.mod-head { padding: 40px 0 24px; max-width: 760px; }
.back {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 14px; color: var(--muted-foreground); text-decoration: none; margin-bottom: 16px;
}
.back:hover { color: var(--foreground); }
.mod-head h1 { font-size: 30px; font-weight: 500; letter-spacing: -.015em; margin: 0 0 10px; }
.mod-head p  { margin: 0 0 16px; color: var(--muted-foreground); font-size: 16px; }

.pill {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--card-glass); border: 1px solid var(--border); border-radius: 999px;
  padding: 6px 14px 6px 11px; font-size: 13px; box-shadow: var(--shadow-soft);
}
.dot { width: 7px; height: 7px; border-radius: 50%; background: var(--primary); position: relative; }
.dot::after {
  content: ''; position: absolute; inset: -4px; border-radius: 50%;
  border: 1px solid var(--primary); opacity: .35; animation: ping 2.6s ease-out infinite;
}
@keyframes ping {
  0%   { transform: scale(.6); opacity: .5 }
  70%  { transform: scale(1.5); opacity: 0 }
  100% { opacity: 0 }
}

.workspace { display: flex; flex-direction: column; gap: 20px; margin-top: 18px; }

.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.col { display: flex; flex-direction: column; gap: 8px; }
.col-label {
  font-size: 12px; color: var(--muted-foreground);
  text-transform: uppercase; letter-spacing: .04em;
}

.text-input {
  width: 100%; min-height: 200px; font: inherit; font-size: 14px;
  padding: 16px 18px; resize: vertical;
  background: var(--card-glass); border: 1px solid var(--border-soft);
  border-radius: var(--radius-card); color: var(--foreground);
  box-shadow: var(--shadow-soft);
  outline: none; transition: border-color .15s;
  box-sizing: border-box;
}
.text-input::placeholder { color: var(--muted-foreground); opacity: .7; }
.text-input:focus { border-color: var(--primary); }

.action-bar { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }

.diff-legend {
  display: flex; gap: 20px; flex-wrap: wrap;
  font-size: 13px; color: var(--muted-foreground); margin-bottom: 12px;
}
.legend-item { display: flex; align-items: center; gap: 6px; }
.legend-dot {
  width: 10px; height: 10px; border-radius: 2px; display: inline-block;
}
.dot-add { background: rgba(22,163,74,.25); border: 1px solid rgba(22,163,74,.4); }
.dot-del { background: rgba(220,38,38,.2);  border: 1px solid rgba(220,38,38,.35); }
.dot-eq  { background: var(--border); }

.diff-stats {
  font-size: 13.5px; color: var(--muted-foreground);
  margin-bottom: 14px;
}
.diff-stats strong { color: var(--foreground); }

.diff-output {
  padding: 22px 24px;
  background: var(--card-glass); border: 1px solid var(--border-soft);
  border-radius: var(--radius-card); box-shadow: var(--shadow-soft);
  font-size: 14.5px; line-height: 1.85; word-break: break-word;
  white-space: pre-wrap;
}
.diff-add {
  background: rgba(22,163,74,.18); color: #15803d;
  border-radius: 3px; padding: 1px 3px;
}
.diff-del {
  background: rgba(220,38,38,.15); color: #dc2626;
  border-radius: 3px; padding: 1px 3px;
  text-decoration: line-through;
}

.explainer { margin-top: 46px; }
.explainer h2 { font-size: 19px; font-weight: 500; margin: 0 0 16px; }
.ex-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.ex-item {
  background: var(--card-glass); border: 1px solid var(--border-soft);
  border-radius: var(--radius-card); padding: 20px;
}
.ex-item .ti { font-size: 20px; color: var(--primary); }
.ex-item h3  { font-size: 15px; font-weight: 500; margin: 8px 0 5px; }
.ex-item p   { margin: 0; font-size: 13.5px; line-height: 1.55; color: var(--muted-foreground); }

@media (max-width: 900px) {
  .two-col { grid-template-columns: 1fr; }
  .ex-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .ex-grid { grid-template-columns: 1fr; }
  .mod-head h1 { font-size: 24px; }
  .mod-head { padding: 28px 0 18px; }
}