:root {
  color-scheme: light dark;
  --page: #eef4f4;
  --surface: #f9fbfb;
  --surface-strong: #e2eeee;
  --surface-subtle: #e8f0f0;
  --text: #12282b;
  --text-soft: #506568;
  --line: #c8d7d8;
  --line-strong: #9db6b8;
  --accent: #0b727d;
  --accent-hover: #075d66;
  --accent-soft: #d6eaea;
  --accent-text: #f4fbfb;
  --danger: #a33c3c;
  --danger-hover: #873030;
  --danger-soft: #f4dfde;
  --success: #24654f;
  --warning: #896317;
  --shadow: 0 24px 64px rgba(28, 72, 76, 0.12);
  --radius-panel: 18px;
  --radius-control: 12px;
  --shell: 1160px;
  font-family: "Avenir Next", "Segoe UI Variable", "Segoe UI", Helvetica, Arial, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

@media (prefers-color-scheme: dark) {
  :root {
    --page: #10191a;
    --surface: #162224;
    --surface-strong: #203335;
    --surface-subtle: #1b2b2d;
    --text: #edf5f5;
    --text-soft: #a7babc;
    --line: #304547;
    --line-strong: #506b6e;
    --accent: #67bbc2;
    --accent-hover: #81cbd1;
    --accent-soft: #173c40;
    --accent-text: #0d2426;
    --danger: #ee8d87;
    --danger-hover: #f4a49f;
    --danger-soft: #482726;
    --success: #80c4a9;
    --warning: #dfbd72;
    --shadow: 0 28px 70px rgba(2, 10, 11, 0.3);
  }
}

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

html {
  min-width: 320px;
}

body {
  min-width: 320px;
  min-height: 100dvh;
  margin: 0;
  background:
    radial-gradient(circle at 8% 10%, color-mix(in srgb, var(--accent-soft) 62%, transparent), transparent 30rem),
    var(--page);
  color: var(--text);
  line-height: 1.5;
}

button,
input {
  font: inherit;
}

button,
a,
input {
  -webkit-tap-highlight-color: transparent;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent) 72%, transparent);
  outline-offset: 3px;
}

[hidden] {
  display: none !important;
}

.shell {
  width: min(var(--shell), calc(100% - 48px));
  margin-inline: auto;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 20;
  padding: 10px 14px;
  border-radius: var(--radius-control);
  background: var(--text);
  color: var(--surface);
  font-weight: 700;
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  border-bottom: 1px solid color-mix(in srgb, var(--line) 78%, transparent);
  background: color-mix(in srgb, var(--page) 92%, transparent);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.header-inner {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

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

.brand span:first-child {
  font-size: 1.05rem;
  font-weight: 800;
  letter-spacing: -0.03em;
}

.brand span:last-child {
  color: var(--text-soft);
  font-size: 0.88rem;
  font-weight: 600;
}

.technical-link,
.text-button {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  border: 0;
  background: none;
  color: var(--text-soft);
  font-size: 0.875rem;
  font-weight: 700;
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--text-soft) 44%, transparent);
  text-underline-offset: 4px;
  cursor: pointer;
}

.technical-link:hover,
.text-button:hover {
  color: var(--accent);
  text-decoration-color: currentColor;
}

.page {
  padding-block: 34px 70px;
}

.demo-layout {
  min-height: calc(100dvh - 68px - 84px);
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(420px, 1.1fr);
  gap: clamp(40px, 7vw, 96px);
  align-items: center;
}

.story-panel {
  min-width: 0;
}

.eyebrow {
  margin: 0 0 14px;
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

h1,
h2,
p {
  overflow-wrap: anywhere;
}

h1 {
  max-width: 650px;
  margin: 0;
  font-size: clamp(2.65rem, 5.4vw, 4.5rem);
  font-weight: 720;
  letter-spacing: -0.066em;
  line-height: 0.98;
  text-wrap: balance;
}

.hero-copy {
  max-width: 520px;
  margin: 18px 0 0;
  color: var(--text-soft);
  font-size: 1.08rem;
}

.journey {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
  margin-top: 28px;
  border-bottom: 1px solid var(--line);
}

.journey span {
  position: relative;
  padding: 0 0 10px;
  color: var(--text-soft);
  font-size: 0.8rem;
  font-weight: 700;
  text-align: center;
}

.journey span[data-state="current"] {
  color: var(--accent);
}

.journey span[data-state="current"]::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: -1px;
  left: 0;
  height: 3px;
  border-radius: 3px 3px 0 0;
  background: var(--accent);
}

.journey span[data-state="complete"] {
  color: var(--text);
}

.action-panel {
  margin-top: 18px;
  padding: 24px;
  border: 1px solid color-mix(in srgb, var(--accent) 28%, var(--line));
  border-radius: var(--radius-panel);
  background: color-mix(in srgb, var(--accent-soft) 68%, var(--surface));
}

.action-copy {
  margin-bottom: 20px;
}

.state-label,
.preview-label {
  margin: 0 0 5px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 800;
}

.action-copy h2,
.preview-heading h2,
.proof-intro h2,
.confirm-dialog h2 {
  margin: 0;
  font-size: clamp(1.35rem, 2.4vw, 1.8rem);
  letter-spacing: -0.035em;
  line-height: 1.1;
}

.action-copy > p:last-child {
  margin: 9px 0 0;
  color: var(--text-soft);
}

.button {
  min-height: 48px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 18px;
  border: 1px solid transparent;
  border-radius: var(--radius-control);
  font-weight: 800;
  line-height: 1;
  white-space: nowrap;
  cursor: pointer;
  transition: transform 140ms ease, background-color 140ms ease, border-color 140ms ease;
}

.button:active:not(:disabled) {
  transform: translateY(1px);
}

.button:disabled {
  border-color: var(--line);
  background: var(--surface-subtle);
  color: var(--text-soft);
  cursor: not-allowed;
}

.button-primary:not(:disabled) {
  background: var(--accent);
  color: var(--accent-text);
}

.button-primary:hover:not(:disabled) {
  background: var(--accent-hover);
}

.button-secondary {
  border-color: var(--line-strong);
  background: var(--surface);
  color: var(--text);
}

.button-secondary:hover:not(:disabled) {
  border-color: var(--accent);
}

.button-danger:not(:disabled) {
  background: var(--danger);
  color: #fff8f7;
}

.button-danger:hover:not(:disabled) {
  background: var(--danger-hover);
}

#primary-action,
.upload-form > .button {
  width: 100%;
}

.upload-form {
  display: grid;
  gap: 18px;
}

.field {
  display: grid;
  gap: 7px;
}

.field label {
  font-size: 0.9rem;
  font-weight: 800;
}

.field input {
  width: 100%;
  min-height: 48px;
  padding: 8px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-control);
  background: var(--surface);
  color: var(--text);
}

.field input::file-selector-button {
  margin-right: 12px;
  padding: 8px 12px;
  border: 0;
  border-radius: 8px;
  background: var(--surface-strong);
  color: var(--text);
  font-weight: 750;
  cursor: pointer;
}

.field-help,
.field-feedback {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.8rem;
}

.field-feedback[data-state="error"] {
  color: var(--danger);
  font-weight: 700;
}

.field-feedback[data-state="ready"] {
  color: var(--success);
  font-weight: 700;
}

.no-action p {
  margin: 0 0 12px;
  color: var(--text-soft);
}

.preview-panel {
  min-width: 0;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius-panel);
  background: var(--surface);
  box-shadow: var(--shadow);
}

.preview-heading {
  min-height: 48px;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 18px;
}

.file-kind {
  flex: 0 0 auto;
  padding: 6px 9px;
  border-radius: 8px;
  background: var(--surface-strong);
  color: var(--text-soft);
  font-size: 0.74rem;
  font-weight: 800;
}

.preview-frame {
  position: relative;
  min-height: 350px;
  display: grid;
  overflow: hidden;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface-subtle);
}

.preview-loading {
  width: 100%;
  height: 100%;
  min-height: 350px;
  background: linear-gradient(145deg, var(--surface-strong), var(--surface-subtle));
}

.preview-frame img {
  width: 100%;
  height: 100%;
  min-height: 350px;
  max-height: 470px;
  display: block;
  object-fit: contain;
  background: var(--surface-strong);
}

.image-slot {
  width: 100%;
  height: 100%;
  align-self: stretch;
}

.preview-empty {
  max-width: 280px;
  display: grid;
  gap: 8px;
  padding: 44px 28px;
  text-align: center;
}

.preview-empty strong {
  font-size: 1.08rem;
}

.preview-empty span {
  color: var(--text-soft);
  font-size: 0.9rem;
}

.text-preview-wrap {
  width: 100%;
  min-height: 350px;
  align-self: stretch;
  padding: 26px;
  background: var(--surface);
}

.text-preview {
  max-height: 350px;
  margin: 0;
  overflow: auto;
  color: var(--text);
  font: 0.92rem/1.65 "Avenir Next", "Segoe UI Variable", "Segoe UI", Helvetica, Arial, sans-serif;
  overflow-wrap: anywhere;
  white-space: pre-wrap;
  unicode-bidi: plaintext;
}

.text-truncated {
  margin: 18px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  color: var(--text-soft);
  font-size: 0.8rem;
  font-weight: 700;
}

.file-facts {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin: 18px 0 0;
}

.file-facts div {
  min-width: 0;
}

.file-facts dt,
.copy-status dt {
  color: var(--text-soft);
  font-size: 0.72rem;
  font-weight: 700;
}

.file-facts dd,
.copy-status dd {
  margin: 4px 0 0;
  font-size: 0.9rem;
  font-weight: 800;
  overflow-wrap: anywhere;
}

.storage-proof {
  display: grid;
  grid-template-columns: minmax(230px, 0.8fr) minmax(420px, 1.4fr);
  gap: 34px 72px;
  align-items: end;
  margin-top: 68px;
  padding: 36px 0 0;
  border-top: 1px solid var(--line);
}

.proof-intro p {
  max-width: 480px;
  margin: 10px 0 0;
  color: var(--text-soft);
}

.copy-status {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
  margin: 0;
}

.copy-status dd[data-state="present"],
.copy-status dd[data-state="verified"] {
  color: var(--success);
}

.copy-status dd[data-state="missing"] {
  color: var(--warning);
}

.copy-status dd[data-state="attention"] {
  color: var(--danger);
}

.checked-at {
  grid-column: 1 / -1;
  margin: -12px 0 0;
  color: var(--text-soft);
  font-size: 0.8rem;
}

.error-banner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-top: 28px;
  padding: 18px 20px;
  border: 1px solid color-mix(in srgb, var(--danger) 45%, var(--line));
  border-radius: var(--radius-panel);
  background: var(--danger-soft);
}

.error-banner div {
  display: grid;
  gap: 4px;
}

.error-banner span {
  color: var(--text-soft);
}

.confirm-dialog {
  width: min(460px, calc(100% - 32px));
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-panel);
  background: var(--surface);
  color: var(--text);
  box-shadow: var(--shadow);
}

.confirm-dialog::backdrop {
  background: rgba(8, 24, 26, 0.62);
  backdrop-filter: blur(4px);
}

.confirm-dialog form {
  padding: 28px;
}

.confirm-dialog p {
  margin: 12px 0 24px;
  color: var(--text-soft);
}

.dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
}

.site-footer {
  border-top: 1px solid var(--line);
}

.footer-inner {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  color: var(--text-soft);
  font-size: 0.82rem;
}

@media (max-width: 900px) {
  .page {
    padding-top: 52px;
  }

  .demo-layout {
    min-height: auto;
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .story-panel {
    max-width: 680px;
  }

  .preview-panel {
    width: 100%;
  }

  .storage-proof {
    grid-template-columns: 1fr;
    gap: 24px;
  }
}

@media (max-width: 620px) {
  .shell {
    width: min(100% - 32px, var(--shell));
  }

  .header-inner {
    min-height: 64px;
  }

  .brand span:last-child {
    display: none;
  }

  .technical-link {
    font-size: 0.8rem;
  }

  .page {
    padding-block: 38px 56px;
  }

  h1 {
    font-size: clamp(2.5rem, 13vw, 3.45rem);
  }

  .journey {
    margin-top: 28px;
  }

  .action-panel,
  .preview-panel {
    padding: 18px;
  }

  .preview-frame,
  .preview-loading,
  .preview-frame img,
  .text-preview-wrap {
    min-height: 280px;
  }

  .preview-frame img {
    max-height: 380px;
  }

  .file-facts,
  .copy-status {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .storage-proof {
    margin-top: 52px;
  }

  .checked-at {
    margin-top: 0;
  }

  .error-banner,
  .dialog-actions,
  .footer-inner {
    align-items: stretch;
    flex-direction: column;
  }

  .error-banner .button,
  .dialog-actions .button {
    width: 100%;
  }

  .footer-inner {
    justify-content: center;
    padding-block: 18px;
  }
}

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

@media (prefers-reduced-transparency: reduce) {
  .site-header {
    background: var(--page);
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
  }
}