:root {
  --page-bg: #edf2f7;
  --paper: #f9fafc;
  --panel: rgba(255, 255, 255, 0.86);
  --panel-strong: #ffffff;
  --ink: #111b2a;
  --ink-soft: #243245;
  --muted: #596a7d;
  --border: rgba(17, 27, 42, 0.12);
  --shadow: 0 18px 40px rgba(17, 27, 42, 0.08);
  --shadow-soft: 0 8px 20px rgba(17, 27, 42, 0.05);
  --radius: 18px;
  --radius-sm: 10px;
  --max-width: 1280px;

  --c1: #f0b84d;
  --c2: #db6b73;
  --c3: #4f8dc9;
  --c4: #7f68d7;
  --c5: #4bb08a;
  --c6: #3ca6b6;
  --c7: #e56d3f;
  --c8: #64748b;

  --accent: var(--c3);
  --line: rgba(17, 27, 42, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Inter", sans-serif;
  background:
    linear-gradient(
      180deg,
      rgba(255, 255, 255, 0.48),
      rgba(237, 242, 247, 0.9)
    ),
    var(--page-bg);
  color: var(--ink);
  line-height: 1.6;
}

img {
  max-width: 100%;
  display: block;
}

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

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

.shell {
  width: min(var(--max-width), calc(100% - 2rem));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(12px);
  background: rgba(245, 248, 252, 0.85);
  border-bottom: 1px solid var(--border);
}

.masthead {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(260px, 0.9fr);
  gap: 2rem;
  align-items: end;
  padding: 2rem 0 1.2rem;
}

.title-block {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.eyebrow {
  margin: 0;
  font-size: 0.78rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 700;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  line-height: 1.1;
  letter-spacing: -0.04em;
}

h1 {
  font-size: clamp(2.4rem, 4vw, 4.5rem);
  font-weight: 900;
  letter-spacing: -0.08em;
}

h2 {
  font-size: clamp(1.3rem, 2vw, 2rem);
  font-weight: 700;
  color: var(--ink-soft);
}

.meta {
  margin-top: 0.35rem;
  color: var(--muted);
  font-size: 0.92rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 600;
}

.header-meta {
  display: grid;
  gap: 0.9rem;
  justify-items: end;
}

.flow-strip {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 0.55rem;
  align-items: center;
  font-size: 0.73rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 800;
  color: var(--ink-soft);
}

.flow-strip span {
  padding: 0.48rem 0.72rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.7);
}

.flow-strip .arrow {
  padding: 0;
  border: none;
  background: transparent;
  color: var(--muted);
}

.turn-strip {
  display: inline-flex;
  align-items: center;
  gap: 0.9rem;
  padding: 0.7rem 1rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.7);
  box-shadow: var(--shadow-soft);
}

.turn-label {
  font-size: 0.72rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  font-weight: 700;
  color: var(--muted);
}

.turn-sequence {
  font-size: 0.9rem;
  font-weight: 800;
  letter-spacing: 0.09em;
  color: var(--ink);
}

.section-nav {
  padding-bottom: 0.9rem;
}

.nav-toggle {
  display: none;
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  align-items: center;
  padding-top: 0.55rem;
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  padding: 0.45rem 0.72rem;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.58);
  color: var(--ink-soft);
  font-size: 0.72rem;
  line-height: 1.3;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition:
    transform 0.2s ease,
    border-color 0.2s ease,
    background 0.2s ease;
}

.nav-links a:hover,
.nav-links a:focus-visible,
.nav-links a.is-active {
  background: rgba(79, 141, 201, 0.1);
  border-color: rgba(79, 141, 201, 0.35);
  transform: translateY(-1px);
}

.page-layout {
  padding: 1.5rem 0 4rem;
}

.content {
  display: grid;
  gap: 1.35rem;
}

.rules-banner {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 0.85rem;
  padding: 0.8rem 1rem;
  border: 1px solid rgba(17, 27, 42, 0.1);
  border-radius: 12px;
  background: rgba(79, 141, 201, 0.08);
  color: var(--ink-soft);
}

.rules-banner p {
  margin: 0;
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.objective-block {
  margin-bottom: 1rem;
  padding: 0.9rem 1rem;
  border-left: 4px solid var(--c1);
  background: rgba(240, 184, 77, 0.05);
  border-radius: 12px;
}

.objective-block h4 {
  margin-bottom: 0.5rem;
  font-size: 0.82rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.rule-section {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem 1.4rem 1.5rem;
  box-shadow: var(--shadow-soft);
}

.section-header {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 1rem;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid var(--border);
}

.section-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 3.1rem;
  padding: 0.4rem 0.5rem;
  background: rgba(79, 141, 201, 0.08);
  border: 1px solid rgba(79, 141, 201, 0.22);
  border-radius: 10px;
  color: var(--c3);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  font-weight: 800;
}

.section-header h3 {
  font-size: clamp(1.2rem, 2vw, 1.8rem);
}

p,
li,
dd,
dt,
td,
th {
  font-size: 0.98rem;
}

p {
  margin: 0 0 0.8rem;
}

ul,
ol {
  margin: 0.2rem 0 1rem 1.2rem;
  padding: 0;
}

li + li {
  margin-top: 0.4rem;
}

.intro-grid,
.two-col {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 1rem;
}

.callout-box,
.mini-card,
.rule-block,
.important-note,
.formula-box,
.sequence-box {
  background: rgba(255, 255, 255, 0.68);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.5);
}

.callout-box,
.mini-card,
.rule-block,
.important-note {
  padding: 1rem 1rem 0.9rem;
}

.callout-box h4,
.mini-card h4,
.rule-block h4,
.utility-item h4 {
  font-size: 0.96rem;
  margin-bottom: 0.6rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink-soft);
}

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

.stacked-boxes {
  display: grid;
  gap: 1rem;
}

.swatches {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.swatch {
  width: 2.5rem;
  height: 2.5rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  font-size: 0.56rem;
  font-weight: 800;
  color: #fff;
  box-shadow: inset 0 -2px 0 rgba(0, 0, 0, 0.08);
}

.c1 {
  background: var(--c1);
}
.c2 {
  background: var(--c2);
}
.c3 {
  background: var(--c3);
}
.c4 {
  background: var(--c4);
}
.c5 {
  background: var(--c5);
}
.c6 {
  background: var(--c6);
}
.c7 {
  background: var(--c7);
}
.c8 {
  background: var(--c8);
}

.formula-box {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  margin: 1rem 0;
  padding: 1rem 1.1rem;
  border-left: 4px solid var(--c3);
}

.formula-box strong {
  font-size: 1.1rem;
}

.sequence-box {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  padding: 0.9rem 1rem;
  margin-bottom: 1rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.sequence-box span {
  padding: 0.55rem 0.8rem;
  border-radius: 999px;
  background: rgba(79, 141, 201, 0.08);
  border: 1px solid rgba(79, 141, 201, 0.18);
  color: var(--ink-soft);
}

.important-note {
  margin-top: 1rem;
  border-left: 4px solid var(--c7);
  background: rgba(229, 109, 63, 0.05);
}

.rule-dl {
  display: grid;
  gap: 0.8rem;
  margin: 0;
}

.rule-dl div {
  display: grid;
  gap: 0.2rem;
}

.rule-dl dt {
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.rule-dl dd {
  margin: 0;
}

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

.utility-item {
  background: rgba(255, 255, 255, 0.68);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1rem;
}

.utility-item.wide {
  grid-column: 1 / -1;
}

.notes-list {
  display: grid;
  gap: 0.8rem;
}

.note-item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.8rem;
  align-items: center;
  padding: 0.8rem 0.9rem;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--border);
  border-radius: 12px;
}

.note-tag {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 4.8rem;
  padding: 0.45rem 0.55rem;
  border-radius: 999px;
  color: #fff;
  font-size: 0.65rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

th,
td {
  padding: 0.8rem 0.9rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

thead th {
  background: rgba(17, 27, 42, 0.03);
  font-size: 0.74rem;
  letter-spacing: 0.11em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

tbody tr:nth-child(even) {
  background: rgba(17, 27, 42, 0.015);
}

.compact-table td:first-child {
  font-weight: 600;
}

.back-to-top {
  position: fixed;
  right: 1.2rem;
  bottom: 1.2rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.8rem;
  height: 2.8rem;
  border-radius: 50%;
  background: rgba(17, 27, 42, 0.9);
  color: white;
  box-shadow: var(--shadow);
  opacity: 0.9;
  transition:
    opacity 0.2s ease,
    transform 0.2s ease;
}

.back-to-top:hover,
.back-to-top:focus-visible {
  opacity: 1;
  transform: translateY(-2px);
}

@media (max-width: 980px) {
  .masthead,
  .intro-grid,
  .two-col,
  .utility-grid {
    grid-template-columns: 1fr;
  }

  .header-meta {
    justify-items: start;
  }

  .flow-strip {
    justify-content: flex-start;
  }
}

@media (max-width: 760px) {
  .site-header {
    position: static;
  }

  .masthead {
    padding-top: 1.6rem;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    margin-top: 0.5rem;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.8);
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--ink-soft);
  }

  .nav-links {
    display: none;
    margin-top: 0.65rem;
  }

  .nav-links.is-open {
    display: flex;
  }

  .title-block {
    gap: 0.35rem;
  }

  .meta {
    letter-spacing: 0.05em;
  }

  .rule-section {
    padding: 1.1rem 1rem;
  }

  table,
  thead,
  tbody,
  th,
  td,
  tr {
    display: block;
  }

  thead {
    display: none;
  }

  tr {
    border-bottom: 1px solid var(--border);
  }

  td {
    border-bottom: none;
    padding: 0.55rem 0.8rem;
  }

  td::before {
    content: attr(data-label);
    display: block;
    font-size: 0.68rem;
    letter-spacing: 0.11em;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 0.28rem;
  }
}

@media print {
  body {
    background: white;
  }

  .site-header,
  .back-to-top {
    display: none !important;
  }

  .rule-section {
    break-inside: avoid;
    box-shadow: none;
  }

  .nav-links,
  .callout-box,
  .mini-card,
  .important-note,
  .formula-box,
  .sequence-box,
  .utility-item,
  .note-item {
    background: white;
  }
}