/* MCP 协议开发指南 — common.css */
:root {
  --bg: #0b0e14;
  --surface: #12161f;
  --surface-2: #181d28;
  --card: #1c2230;
  --card-hover: #222a3a;
  --border: rgba(45,212,191,0.14);
  --border-bright: rgba(45,212,191,0.38);
  --text: #dce8f0;
  --text-2: #6888a8;
  --text-3: #374f68;
  --accent: #2dd4bf;
  --accent-2: #5eead4;
  --accent-glow: rgba(45,212,191,0.18);
  --cyan: #38bdf8;
  --green: #6ee7b7;
  --orange: #fdba74;
  --red: #f87171;
  --yellow: #fcd34d;
  --radius: 10px;
  --radius-lg: 14px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'SF Pro Text', 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  line-height: 1.75;
  min-height: 100vh;
}

/* ─── 导航栏 ─── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0 2rem;
  height: 56px;
  background: rgba(11, 14, 20, 0.88);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav-back {
  color: var(--accent-2);
  text-decoration: none;
  font-size: 0.875rem;
  padding: 0.3rem 0.75rem;
  border: 1px solid var(--border-bright);
  border-radius: 6px;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
  white-space: nowrap;
}
.nav-back:hover {
  background: var(--accent-glow);
  color: var(--accent-2);
  border-color: var(--accent);
}

.nav-title {
  color: var(--text-2);
  font-size: 0.9rem;
  font-weight: 500;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* ─── Hero 首页 ─── */
.hero {
  text-align: center;
  padding: 6rem 2rem 4rem;
  position: relative;
  overflow: hidden;
  background: radial-gradient(ellipse 120% 60% at 50% 0%, rgba(45,212,191,0.13) 0%, transparent 70%);
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 50%, rgba(45,212,191,0.07) 0%, transparent 50%),
    radial-gradient(circle at 80% 30%, rgba(56,189,248,0.06) 0%, transparent 50%);
  pointer-events: none;
}

.hero-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-2);
  border: 1px solid var(--border-bright);
  border-radius: 20px;
  padding: 0.3rem 1rem;
  margin-bottom: 1.5rem;
  background: rgba(45,212,191,0.08);
}

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.6rem);
  font-weight: 800;
  line-height: 1.15;
  background: linear-gradient(135deg, var(--cyan) 0%, var(--accent-2) 50%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 1.25rem;
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--text-2);
  max-width: 600px;
  margin: 0 auto 2.5rem;
  line-height: 1.8;
}

/* ASCII 艺术图 */
.hero-ascii {
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;
  font-size: 0.72rem;
  line-height: 1.4;
  color: var(--text-3);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem 2rem;
  max-width: 700px;
  margin: 0 auto 3rem;
  text-align: left;
  overflow-x: auto;
  position: relative;
}
.hero-ascii .hl-purple { color: var(--accent-2); }
.hero-ascii .hl-cyan   { color: var(--cyan); }
.hero-ascii .hl-green  { color: var(--green); }
.hero-ascii .hl-orange { color: var(--orange); }
.hero-ascii .hl-dim    { color: var(--text-3); }

/* ─── 容器 ─── */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 2rem 4rem;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.5rem;
}
.section-desc {
  color: var(--text-2);
  margin-bottom: 2rem;
}

/* ─── 章节卡片网格 ─── */
.chapters-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.25rem;
}

.ch-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-decoration: none;
  color: var(--text);
  transition: background 0.2s, border-color 0.2s, transform 0.2s, box-shadow 0.2s;
  display: block;
  position: relative;
  overflow: hidden;
}
.ch-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--cyan));
  opacity: 0;
  transition: opacity 0.2s;
}
.ch-card:hover {
  background: var(--card-hover);
  border-color: var(--border-bright);
  transform: translateY(-3px);
  box-shadow: 0 8px 32px rgba(45,212,191,0.12);
}
.ch-card:hover::before { opacity: 1; }

.ch-card-num {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
  font-family: 'SF Mono', monospace;
}
.ch-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text);
}
.ch-card p {
  font-size: 0.85rem;
  color: var(--text-2);
  line-height: 1.6;
}

.ch-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 1rem;
}
.tag {
  font-size: 0.7rem;
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  background: rgba(45,212,191,0.10);
  color: var(--accent-2);
  border: 1px solid rgba(45,212,191,0.2);
  font-family: 'SF Mono', monospace;
}
.tag.cyan  { background: rgba(34,211,238,0.1);  color: var(--cyan);   border-color: rgba(34,211,238,0.2); }
.tag.green { background: rgba(74,222,128,0.1);  color: var(--green);  border-color: rgba(74,222,128,0.2); }
.tag.orange{ background: rgba(251,146,60,0.1);  color: var(--orange); border-color: rgba(251,146,60,0.2); }

/* ─── 章节 Hero ─── */
.chapter-hero {
  background: radial-gradient(ellipse at top, #141c28, #0b0e14);
  padding: 4.5rem 2rem 3.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--border);
}
.chapter-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 15% 60%, rgba(45,212,191,0.10) 0%, transparent 45%),
    radial-gradient(circle at 85% 30%, rgba(56,189,248,0.07) 0%, transparent 45%);
  pointer-events: none;
}

.ch-num {
  font-family: 'SF Mono', monospace;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
}

.chapter-hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.8rem);
  font-weight: 800;
  line-height: 1.2;
  background: linear-gradient(135deg, #d0eef8, var(--accent-2), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 1rem;
}

.chapter-hero p {
  font-size: 1.05rem;
  color: var(--text-2);
  max-width: 560px;
  margin: 0 auto;
  line-height: 1.8;
}

/* ─── 内容区 ─── */
.content {
  max-width: 860px;
  margin: 0 auto;
  padding: 3rem 2rem 5rem;
}

.content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  margin: 3rem 0 1rem;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--border);
  position: relative;
}
.content h2::after {
  content: '';
  position: absolute;
  bottom: -1px; left: 0;
  width: 3rem;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
}

.content h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--accent-2);
  margin: 2rem 0 0.75rem;
}

.content h4 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--cyan);
  margin: 1.5rem 0 0.5rem;
}

.content p {
  color: var(--text-2);
  margin-bottom: 1rem;
  line-height: 1.85;
}

.content a {
  color: var(--accent-2);
  text-decoration: underline;
  text-decoration-color: rgba(94,234,212,0.4);
}
.content a:hover { color: var(--cyan); }

.content ul, .content ol {
  color: var(--text-2);
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}
.content li { margin-bottom: 0.4rem; line-height: 1.8; }
.content li strong { color: var(--text); }

/* ─── 进度条 ─── */
.progress {
  height: 4px;
  background: var(--surface-2);
  border-radius: 2px;
  margin-bottom: 3rem;
  overflow: hidden;
}
.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--cyan));
  border-radius: 2px;
  transition: width 0.6s ease;
}

/* ─── Callout 盒子 ─── */
.callout {
  border-radius: var(--radius);
  padding: 1.1rem 1.4rem;
  margin: 1.5rem 0;
  border-left: 3px solid;
  font-size: 0.92rem;
  line-height: 1.75;
}
.callout strong { display: block; margin-bottom: 0.3rem; font-size: 0.8rem; letter-spacing: 0.06em; text-transform: uppercase; }

.callout.info {
  background: rgba(45,212,191,0.07);
  border-color: var(--accent);
  color: #b0dde0;
}
.callout.info strong { color: var(--accent-2); }

.callout.tip {
  background: rgba(74,222,128,0.08);
  border-color: var(--green);
  color: #c0f0d0;
}
.callout.tip strong { color: var(--green); }

.callout.warning {
  background: rgba(251,191,36,0.08);
  border-color: var(--yellow);
  color: #f0e4b0;
}
.callout.warning strong { color: var(--yellow); }

.callout.danger {
  background: rgba(248,113,113,0.08);
  border-color: var(--red);
  color: #f0c0c0;
}
.callout.danger strong { color: var(--red); }

.callout.cyan {
  background: rgba(34,211,238,0.08);
  border-color: var(--cyan);
  color: #b0ecf8;
}
.callout.cyan strong { color: var(--cyan); }

/* ─── 代码块 ─── */
pre {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.4rem 1.6rem;
  overflow-x: auto;
  margin: 1.25rem 0;
  font-size: 0.875rem;
  line-height: 1.7;
  position: relative;
}
pre::before {
  content: attr(data-lang);
  position: absolute;
  top: 0.6rem; right: 1rem;
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-3);
  font-family: 'SF Mono', monospace;
}

code {
  font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace;
  font-size: 0.875em;
}

p code, li code {
  background: rgba(45,212,191,0.10);
  color: var(--accent-2);
  padding: 0.15em 0.45em;
  border-radius: 4px;
  border: 1px solid rgba(45,212,191,0.2);
  font-size: 0.85em;
}

/* 代码高亮 */
.kw { color: var(--accent);  font-weight: 600; }  /* keyword — 紫 */
.fn { color: var(--cyan); }                        /* function — 青 */
.st { color: var(--green); }                       /* string — 绿 */
.cm { color: var(--text-3); font-style: italic; }  /* comment — 灰 */
.ty { color: var(--yellow); }                      /* type — 黄 */
.nu { color: var(--orange); }                      /* number — 橙 */
.at { color: var(--accent-2); }                    /* attribute — 浅紫 */
.pr { color: var(--text-2); }                      /* punctuation */
.op { color: var(--text-2); }                      /* operator */

/* ─── ASCII 架构图 ─── */
.ascii-diagram {
  font-family: 'SF Mono', 'Fira Code', Consolas, monospace;
  font-size: 0.78rem;
  line-height: 1.5;
  background: var(--surface);
  border: 1px solid var(--border-bright);
  border-radius: var(--radius-lg);
  padding: 1.5rem 2rem;
  overflow-x: auto;
  color: var(--text-2);
  margin: 1.5rem 0;
}
.ascii-diagram .hl-p { color: var(--accent-2); font-weight: bold; }
.ascii-diagram .hl-c { color: var(--cyan); }
.ascii-diagram .hl-g { color: var(--green); }
.ascii-diagram .hl-o { color: var(--orange); }
.ascii-diagram .hl-y { color: var(--yellow); }
.ascii-diagram .hl-d { color: var(--text-3); }

/* ─── 定义列表 ─── */
.def-list {
  margin: 1.25rem 0;
}
.def-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.4rem;
  margin-bottom: 0.75rem;
  transition: border-color 0.2s;
}
.def-item:hover { border-color: var(--border-bright); }
.def-term {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--accent-2);
  font-family: 'SF Mono', monospace;
  margin-bottom: 0.3rem;
}
.def-desc {
  font-size: 0.9rem;
  color: var(--text-2);
  line-height: 1.75;
}
.def-desc strong { color: var(--text); }

/* ─── 双列布局 ─── */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  margin: 1.25rem 0;
}
@media (max-width: 640px) { .two-col { grid-template-columns: 1fr; } }

.col-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
}
.col-card h4 {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--accent-2);
  margin: 0 0 0.75rem;
}
.col-card ul {
  font-size: 0.875rem;
  color: var(--text-2);
  padding-left: 1.2rem;
}
.col-card li { margin-bottom: 0.3rem; }

/* ─── 步骤列表 ─── */
.steps {
  counter-reset: step;
  list-style: none;
  padding: 0;
  margin: 1.25rem 0;
}
.steps li {
  counter-increment: step;
  padding: 1rem 1.25rem 1rem 3.5rem;
  position: relative;
  margin-bottom: 0.75rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text-2);
  font-size: 0.9rem;
  line-height: 1.7;
}
.steps li::before {
  content: counter(step);
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  width: 1.6rem; height: 1.6rem;
  background: var(--accent);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'SF Mono', monospace;
}
.steps li strong { color: var(--text); }

/* ─── 信息卡片 ─── */
.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
  margin: 1.25rem 0;
}
.info-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  text-align: center;
  transition: border-color 0.2s, transform 0.2s;
}
.info-card:hover { border-color: var(--border-bright); transform: translateY(-2px); }
.info-card-icon {
  font-size: 1.75rem;
  margin-bottom: 0.5rem;
}
.info-card h4 {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-2);
  margin: 0 0 0.3rem;
}
.info-card p {
  font-size: 0.8rem;
  color: var(--text-3);
  margin: 0;
  line-height: 1.5;
}

/* ─── 章节导航 ─── */
.chapter-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin: 4rem 0 2rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.chapter-nav a {
  display: block;
  padding: 1.1rem 1.4rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  transition: background 0.2s, border-color 0.2s;
}
.chapter-nav a:hover {
  background: var(--card);
  border-color: var(--border-bright);
}
.chapter-nav .nav-label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-3);
  margin-bottom: 0.3rem;
}
.chapter-nav .nav-ch {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
}
.chapter-nav .prev { text-align: left; }
.chapter-nav .next { text-align: right; }
.chapter-nav .prev .nav-label::before { content: '← '; }
.chapter-nav .next .nav-label::after  { content: ' →'; }

/* ─── 页脚 ─── */
.site-footer {
  text-align: center;
  padding: 2rem;
  border-top: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-3);
}
.site-footer a {
  color: var(--accent-2);
  text-decoration: none;
}
.site-footer a:hover { color: var(--accent); }

/* ─── 徽章 ─── */
.badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  font-family: 'SF Mono', monospace;
  vertical-align: middle;
}
.badge.purple { background: rgba(45,212,191,0.18); color: var(--accent-2); }
.badge.cyan   { background: rgba(34,211,238,0.15); color: var(--cyan); }
.badge.green  { background: rgba(74,222,128,0.15); color: var(--green); }
.badge.orange { background: rgba(251,146,60,0.15); color: var(--orange); }
.badge.red    { background: rgba(248,113,113,0.15); color: var(--red); }

/* ─── 对比表格 ─── */
.comp-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
  margin: 1.25rem 0;
}
.comp-table th {
  background: var(--surface-2);
  color: var(--accent-2);
  font-weight: 600;
  font-size: 0.8rem;
  letter-spacing: 0.05em;
  padding: 0.7rem 1rem;
  text-align: left;
  border-bottom: 1px solid var(--border-bright);
}
.comp-table td {
  padding: 0.7rem 1rem;
  color: var(--text-2);
  border-bottom: 1px solid var(--border);
}
.comp-table tr:last-child td { border-bottom: none; }
.comp-table tr:hover td { background: rgba(45,212,191,0.04); }
.comp-table td:first-child { color: var(--text); font-weight: 500; }

/* ─── 滚动条 ─── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--surface); }
::-webkit-scrollbar-thumb { background: rgba(45,212,191,0.28); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: rgba(45,212,191,0.48); }

/* ─── 响应式 ─── */
@media (max-width: 768px) {
  .nav { padding: 0 1rem; }
  .hero { padding: 4rem 1rem 3rem; }
  .container { padding: 0 1rem 3rem; }
  .content { padding: 2rem 1rem 4rem; }
  .chapter-hero { padding: 3rem 1rem 2.5rem; }
  .chapter-nav { grid-template-columns: 1fr; }
  .hero-ascii { font-size: 0.62rem; padding: 1rem; }
}