/* birvu · 夜航海图 */
:root {
  color-scheme: dark;
  --bi-di: #232629;
  --bi-zi: #eef0ea;
  --bi-ruo: #b8bdb5;
  --bi-cheng: #ff8f3f;
  --bi-qing: #6fc2c9;
  --bi-xian: #3a3f44;
  --bi-ci: #2c3034;
  --bi-shen: #1b1d20;
  --bi-wangge: #2a2e32;
  --bi-latin: "Baskerville Old Face", "Book Antiqua", Georgia, serif;
  --bi-hei: "SimHei", "Microsoft YaHei", sans-serif;
  --bi-zheng: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif;
  --bi-jiao: 1px;
  --bi-kuan: 1180px;
}

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

html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bi-di);
  color: var(--bi-zi);
  font-family: var(--bi-zheng);
  font-size: 16px;
  line-height: 1.8;
  overflow-wrap: break-word;
}

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

a { color: var(--bi-qing); text-underline-offset: 3px; text-decoration-thickness: 1px; }
a:hover { color: #9ad8dd; }

:focus-visible { outline: 2px solid var(--bi-cheng); outline-offset: 3px; }

code { font-family: Consolas, "Courier New", monospace; }

.bi-tiaoguo {
  position: absolute; left: 12px; top: -60px; z-index: 20;
  background: var(--bi-cheng); color: var(--bi-shen); padding: 10px 16px;
  text-decoration: none; font-weight: 700;
}
.bi-tiaoguo:focus { top: 8px; }

.bi-zhuti:focus { outline: none; }

/* —— 船头（页头） —— */
.bi-chuantou { border-bottom: 1px solid var(--bi-xian); }
.bi-chuantou-nei {
  max-width: var(--bi-kuan); margin: 0 auto; padding: 0 16px;
  display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 64px;
}
.bi-mingpai { display: inline-flex; align-items: center; min-height: 44px; color: var(--bi-zi); }
.bi-biaozhi { display: block; width: 138px; height: auto; }
.bi-hangdao ul { list-style: none; margin: 0; padding: 0; display: flex; gap: 2px; }
.bi-hangdao a {
  display: inline-flex; align-items: center; min-height: 44px; padding: 0 12px;
  color: var(--bi-zi); text-decoration: none; font-size: 15px; border-bottom: 2px solid transparent;
}
.bi-hangdao a:hover { color: var(--bi-cheng); }
.bi-hangdao a[aria-current="page"] { border-bottom-color: var(--bi-cheng); }

/* —— 通用标题 —— */
.bi-h1 {
  font-family: var(--bi-hei);
  font-weight: 700;
  line-break: strict;
  text-wrap: balance;
  letter-spacing: 0.01em;
  margin: 0;
}
h2, h3 { font-family: var(--bi-hei); line-break: strict; text-wrap: balance; }

/* —— 首屏 —— */
.bi-shouping {
  max-width: var(--bi-kuan); margin: 0 auto; padding: 40px 16px 56px;
  display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 48px; align-items: start;
}
.bi-shouping .bi-h1 { font-size: 77px; line-height: 1.08; }
.bi-shouping-yin { color: var(--bi-ruo); font-size: 17px; margin: 22px 0 0; max-width: 34em; }
.bi-tuijian {
  margin-top: 30px; padding: 16px 0 4px 20px; border-left: 3px solid var(--bi-qing); max-width: 36em;
}
.bi-tuijian-biao { margin: 0; font-size: 15px; color: var(--bi-qing); font-weight: 700; }
.bi-tuijian-ti { margin: 6px 0 0; font-size: 21px; line-height: 1.45; font-family: var(--bi-hei); }
.bi-tuijian-ti a { color: var(--bi-zi); text-decoration-color: var(--bi-cheng); text-decoration-thickness: 2px; }
.bi-tuijian-ti a:hover { color: var(--bi-cheng); }
.bi-tuijian-yu { margin: 8px 0 0; color: var(--bi-ruo); font-size: 15px; }

/* 海图图例框：大胆只花在这里 */
.bi-tuli {
  position: relative;
  border: 1px solid var(--bi-xian);
  padding: 22px 22px 54px;
  background-color: var(--bi-shen);
  background-image:
    repeating-radial-gradient(circle at 112% 118%, transparent 0 30px, rgba(111, 194, 201, 0.30) 30px 31px, transparent 31px 46px),
    linear-gradient(var(--bi-wangge) 1px, transparent 1px),
    linear-gradient(90deg, var(--bi-wangge) 1px, transparent 1px);
  background-size: auto, 24px 24px, 24px 24px;
  border-radius: var(--bi-jiao);
}
.bi-tuli::after {
  content: ""; position: absolute; right: 18px; top: 18px;
  width: 14px; height: 14px; border: 2px solid var(--bi-cheng); border-radius: 50%;
  box-shadow: 0 0 0 6px rgba(255, 143, 63, 0.14);
}
.bi-tuli-tou {
  margin: 0 0 14px; font-size: 13px; color: var(--bi-ruo);
  display: flex; flex-wrap: wrap; gap: 4px 10px; align-items: baseline;
}
.bi-tuli-tou::first-letter { color: var(--bi-zi); }
.bi-tuli-tou span { color: var(--bi-ruo); }
.bi-tuli-hang { list-style: none; margin: 0; padding: 0; position: relative; z-index: 1; }
.bi-tuli-hang li {
  display: grid; grid-template-columns: 26px minmax(0, 1fr); column-gap: 10px;
  padding: 10px 0; border-top: 1px dashed var(--bi-xian); font-size: 15px; line-height: 1.55;
}
.bi-tuli-hang li:first-child { border-top: 0; }
.bi-tuli-hang b { font-weight: 700; color: var(--bi-zi); }
.bi-tuli-hang li > span:last-child { grid-column: 2; color: var(--bi-ruo); font-size: 14px; }
.bi-fu { grid-row: span 2; width: 18px; height: 18px; margin-top: 4px; display: block; }
.bi-fu-ke { border: 3px solid var(--bi-cheng); border-radius: 50%; }
.bi-fu-hui { background: #6a6f73; border-radius: 50%; }
.bi-fu-tiao { border: 2px solid var(--bi-qing); }

/* —— 码卡 —— */
.bi-maka {
  background: var(--bi-ci);
  border: 1px solid var(--bi-xian);
  border-top: 3px solid var(--bi-cheng);
  padding: 16px 18px 18px;
  border-radius: var(--bi-jiao);
}
.bi-maka-ya { position: relative; z-index: 2; margin: -34px 18px 0; box-shadow: 0 10px 28px rgba(0, 0, 0, 0.35); }
.bi-maka-hang { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 14px; }
.bi-maka-ming { font-size: 14px; color: var(--bi-ruo); width: 100%; }
.bi-ma {
  font-family: var(--bi-latin); font-size: 34px; line-height: 1.1; letter-spacing: 0.08em;
  color: var(--bi-zi); background: none; padding: 0;
}
.bi-fuzhi {
  min-height: 44px; min-width: 72px; padding: 0 16px;
  font: inherit; font-size: 15px; color: var(--bi-zi);
  background: transparent; border: 1px solid var(--bi-qing); border-radius: var(--bi-jiao); cursor: pointer;
}
.bi-fuzhi:hover { background: rgba(111, 194, 201, 0.12); }
.bi-fuzhi.bi-yifuzhi { border-color: var(--bi-cheng); color: var(--bi-cheng); }
.bi-maka-shuoming { margin: 10px 0 0; font-size: 14px; line-height: 1.65; color: var(--bi-ruo); }
.bi-maka-qu {
  display: flex; align-items: center; justify-content: center; min-height: 48px; margin-top: 14px; padding: 8px 18px;
  background: var(--bi-cheng); color: var(--bi-shen); font-weight: 700; text-decoration: none; border-radius: var(--bi-jiao);
}
.bi-maka-qu:hover { background: #ffa765; color: var(--bi-shen); }
.bi-maka-pilu { margin: 10px 0 0; font-size: 13px; line-height: 1.65; color: var(--bi-ruo); }
.bi-maka-wen { margin: 28px 0; }

/* —— 首页下方区块 —— */
.bi-shouye-qu {
  max-width: var(--bi-kuan); margin: 0 auto; padding: 8px 16px 56px;
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 56px;
}
.bi-shouye-qu > section { border-top: 1px solid var(--bi-xian); padding: 26px 0 8px; }
.bi-shouye-qu h2 { font-size: 24px; margin: 0 0 12px; }
.bi-shouye-qu p, .bi-shouye-qu li { font-size: 16px; }
.bi-shouye-qu ol, .bi-shouye-qu ul { padding-left: 1.3em; }
.bi-shouye-qu li { margin: 6px 0; }
.bi-shouye-qu .bi-kua { grid-column: 1 / -1; }
.bi-liangke { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 32px; }
.bi-liangke h3 { font-size: 17px; margin: 4px 0 6px; color: var(--bi-qing); }

/* —— 版心与面包屑 —— */
.bi-kuan { max-width: 860px; margin: 0 auto; padding: 24px 16px 64px; }
.bi-mianbao ol { list-style: none; margin: 0 0 8px; padding: 0; display: flex; flex-wrap: wrap; font-size: 14px; color: var(--bi-ruo); }
.bi-mianbao li { display: inline-flex; align-items: center; }
.bi-mianbao li + li::before { content: "/"; margin: 0 8px; color: var(--bi-xian); }
.bi-mianbao a { display: inline-flex; align-items: center; min-height: 44px; color: var(--bi-ruo); }
.bi-mianbao a { min-width: 44px; justify-content: center; }
.bi-mianbao span { display: inline-flex; align-items: center; min-height: 44px; }
.bi-h1-ci { font-size: 44px; line-height: 1.2; margin: 6px 0 18px; }
.bi-daoyu { color: var(--bi-ruo); max-width: 38em; }
.bi-gongji { font-size: 14px; color: var(--bi-ruo); border-bottom: 1px solid var(--bi-xian); padding-bottom: 10px; }
.bi-wenzhang-list { list-style: none; margin: 0; padding: 0; }
.bi-wenzhang-tiao { padding: 22px 0; border-bottom: 1px solid var(--bi-xian); }
.bi-wenzhang-ri { font-size: 13px; color: var(--bi-ruo); }
.bi-wenzhang-ming { font-size: 24px; line-height: 1.4; margin: 6px 0 8px; }
.bi-wenzhang-ming a { color: var(--bi-zi); text-decoration-color: var(--bi-cheng); }
.bi-wenzhang-yao { margin: 0; color: var(--bi-ruo); }
.bi-fanye { display: flex; gap: 16px; align-items: center; margin-top: 24px; }
.bi-fanye a { min-height: 44px; display: inline-flex; align-items: center; padding: 0 12px; border: 1px solid var(--bi-xian); }
.bi-tongyi { color: var(--bi-ruo); font-size: 14px; }

/* —— 文章页 —— */
.bi-wz { max-width: var(--bi-kuan); margin: 0 auto; padding: 20px 16px 64px; }
.bi-wz-tou { max-width: 900px; }
.bi-h1-wz { font-size: 48px; line-height: 1.2; margin: 4px 0 14px; }
.bi-shuming { display: flex; flex-wrap: wrap; gap: 4px 22px; font-size: 14px; color: var(--bi-ruo); }
.bi-shuming a { color: var(--bi-zi); }
.bi-fengmian { margin: 26px 0 8px; max-width: 900px; }
.bi-fengmian img { border: 1px solid var(--bi-xian); width: 100%; }
.bi-fengmian figcaption { font-size: 13px; color: var(--bi-ruo); margin-top: 8px; }
.bi-wz-ti {
  display: grid; grid-template-columns: 240px minmax(0, 1fr); gap: 48px; align-items: start; margin-top: 24px;
}
.bi-mulu {
  position: sticky; top: 16px; border: 1px solid var(--bi-xian); background: var(--bi-shen);
  padding: 0 14px 10px; font-size: 14px; border-radius: var(--bi-jiao);
}
.bi-mulu summary {
  min-height: 44px; display: flex; align-items: center; cursor: pointer; font-weight: 700; color: var(--bi-qing);
  list-style: none;
}
.bi-mulu summary::-webkit-details-marker { display: none; }
.bi-mulu summary::after { content: "+"; margin-left: auto; color: var(--bi-ruo); font-weight: 400; }
.bi-mulu[open] summary::after { content: "−"; }
.bi-mulu-hang { list-style: none; margin: 0; padding: 0; counter-reset: bi-hd; }
.bi-mulu-hang li { counter-increment: bi-hd; border-top: 1px solid var(--bi-xian); }
.bi-mulu-hang a {
  display: flex; gap: 8px; min-height: 44px; align-items: center; padding: 6px 0; line-height: 1.45;
  color: var(--bi-zi); text-decoration: none;
}
.bi-mulu-hang a::before { content: counter(bi-hd, decimal-leading-zero); font-family: var(--bi-latin); color: var(--bi-cheng); flex: 0 0 auto; }
.bi-mulu-hang a:hover { color: var(--bi-cheng); }

.bi-wen { max-width: 38em; font-size: 17px; line-height: 1.9; }
.bi-wen > p, .bi-wen li { margin: 0 0 1em; }
.bi-wen h2 {
  position: relative; font-size: 29px; line-height: 1.35; margin: 2.2em 0 0.8em; padding-left: 38px;
  scroll-margin-top: 16px;
}
.bi-wen h2::before {
  content: ""; position: absolute; left: 0; top: 0.32em; width: 24px; height: 24px;
  border: 2px solid var(--bi-qing); border-radius: 50%;
  background:
    linear-gradient(var(--bi-qing), var(--bi-qing)) center 1px / 2px 5px no-repeat,
    linear-gradient(var(--bi-qing), var(--bi-qing)) center calc(100% - 1px) / 2px 5px no-repeat,
    linear-gradient(var(--bi-qing), var(--bi-qing)) 1px center / 5px 2px no-repeat,
    linear-gradient(var(--bi-qing), var(--bi-qing)) calc(100% - 1px) center / 5px 2px no-repeat;
}
.bi-wen h2::after {
  content: ""; position: absolute; left: 11px; top: calc(0.32em + 5px); width: 2px; height: 9px;
  background: var(--bi-cheng); transform-origin: 50% 100%; transform: rotate(38deg);
}
.bi-wen h3 { font-size: 21px; margin: 1.8em 0 0.6em; color: var(--bi-zi); }
.bi-wen ul, .bi-wen ol { padding-left: 1.4em; }
.bi-wen strong { color: #fff; }
.bi-wen blockquote {
  margin: 1.4em 0; padding: 12px 18px; border-left: 3px solid var(--bi-cheng); background: var(--bi-ci); color: var(--bi-zi);
}
.bi-wen blockquote p { margin: 0.4em 0; }
.bi-jiaozheng {
  border: 1px solid var(--bi-xian); border-left: 3px solid var(--bi-qing); background: var(--bi-shen);
  padding: 12px 16px; font-size: 16px;
}
.bi-tixing { border-left: 3px solid var(--bi-cheng); padding: 4px 0 4px 14px; color: var(--bi-zi); }

.bi-tu { margin: 1.6em 0; }
.bi-tu-kuang { background: var(--bi-ci); border: 1px solid var(--bi-xian); padding: 10px; }
.bi-tu-shu .bi-tu-kuang { max-width: 380px; }
.bi-tu figcaption { margin-top: 8px; font-size: 14px; line-height: 1.65; color: var(--bi-ruo); }

.bi-biao-kuang { overflow-x: auto; margin: 1.4em 0; border: 1px solid var(--bi-xian); -webkit-overflow-scrolling: touch; }
.bi-biao-kuang table { border-collapse: collapse; width: 100%; min-width: 560px; font-size: 15px; line-height: 1.65; }
.bi-biao-kuang th, .bi-biao-kuang td { padding: 10px 12px; text-align: left; vertical-align: top; border-bottom: 1px solid var(--bi-xian); }
.bi-biao-kuang th { background: var(--bi-ci); color: var(--bi-qing); font-family: var(--bi-hei); font-weight: 700; white-space: nowrap; }
.bi-biao-kuang tr:last-child td { border-bottom: 0; }
.bi-biao-kuang td:first-child { color: var(--bi-zi); font-weight: 700; }
.bi-dui-center { text-align: center; }
.bi-dui-right { text-align: right; }

.bi-wenda { margin-top: 3em; border-top: 1px solid var(--bi-xian); }
.bi-wenda h2 { padding-left: 0; }
.bi-wenda h2::before, .bi-wenda h2::after { display: none; }
.bi-wen-q { font-size: 19px; margin: 1.4em 0 0.4em; padding-left: 14px; border-left: 3px solid var(--bi-cheng); }
.bi-wen-a { margin: 0 0 1em; color: var(--bi-zi); }

.bi-quchu { max-width: 860px; margin: 48px 0 0 288px; border-top: 1px solid var(--bi-xian); padding-top: 18px; font-size: 15px; }
.bi-quchu-biao { font-family: var(--bi-hei); font-size: 18px; margin: 0 0 8px; }
.bi-biaoqian { color: var(--bi-ruo); }
.bi-biaoqian span { color: var(--bi-zi); }
.bi-quchu-hang { list-style: none; padding: 0; margin: 0; }
.bi-quchu-hang li { min-height: 44px; display: flex; align-items: center; flex-wrap: wrap; gap: 0 4px; border-top: 1px dashed var(--bi-xian); }
.bi-quchu-hang a { display: inline-flex; align-items: center; min-height: 44px; }

/* —— 站务页 —— */
.bi-wen-zhanwu { margin-top: 18px; }
.bi-wen-zhanwu h2 { padding-left: 0; font-size: 23px; margin-top: 1.8em; }
.bi-wen-zhanwu h2::before, .bi-wen-zhanwu h2::after { display: none; }

/* —— 搜索页 —— */
.bi-dingwei-biao label { display: block; font-size: 14px; color: var(--bi-ruo); margin: 18px 0 6px; }
.bi-dingwei-hang { display: flex; gap: 8px; }
.bi-dingwei-hang input {
  flex: 1 1 auto; min-width: 0; min-height: 48px; padding: 0 12px; font: inherit; font-size: 16px;
  color: var(--bi-zi); background: var(--bi-shen); border: 1px solid var(--bi-xian); border-radius: var(--bi-jiao);
}
.bi-dingwei-an {
  min-height: 48px; padding: 0 18px; font: inherit; font-size: 16px; font-weight: 700;
  color: var(--bi-shen); background: var(--bi-qing); border: 0; border-radius: var(--bi-jiao); cursor: pointer;
}
.bi-dingwei-zhuang { color: var(--bi-ruo); font-size: 14px; }
.bi-dingwei-jieguo { list-style: none; padding: 0; margin: 0; }
.bi-dingwei-jieguo li { border-top: 1px solid var(--bi-xian); padding: 14px 0; }
.bi-dingwei-jieguo a { font-size: 18px; font-family: var(--bi-hei); display: inline-flex; min-height: 44px; align-items: center; }
.bi-dingwei-jieguo p { margin: 2px 0 0; color: var(--bi-ruo); font-size: 15px; }
.bi-dingwei-jieguo mark { background: rgba(255, 143, 63, 0.25); color: var(--bi-zi); }

.bi-wuci-hang { padding-left: 1.2em; }
.bi-wuci-hang a { display: inline-flex; min-height: 44px; align-items: center; }

/* —— 船尾（页脚） —— */
.bi-chuanwei { border-top: 1px solid var(--bi-xian); background: var(--bi-shen); margin-top: 24px; }
.bi-chuanwei-nei { max-width: var(--bi-kuan); margin: 0 auto; padding: 28px 16px 32px; display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); gap: 16px 48px; }
.bi-shengming { margin: 8px 0 0; font-size: 14px; color: var(--bi-ruo); line-height: 1.7; }
.bi-shengming a, .bi-shuming a { display: inline-block; min-width: 44px; padding: 13px 4px; margin: -13px 0; text-align: center; }
.bi-zhanwu ul { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0 16px; }
.bi-zhanwu a { display: flex; align-items: center; min-height: 44px; color: var(--bi-zi); font-size: 15px; text-decoration: none; border-bottom: 1px solid var(--bi-xian); }
.bi-zhanwu a:hover { color: var(--bi-cheng); }
.bi-chuanwei-di { grid-column: 1 / -1; display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 8px; font-size: 14px; color: var(--bi-ruo); border-top: 1px solid var(--bi-xian); padding-top: 12px; }
.bi-rss { display: inline-flex; align-items: center; min-height: 44px; }

/* —— 窄屏 —— */
@media (max-width: 999px) {
  .bi-wz-ti { grid-template-columns: minmax(0, 1fr); gap: 16px; }
  .bi-mulu { position: static; }
  .bi-quchu { margin-left: 0; }
  .bi-shouping { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .bi-shouye-qu { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 640px) {
  body { font-size: 16px; }
  .bi-chuantou-nei { min-height: 56px; padding: 0 12px; gap: 6px; }
  .bi-biaozhi { width: 104px; }
  .bi-hangdao a { padding: 0 9px; font-size: 15px; }
  .bi-shouping { padding: 18px 16px 40px; display: flex; flex-direction: column; gap: 0; }
  .bi-shouping-wen, .bi-shouping-tu { display: contents; }
  .bi-shouping .bi-h1 { order: 1; font-size: 40px; line-height: 1.15; }
  .bi-shouping-yin { order: 2; font-size: 15px; margin-top: 10px; line-height: 1.7; }
  .bi-tuijian { order: 3; margin-top: 14px; padding: 6px 0 2px 14px; }
  .bi-tuijian-ti { font-size: 18px; margin-top: 2px; }
  .bi-tuijian-yu { font-size: 14px; margin-top: 4px; line-height: 1.6; }
  .bi-maka-ya { order: 4; margin: 16px 0 0; box-shadow: none; }
  .bi-tuli { order: 5; margin-top: 18px; padding-bottom: 22px; }
  .bi-maka { padding: 12px 14px 14px; }
  .bi-ma { font-size: 28px; }
  .bi-maka-ming { width: auto; }
  .bi-maka-shuoming { margin-top: 6px; }
  .bi-h1-ci { font-size: 32px; }
  .bi-h1-wz { font-size: 32px; }
  .bi-wen { font-size: 16px; line-height: 1.85; }
  .bi-wen h2 { font-size: 23px; padding-left: 34px; }
  .bi-wen h2::before { width: 22px; height: 22px; top: 0.25em; }
  .bi-wen h2::after { left: 10px; top: calc(0.25em + 4px); }
  .bi-wen h3 { font-size: 19px; }
  .bi-tu-kuang { padding: 6px; }
  .bi-liangke { grid-template-columns: minmax(0, 1fr); }
  .bi-chuanwei-nei { grid-template-columns: minmax(0, 1fr); }
  .bi-zhanwu ul { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (prefers-reduced-motion: no-preference) {
  .bi-fuzhi, .bi-maka-qu, .bi-hangdao a { transition: background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease; }
}

.bi-mulu:not([open]) { padding-bottom: 0; }