:root {
  --page: #fbfdff;
  --ink: #071a43;
  --muted: #49617f;
  --blue: #1677ee;
  --blue-hover: #0867dc;
  --success: #15803d;
  --success-hover: #116530;
  --progress: #f4a261;
  --progress-complete: #7bcf9a;
  --line: #b7c8df;
  --track: #e5ebf4;
  --focus: rgba(22, 119, 238, 0.2);
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  background: var(--page);
}

body {
  margin: 0;
  background:
    radial-gradient(circle at 50% 30%, #ffffff 0, #ffffff 30%, transparent 62%),
    var(--page);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  text-rendering: optimizeLegibility;
}

button,
input {
  font: inherit;
}

button {
  color: inherit;
}

[hidden] {
  display: none !important;
}

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.page-shell {
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding: clamp(48px, 8vh, 92px) 28px;
}

.isolation-panel {
  width: min(100%, 900px);
  transform: translateY(-2.5vh);
}

.hero {
  text-align: center;
}

.hero h1 {
  margin: 0;
  color: var(--ink);
  font-size: clamp(2.35rem, 4vw, 3.8rem);
  font-weight: 720;
  letter-spacing: -0.052em;
  line-height: 0.98;
}

.hero p {
  margin: clamp(22px, 2.5vw, 32px) 0 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 1.45vw, 1.4rem);
  font-weight: 400;
  letter-spacing: -0.018em;
  line-height: 1.45;
}

.workflow {
  margin-top: clamp(72px, 10vh, 112px);
  transition:
    color 160ms ease,
    filter 160ms ease;
}

.workflow.is-dragging {
  filter: saturate(1.08);
}

.workflow.is-dragging .upload-row {
  border-color: var(--blue);
  background: rgba(22, 119, 238, 0.035);
}

.workflow.is-dragging .upload-icon {
  transform: translateY(-3px);
}

.upload-row {
  min-height: 128px;
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr) auto;
  align-items: center;
  gap: 28px;
  padding: 20px 22px 26px 8px;
  border-bottom: 1px solid var(--line);
  border-radius: 10px 10px 0 0;
  transition:
    border-color 160ms ease,
    background 160ms ease;
}

.upload-icon {
  width: 66px;
  height: 66px;
  display: block;
  color: var(--blue);
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.9;
  transition: transform 160ms ease;
}

.upload-copy {
  display: grid;
  gap: 9px;
}

.upload-title {
  color: var(--ink);
  font-size: clamp(1.3rem, 1.9vw, 1.72rem);
  font-weight: 680;
  letter-spacing: -0.025em;
}

.upload-hint {
  color: var(--muted);
  font-size: clamp(1.05rem, 1.55vw, 1.4rem);
  letter-spacing: -0.014em;
}

.browse-action {
  appearance: none;
  border: 0;
  border-radius: 8px;
  background: transparent;
  padding: 12px 4px 12px 22px;
  color: var(--blue);
  font-size: clamp(1.08rem, 1.55vw, 1.45rem);
  font-weight: 680;
  letter-spacing: -0.025em;
  cursor: pointer;
  transition:
    color 160ms ease,
    transform 160ms ease;
}

.browse-action:hover {
  color: var(--blue-hover);
}

.browse-action:active {
  transform: translateY(1px);
}

.browse-action:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 5px;
}

.file-row {
  min-height: 112px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 28px;
  padding: 24px 22px 24px 8px;
  border-bottom: 1px solid var(--line);
}

.file-name {
  overflow: hidden;
  color: var(--ink);
  font-size: clamp(1.1rem, 1.55vw, 1.45rem);
  font-weight: 520;
  letter-spacing: -0.02em;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.file-name.is-placeholder {
  color: #7b8da4;
}

.file-size {
  color: var(--muted);
  font-size: clamp(1.05rem, 1.42vw, 1.32rem);
  white-space: nowrap;
}

.file-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: clamp(18px, 2.5vw, 32px);
}

.upload-action {
  appearance: none;
  min-width: 158px;
  border: 0;
  border-radius: 9px;
  background: var(--blue);
  padding: 11px 19px;
  color: #ffffff;
  font-size: 1rem;
  font-weight: 680;
  letter-spacing: -0.015em;
  cursor: pointer;
  transition:
    background 160ms ease,
    box-shadow 160ms ease,
    transform 160ms ease;
}

.upload-action:hover:not(:disabled) {
  background: var(--blue-hover);
}

.upload-action:active:not(:disabled) {
  transform: translateY(1px);
}

.upload-action:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 4px;
}

.upload-action:disabled {
  background: #88b7ed;
  cursor: default;
}

.upload-action.is-download {
  background: var(--success);
}

.upload-action.is-download:hover {
  background: var(--success-hover);
}

.progress-region {
  min-height: 89px;
  padding: 26px 0 0 8px;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(-4px);
  transition:
    opacity 220ms ease-out,
    transform 220ms ease-out,
    visibility 0s linear 220ms;
}

.progress-region.is-visible {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: none;
  transition-delay: 0s;
}

.progress-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-right: 22px;
  color: var(--muted);
  font-size: clamp(1.06rem, 1.45vw, 1.34rem);
  letter-spacing: -0.015em;
}

.progress-meta strong {
  color: var(--ink);
  font-size: clamp(1.22rem, 1.62vw, 1.48rem);
  font-weight: 720;
  letter-spacing: -0.03em;
}

.progress-track {
  height: 7px;
  margin-top: 22px;
  overflow: hidden;
  border-radius: 999px;
  background: var(--track);
}

.progress-fill {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: var(--progress);
  transition: width 320ms ease;
}

.progress-fill.is-complete {
  background: var(--progress-complete);
}

.status-message {
  min-height: 24px;
  margin: 16px 0 0;
  color: #b33a3a;
  font-size: 0.96rem;
  line-height: 1.5;
  opacity: 0;
  transform: translateY(-3px);
  transition:
    opacity 160ms ease,
    transform 160ms ease;
}

.status-message.is-visible {
  opacity: 1;
  transform: none;
}

@media (max-width: 700px) {
  .page-shell {
    display: block;
    padding: 64px 22px 48px;
  }

  .isolation-panel {
    transform: none;
  }

  .hero h1 {
    font-size: clamp(2rem, 9.5vw, 3rem);
  }

  .hero p {
    margin-top: 20px;
    font-size: 1rem;
  }

  .workflow {
    margin-top: 64px;
  }

  .upload-row {
    grid-template-columns: 58px minmax(0, 1fr);
    gap: 18px;
    padding: 18px 0 24px;
  }

  .upload-icon {
    width: 52px;
    height: 55px;
    transform: scale(0.82);
    transform-origin: left center;
  }

  .browse-action {
    grid-column: 2;
    justify-self: start;
    margin-top: -4px;
    padding: 8px 0;
  }

  .file-row {
    min-height: 94px;
    padding: 20px 0;
  }

  .file-actions {
    gap: 12px;
  }

  .upload-action {
    padding: 9px 14px;
  }

  .progress-region {
    padding-left: 0;
  }

  .progress-meta {
    padding-right: 0;
  }
}

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