/* AIS to Excel — accessibility-first styling.
   Base font size 18px+, big touch targets, strong contrast, dark mode,
   respects prefers-reduced-motion. Single-column layout throughout. */

:root {
  --color-bg: #ffffff;
  --color-text: #16181c;
  --color-muted: #43494f;
  --color-border: #6b7280;
  --color-primary: #0b4fa0;
  --color-primary-text: #ffffff;
  --color-primary-hover: #08387a;
  --color-secondary-bg: #eef2f7;
  --color-secondary-border: #16181c;
  --color-focus: #d9480f;
  --color-ok-bg: #e6f4ea;
  --color-ok-text: #0b3d1f;
  --color-ok-border: #1a7431;
  --color-error-bg: #fdecea;
  --color-error-text: #6b0f0f;
  --color-error-border: #b3261e;
  --color-privacy-bg: #eef7ee;
  --color-privacy-text: #0b3d1f;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #101214;
    --color-text: #f3f5f7;
    --color-muted: #cfd6dd;
    --color-border: #9aa4af;
    --color-primary: #5fa8ff;
    --color-primary-text: #071526;
    --color-primary-hover: #86bfff;
    --color-secondary-bg: #1d2226;
    --color-secondary-border: #f3f5f7;
    --color-focus: #ffb454;
    --color-ok-bg: #10321c;
    --color-ok-text: #b6f2c6;
    --color-ok-border: #4bbf6b;
    --color-error-bg: #3a1414;
    --color-error-text: #ffc4bc;
    --color-error-border: #ff8a80;
    --color-privacy-bg: #10291a;
    --color-privacy-text: #c9f2d3;
  }
}

* {
  box-sizing: border-box;
}

html {
  font-size: 18px;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.5;
}

.page {
  max-width: 42rem;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
}

h1 {
  font-size: 1.8rem;
  line-height: 1.25;
  margin: 0 0 0.75rem;
}

h2 {
  font-size: 1.3rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin: 0 0 0.5rem;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.9rem;
  height: 1.9rem;
  flex: none;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-primary-text);
  font-size: 1.05rem;
  font-weight: 700;
}

.lede {
  font-size: 1.15rem;
  color: var(--color-muted);
  margin: 0 0 1rem;
}

.privacy-banner {
  font-size: 1.05rem;
  background: var(--color-privacy-bg);
  color: var(--color-privacy-text);
  border: 2px solid var(--color-ok-border);
  border-radius: 0.5rem;
  padding: 0.85rem 1rem;
  margin: 0 0 1.5rem;
}

.step {
  border-top: 2px solid var(--color-secondary-bg);
  padding: 1.5rem 0;
}

.step:first-of-type {
  border-top: none;
  padding-top: 0.5rem;
}

.optional-tag {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--color-muted);
}

.step.step-optional {
  opacity: 0.55;
}

.password-paste {
  margin-top: 0.5rem;
}

.password-paste label {
  margin-top: 0.75rem;
}

.step-hint,
.field-hint {
  color: var(--color-muted);
  font-size: 1rem;
  margin: 0.25rem 0 0.9rem;
}

label {
  display: block;
  font-weight: 700;
  font-size: 1.05rem;
  margin-bottom: 0.4rem;
}

.text-input {
  width: 100%;
  max-width: 22rem;
  font-size: 1.2rem;
  padding: 0.7rem 0.8rem;
  min-height: 3rem;
  border: 2px solid var(--color-border);
  border-radius: 0.5rem;
  background: var(--color-bg);
  color: var(--color-text);
}

.pan-input {
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-variant-numeric: tabular-nums;
}

input[type="date"] {
  font-size: 1.2rem;
}

.text-input:focus-visible,
.big-button:focus-visible,
a:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

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

.big-button {
  display: inline-block;
  font-size: 1.2rem;
  font-weight: 700;
  min-height: 3.2rem;
  padding: 0.75rem 1.5rem;
  border-radius: 0.6rem;
  cursor: pointer;
  border: 2px solid transparent;
}

.primary-button {
  background: var(--color-primary);
  color: var(--color-primary-text);
  width: 100%;
  max-width: 22rem;
}

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

.primary-button:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.secondary-button {
  background: var(--color-secondary-bg);
  color: var(--color-text);
  border-color: var(--color-secondary-border);
}

.secondary-button:hover {
  background: var(--color-bg);
}

.file-chosen {
  margin: 0.75rem 0 0;
  font-size: 1.05rem;
  color: var(--color-muted);
}

.file-chosen.has-file {
  color: var(--color-ok-text);
  font-weight: 600;
}

.help {
  margin-top: 1rem;
  font-size: 1.02rem;
}

.help summary {
  cursor: pointer;
  font-weight: 700;
  padding: 0.5rem 0;
}

.help ol {
  padding-left: 1.4rem;
}

.help li {
  margin-bottom: 0.4rem;
}

.submit-area {
  margin-top: 1.5rem;
}

.status {
  margin-top: 1.5rem;
  font-size: 1.15rem;
  min-height: 1.5rem;
}

.status:empty {
  display: none;
}

.error-box {
  margin-top: 1.25rem;
  padding: 1rem 1.1rem;
  border-radius: 0.6rem;
  font-size: 1.15rem;
  background: var(--color-error-bg);
  color: var(--color-error-text);
  border: 2px solid var(--color-error-border);
}

.error-box[hidden] {
  display: none;
}

.success-box {
  margin-top: 2rem;
  padding: 1.5rem;
  border-radius: 0.75rem;
  background: var(--color-ok-bg);
  color: var(--color-ok-text);
  border: 2px solid var(--color-ok-border);
}

.success-box[hidden] {
  display: none;
}

.success-box h2 {
  margin-top: 0;
}

.success-main {
  font-size: 1.2rem;
  font-weight: 600;
}

.success-details {
  font-size: 1.05rem;
  padding-left: 1.2rem;
}

.success-details li {
  margin-bottom: 0.3rem;
  word-break: break-word;
}

.site-footer {
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 2px solid var(--color-secondary-bg);
  font-size: 0.95rem;
  color: var(--color-muted);
}

.site-footer p {
  margin: 0.25rem 0;
}

/* Drag-and-drop: silent bonus, never the advertised main path. Only visual
   feedback is a highlight while a file is dragged over the whole page. */
.page.drag-active {
  outline: 3px dashed var(--color-primary);
  outline-offset: -8px;
  border-radius: 0.75rem;
}

@media (prefers-reduced-motion: no-preference) {
  .big-button,
  .text-input {
    transition: background-color 0.15s ease, border-color 0.15s ease;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    animation: none !important;
  }
}

@media (max-width: 480px) {
  html {
    font-size: 17px;
  }
  .page {
    padding: 1rem 1rem 2.5rem;
  }
  .text-input,
  .primary-button {
    max-width: 100%;
  }
}