/* 날짜 계산기 전용 스타일 */

nav { max-width: 820px; }
main { max-width: 820px; }

.subtitle {
  color: var(--text-sub);
  margin-bottom: 1.25rem;
}

/* 모드 탭 */
.mode-tabs {
  display: flex;
  gap: 0.4rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
}

.mode-tab {
  flex: 1;
  min-width: 180px;
  padding: 0.65rem 1rem;
  font-size: 0.88rem;
  font-weight: 600;
  background: var(--surface);
  color: var(--text-sub);
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.15s;
}

.mode-tab:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.mode-tab.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* 폼 */
.form {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.95rem 1rem;
  margin-bottom: 1.25rem;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  margin-bottom: 0.7rem;
}

.field:last-child { margin-bottom: 0; }

.field label {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text);
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem;
}

.field input[type="date"], .field input[type="number"] {
  padding: 0.6rem 0.75rem;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.95rem;
  font-weight: 600;
  border: 1px solid var(--border);
  border-radius: 7px;
  background: var(--bg);
  color: var(--text);
  outline: none;
  width: 100%;
  box-sizing: border-box;
}

.field input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.12);
}

/* 더하기/빼기 컨트롤 */
.op-row {
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}

.op-toggle {
  display: flex;
  gap: 0.4rem;
}

.op-btn {
  flex: 1;
  padding: 0.55rem 1rem;
  font-size: 0.88rem;
  font-weight: 600;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 7px;
  cursor: pointer;
  transition: all 0.15s;
}

.op-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.op-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.duration-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.5rem;
}

.dur-field {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.dur-field label {
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-sub);
  text-align: center;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.dur-field input {
  padding: 0.5rem 0.55rem;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.95rem;
  font-weight: 700;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  outline: none;
  text-align: center;
  width: 100%;
  box-sizing: border-box;
}

.dur-field input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.12);
}

/* 결과 박스 (모드1) */
.result-box {
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.06));
  border: 1px solid var(--primary);
  border-radius: 12px;
  padding: 1.1rem 1.4rem;
  margin-bottom: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.rb-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-sub);
}

.rb-value {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--primary);
  line-height: 1.1;
}

.rb-sub {
  font-size: 0.85rem;
  color: var(--text-sub);
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

/* 차이 모드 결과 */
.diff-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.6rem;
  margin-bottom: 1rem;
}

.dcell {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.75rem 0.95rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.dcell.highlight {
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.06));
  border-color: var(--primary);
  grid-column: 1 / -1;
}

.dcell-label {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-sub);
}

.dcell-val {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--text);
  line-height: 1.1;
}

.dcell.highlight .dcell-val {
  color: var(--primary);
  font-size: 1.5rem;
}

.dcell-val.sub {
  font-size: 1.05rem;
  color: var(--text-sub);
  font-weight: 600;
}

/* 액션 */
.action-row {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 1.5rem;
}

.btn-copy {
  padding: 0.55rem 1.2rem;
  font-size: 0.85rem;
  font-weight: 600;
  background: var(--primary);
  color: #fff;
  border: 1px solid var(--primary);
  border-radius: 7px;
  cursor: pointer;
  transition: all 0.15s;
}

.btn-copy:hover {
  filter: brightness(1.08);
}

@media (max-width: 600px) {
  .field-row { grid-template-columns: 1fr; }
  .duration-grid { grid-template-columns: repeat(2, 1fr); }
  .rb-value { font-size: 1.25rem; }
  .dcell.highlight .dcell-val { font-size: 1.25rem; }
  .dcell-val { font-size: 1.05rem; }
  .mode-tab { min-width: 0; padding: 0.55rem 0.7rem; font-size: 0.8rem; }
}