:root {
  --bg: #f4f7fb;
  --panel: #ffffff;
  --line: #d9e1ee;
  --text: #1c2430;
  --sub: #5a6678;
  --primary: #1877f2;
  --primary-hover: #0f63cd;
  --soft: #eef4ff;
  --warn: #d44b34;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Noto Sans KR", "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #f8fbff 0%, var(--bg) 100%);
}

.app {
  width: min(1120px, 92vw);
  margin: 32px auto;
}

h1 {
  margin: 0 0 8px;
  font-size: 1.8rem;
}

.subtitle {
  margin: 0 0 20px;
  color: var(--sub);
}

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 18px;
  box-shadow: 0 8px 20px rgba(22, 32, 56, 0.05);
}

.panel h2 {
  margin-top: 0;
  margin-bottom: 14px;
  font-size: 1.2rem;
}

.field {
  display: block;
  margin-bottom: 12px;
}

.field span {
  display: block;
  margin-bottom: 6px;
  font-size: 0.93rem;
  color: var(--sub);
}

input,
textarea,
select,
button {
  font: inherit;
}

input[type="number"],
input[type="file"],
textarea,
select {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 12px;
  background: #fff;
}

textarea {
  resize: vertical;
  min-height: 220px;
}

.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.checkbox {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
  color: var(--sub);
}

.preview-wrap {
  border: 1px dashed var(--line);
  border-radius: 10px;
  min-height: 180px;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background: #fbfdff;
  position: relative;
  cursor: pointer;
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.preview-wrap img {
  max-width: 100%;
  max-height: 280px;
  display: block;
}

.preview-wrap.empty img {
  display: none;
}

#imagePlaceholder {
  color: var(--sub);
  margin: 0;
  font-size: 0.9rem;
  text-align: center;
  padding: 18px;
}

.preview-wrap:not(.empty) #imagePlaceholder {
  display: none;
}

.preview-wrap.dragover {
  border-color: var(--primary);
  background: #f1f7ff;
}

.actions {
  display: flex;
  gap: 10px;
  margin: 14px 0 10px;
}

button,
.download {
  border: 0;
  border-radius: 10px;
  padding: 10px 14px;
  cursor: pointer;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

button,
.download {
  background: var(--primary);
  color: #fff;
}

button:hover,
.download:hover {
  background: var(--primary-hover);
}

button.ghost {
  background: var(--soft);
  color: #23457b;
}

button.ghost:hover {
  background: #dfeaff;
}

.download.disabled {
  pointer-events: none;
  opacity: 0.5;
}

.info {
  margin: 6px 0;
  font-size: 0.9rem;
  color: var(--sub);
}

.result-box {
  border: 1px solid var(--line);
  background: #fcfdff;
  border-radius: 10px;
  padding: 12px;
  margin-top: 10px;
}

.result-box h3 {
  margin: 0 0 8px;
  font-size: 0.98rem;
}

.proof-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 10px;
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 0.8rem;
  border: 1px solid var(--line);
  background: #fff;
}

.legend-space-add {
  color: #00605a;
  border-color: #9dd8d3;
}

.legend-space-remove {
  color: #8a4a00;
  border-color: #e5c2a1;
}

.legend-grammar {
  color: #7d2fa0;
  border-color: #d3b3e4;
}

.legend-replace {
  color: #1e4a8f;
  border-color: #b9d1f8;
}

#spellOutput {
  margin: 0;
  line-height: 1.6;
  white-space: pre-wrap;
}

.mark {
  background: #ffe9e5;
  color: #8f2414;
  padding: 0 2px;
  border-radius: 4px;
}

.proof-mark {
  margin-left: 4px;
  border: 0;
  border-bottom: 2px solid #1e4a8f;
  background: transparent;
  color: #1e4a8f;
  border-radius: 0;
  padding: 0 2px;
  font-size: 0.84rem;
  cursor: pointer;
  line-height: 1;
}

.proof-mark.active {
  color: #0b5ad1;
  border-bottom-color: #0b5ad1;
  font-weight: 700;
}

.proof-mark-space-add {
  color: #00605a;
  border-bottom-color: #00605a;
}

.proof-mark-space-remove {
  color: #8a4a00;
  border-bottom-color: #8a4a00;
}

.proof-mark-grammar {
  color: #7d2fa0;
  border-bottom-color: #7d2fa0;
}

.proof-mark-replace {
  color: #1e4a8f;
  border-bottom-color: #1e4a8f;
}

.proof-wrong {
  color: #8f2414;
  text-decoration: line-through;
  text-decoration-thickness: 1.5px;
  text-decoration-color: #d44b34;
}

.proof-unit {
  display: inline-flex;
  align-items: baseline;
  margin-right: 2px;
}

.proof-caret {
  color: #d44b34;
  margin-right: 1px;
  font-weight: 700;
}

@media (max-width: 900px) {
  .app {
    margin: 18px auto;
  }

  .split {
    grid-template-columns: 1fr;
  }
}