* {
  box-sizing: border-box;
}

:root {
  --bg: #f7f8fb;
  --surface: #ffffff;
  --surface-2: #f1f4f9;
  --text: #1c2430;
  --muted: #6e7888;
  --line: #e6eaf0;
  --accent: #315bdb;
  --accent-soft: #eaf0ff;
  --shadow: 0 16px 45px rgba(22, 34, 58, 0.08);
  --radius-lg: 24px;
  --radius-md: 16px;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.7;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input {
  font: inherit;
}

.container {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(16px);
  background: rgba(247, 248, 251, 0.88);
  border-bottom: 1px solid rgba(230, 234, 240, 0.8);
}

.header-inner {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  color: #fff;
  background: linear-gradient(135deg, #315bdb, #7896f6);
  font-weight: 800;
  box-shadow: 0 10px 22px rgba(49, 91, 219, 0.22);
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 15px;
  line-height: 1.2;
}

.brand small {
  margin-top: 2px;
  color: var(--muted);
  font-size: 11px;
}

.nav {
  display: flex;
  gap: 24px;
  color: var(--muted);
  font-size: 14px;
}

.nav a:hover {
  color: var(--text);
}

.hero {
  padding: 76px 0 48px;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1.45fr 0.75fr;
  gap: 36px;
  align-items: stretch;
}

.hero-copy {
  padding: 20px 0;
}

.eyebrow {
  display: inline-block;
  margin-bottom: 12px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.hero h1 {
  margin: 0;
  font-size: clamp(38px, 5.4vw, 68px);
  line-height: 1.1;
  letter-spacing: -0.04em;
}

.hero h1 span {
  color: var(--accent);
}

.hero p {
  max-width: 720px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: 12px;
  font-weight: 700;
  font-size: 14px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn.primary {
  color: #fff;
  background: var(--accent);
  box-shadow: 0 10px 28px rgba(49, 91, 219, 0.22);
}

.btn.ghost {
  background: var(--surface);
  border: 1px solid var(--line);
}

.hero-card {
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(circle at top right, rgba(49, 91, 219, 0.11), transparent 36%),
    var(--surface);
  box-shadow: var(--shadow);
}

.hero-card-title {
  margin-bottom: 18px;
  font-weight: 800;
}

.topic-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.topic-list span {
  padding: 8px 11px;
  border-radius: 10px;
  background: var(--surface-2);
  color: #4c5869;
  font-size: 13px;
}

.quote {
  margin-top: 28px;
  padding-top: 22px;
  border-top: 1px dashed var(--line);
  color: var(--muted);
  font-size: 14px;
}

.toolbar-section {
  padding: 10px 0 4px;
}

.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.search-wrap {
  position: relative;
  width: min(410px, 100%);
}

.search-icon {
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  color: #919aaa;
  font-size: 20px;
}

.search-wrap input {
  width: 100%;
  height: 44px;
  padding: 0 16px 0 42px;
  border: 1px solid var(--line);
  border-radius: 12px;
  outline: none;
  color: var(--text);
  background: var(--surface);
}

.search-wrap input:focus {
  border-color: rgba(49, 91, 219, 0.55);
  box-shadow: 0 0 0 4px rgba(49, 91, 219, 0.09);
}

.filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.filter {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 8px 14px;
  color: var(--muted);
  background: var(--surface);
  cursor: pointer;
}

.filter.active,
.filter:hover {
  border-color: transparent;
  color: var(--accent);
  background: var(--accent-soft);
}

.notes-section {
  padding: 52px 0 72px;
}

.section-head {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 24px;
}

.section-head h2,
.about-card h2 {
  margin: 0;
  font-size: 30px;
  letter-spacing: -0.02em;
}

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

.notes-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.note-card {
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.note-card:hover {
  transform: translateY(-3px);
  border-color: #d9e1ef;
  box-shadow: 0 14px 34px rgba(25, 40, 70, 0.08);
}

.note-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
  color: var(--muted);
  font-size: 12px;
}

.tag {
  padding: 4px 9px;
  border-radius: 999px;
  color: var(--accent);
  background: var(--accent-soft);
  font-weight: 700;
}

.note-card h3 {
  margin: 0 0 10px;
  font-size: 21px;
  line-height: 1.4;
}

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

.note-card ul {
  margin: 16px 0 0;
  padding-left: 18px;
  color: #4f5b6a;
  font-size: 13px;
}

.note-card code {
  padding: 1px 5px;
  border-radius: 6px;
  background: var(--surface-2);
}

.empty-state {
  padding: 60px 20px;
  text-align: center;
  color: var(--muted);
  border: 1px dashed var(--line);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.about-section {
  padding: 0 0 74px;
}

.about-card {
  display: grid;
  grid-template-columns: 0.75fr 1.6fr;
  gap: 40px;
  padding: 34px;
  border-radius: var(--radius-lg);
  background: #172033;
  color: #fff;
}

.about-card .eyebrow {
  color: #9db4ff;
}

.about-text {
  color: #c5cedd;
  font-size: 14px;
}

.about-text p {
  margin: 0 0 12px;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: var(--surface);
}

.footer-inner {
  min-height: 96px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.footer-inner strong,
.footer-inner span {
  display: block;
}

.footer-inner > div:first-child span {
  margin-top: 3px;
  color: var(--muted);
  font-size: 12px;
}

.filings {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 13px;
}

.filings .dot {
  display: inline;
}

.filings a:hover {
  color: var(--accent);
}

@media (max-width: 820px) {
  .hero {
    padding-top: 46px;
  }

  .hero-inner,
  .about-card {
    grid-template-columns: 1fr;
  }

  .toolbar {
    align-items: stretch;
    flex-direction: column;
  }

  .search-wrap {
    width: 100%;
  }

  .notes-grid {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    padding: 24px 0;
    align-items: flex-start;
    flex-direction: column;
  }

  .filings {
    flex-wrap: wrap;
  }
}

@media (max-width: 560px) {
  .container {
    width: min(100% - 28px, 1120px);
  }

  .nav {
    gap: 12px;
    font-size: 13px;
  }

  .hero h1 {
    font-size: 40px;
  }

  .hero p {
    font-size: 15px;
  }

  .note-card {
    padding: 21px;
  }

  .about-card {
    padding: 26px;
  }
}