/* ── 타임스탬프 변환기 ── */
:root {
  --blue:   #2563eb;
  --blue2:  #1d4ed8;
  --sky:    #eff6ff;
  --sky2:   #dbeafe;
  --ink:    #1e293b;
  --muted:  #64748b;
  --line:   #e2e8f0;
  --bg:     #f8fafc;
  --radius: 14px;
  --radius2:10px;
  --shadow: 0 2px 8px rgba(0,0,0,.06);
}

/* ── 기본 ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body { background: var(--bg); color: var(--ink); font-family: 'Pretendard', 'Apple SD Gothic Neo', sans-serif; }

.wrap { max-width: 100%; padding: 0 0 60px; }

/* ── 상단 타이틀 ── */
.top { display: flex; align-items: center; gap: 12px; padding: 20px 0 16px; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 14px; }
.logo {
  width: 48px; height: 48px; border-radius: var(--radius2);
  background: linear-gradient(135deg, #2563eb, #7c3aed);
  display: flex; align-items: center; justify-content: center;
  font-size: 22px;
}
.brand h1 { font-size: 22px; font-weight: 700; color: var(--ink); }
.brand .sub { font-size: 13px; color: var(--muted); margin-top: 2px; }

/* ── 현재 시간 배너 ── */
.now-banner {
  background: linear-gradient(135deg, #1e40af 0%, #4338ca 100%);
  border-radius: var(--radius);
  padding: 20px 24px;
  color: #fff;
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 12px;
  margin-bottom: 20px;
}
.now-banner .label { font-size: 12px; opacity: .75; margin-bottom: 4px; }
.now-time { font-size: 28px; font-weight: 800; letter-spacing: -0.5px; font-variant-numeric: tabular-nums; }
.now-unix { font-size: 14px; opacity: .85; margin-top: 4px; }
.now-right { text-align: right; }
.now-right .utc { font-size: 13px; opacity: .8; }
.now-right .local { font-size: 13px; opacity: .8; margin-top: 3px; }
.refresh-btn {
  background: rgba(255,255,255,.18); border: 1px solid rgba(255,255,255,.35);
  color: #fff; border-radius: 8px; padding: 6px 14px;
  font-size: 13px; font-weight: 600; cursor: pointer;
  transition: background .15s;
}
.refresh-btn:hover { background: rgba(255,255,255,.28); }

/* ── 탭 ── */
.tab-bar {
  display: flex; gap: 6px;
  margin-bottom: 16px;
}
.tab-btn {
  padding: 8px 18px; border-radius: 100px;
  border: 1.5px solid var(--line); background: #fff;
  font-size: 13px; font-weight: 600; cursor: pointer;
  color: var(--muted); transition: all .15s;
}
.tab-btn.active {
  background: var(--blue); border-color: var(--blue);
  color: #fff;
}
.tab-btn:hover:not(.active) { border-color: var(--blue); color: var(--blue); }

/* ── 카드 공통 ── */
.card {
  background: #fff; border: 1px solid var(--line);
  border-radius: var(--radius); padding: 22px;
  box-shadow: var(--shadow); margin-bottom: 16px;
}
.card-title {
  font-size: 14px; font-weight: 700; color: var(--ink);
  margin-bottom: 14px; display: flex; align-items: center; gap: 7px;
}
.card-title .icon { font-size: 16px; }

/* ── 입력 그룹 ── */
.input-row {
  display: flex; gap: 8px; align-items: stretch;
}
.input-row input {
  flex: 1; height: 44px; padding: 0 14px;
  border: 1.5px solid var(--line); border-radius: var(--radius2);
  font-size: 15px; font-family: 'JetBrains Mono', 'Cascadia Code', monospace;
  color: var(--ink); background: #fff; outline: none;
  transition: border-color .15s;
}
.input-row input:focus { border-color: var(--blue); }
.input-row input.err { border-color: #ef4444; }

.conv-btn {
  height: 44px; padding: 0 18px;
  background: var(--blue); border: none; border-radius: var(--radius2);
  color: #fff; font-size: 14px; font-weight: 700; cursor: pointer;
  white-space: nowrap; transition: background .15s;
}
.conv-btn:hover { background: var(--blue2); }

/* ── 결과 박스 ── */
.result-box {
  margin-top: 12px;
  background: var(--sky); border: 1px solid var(--sky2);
  border-radius: var(--radius2); padding: 16px;
  display: none;
}
.result-box.show { display: block; }

.result-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 10px;
}
.result-item {
  background: #fff; border: 1px solid var(--line);
  border-radius: 10px; padding: 12px 14px;
  display: flex; align-items: center; justify-content: space-between; gap: 8px;
}
.result-item .ri-label { font-size: 11px; color: var(--muted); margin-bottom: 2px; }
.result-item .ri-val {
  font-size: 14px; font-weight: 700; color: var(--ink);
  font-family: 'JetBrains Mono', 'Cascadia Code', monospace;
}
.copy-mini {
  background: none; border: 1px solid var(--line);
  border-radius: 6px; padding: 4px 9px;
  font-size: 11px; color: var(--muted); cursor: pointer;
  white-space: nowrap; transition: all .15s; flex-shrink: 0;
}
.copy-mini:hover { border-color: var(--blue); color: var(--blue); }

/* ── 날짜→타임스탬프 ── */
.dt-row {
  display: grid; grid-template-columns: 1fr 1fr; gap: 8px;
  margin-bottom: 8px;
}
@media (max-width: 540px) { .dt-row { grid-template-columns: 1fr; } }

.dt-row label { display: block; font-size: 12px; color: var(--muted); margin-bottom: 4px; }
.dt-row input, .dt-row select {
  width: 100%; height: 40px; padding: 0 12px;
  border: 1.5px solid var(--line); border-radius: var(--radius2);
  font-size: 14px; color: var(--ink); background: #fff; outline: none;
  transition: border-color .15s;
}
.dt-row input:focus, .dt-row select:focus { border-color: var(--blue); }
.dt-row .full { grid-column: 1 / -1; }

/* ── 차이 계산 ── */
.diff-row {
  display: flex; gap: 8px; align-items: flex-end; margin-bottom: 8px;
}
.diff-row > div { flex: 1; }
.diff-row label { display: block; font-size: 12px; color: var(--muted); margin-bottom: 4px; }
.diff-row input {
  width: 100%; height: 40px; padding: 0 12px;
  border: 1.5px solid var(--line); border-radius: var(--radius2);
  font-size: 14px; color: var(--ink); background: #fff; outline: none;
}
.diff-row input:focus { border-color: var(--blue); }
.diff-sep {
  height: 40px; display: flex; align-items: center;
  font-size: 18px; color: var(--muted); flex-shrink: 0;
}

.diff-result {
  background: var(--sky); border: 1px solid var(--sky2);
  border-radius: var(--radius2); padding: 14px;
  display: none; flex-wrap: wrap; gap: 10px;
}
.diff-result.show { display: flex; }
.diff-badge {
  background: #fff; border: 1px solid var(--line);
  border-radius: 8px; padding: 8px 14px;
  text-align: center;
}
.diff-badge .db-num { font-size: 18px; font-weight: 800; color: var(--blue); }
.diff-badge .db-unit { font-size: 11px; color: var(--muted); margin-top: 1px; }

/* ── 세계 시간 ── */
.tz-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 10px;
}
.tz-item {
  background: var(--sky); border: 1px solid var(--sky2);
  border-radius: 10px; padding: 12px 14px;
}
.tz-item .tz-city { font-size: 12px; color: var(--muted); margin-bottom: 4px; }
.tz-item .tz-time { font-size: 15px; font-weight: 700; color: var(--ink); font-variant-numeric: tabular-nums; }
.tz-item .tz-offset { font-size: 11px; color: var(--muted); margin-top: 2px; }

/* ── 에러 메시지 ── */
.err-msg {
  color: #ef4444; font-size: 12px; margin-top: 6px; display: none;
}
.err-msg.show { display: block; }

/* ── 토스트 ── */
.toast {
  position: fixed; bottom: 28px; left: 50%; transform: translateX(-50%) translateY(12px);
  background: #1e293b; color: #fff; border-radius: 100px;
  padding: 10px 20px; font-size: 13px; font-weight: 600;
  opacity: 0; pointer-events: none;
  transition: all .2s; z-index: 9999;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ── 사용 안내 섹션 공통 ── */
.guide-section {
  margin-top: 24px;
  background: rgba(246,248,255,.6);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
}
.guide-section h2 { font-size: 15px; font-weight: 800; margin: 0 0 10px; color: var(--ink); }
.guide-section h2:not(:first-child) { margin-top: 18px; }
.guide-steps, .guide-features, .guide-usecase {
  margin: 0; padding-left: 18px;
  color: var(--muted); font-size: 13px; line-height: 1.8;
}
.guide-steps li, .guide-features li, .guide-usecase li { margin-bottom: 4px; }
.guide-steps strong, .guide-features strong { color: var(--ink); }
.guide-privacy {
  margin-top: 16px;
  background: #eff6ff; border: 1px solid rgba(37,99,235,.22);
  border-radius: 12px; padding: 12px 14px;
  font-size: 12px; color: #1e40af; line-height: 1.55;
}