/* InboxFly 官网 · datafa.st 风格（暖白底 + 品牌蓝主色 + 珊瑚点缀 + DM Sans） */
* { margin: 0; padding: 0; box-sizing: border-box; }
:root {
  --bg: #fcfbfa; --surface: #ffffff;
  --text: #262626; --text-2: #595451; --text-3: #8a857f;
  --brand: #0a84ff; --brand-2: #5ac8fa;
  --coral: #e16540;
  --border: rgba(38,38,38,.1);
  --card-shadow: 0 0 0 1px rgba(0,0,0,.06), 0 1px 2px -1px rgba(0,0,0,.06), 0 2px 4px 0 rgba(0,0,0,.04);
  --r-card: 16px; --r-btn: 10px;
}
:root[data-mode="dark"] {
  --bg: #171717; --surface: #202020;
  --text: #f5f5f5; --text-2: #b8b8b8; --text-3: #8a8a8a;
  --brand: #6db2ff; --brand-2: #5ac8fa;
  --coral: #ff8a66;
  --border: rgba(255,255,255,.12);
  --card-shadow: 0 0 0 1px rgba(255,255,255,.06), 0 2px 8px rgba(0,0,0,.4);
}
html { scroll-behavior: smooth; }
body {
  font-family: "DM Sans", -apple-system, BlinkMacSystemFont, "PingFang SC", "Segoe UI", sans-serif;
  background: var(--bg); color: var(--text);
  -webkit-font-smoothing: antialiased; line-height: 1.55;
  transition: background .25s ease, color .25s ease;
}
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }
a { color: inherit; }

/* ---------- 导航 ---------- */
.nav { position: sticky; top: 0; z-index: 50; background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px); border-bottom: 1px solid var(--border); }
.nav-inner { max-width: 1080px; margin: 0 auto; padding: 12px 24px; display: flex; align-items: center; gap: 28px; }
.logo { display: flex; align-items: center; gap: 9px; text-decoration: none; font-weight: 800; font-size: 17px; letter-spacing: -.01em; }
.logo img { height: 30px; width: auto; }
.logo-senderfly-badge { display: inline-flex; align-items: center; align-self: center; font-size: 9px; line-height: 1; font-weight: 750; letter-spacing: .07em; text-transform: uppercase; color: var(--brand); background: color-mix(in srgb, var(--brand) 10%, transparent); border: 1px solid color-mix(in srgb, var(--brand) 28%, transparent); border-radius: 6px; padding: 4px 6px; white-space: nowrap; pointer-events: none; }
.nav-links { display: flex; gap: 26px; margin-right: auto; }
.nav-links a { text-decoration: none; font-size: 14px; font-weight: 550; color: var(--text-2); }
.nav-links a:hover { color: var(--text); }
.nav-actions { display: flex; align-items: center; gap: 10px; margin-left: auto; }
.lang-sw { display: flex; gap: 2px; background: rgba(38,38,38,.06); border-radius: 8px; padding: 2px; }
:root[data-mode="dark"] .lang-sw { background: rgba(255,255,255,.1); }
.lang-sw a { text-decoration: none; font-size: 12px; font-weight: 620; color: var(--text-2); padding: 4px 9px; border-radius: 6px; }
.lang-sw a.on { background: var(--surface); color: var(--text); box-shadow: 0 1px 2px rgba(0,0,0,.12); }
.mode-btn { border: 1px solid var(--border); background: transparent; color: var(--text-2); cursor: pointer;
  width: 30px; height: 30px; border-radius: 8px; display: grid; place-items: center; }
.mode-btn:hover { color: var(--brand); border-color: var(--brand); }
.burger { display: none; }
.mobile-menu { display: none; }
.mm-actions { display: none; }
/* 反馈图标（移动端页眉 · GitHub 图标左侧；桌面端已有文字链接故隐藏） */
.fb-link { display: none; place-items: center; width: 30px; height: 30px; border: 1px solid var(--border);
  border-radius: 8px; color: var(--text-2); transition: color 140ms ease, border-color 140ms ease; }
.fb-link:hover { color: var(--brand); border-color: var(--brand); }
.btn { display: inline-flex; align-items: center; gap: 8px; text-decoration: none; cursor: pointer; border: none;
  font: 640 14px/1 "DM Sans", -apple-system, "PingFang SC", sans-serif; padding: 11px 20px;
  border-radius: var(--r-btn); transition: transform 100ms ease-out, filter 160ms ease; }
.btn:active { transform: scale(.97); }
.btn-primary { background: var(--brand); color: #fff; box-shadow: 0 4px 14px rgba(10,132,255,.3); }
.btn-primary:hover { filter: brightness(1.08); }
.btn-ghost { background: transparent; color: var(--text); border: 1px solid var(--border); }
.btn-ghost:hover { border-color: var(--text-3); }
.btn-sm { padding: 8px 14px; font-size: 13px; }

/* ---------- Hero ---------- */
.hero { text-align: center; padding: 84px 24px 40px; }
.eyebrow { display: inline-flex; align-items: center; gap: 7px; font-size: 12.5px; font-weight: 700;
  letter-spacing: .12em; text-transform: uppercase; color: var(--coral); margin-bottom: 18px; }
.eyebrow::before { content: ""; width: 18px; height: 1.5px; background: var(--coral); }
h1.display { font-size: clamp(34px, 5.4vw, 58px); font-weight: 800; letter-spacing: -.028em; line-height: 1.06; }
h1.display .accent { color: var(--brand); }
.sub { font-size: 18px; color: var(--text-2); max-width: 620px; margin: 20px auto 0; }
.cta-row { display: flex; gap: 12px; justify-content: center; margin-top: 30px; flex-wrap: wrap; }
.btn-wide { padding: 14px 26px; font-size: 15px; }
.micro { font-size: 12.5px; color: var(--text-3); margin-top: 12px; }
.avatars { display: flex; justify-content: center; align-items: center; gap: 10px; margin-top: 26px;
  font-size: 13px; font-weight: 600; color: var(--text-2); }
.avatars .st { display: flex; }
.avatars .st i { width: 30px; height: 30px; border-radius: 50%; border: 2px solid var(--bg); margin-left: -8px;
  display: grid; place-items: center; font-style: normal; font-size: 12px; font-weight: 700; color: #fff; }
.avatars .st i:first-child { margin-left: 0; }

/* ---------- macOS 窗口 mockup ---------- */
.mac-wrap { max-width: 980px; margin: 44px auto 0; padding: 7px; background: rgba(38,38,38,.05);
  border-radius: 22px; box-shadow: var(--card-shadow), 0 24px 60px -20px rgba(0,0,0,.25); }
:root[data-mode="dark"] .mac-wrap { background: rgba(255,255,255,.06); }
.mac { border-radius: 16px; overflow: hidden; background: var(--surface); border: 1px solid var(--border); }
.mac-bar { display: flex; align-items: center; gap: 7px; padding: 11px 14px; background: rgba(38,38,38,.045);
  border-bottom: 1px solid var(--border); }
:root[data-mode="dark"] .mac-bar { background: rgba(255,255,255,.05); }
.mac-bar i { width: 11px; height: 11px; border-radius: 50%; }
.mac-bar .r { background: #ff5f57; } .mac-bar .y { background: #febc2e; } .mac-bar .g { background: #28c840; }
.mac-bar .url { margin-left: 10px; flex: 1; text-align: center; font-size: 11.5px; color: var(--text-3);
  background: rgba(120,120,128,.1); border-radius: 6px; padding: 3px 10px; font-family: ui-monospace, Menlo, monospace; }
.mac-body img { display: block; width: 100%; height: auto; }
.mac-body .demo-dark { display: none; }
:root[data-mode="dark"] .mac-body .demo-dark { display: block; }
:root[data-mode="dark"] .mac-body .demo-light { display: none; }
.mac-fade { height: 70px; background: linear-gradient(to top, var(--bg), transparent); margin-top: -70px; position: relative; }

/* ---------- 区块通用 ---------- */
.sec { padding: 88px 0; }
.sec-head { max-width: 640px; margin: 0 auto 44px; text-align: center; }
.sec-head .eyebrow::before { display: none; }
.sec-head h2 { font-size: clamp(26px, 3.6vw, 40px); font-weight: 800; letter-spacing: -.022em; line-height: 1.12; margin-top: 10px; }
.sec-head p { color: var(--text-2); font-size: 16px; margin-top: 12px; }
.wavy { text-decoration: underline wavy var(--coral); text-decoration-thickness: 2px; text-underline-offset: 5px; }

/* 三步 */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.step { background: var(--surface); border: 1px solid var(--border); border-radius: var(--r-card);
  padding: 24px; box-shadow: var(--card-shadow);
  display: grid; grid-template-columns: auto 1fr; column-gap: 13px; align-items: center; }
.step .no { width: 34px; height: 34px; border-radius: 10px; display: grid; place-items: center;
  background: var(--brand); color: #fff; font-weight: 800; font-size: 15px; }
.step h3 { font-size: 16.5px; font-weight: 720; letter-spacing: -.01em; margin: 0; }
.step p { font-size: 13.5px; color: var(--text-2); grid-column: 1 / -1; margin-top: 12px; }

/* 功能卡 */
.feat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.feat { background: var(--surface); border: 1px solid var(--border); border-radius: var(--r-card);
  padding: 24px; box-shadow: var(--card-shadow);
  display: grid; grid-template-columns: auto 1fr; column-gap: 13px; align-items: center; }
.feat .ic { width: 40px; height: 40px; border-radius: 11px; display: grid; place-items: center;
  background: var(--accent-soft, rgba(10,132,255,.1)); color: var(--brand); }
.feat h3 { font-size: 15.5px; font-weight: 720; margin: 0; }
.feat p { font-size: 13.5px; color: var(--text-2); grid-column: 1 / -1; margin-top: 12px; }
:root[data-mode="dark"] .feat .ic { background: rgba(109,178,255,.14); color: #6db2ff; }

/* 增强 vs CF */
.vs-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.vs-card { padding: 26px; }
.vs-card h3 { font-size: 15px; font-weight: 720; margin-bottom: 14px; }
.vs-card ul { list-style: none; }
.vs-card li { display: flex; gap: 9px; align-items: flex-start; font-size: 13.5px; padding: 6px 0; color: var(--text-2); }
.vs-card li svg { flex-shrink: 0; margin-top: 2px; }
.vs-card li .tag { font-size: 10px; font-weight: 700; padding: 1px 6px; border-radius: 5px;
  background: rgba(225,101,64,.12); color: var(--coral); margin-left: 4px; }
:root[data-mode="dark"] .vs-card li .tag { background: rgba(255,138,102,.16); color: #ff9d7a; }

/* FAQ */
.faq { max-width: 720px; margin: 0 auto; }
.faq details { background: var(--surface); border: 1px solid var(--border); border-radius: 14px;
  padding: 16px 20px; margin-bottom: 10px; box-shadow: var(--card-shadow); }
.faq summary { cursor: pointer; font-weight: 680; font-size: 14.5px; list-style: none;
  display: flex; justify-content: space-between; align-items: center; gap: 10px; }
.faq summary::after { content: "+"; font-size: 18px; color: var(--text-3); font-weight: 500; }
.faq details[open] summary::after { content: "–"; }
.faq details p { margin-top: 10px; font-size: 13.5px; color: var(--text-2); line-height: 1.65; }

/* Footer */
.footer { border-top: 1px solid var(--border); padding: 44px 0 60px; }
.footer-inner { max-width: 1080px; margin: 0 auto; padding: 0 24px; display: flex;
  justify-content: space-between; gap: 24px; flex-wrap: wrap; align-items: flex-start; }
.footer .col h4 { font-size: 11px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase;
  color: var(--text-3); margin-bottom: 12px; }
.footer .col a { display: block; text-decoration: none; font-size: 13.5px; color: var(--text-2); padding: 4px 0; }
.footer .col a:hover { color: var(--brand); }
.footer .brandline { display: flex; align-items: center; gap: 9px; font-weight: 800; font-size: 16px; margin-bottom: 10px; }
.footer .brandline img { height: 26px; width: auto; }
.copy { text-align: center; padding: 10px 0 40px; font-size: 12px; color: var(--text-3); }

/* 回到顶部按钮 */
.btt {
  position: fixed; right: 22px; bottom: 22px; z-index: 60;
  width: 46px; height: 46px; display: flex; align-items: center; justify-content: center;
  border: none; cursor: pointer; border-radius: 50%;
  background: var(--brand); color: #fff; box-shadow: var(--card-shadow);
  opacity: 0; visibility: hidden; transform: translateY(10px);
  transition: opacity .2s ease, visibility .2s ease, transform .2s ease, background .2s ease;
}
.btt.show { opacity: 1; visibility: visible; transform: translateY(0); }
.btt:hover { background: var(--brand-2); }
.btt svg { width: 20px; height: 20px; }
@media (max-width: 560px) { .btt { right: 16px; bottom: 16px; } }
@media (prefers-reduced-motion: reduce) { .btt { transition: none; } }

:root[data-mode="dark"] .nav { background: color-mix(in srgb, var(--bg) 82%, transparent); }
:focus-visible { outline: 2px solid var(--brand); outline-offset: 2px; border-radius: 6px; }
@media (max-width: 860px) {
  .steps, .feat-grid, .vs-wrap { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .hero { padding-top: 56px; }
  /* 汉堡 + 移动菜单 */
  .burger { display: grid; place-items: center; border: 1px solid var(--border); background: transparent;
    color: var(--text); width: 34px; height: 34px; border-radius: 9px; cursor: pointer; }
  .burger:active { transform: scale(.95); }
  .nav-actions .btn { display: none; } /* 打开面板移入下拉菜单底部 */
  .fb-link { display: grid; } /* 移动端页眉显示反馈图标（GitHub 左侧） */
  .mobile-menu { display: none; flex-direction: column; padding: 6px 24px 16px;
    border-top: 1px solid var(--border); background: var(--surface); }
  .mobile-menu.open { display: flex; }
  .mobile-menu > a { padding: 12px 4px; text-decoration: none; font-size: 14.5px; font-weight: 620;
    color: var(--text); border-bottom: 1px solid var(--border); }
  .mm-actions { display: flex; align-items: center; padding-top: 14px; }
  .mobile-menu .mm-panel { display: inline-flex; width: auto; margin: 14px 4px 0; font-size: 13px; padding: 8px 14px; } /* 靠左与菜单项一致 · 白字 · 左侧图标 */
}

@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; scroll-behavior: auto !important; } }

/* ---------- 文档页 ---------- */
.doc-wrap { max-width: 860px; margin: 0 auto; padding: 48px 24px 80px; }
.doc-wrap .crumb { font-size: 12.5px; color: var(--text-3); margin-bottom: 20px; }
.doc-wrap .crumb a { color: var(--brand); text-decoration: none; }
.doc-wrap h1 { font-size: 32px; font-weight: 800; letter-spacing: -.024em; margin-bottom: 8px; }
.doc-wrap .doc-sub { color: var(--text-2); font-size: 15px; margin-bottom: 36px; }
.doc-wrap h2 { font-size: 22px; font-weight: 780; letter-spacing: -.018em; margin: 44px 0 14px;
  padding-top: 28px; border-top: 1px solid var(--border); }
.doc-wrap h3 { font-size: 16px; font-weight: 720; margin: 24px 0 8px; }
.doc-wrap p, .doc-wrap li { font-size: 14px; color: var(--text-2); line-height: 1.75; }
.doc-wrap ul, .doc-wrap ol { padding-left: 22px; margin: 10px 0; }
.doc-wrap li { margin: 5px 0; }
.doc-wrap strong { color: var(--text); }
.doc-wrap code { font-family: ui-monospace, Menlo, monospace; font-size: 12.5px;
  background: rgba(120,120,128,.12); border-radius: 5px; padding: 1.5px 6px; color: var(--text); }
:root[data-mode="dark"] .doc-wrap code { background: rgba(255,255,255,.1); }
.doc-wrap pre { background: #1e1e22; color: #e8e8ec; border-radius: 12px; padding: 15px 18px;
  overflow-x: auto; margin: 12px 0 18px; font-size: 12.5px; line-height: 1.7; }
.doc-wrap pre code { background: transparent; padding: 0; color: inherit; }
.doc-wrap table { width: 100%; border-collapse: collapse; margin: 14px 0 20px; font-size: 13px; }
.doc-wrap th { text-align: left; font-weight: 700; color: var(--text-3); padding: 8px 10px;
  border-bottom: 1px solid var(--border); white-space: nowrap; }
.doc-wrap td { padding: 8px 10px; border-bottom: 1px solid var(--border); color: var(--text-2); vertical-align: top; }
.doc-wrap .tip { border-left: 3px solid var(--brand); background: rgba(10,132,255,.06);
  border-radius: 0 10px 10px 0; padding: 12px 16px; margin: 14px 0; font-size: 13.5px; }
.doc-wrap .tip.warn { border-color: var(--coral); background: rgba(225,101,64,.07); }
.toc { background: var(--surface); border: 1px solid var(--border); border-radius: 14px;
  padding: 18px 22px; margin-bottom: 10px; box-shadow: var(--card-shadow); }
.toc h3 { margin: 0 0 10px; font-size: 13px; letter-spacing: .08em; text-transform: uppercase; color: var(--text-3); }
.toc ol { margin: 0; columns: 2; column-gap: 30px; }
.toc a { color: var(--text-2); text-decoration: none; font-size: 13.5px; }
.toc a:hover { color: var(--brand); }

/* ---------- 文章列表页 ---------- */
.art-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 18px; }
.art-card { display: flex; flex-direction: column; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--r-card); padding: 22px; box-shadow: var(--card-shadow); text-decoration: none; transition: transform 120ms ease; }
.art-card:hover { transform: translateY(-2px); border-color: var(--brand); }
.art-card .cat { font-size: 11px; font-weight: 700; letter-spacing: .1em; text-transform: uppercase; color: var(--coral); }
.art-card h3 { font-size: 17px; font-weight: 740; letter-spacing: -.014em; margin: 8px 0 6px; color: var(--text); line-height: 1.3; }
.art-card p { font-size: 13px; color: var(--text-2); line-height: 1.6; flex: 1; }
.art-card .meta { font-size: 11.5px; color: var(--text-3); margin-top: 12px; }
/* 文章正文增强 */
.doc-wrap .art-body h2 { margin-top: 40px; }
.doc-wrap .art-body ul, .doc-wrap .art-body ol { margin: 10px 0 16px; }
.doc-wrap .art-body li { margin: 6px 0; }
.art-cta { display: flex; gap: 12px; margin: 28px 0 8px; flex-wrap: wrap; }
@media (max-width: 640px) { .art-grid { grid-template-columns: 1fr; } }

/* ---------- 语言下拉（lucide languages 图标） ---------- */
.lang-drop { position: relative; }
.lang-btn { display: grid; place-items: center; border: 1px solid var(--border); background: transparent;
  color: var(--text-2); width: 30px; height: 30px; border-radius: 8px; cursor: pointer; }
.lang-btn:hover { color: var(--brand); border-color: var(--brand); }
.lang-menu { display: none; position: absolute; right: 0; top: calc(100% + 6px); z-index: 80;
  min-width: 168px; background: var(--surface); border: 1px solid var(--border); border-radius: 12px;
  padding: 6px; box-shadow: var(--card-shadow); }
.lang-menu.open { display: block; }
.lang-menu a { display: flex; align-items: center; justify-content: space-between; padding: 8px 12px;
  font-size: 13px; color: var(--text-2); text-decoration: none; border-radius: 8px; }
.lang-menu a:hover { background: var(--accent-soft, rgba(10,132,255,.1)); color: var(--text); }
.lang-menu a.on { color: var(--brand); font-weight: 700; }
.lang-menu a .tick { font-weight: 700; }
.mm-actions .lang-drop { margin-left: auto; }
.mobile-menu .lang-menu { right: auto; left: 0; }

/* GitHub 图标链接 */
.gh-link { display: grid; place-items: center; width: 30px; height: 30px; border: 1px solid var(--border);
  border-radius: 8px; color: var(--text-2); transition: color 140ms ease, border-color 140ms ease; }
.gh-link:hover { color: var(--brand); border-color: var(--brand); }

@media (max-width: 380px) { .logo-senderfly-badge { display: none; } }