/* ===================================================================
   Originality — Plagiarism Scanner
   Design language: forensic document review.
   Ink-navy stage, paper-white working surface, amber highlighter accent.
   =================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Source+Serif+4:ital,opsz,wght@0,8..60,400;0,8..60,600;0,8..60,700;1,8..60,400&family=Inter:wght@400;500;600;700&family=IBM+Plex+Mono:wght@400;500&display=swap');

:root {
  --ink-900: #11151c;
  --ink-800: #181d27;
  --ink-700: #232a37;
  --paper-50: #faf8f4;
  --paper-100: #f1ede3;
  --paper-200: #e4ddcd;
  --rule: #d8d0bb;
  --amber-500: #d4a24c;
  --amber-600: #b8842f;
  --amber-100: #f3dfaf;
  --ink-text: #1c1f26;
  --muted: #6b7280;
  --muted-on-dark: #8b93a3;
  --red-flag: #b5482f;
  --green-ok: #4a7a5a;

  --font-display: 'Source Serif 4', Georgia, serif;
  --font-body: 'Inter', -apple-system, sans-serif;
  --font-mono: 'IBM Plex Mono', monospace;

  --radius: 3px;
  --shadow-paper: 0 1px 2px rgba(17,21,28,0.06), 0 8px 24px -8px rgba(17,21,28,0.18);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--ink-900);
  color: var(--ink-text);
  font-family: var(--font-body);
  -webkit-font-smoothing: antialiased;
}

body {
  background-image:
    radial-gradient(circle at 15% 0%, rgba(212,162,76,0.06), transparent 45%),
    radial-gradient(circle at 100% 100%, rgba(212,162,76,0.04), transparent 50%);
  min-height: 100vh;
}

.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.035;
  z-index: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

a { color: var(--amber-500); }

/* ---------- Masthead ---------- */
.masthead {
  position: relative;
  z-index: 1;
  padding: 56px 24px 40px;
  text-align: center;
  color: var(--paper-50);
}
.masthead__inner { max-width: 640px; margin: 0 auto; }
.masthead__mark {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 18px;
}
.mark-icon { width: 28px; height: 28px; color: var(--amber-500); }
.masthead__title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: 0.01em;
}
.masthead__tagline {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.15rem;
  color: var(--muted-on-dark);
  line-height: 1.5;
  margin: 0;
}

/* ---------- Layout ---------- */
.layout {
  position: relative;
  z-index: 1;
  max-width: 920px;
  margin: 0 auto;
  padding: 0 20px 80px;
}

.stage { animation: rise 0.35s ease both; }
@keyframes rise {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
.stage--center {
  display: flex;
  justify-content: center;
  padding: 80px 0;
}

/* ---------- Panel (paper surface) ---------- */
.panel {
  background: var(--paper-50);
  border-radius: var(--radius);
  box-shadow: var(--shadow-paper);
  padding: 40px;
  position: relative;
}
.panel--error { text-align: center; }
.panel::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--amber-500), var(--amber-600));
  border-radius: var(--radius) var(--radius) 0 0;
}

.panel__head { margin-bottom: 24px; }
.panel__head--tight { margin-bottom: 14px; }
.panel__eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--amber-600);
  margin-bottom: 10px;
}
.panel__eyebrow--error { color: var(--red-flag); }
.panel__title {
  font-family: var(--font-display);
  font-size: 1.7rem;
  font-weight: 600;
  margin: 0;
  line-height: 1.3;
}
.panel__title--sm { font-size: 1.2rem; }

/* ---------- Editor ---------- */
.editor {
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  background: #fff;
  overflow: hidden;
}
.editor__textarea {
  width: 100%;
  min-height: 280px;
  border: none;
  outline: none;
  resize: vertical;
  padding: 20px;
  font-family: var(--font-body);
  font-size: 1.02rem;
  line-height: 1.65;
  color: var(--ink-text);
  background: transparent;
}
.editor__textarea::placeholder { color: #a9a298; }
.editor__footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 16px;
  border-top: 1px solid var(--rule);
  background: var(--paper-100);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--muted);
}
.editor__warning { color: var(--red-flag); font-weight: 500; }

/* ---------- Actions / Buttons ---------- */
.actions {
  display: flex;
  gap: 12px;
  margin-top: 24px;
}
.btn {
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius);
  border: 1px solid transparent;
  padding: 13px 22px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: transform 0.12s ease, box-shadow 0.12s ease, background 0.12s ease;
}
.btn:active { transform: translateY(1px); }
.btn__icon { width: 16px; height: 16px; }
.btn--primary {
  background: var(--ink-900);
  color: var(--paper-50);
}
.btn--primary:hover { background: var(--ink-700); }
.btn--primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}
.btn--ghost {
  background: transparent;
  color: var(--ink-text);
  border-color: var(--rule);
}
.btn--ghost:hover { background: var(--paper-100); }
.btn--small { padding: 9px 16px; font-size: 0.85rem; }

.hint {
  margin: 20px 0 0;
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.6;
}

/* ---------- Loading ---------- */
.scan-loader {
  text-align: center;
  color: var(--paper-50);
  max-width: 360px;
}
.scan-loader__bar {
  position: relative;
  width: 280px;
  height: 3px;
  background: rgba(255,255,255,0.12);
  border-radius: 2px;
  overflow: hidden;
  margin: 0 auto 26px;
}
.scan-loader__sweep {
  position: absolute;
  top: 0; bottom: 0;
  width: 40%;
  background: linear-gradient(90deg, transparent, var(--amber-500), transparent);
  animation: sweep 1.3s ease-in-out infinite;
}
@keyframes sweep {
  0% { left: -40%; }
  100% { left: 100%; }
}
.scan-loader__label {
  font-family: var(--font-display);
  font-size: 1.15rem;
  margin: 0 0 6px;
}
.scan-loader__sub {
  font-size: 0.85rem;
  color: var(--muted-on-dark);
  margin: 0;
}

/* ---------- Error ---------- */
.error-message {
  color: var(--ink-text);
  font-size: 1rem;
  line-height: 1.6;
  margin: 0 0 24px;
}

/* ---------- Score banner ---------- */
.score-banner {
  background: var(--paper-50);
  border-radius: var(--radius);
  box-shadow: var(--shadow-paper);
  padding: 36px 40px;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 32px;
  align-items: center;
  margin-bottom: 28px;
  position: relative;
  overflow: hidden;
}
.score-banner::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--amber-500), var(--amber-600));
}

.score-banner__ring { position: relative; width: 120px; height: 120px; flex-shrink: 0; }
.ring-svg { width: 120px; height: 120px; transform: rotate(-90deg); }
.ring-svg__track { fill: none; stroke: var(--paper-200); stroke-width: 9; }
.ring-svg__progress {
  fill: none;
  stroke: var(--amber-500);
  stroke-width: 9;
  stroke-linecap: round;
  stroke-dasharray: 326.7;
  stroke-dashoffset: 326.7;
  transition: stroke-dashoffset 1s cubic-bezier(0.4,0,0.2,1), stroke 0.3s ease;
}
.score-banner__number {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.score-banner__number span:first-child {
  font-family: var(--font-mono);
  font-size: 1.7rem;
  font-weight: 500;
  color: var(--ink-text);
}
.score-banner__label {
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.score-banner__verdict {
  font-family: var(--font-display);
  font-size: 1.5rem;
  margin: 0 0 6px;
}
.score-banner__detail {
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 0.92rem;
}
.score-banner__stats {
  display: flex;
  gap: 28px;
  margin: 0;
}
.score-banner__stats dt {
  font-size: 0.68rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 4px;
}
.score-banner__stats dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--ink-text);
}

/* ---------- API notice ---------- */
.api-notice {
  background: var(--amber-100);
  border: 1px solid var(--amber-600);
  border-radius: var(--radius);
  padding: 14px 18px;
  font-size: 0.85rem;
  color: #6b4d1a;
  margin-bottom: 24px;
  line-height: 1.5;
}

/* ---------- Results grid ---------- */
.results-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr;
  gap: 20px;
}
@media (max-width: 760px) {
  .results-grid { grid-template-columns: 1fr; }
  .score-banner { grid-template-columns: auto 1fr; }
  .score-banner > .btn { grid-column: 1 / -1; justify-self: start; }
}

.annotated-panel, .sources-panel {
  background: var(--paper-50);
  border-radius: var(--radius);
  box-shadow: var(--shadow-paper);
  padding: 28px 32px;
}

.annotated-panel__legend {
  font-size: 0.8rem;
  color: var(--muted);
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 18px;
}
.legend-mark {
  display: inline-block;
  width: 14px;
  height: 10px;
  background: var(--amber-100);
  border-bottom: 2px solid var(--amber-600);
}

.annotated-text {
  font-family: var(--font-display);
  font-size: 1.08rem;
  line-height: 1.85;
  color: var(--ink-text);
  white-space: pre-wrap;
}
.annotated-text mark {
  background: var(--amber-100);
  border-bottom: 2px solid var(--amber-600);
  padding: 0.05em 0.15em;
  border-radius: 2px;
  cursor: help;
  position: relative;
}

/* ---------- Sources list ---------- */
.sources-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.sources-list li {
  border: 1px solid var(--rule);
  border-radius: var(--radius);
  padding: 14px 16px;
}
.source-item__count {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  background: var(--ink-900);
  color: var(--paper-50);
  border-radius: 10px;
  padding: 2px 8px;
  margin-bottom: 8px;
}
.source-item__title {
  font-weight: 600;
  font-size: 0.92rem;
  margin: 0 0 4px;
  line-height: 1.4;
}
.source-item__link {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--amber-600);
  word-break: break-all;
  text-decoration: none;
}
.source-item__link:hover { text-decoration: underline; }
.sources-empty {
  color: var(--muted);
  font-size: 0.9rem;
  text-align: center;
  padding: 24px 0;
}

/* ---------- Footer ---------- */
.site-footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 0 24px 50px;
  color: var(--muted-on-dark);
  font-size: 0.78rem;
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ---------- Focus states ---------- */
button:focus-visible, textarea:focus-visible, a:focus-visible {
  outline: 2px solid var(--amber-500);
  outline-offset: 2px;
}

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  .stage, .scan-loader__sweep, .ring-svg__progress { animation: none !important; transition: none !important; }
}

/* ---------- Responsive ---------- */
@media (max-width: 600px) {
  .panel { padding: 28px 22px; }
  .masthead { padding: 40px 20px 32px; }
  .masthead__tagline { font-size: 1rem; }
  .score-banner { padding: 28px 24px; grid-template-columns: 1fr; text-align: center; justify-items: center; }
  .score-banner__stats { justify-content: center; }
}