/* ===== 全局重置 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary:     #1a56db;
  --primary-dk:  #1e429f;
  --accent:      #16bdca;
  --gray-50:     #f9fafb;
  --gray-100:    #f3f4f6;
  --gray-200:    #e5e7eb;
  --gray-600:    #4b5563;
  --gray-700:    #374151;
  --gray-900:    #111827;
  --code-bg:     #1e2433;
  --code-fg:     #e2e8f0;
  --radius:      8px;
  --shadow:      0 1px 3px rgba(0,0,0,.1), 0 1px 2px rgba(0,0,0,.06);
  --shadow-md:   0 4px 6px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.06);
}

html { scroll-behavior: smooth; }
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif; color: var(--gray-700); line-height: 1.65; background: #fff; }

/* ===== 导航 ===== */
.navbar {
  position: sticky; top: 0; z-index: 100;
  background: #fff; border-bottom: 1px solid var(--gray-200);
  box-shadow: var(--shadow);
}
.nav-inner {
  max-width: 1200px; margin: 0 auto;
  padding: 0 1.5rem;
  display: flex; align-items: center; gap: 2rem;
  height: 60px;
}
.nav-brand { font-weight: 700; font-size: 1.1rem; color: var(--gray-900); text-decoration: none; white-space: nowrap; }
.nav-links { display: flex; gap: 0.25rem; list-style: none; margin-left: auto; }
.nav-links a { padding: .4rem .8rem; border-radius: 6px; text-decoration: none; color: var(--gray-600); font-size: .9rem; transition: background .15s, color .15s; }
.nav-links a:hover, .nav-links a.active { background: var(--gray-100); color: var(--primary); font-weight: 500; }

/* ===== 英雄区 ===== */
.hero {
  background: linear-gradient(135deg, #0f2057 0%, #1a56db 50%, #0e7490 100%);
  color: #fff; text-align: center;
  padding: 5rem 1.5rem 4rem;
}
.hero-inner { max-width: 800px; margin: 0 auto; }
.badge {
  display: inline-block; padding: .25rem .75rem;
  background: rgba(255,255,255,.15); border-radius: 20px;
  font-size: .8rem; letter-spacing: .05em; font-weight: 600;
  margin-bottom: 1.25rem;
}
.hero h1 { font-size: clamp(2rem, 5vw, 3.25rem); font-weight: 800; margin-bottom: 1rem; }
.hero-sub { font-size: 1.1rem; opacity: .88; line-height: 1.8; margin-bottom: 2rem; }
.hero-btns { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; margin-bottom: 1.75rem; }
.btn { display: inline-flex; align-items: center; padding: .65rem 1.6rem; border-radius: var(--radius); font-weight: 600; font-size: .95rem; text-decoration: none; transition: all .15s; }
.btn-primary { background: #fff; color: var(--primary); }
.btn-primary:hover { background: #f0f4ff; transform: translateY(-1px); }
.btn-outline { background: transparent; color: #fff; border: 2px solid rgba(255,255,255,.6); }
.btn-outline:hover { border-color: #fff; background: rgba(255,255,255,.1); }
.hero-badges { display: flex; gap: .5rem; justify-content: center; flex-wrap: wrap; }
.tag { background: rgba(255,255,255,.15); padding: .2rem .65rem; border-radius: 20px; font-size: .8rem; }

/* ===== Section ===== */
.section { padding: 4rem 1.5rem; }
.section-gray { background: var(--gray-50); }
.container { max-width: 1200px; margin: 0 auto; }
.section-title { font-size: 1.75rem; font-weight: 700; color: var(--gray-900); text-align: center; margin-bottom: .75rem; }
.section-sub { text-align: center; color: var(--gray-600); margin-bottom: 2.5rem; }

/* ===== 特性卡片 ===== */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 1.5rem; margin-top: 2.5rem; }
.card { background: #fff; border: 1px solid var(--gray-200); border-radius: var(--radius); padding: 1.75rem; box-shadow: var(--shadow); transition: box-shadow .2s, transform .2s; }
.card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.card-icon { font-size: 2rem; margin-bottom: .75rem; }
.card h3 { font-size: 1.05rem; color: var(--gray-900); margin-bottom: .5rem; }
.card p { font-size: .9rem; color: var(--gray-600); }

/* ===== 调用流程 ===== */
.flow { display: flex; align-items: flex-start; flex-wrap: wrap; gap: .5rem; justify-content: center; margin-top: 2.5rem; }
.flow-step { text-align: center; min-width: 120px; max-width: 160px; }
.flow-num { width: 36px; height: 36px; border-radius: 50%; background: var(--primary); color: #fff; font-weight: 700; display: flex; align-items: center; justify-content: center; margin: 0 auto .5rem; font-size: .9rem; }
.flow-label { font-size: .8rem; font-weight: 600; color: var(--gray-900); margin-bottom: .25rem; word-break: break-all; }
.flow-desc { font-size: .75rem; color: var(--gray-600); }
.flow-arrow { font-size: 1.5rem; color: var(--gray-200); padding-top: .5rem; }

/* ===== 代码块 ===== */
pre {
  background: var(--code-bg); color: var(--code-fg);
  border-radius: var(--radius); padding: 1.25rem 1.5rem;
  overflow-x: auto; font-size: .875rem; line-height: 1.7;
  margin: 1rem 0;
}
code { font-family: "JetBrains Mono", "Fira Code", Consolas, monospace; }
p code, li code, td code { background: var(--gray-100); padding: .1rem .35rem; border-radius: 4px; font-size: .85em; color: #e11d48; }

/* 代码语法高亮 */
.kw { color: #81a1c1; }
.str { color: #a3be8c; }
.cm { color: #616e88; font-style: italic; }
.num { color: #b48ead; }

/* ===== 代码标签页 ===== */
.code-tabs { background: var(--gray-50); border: 1px solid var(--gray-200); border-radius: var(--radius); overflow: hidden; }
.tab-bar { display: flex; background: var(--gray-100); border-bottom: 1px solid var(--gray-200); }
.tab-btn { padding: .6rem 1.25rem; border: none; background: transparent; cursor: pointer; font-size: .9rem; color: var(--gray-600); border-bottom: 2px solid transparent; transition: all .15s; }
.tab-btn:hover { color: var(--primary); }
.tab-btn.active { color: var(--primary); font-weight: 600; border-bottom-color: var(--primary); background: #fff; }
.tab-content { padding: 0; }
.tab-content pre { margin: 0; border-radius: 0; }

/* ===== 算法表格 ===== */
table { width: 100%; border-collapse: collapse; margin: 1rem 0; }
th { background: var(--gray-100); font-weight: 600; }
th, td { padding: .65rem 1rem; border: 1px solid var(--gray-200); font-size: .9rem; }
tr:hover td { background: var(--gray-50); }
.status.ok { color: #059669; font-weight: 600; }
.status.wip { color: #d97706; font-weight: 600; }

/* ===== 文档布局 ===== */
.doc-layout { display: flex; max-width: 1200px; margin: 0 auto; min-height: calc(100vh - 60px - 80px); }

.sidebar {
  width: 220px; flex-shrink: 0;
  padding: 2rem 1rem 2rem 1.5rem;
  border-right: 1px solid var(--gray-200);
  position: sticky; top: 60px; align-self: flex-start;
  max-height: calc(100vh - 60px); overflow-y: auto;
}
.sidebar ul { list-style: none; }
.sidebar li { margin: .15rem 0; }
.sidebar a { display: block; padding: .35rem .6rem; border-radius: 6px; text-decoration: none; color: var(--gray-600); font-size: .875rem; transition: all .15s; }
.sidebar a:hover, .sidebar a.active { color: var(--primary); background: var(--gray-100); }
.sidebar .sidebar-group { font-size: .75rem; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--gray-600); margin: 1rem 0 .25rem .6rem; }

.doc-main { flex: 1; padding: 2.5rem 3rem; max-width: 900px; }
.doc-main h1 { font-size: 2rem; font-weight: 800; color: var(--gray-900); margin-bottom: 1rem; padding-bottom: .75rem; border-bottom: 2px solid var(--gray-200); }
.doc-main h2 { font-size: 1.35rem; font-weight: 700; color: var(--gray-900); margin: 2.5rem 0 1rem; padding-top: .5rem; }
.doc-main h3 { font-size: 1.05rem; font-weight: 600; color: var(--gray-900); margin: 1.5rem 0 .5rem; }
.doc-main p { margin-bottom: .75rem; }
.doc-main ul, .doc-main ol { padding-left: 1.5rem; margin-bottom: .75rem; }
.doc-main li { margin-bottom: .3rem; }

/* ===== API 条目 ===== */
.api-entry { border: 1px solid var(--gray-200); border-radius: var(--radius); padding: 1.5rem; margin: 1.5rem 0; background: #fff; box-shadow: var(--shadow); scroll-margin-top: 80px; }
.api-sig { font-family: "JetBrains Mono", Consolas, monospace; font-size: .875rem; background: var(--code-bg); color: #93c5fd; padding: .75rem 1rem; border-radius: 6px; margin-bottom: 1rem; overflow-x: auto; white-space: nowrap; }

/* ===== 提示框 ===== */
.callout { padding: .85rem 1rem; border-radius: var(--radius); margin: 1rem 0; font-size: .9rem; }
.callout-info { background: #eff6ff; border-left: 3px solid #3b82f6; color: #1e40af; }
.callout-warn { background: #fffbeb; border-left: 3px solid #f59e0b; color: #92400e; }

/* ===== Footer ===== */
.footer { background: var(--gray-900); color: var(--gray-200); text-align: center; padding: 2rem 1.5rem; font-size: .875rem; }
.footer a { color: var(--accent); text-decoration: none; }
.footer a:hover { text-decoration: underline; }
.footer-sub { margin-top: .4rem; opacity: .6; font-size: .8rem; }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .doc-layout { flex-direction: column; }
  .sidebar { width: 100%; position: static; border-right: none; border-bottom: 1px solid var(--gray-200); padding: 1rem 1.5rem; }
  .doc-main { padding: 1.5rem; }
  .flow-arrow { display: none; }
  .nav-links { gap: 0; }
  .nav-links a { padding: .4rem .5rem; font-size: .8rem; }
}