:root {
  color-scheme: dark;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  font-family:
    system-ui,
    -apple-system,
    Segoe UI,
    Roboto,
    Helvetica,
    Arial,
    sans-serif;
  background: #0b0b0d;
  color: #f1f1f4;
}
.app {
  max-width: 720px;
  margin: 0 auto;
  padding: 18px;
}
.header {
  margin: 6px 0 14px;
}
h1 {
  font-size: 28px;
  margin: 0 0 6px;
}
.sub {
  margin: 0;
  opacity: 0.85;
}
.card {
  background: #141419;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 16px;
  padding: 16px;
  margin: 12px 0;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.25);
}
.row {
  display: flex;
  justify-content: space-between;
  gap: 12px;
}
.right {
  text-align: right;
}
.label {
  font-size: 12px;
  opacity: 0.65;
}
.value {
  font-size: 16px;
  margin-top: 2px;
}
.countdown {
  margin-top: 14px;
}
.time {
  font-size: 46px;
  font-weight: 700;
  letter-spacing: 1px;
}
.sep {
  opacity: 0.35;
  margin: 0 2px;
}
.hint {
  margin-top: 6px;
  opacity: 0.75;
}
.controls {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 14px;
}
.btn {
  border: 1px solid rgba(255, 255, 255, 0.14);
  background: #1f1f28;
  color: #fff;
  padding: 10px 12px;
  border-radius: 12px;
  cursor: pointer;
  font-weight: 600;
}
.btn:hover {
  filter: brightness(1.08);
}
.btn:active {
  transform: translateY(1px);
}
.btn-secondary {
  background: transparent;
}
.panel {
  margin-top: 12px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 12px;
}
.hidden {
  display: none;
}
.grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}
label span {
  display: block;
  font-size: 12px;
  opacity: 0.7;
  margin-bottom: 6px;
}
input {
  width: 100%;
  padding: 10px 10px;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  background: #0f0f14;
  color: #fff;
}
.footer {
  margin-top: 8px;
  opacity: 0.65;
}
.tiny {
  font-size: 12px;
  opacity: 0.75;
  line-height: 1.4;
}