/* ─── Reset & base ─────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --color-bg:        #f7f8fa;
  --color-surface:   #ffffff;
  --color-border:    #e2e6ea;
  --color-text:      #1a1d23;
  --color-muted:     #6b7280;
  --color-primary:   #4f46e5;
  --color-primary-h: #4338ca;
  --color-success:   #16a34a;
  --color-danger:    #dc2626;
  --color-info:      #0ea5e9;
  --radius:          8px;
  --shadow:          0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
}

/* ─── Nav ───────────────────────────────────────────────────── */
header { background: var(--color-surface); border-bottom: 1px solid var(--color-border); }

nav {
  max-width: 860px;
  margin: 0 auto;
  padding: .75rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-brand { font-weight: 700; font-size: 1.15rem; color: var(--color-primary); text-decoration: none; }

.nav-links { display: flex; gap: 1.5rem; }

.nav-links a {
  color: var(--color-muted);
  text-decoration: none;
  font-size: .9rem;
  font-weight: 500;
  padding-bottom: 2px;
  border-bottom: 2px solid transparent;
  transition: color .15s, border-color .15s;
}

.nav-links a:hover, .nav-links a.active {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

/* ─── Main ──────────────────────────────────────────────────── */
main {
  max-width: 860px;
  margin: 0 auto;
  padding: 2rem 1.5rem 4rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* ─── Flash messages ────────────────────────────────────────── */
.flash-container { display: flex; flex-direction: column; gap: .5rem; }

.flash {
  padding: .75rem 1rem;
  border-radius: var(--radius);
  font-size: .9rem;
  border-left: 4px solid;
}
.flash--success { background: #f0fdf4; border-color: var(--color-success); color: #15803d; }
.flash--error   { background: #fef2f2; border-color: var(--color-danger);  color: #b91c1c; }
.flash--info    { background: #f0f9ff; border-color: var(--color-info);    color: #0369a1; }

/* ─── Page header ───────────────────────────────────────────── */
.page-header { padding-bottom: .5rem; }
.page-header h1 { font-size: 1.6rem; font-weight: 700; }
.page-header .subtitle { color: var(--color-muted); font-size: .95rem; margin-top: .25rem; }

/* ─── Card ──────────────────────────────────────────────────── */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}
.card h2 { font-size: 1.05rem; font-weight: 600; margin-bottom: 1rem; }

.card--highlight { border-color: var(--color-primary); background: #f5f3ff; }
.card--highlight p { color: var(--color-primary); font-weight: 500; display: flex; align-items: center; gap: 1rem; }

/* ─── Forms ─────────────────────────────────────────────────── */
.upload-form { display: flex; flex-direction: column; gap: 1rem; }

.form-row { display: flex; gap: 1rem; flex-wrap: wrap; }

.form-group { display: flex; flex-direction: column; gap: .35rem; }
.form-group--grow { flex: 1; min-width: 200px; }

label { font-size: .85rem; font-weight: 500; color: var(--color-muted); }

.input-text {
  padding: .5rem .75rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  font-size: .95rem;
  outline: none;
  transition: border-color .15s;
  background: var(--color-bg);
}
.input-text:focus { border-color: var(--color-primary); }

.input-file { font-size: .9rem; }

/* ─── Buttons ───────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .55rem 1.25rem;
  border-radius: var(--radius);
  font-size: .9rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: background .15s, opacity .15s;
}
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn--primary   { background: var(--color-primary); color: #fff; }
.btn--primary:hover   { background: var(--color-primary-h); }
.btn--success   { background: var(--color-success); color: #fff; }
.btn--success:hover   { background: #15803d; }
.btn--danger    { background: var(--color-danger);  color: #fff; }
.btn--danger:hover    { background: #b91c1c; }
.btn--secondary { background: var(--color-bg); color: var(--color-text); border: 1px solid var(--color-border); }
.btn--secondary:hover { background: var(--color-border); }
.btn--sm { padding: .35rem .85rem; font-size: .82rem; }

.action-row { display: flex; gap: .75rem; flex-wrap: wrap; margin-top: 1rem; }

/* ─── Tables ────────────────────────────────────────────────── */
.file-table { width: 100%; border-collapse: collapse; font-size: .9rem; }
.file-table th, .file-table td { padding: .6rem .75rem; text-align: left; border-bottom: 1px solid var(--color-border); }
.file-table th { font-weight: 600; color: var(--color-muted); font-size: .82rem; text-transform: uppercase; letter-spacing: .04em; }
.file-table tbody tr:last-child td { border-bottom: none; }
.row--target { background: #f5f3ff; font-weight: 600; }

/* ─── Badges ────────────────────────────────────────────────── */
.badge {
  display: inline-flex;
  align-items: center;
  padding: .1rem .5rem;
  border-radius: 99px;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  font-size: .78rem;
  font-weight: 600;
  color: var(--color-muted);
  margin-left: .5rem;
}

.label-badge {
  display: inline-block;
  padding: .15rem .6rem;
  border-radius: 4px;
  background: var(--color-primary);
  color: #fff;
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .05em;
}

/* ─── Result card ───────────────────────────────────────────── */
.result-card { display: flex; flex-direction: column; gap: 1.25rem; }

.result-card--correct  { border-color: var(--color-success); }
.result-card--incorrect { border-color: var(--color-danger); }

.result-verdict { display: flex; align-items: center; gap: .75rem; }

.verdict-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  font-size: 1.2rem;
  font-weight: 700;
  flex-shrink: 0;
}

.result-card--correct  .verdict-icon { background: #dcfce7; color: var(--color-success); }
.result-card--incorrect .verdict-icon { background: #fee2e2; color: var(--color-danger); }

.verdict-text { font-size: 1.4rem; font-weight: 700; }

.result-card--correct  .verdict-text { color: var(--color-success); }
.result-card--incorrect .verdict-text { color: var(--color-danger); }

.result-details { display: grid; grid-template-columns: 10rem 1fr; gap: .5rem 1rem; font-size: .9rem; }
.result-details dt { font-weight: 600; color: var(--color-muted); align-self: center; }
.result-details dd { align-self: center; }

.similarity-bar {
  display: inline-block;
  width: 120px;
  height: 8px;
  background: var(--color-border);
  border-radius: 99px;
  overflow: hidden;
  vertical-align: middle;
  margin-right: .4rem;
}
.similarity-bar__fill { height: 100%; background: var(--color-primary); border-radius: 99px; }

/* ─── Hints ─────────────────────────────────────────────────── */
.hint { color: var(--color-muted); font-size: .85rem; }