem 0.5rem 0.25rem auto;
  flex-direction: column;
  align-items: center;
  gap: 0.2rem;
  padding: 0.55rem 1.1rem 0.5rem;
  border: 3px double var(--stamp);
  border-radius: 6px;
  color: var(--stamp);
  transform: rotate(-7deg);
  mix-blend-mode: multiply;
  -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3CfeColorMatrix values='0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1.6 1.45'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
  mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3CfeColorMatrix values='0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1.6 1.45'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}

.stamp-label {
  font: 700 1.75rem/1 var(--display);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.stamp-time {
  font-size: 0.75rem;
  letter-spacing: 0.02em;
}

.status {
  padding: 0 1.5rem;
  font-size: 0.9375rem;
}

.status:not(:empty) {
  padding-bottom: 1.5rem;
}

/* States */

.protocol[data-state='confirmed'] .confirm,
.protocol[data-state='confirmed'] .note,
.protocol[data-state='already'] .confirm,
.protocol[data-state='already'] .note,
.protocol[data-state='invalid'] .confirm,
.protocol[data-state='invalid'] .sign {
  display: none;
}

.protocol[data-state='confirmed'] .stamp,
.protocol[data-state='already'] .stamp {
  display: flex;
}

.protocol[data-state='confirmed'] .stamp {
  animation: stamp-down 420ms cubic-bezier(0.2, 0.9, 0.3, 1.2) both;
}

.protocol[data-state='error'] .status,
.protocol[data-state='invalid'] .status {
  color: var(--alert);
}

.protocol[data-state='invalid'] .status {
  padding-top: 1.5rem;
}

@keyframes stamp-down {
  0% {
    opacity: 0;
    transform: rotate(-12deg) scale(1.6);
  }
  60% {
    opacity: 1;
  }
  100% {
    opacity: 1;
    transform: rotate(-7deg) scale(1);
  }
}

@media (prefers-reduced-motion: reduce) {
  .protocol[data-state='confirmed'] .stamp {
    animation: none;
  }
}

/* Aside and footer */

.aside {
  margin-top: 1.25rem;
  font-size: 0.875rem;
  color: var(--ink-soft);
}

.footer {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  padding: 1.25rem clamp(1.25rem, 4vw, 3rem);
  border-top: 1px solid var(--rule);
  font-size: 0.875rem;
  color: var(--ink-soft);
}

.footer[hidden] {
  display: none;
}

.footer a {
  color: inherit;
}

.noscript {
  padding: 1rem clamp(1.25rem, 4vw, 3rem);
  background: var(--ink);
  color: var(--sheet);
}