:root {
  --bg: #f6efe4;
  --bg-accent: radial-gradient(circle at top left, rgba(200, 86, 36, 0.18), transparent 34%),
    radial-gradient(circle at right, rgba(17, 88, 79, 0.18), transparent 28%),
    linear-gradient(180deg, #f6efe4, #f1e7d7 45%, #ecdec7);
  --panel: rgba(255, 250, 242, 0.82);
  --card: rgba(255, 255, 255, 0.76);
  --text: #1d2a26;
  --muted: #6f6d63;
  --line: rgba(29, 42, 38, 0.12);
  --primary: #b14617;
  --secondary: #11584f;
  --success: #1f7a59;
  --error: #c94242;
  --shadow: 0 20px 60px rgba(85, 56, 21, 0.12);
}

:root[data-theme="dark"] {
  --bg-accent: radial-gradient(circle at top left, rgba(200, 86, 36, 0.22), transparent 30%),
    radial-gradient(circle at right, rgba(62, 167, 145, 0.18), transparent 24%),
    linear-gradient(180deg, #121714, #16201c 48%, #1b2621);
  --panel: rgba(24, 31, 28, 0.8);
  --card: rgba(20, 26, 24, 0.84);
  --text: #ecf4ed;
  --muted: #98a29a;
  --line: rgba(255, 255, 255, 0.1);
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg-accent);
}

.skip-link {
  position: absolute;
  left: 16px;
  top: -48px;
  z-index: 20;
  padding: 10px 14px;
  border-radius: 12px;
  background: var(--secondary);
  color: #fff;
  text-decoration: none;
}

.skip-link:focus {
  top: 16px;
}

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

.theme-toggle {
  position: fixed;
  top: 18px;
  right: 18px;
  z-index: 10;
  width: 48px;
  height: 48px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--panel);
  color: var(--text);
  box-shadow: var(--shadow);
  cursor: pointer;
}

.shell {
  width: min(1200px, calc(100% - 32px));
  margin: 0 auto;
  padding: 72px 0 48px;
}

.hero,
.panel,
.card {
  backdrop-filter: blur(16px);
}

.hero {
  padding: 32px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 12px;
  font-weight: 700;
}

.hero h1 {
  margin: 0;
  font-size: clamp(32px, 6vw, 56px);
  line-height: 1.05;
}

.hero-copy {
  max-width: 760px;
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.hero-meta span,
.pill {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.2);
  padding: 8px 14px;
}

.panel {
  margin-top: 22px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--panel);
  box-shadow: var(--shadow);
}

.tabs,
.actions,
.offset-row,
.quick-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tabs { margin-bottom: 20px; }
.actions { margin-bottom: 14px; }
.quick-grid { margin: 14px 0 16px; }

.tab,
.primary,
.secondary,
.ghost,
.pill,
.collapse-toggle {
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 12px 16px;
  cursor: pointer;
  transition: transform 0.18s ease, background 0.18s ease, border-color 0.18s ease;
}

.tab:hover,
.primary:hover,
.secondary:hover,
.ghost:hover,
.pill:hover,
.collapse-toggle:hover {
  transform: translateY(-1px);
}

.tab:focus-visible,
.primary:focus-visible,
.secondary:focus-visible,
.ghost:focus-visible,
.pill:focus-visible,
.collapse-toggle:focus-visible,
.recent-item:focus-visible,
.history-delete:focus-visible,
.theme-toggle:focus-visible {
  outline: 3px solid rgba(17, 88, 79, 0.9);
  outline-offset: 3px;
}

.tab { background: transparent; color: var(--text); }
.tab.active { background: var(--secondary); color: #fff; border-color: transparent; }
.primary { background: var(--primary); color: #fff; border-color: transparent; }
.secondary { background: var(--secondary); color: #fff; border-color: transparent; }
.ghost, .collapse-toggle { background: transparent; color: var(--text); }

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.tab-panel { display: none; }
.tab-panel.active { display: block; }

.grid {
  display: grid;
  gap: 18px;
}

.grid.two {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.card {
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: var(--card);
}

.card h2 {
  margin: 0 0 18px;
  font-size: 22px;
}

.field {
  display: block;
  margin-bottom: 14px;
}

.field span {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 14px;
}

input,
select,
textarea {
  width: 100%;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.62);
  color: var(--text);
  outline: none;
}

:root[data-theme="dark"] input,
:root[data-theme="dark"] select,
:root[data-theme="dark"] textarea {
  background: rgba(255, 255, 255, 0.03);
}

input:focus,
select:focus,
textarea:focus {
  border-color: rgba(200, 86, 36, 0.5);
  box-shadow: 0 0 0 4px rgba(200, 86, 36, 0.1);
}

input[aria-invalid="true"],
select[aria-invalid="true"],
textarea[aria-invalid="true"] {
  border-color: var(--error);
  box-shadow: 0 0 0 4px rgba(201, 66, 66, 0.12);
}

input::placeholder,
textarea::placeholder {
  color: var(--muted);
  opacity: 1;
}

.input-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
}

.offset-row > * { flex: 1; }

.result,
.countdown-card,
.recent-box,
.history-list {
  border: 1px solid var(--line);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.36);
}

:root[data-theme="dark"] .result,
:root[data-theme="dark"] .countdown-card,
:root[data-theme="dark"] .recent-box,
:root[data-theme="dark"] .history-list {
  background: rgba(255, 255, 255, 0.03);
}

.result,
.countdown-card {
  min-height: 98px;
  padding: 16px;
  white-space: pre-wrap;
  line-height: 1.7;
}

.result.large { min-height: 280px; }

.tip {
  margin: 0 0 14px;
  color: var(--muted);
  font-size: 14px;
}

.field-error {
  margin: -4px 0 14px;
  color: var(--error);
  font-size: 14px;
  line-height: 1.5;
}

.countdown-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
  margin: 12px 0;
}

.countdown-item {
  padding: 12px;
  border-radius: 16px;
  background: rgba(200, 86, 36, 0.1);
  text-align: center;
}

.countdown-item strong {
  display: block;
  font-size: 28px;
}

.recent-box {
  padding: 16px;
  margin-bottom: 14px;
}

.recent-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 10px;
}

.recent-item {
  border: 1px solid var(--line);
  border-radius: 999px;
  background: transparent;
  color: var(--text);
  padding: 8px 12px;
  cursor: pointer;
}

.history-list {
  display: grid;
  gap: 10px;
  padding: 12px;
}

.history-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.35);
}

:root[data-theme="dark"] .history-item {
  background: rgba(255, 255, 255, 0.04);
}

.history-item.empty {
  justify-content: center;
  color: var(--muted);
}

.history-delete {
  border: 0;
  border-radius: 999px;
  padding: 8px 12px;
  background: rgba(201, 66, 66, 0.12);
  color: var(--error);
  cursor: pointer;
}

.collapsed .collapse-content {
  display: none;
  margin-top: 14px;
  color: var(--muted);
  line-height: 1.8;
}

.info-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 18px;
  margin-top: 22px;
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%) translateY(24px);
  opacity: 0;
  pointer-events: none;
  padding: 12px 18px;
  border-radius: 999px;
  color: #fff;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.toast.success { background: var(--success); }
.toast.error { background: var(--error); }

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.emphasis-10 {
  color: var(--secondary);
  font-weight: 700;
}

.emphasis-13 {
  color: var(--primary);
  font-weight: 700;
}

@media (max-width: 900px) {
  .grid.two,
  .info-grid {
    grid-template-columns: 1fr;
  }

  .input-row {
    grid-template-columns: 1fr;
  }

  .countdown-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .shell {
    width: min(100% - 20px, 1200px);
    padding-top: 64px;
  }

  .hero,
  .panel,
  .card {
    border-radius: 22px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
    scroll-behavior: auto !important;
  }
}