:root {
  color-scheme: light;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #172033;
  background: #f5f7fb;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at 4% 4%, #d9fff1 0, transparent 29rem),
    radial-gradient(circle at 96% 8%, #e0e8ff 0, transparent 27rem),
    #f6f8fc;
}

button, input { font: inherit; }
button { cursor: pointer; }

button:focus-visible, input:focus-visible, a:focus-visible {
  outline: 3px solid #356df3;
  outline-offset: 3px;
}

.page-shell {
  display: grid;
  place-items: center;
  min-height: 100vh;
  padding: 32px 16px;
}

.todo-card {
  width: min(100%, 720px);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, .9);
  border-radius: 28px;
  background: rgba(255, 255, 255, .88);
  box-shadow: 0 24px 64px rgba(42, 59, 98, .15);
  backdrop-filter: blur(14px);
}

.hero { padding: 44px 44px 28px; }
.eyebrow { margin: 0 0 10px; color: #5573c8; font-size: .72rem; font-weight: 800; letter-spacing: .16em; }
h1 { margin: 0; font-size: clamp(2rem, 6vw, 3.2rem); letter-spacing: -.06em; line-height: 1.08; }
.subtitle { margin: 13px 0 0; color: #667188; }

.add-form { display: flex; gap: 10px; padding: 0 44px; }
.add-form input {
  min-width: 0;
  flex: 1;
  border: 1px solid #dce2ee;
  border-radius: 14px;
  padding: 14px 16px;
  color: inherit;
  background: #fff;
}
.add-form input::placeholder { color: #9ba5b7; }
.add-button {
  flex: 0 0 auto;
  border: 0;
  border-radius: 14px;
  padding: 0 22px;
  color: #fff;
  font-weight: 700;
  background: #2458db;
  box-shadow: 0 7px 17px rgba(36, 88, 219, .24);
}
.add-button:hover { background: #1849c7; }

.status-message { min-height: 1.5em; margin: 8px 44px 0; color: #bd3c53; font-size: .88rem; }
.toolbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 18px 44px; }
.todo-count { margin: 0; color: #5c687d; font-size: .9rem; white-space: nowrap; }
.filter-group { display: inline-flex; flex-wrap: wrap; gap: 4px; padding: 4px; border-radius: 11px; background: #edf1f8; }
.filter-button { border: 0; border-radius: 8px; padding: 7px 10px; color: #657086; background: transparent; font-size: .84rem; }
.filter-button:hover { color: #293a5f; }
.filter-button.is-active { color: #1c4ccc; background: #fff; box-shadow: 0 1px 4px rgba(57, 76, 122, .16); }

.todo-list { min-height: 130px; margin: 0; padding: 0 28px; list-style: none; }
.todo-item { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-width: 0; padding: 15px 16px; border-top: 1px solid #edf0f5; }
.todo-label { display: flex; align-items: center; gap: 13px; min-width: 0; cursor: pointer; }
.todo-label input { width: 19px; height: 19px; flex: 0 0 auto; accent-color: #2458db; }
.todo-label span { overflow-wrap: anywhere; }
.is-completed .todo-label span { color: #526176; text-decoration: line-through; }
.delete-button { flex: 0 0 auto; border: 0; border-radius: 8px; padding: 7px 10px; color: #a04a5a; background: transparent; font-size: .84rem; }
.delete-button:hover { color: #8f253a; background: #fff0f2; }

.card-footer { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 17px 44px; color: #536177; border-top: 1px solid #edf0f5; font-size: .8rem; }
.footer-meta { display: flex; align-items: center; flex-wrap: wrap; gap: 6px 14px; }
.guide-link { color: #2458db; font-weight: 700; text-underline-offset: 3px; }
.guide-link:hover { color: #1849c7; }
.clear-button { border: 0; padding: 7px 0; color: #637087; background: transparent; text-decoration: underline; text-underline-offset: 3px; }
.clear-button:hover { color: #273a65; }
.clear-button:disabled { cursor: not-allowed; opacity: .45; }

.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }

.docs-shell {
  width: min(100%, 920px);
  margin: 0 auto;
  padding: 32px 16px 64px;
}

.docs-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}

.docs-nav a {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  color: #2458db;
  font-weight: 700;
  text-underline-offset: 3px;
}

.docs-card {
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, .9);
  border-radius: 24px;
  background: rgba(255, 255, 255, .92);
  box-shadow: 0 24px 64px rgba(42, 59, 98, .13);
  backdrop-filter: blur(14px);
}

.docs-header {
  padding: 40px 48px 28px;
  border-bottom: 1px solid #e8edf5;
}

.docs-header h1 {
  max-width: 16ch;
  font-size: clamp(2rem, 6vw, 3.4rem);
}

.docs-header p { margin: 12px 0 0; color: #667188; line-height: 1.7; }
.markdown-body { padding: 24px 48px 52px; color: #27334a; font-size: 1rem; line-height: 1.75; }
.markdown-body > :first-child { margin-top: 0; }
.markdown-body h1 { font-size: clamp(1.8rem, 4vw, 2.45rem); }
.markdown-body h2 { margin: 2.2em 0 .7em; color: #172033; font-size: 1.55rem; line-height: 1.3; }
.markdown-body h3 { margin: 1.8em 0 .6em; color: #263653; font-size: 1.16rem; }
.markdown-body p { margin: .8em 0; }
.markdown-body ul, .markdown-body ol { padding-left: 1.5rem; }
.markdown-body li + li { margin-top: .35em; }
.markdown-body strong { color: #172033; }
.markdown-body code {
  border-radius: 6px;
  padding: .12em .38em;
  color: #1c4ccc;
  background: #edf2ff;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: .9em;
}
.markdown-body pre {
  overflow-x: auto;
  margin: 1rem 0 1.4rem;
  border: 1px solid #dce3ef;
  border-radius: 14px;
  padding: 18px;
  color: #e8edf8;
  background: #172033;
  line-height: 1.55;
}
.markdown-body pre code { padding: 0; color: inherit; background: transparent; }
.markdown-body a { color: #2458db; text-underline-offset: 3px; }
.markdown-body a:hover { color: #1849c7; }
.docs-status { color: #667188; }
.docs-status.is-error { color: #a52d43; }

@media (max-width: 560px) {
  .page-shell { align-items: start; padding: 16px 10px; }
  .todo-card { border-radius: 20px; }
  .hero { padding: 32px 24px 22px; }
  .add-form { padding: 0 24px; }
  .add-button { padding: 0 15px; }
  .status-message { margin-inline: 24px; }
  .toolbar { align-items: flex-start; flex-direction: column; padding: 18px 24px; }
  .todo-list { padding-inline: 12px; }
  .card-footer { align-items: flex-start; padding: 16px 24px; }
  .footer-meta { align-items: flex-start; flex-direction: column; }
  .docs-shell { padding: 18px 10px 40px; }
  .docs-nav { padding-inline: 8px; }
  .docs-card { border-radius: 20px; }
  .docs-header { padding: 30px 24px 24px; }
  .markdown-body { padding: 22px 24px 38px; }
}