/* 算法介绍页专用视觉 — 克制、可读、有层次；不套通用卡片堆叠 */

@import url("https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,550;9..144,650&family=Source+Sans+3:wght@400;500;600;700&display=swap");

:root {
  --algo-ink: #14181f;
  --algo-muted: #5c6570;
  --algo-faint: #8b949e;
  --algo-line: #e4e7ec;
  --algo-paper: #f7f5f1;
  --algo-panel: #ffffff;
  --algo-accent: #1f6b4a;
  --algo-accent-soft: rgba(31, 107, 74, 0.08);
  --algo-ppo: #334155;
  --algo-grpo: #2563eb;
  --algo-dapo: #c2410c;
  --algo-dr: #0f766e;
  --algo-rloo: #7c3aed;
  --algo-rpp: #be185d;
}

body.algo-body {
  background:
    radial-gradient(900px 420px at 12% -10%, rgba(31, 107, 74, 0.07), transparent 60%),
    radial-gradient(700px 380px at 90% 0%, rgba(37, 99, 235, 0.06), transparent 55%),
    linear-gradient(180deg, #f3f1ec 0%, var(--algo-paper) 40%, #eef0f3 100%);
  color: var(--algo-ink);
  font-family: "Source Sans 3", "PingFang SC", "Noto Sans SC", sans-serif;
  line-height: 1.65;
}

.algo-page {
  max-width: 920px;
  margin: 0 auto;
  padding: 28px 24px 96px;
}

/* 二级页签 */
.algo-subnav {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--algo-line);
  margin: 0 0 32px;
}
.algo-subnav a {
  text-decoration: none;
  color: var(--algo-faint);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.02em;
  padding: 12px 18px 11px;
  margin-bottom: -1px;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}
.algo-subnav a:hover { color: var(--algo-ink); }
.algo-subnav a.active {
  color: var(--algo-accent);
  border-bottom-color: var(--algo-accent);
}

/* Hero */
.algo-hero {
  margin-bottom: 40px;
  animation: algo-in 0.45s ease both;
}
.algo-kicker {
  display: inline-block;
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--algo-accent);
  margin: 0 0 10px;
}
.algo-hero h1 {
  font-family: "Fraunces", "Source Serif 4", Georgia, serif;
  font-size: clamp(28px, 4vw, 36px);
  font-weight: 650;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 0 0 14px;
  color: var(--algo-ink);
}
.algo-hero .lede {
  font-size: 16px;
  color: var(--algo-muted);
  max-width: 62ch;
  margin: 0;
}
.algo-hero .lede a {
  color: var(--algo-accent);
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid rgba(31, 107, 74, 0.35);
}
.algo-hero .lede a:hover { border-bottom-color: var(--algo-accent); }

/* 算法色条 */
.algo-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 22px;
}
.algo-chips span {
  font-size: 12.5px;
  font-weight: 700;
  padding: 5px 11px;
  border-radius: 6px;
  color: #fff;
  letter-spacing: 0.01em;
}
.chip-ppo { background: var(--algo-ppo); }
.chip-grpo { background: var(--algo-grpo); }
.chip-dapo { background: var(--algo-dapo); }
.chip-dr { background: var(--algo-dr); }
.chip-rloo { background: var(--algo-rloo); }
.chip-rpp { background: var(--algo-rpp); }

/* 算法族分类 */
.family-grid {
  display: grid;
  grid-template-columns: 1fr 1.15fr 1fr;
  gap: 14px;
  margin-top: 4px;
}
@media (max-width: 840px) {
  .family-grid { grid-template-columns: 1fr; }
}
.family-card {
  padding: 18px 18px 16px;
  background: var(--algo-panel);
  border: 1px solid var(--algo-line);
  border-radius: 12px;
  border-top: 3px solid var(--family-tone, var(--algo-accent));
}
.family-card .family-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--family-tone, var(--algo-accent));
  margin: 0 0 8px;
}
.family-card h3 {
  font-family: "Fraunces", Georgia, serif;
  font-size: 17px;
  font-weight: 650;
  margin: 0 0 8px;
  letter-spacing: -0.015em;
}
.family-card .family-desc {
  font-size: 13px;
  color: var(--algo-muted);
  margin: 0 0 14px;
  line-height: 1.5;
}
.family-card .family-members {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.family-card .family-members span {
  font-size: 12px;
  font-weight: 700;
  padding: 4px 9px;
  border-radius: 5px;
  color: #fff;
}
.family-card .family-note {
  margin: 12px 0 0;
  font-size: 12px;
  color: var(--algo-faint);
  line-height: 1.45;
}
.family-card[data-f="actor"] { --family-tone: var(--algo-ppo); }
.family-card[data-f="group"] { --family-tone: var(--algo-grpo); }
.family-card[data-f="other"] { --family-tone: var(--algo-rloo); }

.pros-group-label {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--algo-faint);
  margin: 22px 0 0;
  padding-bottom: 6px;
}
.pros-group-label:first-child { margin-top: 0; }

/* 逐算法短介 */
.intro-list {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}
.intro-item {
  display: grid;
  grid-template-columns: 132px 1fr;
  gap: 20px;
  padding: 20px 0 20px 16px;
  border-top: 1px solid var(--algo-line);
  border-left: 3px solid var(--intro-tone, var(--algo-line));
}
.intro-item:last-child { border-bottom: 1px solid var(--algo-line); }
.intro-item[data-a="ppo"] { --intro-tone: var(--algo-ppo); }
.intro-item[data-a="grpo"] { --intro-tone: var(--algo-grpo); }
.intro-item[data-a="dapo"] { --intro-tone: var(--algo-dapo); }
.intro-item[data-a="dr"] { --intro-tone: var(--algo-dr); }
.intro-item[data-a="rloo"] { --intro-tone: var(--algo-rloo); }
.intro-item[data-a="rpp"] { --intro-tone: var(--algo-rpp); }
.intro-meta .name {
  font-family: "Fraunces", Georgia, serif;
  font-size: 18px;
  font-weight: 650;
  letter-spacing: -0.015em;
  color: var(--algo-ink);
  margin: 0 0 4px;
}
.intro-meta .tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--intro-tone);
  margin: 0 0 6px;
}
.intro-meta .full {
  font-size: 12px;
  color: var(--algo-faint);
  margin: 0;
  line-height: 1.4;
}
.intro-body p {
  font-size: 14.5px;
  color: var(--algo-muted);
  margin: 0 0 8px;
  max-width: 68ch;
  line-height: 1.6;
}
.intro-body p:last-child { margin-bottom: 0; }
.intro-body .how {
  font-size: 13.5px;
  color: var(--algo-ink);
}
.intro-body .how strong {
  font-weight: 650;
  color: var(--intro-tone);
}
@media (max-width: 640px) {
  .intro-item { grid-template-columns: 1fr; gap: 8px; }
}

/* Sections */
.algo-section {
  margin-top: 48px;
  animation: algo-in 0.5s ease both;
  animation-delay: 0.05s;
}
.algo-section h2 {
  font-family: "Fraunces", Georgia, serif;
  font-size: 22px;
  font-weight: 650;
  letter-spacing: -0.015em;
  margin: 0 0 6px;
  color: var(--algo-ink);
}
.algo-section .sec-sub {
  font-size: 13.5px;
  color: var(--algo-faint);
  margin: 0 0 22px;
}

/* 区别点：时间线式，无卡片框 */
.diff-list {
  position: relative;
  padding-left: 0;
  margin: 0;
  list-style: none;
}
.diff-list::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--algo-line);
}
.diff-item {
  position: relative;
  padding: 0 0 28px 48px;
}
.diff-item:last-child { padding-bottom: 0; }
.diff-num {
  position: absolute;
  left: 0;
  top: 2px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--algo-panel);
  border: 2px solid var(--algo-accent);
  color: var(--algo-accent);
  font-size: 13px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1;
  font-variant-numeric: tabular-nums;
}
.diff-item h3 {
  font-size: 16px;
  font-weight: 700;
  margin: 4px 0 8px;
  color: var(--algo-ink);
}
.diff-item p {
  font-size: 14.5px;
  color: var(--algo-muted);
  margin: 0;
  max-width: 68ch;
}
.diff-item p strong { color: var(--algo-ink); font-weight: 650; }
.diff-item .mono,
.algo-page .mono {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.9em;
  background: var(--algo-accent-soft);
  color: var(--algo-accent);
  padding: 1px 5px;
  border-radius: 4px;
}

/* Pros/cons — 横向算法块，不用边框盒 */
.pros-grid {
  display: grid;
  gap: 0;
}
.pros-row {
  display: grid;
  grid-template-columns: 140px 1fr 1fr;
  gap: 20px;
  padding: 18px 0;
  border-top: 1px solid var(--algo-line);
}
.pros-row:last-child { border-bottom: 1px solid var(--algo-line); }
.pros-name {
  font-weight: 700;
  font-size: 15px;
  padding-top: 2px;
}
.pros-name .dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  margin-right: 8px;
  vertical-align: 1px;
}
.pros-col h4 {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--algo-faint);
  margin: 0 0 6px;
}
.pros-col p {
  font-size: 13.5px;
  color: var(--algo-muted);
  margin: 0;
  line-height: 1.55;
}
@media (max-width: 720px) {
  .pros-row { grid-template-columns: 1fr; gap: 10px; }
}

/* Config table */
.table-wrap {
  overflow-x: auto;
  margin-top: 4px;
  border-radius: 10px;
  border: 1px solid var(--algo-line);
  background: var(--algo-panel);
}
.algo-page table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
  border: none;
  border-radius: 0;
}
.algo-page table th,
.algo-page table td {
  padding: 11px 14px;
  border-bottom: 1px solid var(--algo-line);
  text-align: center;
  vertical-align: top;
}
.algo-page table tbody tr:last-child td { border-bottom: none; }
.algo-page table th:first-child,
.algo-page table td:first-child {
  text-align: left;
  color: var(--algo-muted);
  font-weight: 600;
  white-space: nowrap;
  background: #faf9f7;
  position: sticky;
  left: 0;
  z-index: 1;
}
.algo-page table thead th {
  background: #f0eeea;
  font-weight: 700;
  font-size: 12.5px;
  color: var(--algo-ink);
}
.algo-page table thead th:first-child { background: #ebe8e2; }
.algo-page .na { color: var(--algo-faint); }
.algo-caption {
  font-size: 12.5px;
  color: var(--algo-faint);
  margin: 12px 0 0;
}

/* Memory list */
.memo-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}
.memo-list li {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 16px;
  align-items: baseline;
  padding: 12px 0 12px 14px;
  border-left: 3px solid var(--algo-line);
  font-size: 14.5px;
  color: var(--algo-muted);
}
.memo-list li .k {
  font-weight: 700;
  color: var(--algo-ink);
  font-size: 14px;
}
.memo-list li[data-a="ppo"] { border-left-color: var(--algo-ppo); }
.memo-list li[data-a="grpo"] { border-left-color: var(--algo-grpo); }
.memo-list li[data-a="dapo"] { border-left-color: var(--algo-dapo); }
.memo-list li[data-a="dr"] { border-left-color: var(--algo-dr); }
.memo-list li[data-a="rloo"] { border-left-color: var(--algo-rloo); }
.memo-list li[data-a="rpp"] { border-left-color: var(--algo-rpp); }
.memo-list li[data-a="mm"] { border-left-color: var(--algo-accent); }
.memo-list li .k { min-width: 0; }
.memo-list li[data-wide] {
  grid-template-columns: 160px 1fr;
}
@media (max-width: 560px) {
  .memo-list li { grid-template-columns: 1fr; gap: 4px; }
}

/* Mix ratio visual for mm page */
.mix-rail {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin: 8px 0 28px;
}
@media (max-width: 720px) { .mix-rail { grid-template-columns: 1fr 1fr; } }
.mix-cell {
  padding: 16px 14px;
  background: var(--algo-panel);
  border-radius: 10px;
  border: 1px solid var(--algo-line);
}
.mix-cell .pct {
  font-family: "Fraunces", Georgia, serif;
  font-size: 28px;
  font-weight: 650;
  color: var(--algo-accent);
  line-height: 1;
  margin-bottom: 8px;
}
.mix-cell .bar {
  height: 6px;
  border-radius: 3px;
  background: #ebe8e2;
  overflow: hidden;
  margin-bottom: 10px;
}
.mix-cell .bar i {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--algo-accent), #3d9b72);
  border-radius: 3px;
}
.mix-cell p {
  font-size: 12.5px;
  color: var(--algo-muted);
  margin: 0;
  line-height: 1.45;
}

@keyframes algo-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}