/* ============================================================
   研究笔记 —— 编辑 / 杂志风(暖色调 · 衬线大标题 · 大留白)
   纯 CSS,系统字体(不含外部字体,国内访问也快)
   ============================================================ */
:root {
  --bg: #f5f0e8;          /* 暖米白背景 */
  --panel: #ffffff;
  --panel-warm: #ece4d7;  /* taupe 灰褐面板(卡片右侧) */
  --panel-warm-2: #f0eadf;
  --ink: #33302a;         /* 暖炭黑 */
  --ink-soft: #4c473d;
  --muted: #8a8072;
  --faint: #a99f8d;
  --line: #e2d9c9;
  --line-soft: #ebe3d5;
  --olive: #7c8a5a;       /* 橄榄绿主色(按钮) */
  --olive-d: #657347;
  --olive-ink: #5c6a3d;
  --up: #b0472f;          /* 涨 = 砖红 */
  --up-tint: #f2e6e0;
  --down: #5f7d3b;        /* 跌 = 橄榄绿 */
  --down-tint: #e9eede;
  --shadow-sm: 0 1px 2px rgba(51,48,42,.05);
  --shadow-md: 0 10px 30px -12px rgba(80,70,50,.28);
  --serif: Georgia, "Times New Roman", "Songti SC", STSong, "SimSun", "Noto Serif SC", serif;
  --sans: "Segoe UI", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --maxw: 1160px;
  --readw: 760px;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font-family: var(--sans); font-size: 15px; line-height: 1.7; letter-spacing: .1px;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--olive-ink); text-decoration: none; transition: color .15s, opacity .15s; }
a:hover { color: var(--ink); }
.hidden { display: none !important; }
img { max-width: 100%; }

/* ---------- 顶部横幅(夕照,纯 CSS;想换自己的照片:把下面 background 改成 url('你的图.jpg') center/cover) ---------- */
.masthead {
  position: relative; height: 190px; display: flex; align-items: center; justify-content: center;
  text-align: center; color: #fff; overflow: hidden;
  background:
    radial-gradient(130% 150% at 76% 14%, rgba(255,244,222,.95), rgba(255,206,150,.30) 32%, transparent 60%),
    linear-gradient(180deg, #b7a48c 0%, #cbb497 8%, #d7c1a2 42%, #ecdcc2 100%);
}
.masthead.home { height: 300px; }
.masthead::after {   /* 底部一层柔和山丘剪影 */
  content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 70px;
  background:
    linear-gradient(180deg, transparent, rgba(120,106,84,.18)),
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 1200 120' preserveAspectRatio='none'%3E%3Cpath d='M0 120 L0 70 Q250 30 500 58 T1000 52 T1200 64 L1200 120 Z' fill='%23887a63' opacity='.35'/%3E%3C/svg%3E") bottom/cover no-repeat;
  pointer-events: none;
}
.mh-inner { position: relative; z-index: 1; padding: 0 20px; }
.mh-name {
  font-family: var(--serif); font-weight: 400; letter-spacing: 2px;
  font-size: clamp(30px, 5.2vw, 48px); line-height: 1.1;
  text-shadow: 0 2px 18px rgba(60,45,25,.35);
}
.masthead.home .mh-name { font-size: clamp(34px, 6vw, 60px); }
.mh-tag {
  font-family: var(--sans); font-weight: 400; font-size: clamp(14px, 2.2vw, 19px);
  letter-spacing: 3px; margin-top: 10px; opacity: .95;
  text-shadow: 0 1px 10px rgba(60,45,25,.35);
}

/* ---------- 站点导航(横幅下方,吸顶) ---------- */
.sitenav {
  position: sticky; top: 0; z-index: 30;
  background: rgba(245,240,232,.88); backdrop-filter: saturate(150%) blur(10px);
  -webkit-backdrop-filter: saturate(150%) blur(10px);
  border-bottom: 1px solid var(--line);
  display: flex; justify-content: center; flex-wrap: wrap; gap: 4px; padding: 14px 16px;
}
.sitenav a {
  font-size: 13.5px; letter-spacing: 1.5px; color: var(--ink-soft); font-weight: 500;
  padding: 6px 16px; border-radius: 2px; position: relative;
}
.sitenav a::after {
  content: ""; position: absolute; left: 16px; right: 16px; bottom: 2px; height: 1px;
  background: var(--olive); transform: scaleX(0); transition: transform .22s; transform-origin: center;
}
.sitenav a:hover { color: var(--ink); }
.sitenav a:hover::after { transform: scaleX(1); }
.sitenav a.active { color: var(--olive-ink); }
.sitenav a.active::after { transform: scaleX(1); }
.lang-toggle {
  position: absolute; right: 18px; top: 50%; transform: translateY(-50%);
  font-size: 15px; letter-spacing: 1px; font-weight: 700; color: #fff;
  background: var(--olive); border: 1px solid var(--olive); border-radius: 4px;
  padding: 8px 18px; cursor: pointer; line-height: 1; min-width: 58px;
  box-shadow: var(--shadow-sm); transition: background .18s, border-color .18s, transform .12s;
}
.lang-toggle:hover { background: var(--olive-ink); border-color: var(--olive-ink); transform: translateY(-50%) scale(1.05); }

/* ---------- 通用容器 & 段首标题 ---------- */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 56px 24px 80px; }
.section-head { text-align: center; max-width: var(--readw); margin: 0 auto 40px; }
.page-title, .section-head h1 {
  font-family: var(--serif); font-weight: 400; letter-spacing: .5px;
  font-size: clamp(30px, 4.6vw, 44px); margin: 0 0 14px; color: var(--ink);
}
.page-sub, .section-head p { color: var(--muted); margin: 0; font-size: 16px; line-height: 1.7; }
.rule { width: 54px; height: 1px; background: var(--olive); margin: 22px auto 0; opacity: .8; }

/* ---------- 按钮(编辑风:方角、字距) ---------- */
.btn {
  display: inline-block; font-size: 12.5px; letter-spacing: 2px; text-transform: uppercase;
  padding: 12px 26px; border-radius: 2px; border: 1px solid var(--ink); color: var(--ink);
  background: transparent; cursor: pointer; transition: background .18s, color .18s, border-color .18s;
}
.btn:hover { background: var(--ink); color: #fff; }
.btn-solid { background: var(--olive); border-color: var(--olive); color: #fff; }
.btn-solid:hover { background: var(--olive-ink); border-color: var(--olive-ink); color: #fff; }

/* ---------- 首页:居中简介 + 编辑卡片 ---------- */
.home-intro { text-align: center; max-width: var(--readw); margin: 0 auto 46px; }
.home-intro .kicker {
  font-size: 12px; letter-spacing: 3px; text-transform: uppercase; color: var(--olive-ink);
  margin-bottom: 16px;
}
.home-intro h1 { font-family: var(--serif); font-weight: 400; font-size: clamp(28px,4.4vw,42px); margin: 0 0 16px; }
.home-intro p { color: var(--muted); font-size: 16px; }

.features { display: grid; gap: 26px; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.feature {
  display: flex; min-height: 168px; background: var(--panel-warm); border: 1px solid var(--line);
  overflow: hidden; transition: box-shadow .2s, transform .2s;
}
.feature:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.feature-media {
  flex: 0 0 6px; align-self: stretch;
  background: linear-gradient(180deg, #b7a68b, #9a8a6e);
}
.feature:nth-child(1) .feature-media { background: linear-gradient(180deg, #8f9a6a, #6f7c4c); }
.feature:nth-child(2) .feature-media { background: linear-gradient(180deg, #c8a67f, #a9814f); }
.feature:nth-child(3) .feature-media { background: linear-gradient(180deg, #a8927e, #82705c); }
.feature:nth-child(4) .feature-media { background: linear-gradient(180deg, #93a0a6, #6d7a80); }
.feature-body { flex: 1; padding: 26px 28px; display: flex; flex-direction: column; align-items: flex-start; }
.feature-body .kicker {
  font-size: 11.5px; letter-spacing: 2px; text-transform: uppercase; color: var(--muted); margin-bottom: 8px;
}
.feature-body h3 { font-family: var(--serif); font-weight: 400; font-size: 24px; margin: 0 0 14px; color: var(--ink); }
.feature-body .btn { margin-top: auto; }

/* ---------- 文章列表(报告 / 交易日志)编辑风 ---------- */
.list { list-style: none; padding: 0; margin: 0 auto; max-width: var(--readw); }
.list li {
  padding: 26px 0; border-bottom: 1px solid var(--line);
  display: flex; flex-direction: column; gap: 8px;
}
.list li:first-child { border-top: 1px solid var(--line); }
.list .item-date {
  font-size: 12px; letter-spacing: 2px; text-transform: uppercase; color: var(--olive-ink); font-weight: 600;
}
.list a.item-title { font-family: var(--serif); font-size: 23px; font-weight: 400; color: var(--ink); }
.list a.item-title:hover { color: var(--olive-ink); }
.list .item-sum { color: var(--muted); font-size: 15px; }
.empty { color: var(--muted); padding: 60px 0; text-align: center; }

/* ---------- 价格折线图卡片 ---------- */
.price-disclaimer {
  max-width: var(--readw); margin: 0 auto 22px; padding: 12px 18px;
  background: var(--panel-warm-2); border-left: 3px solid var(--olive);
  color: var(--ink-soft); font-size: 13.5px; line-height: 1.6; border-radius: 0 4px 4px 0;
}
.price-updated {
  display: inline-block; font-size: 12px; letter-spacing: 1.5px; text-transform: uppercase;
  color: var(--olive-ink); border: 1px solid var(--line); padding: 7px 16px; border-radius: 2px; margin-bottom: 30px;
}
.price-section {
  font-family: var(--serif); font-weight: 400; font-size: 20px; color: var(--ink);
  margin: 38px 0 16px; padding-bottom: 8px; border-bottom: 1px solid var(--line);
  letter-spacing: .3px;
}
.price-section:first-of-type { margin-top: 8px; }
.price-grid { display: grid; gap: 24px; grid-template-columns: repeat(auto-fill, minmax(340px, 1fr)); }
.pc-legend { display: flex; flex-wrap: wrap; gap: 4px 14px; margin-top: 12px; }
.pc-leg { font-size: 12px; color: var(--muted); display: inline-flex; align-items: center; gap: 5px; }
.pc-leg i { width: 10px; height: 2px; border-radius: 1px; display: inline-block; }
.pc-leg b { color: var(--ink); font-variant-numeric: tabular-nums; font-weight: 700; }
.price-card {
  background: var(--panel); border: 1px solid var(--line); padding: 22px 24px 16px;
  transition: box-shadow .2s, transform .2s;
}
.price-card:hover { box-shadow: var(--shadow-md); transform: translateY(-3px); }
.price-card .pc-top { display: flex; align-items: baseline; gap: 8px; }
.price-card .pc-name { font-family: var(--serif); font-weight: 400; font-size: 18px; color: var(--ink); line-height: 1.25; }
.price-card .pc-unit { color: var(--muted); font-size: 11px; letter-spacing: 1px; text-transform: uppercase; white-space: nowrap; }
.price-card svg { width: 100%; height: 116px; display: block; margin-top: 12px; overflow: visible; }
.price-card .pc-foot { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; margin-top: 10px; }
.price-card .pc-chg { font-size: 18px; font-weight: 800; font-variant-numeric: tabular-nums; letter-spacing: -.2px; }
.price-card .pc-chg.up { color: var(--up); }
.price-card .pc-chg.down { color: var(--down); }
.price-card .pc-chg.flat { color: var(--muted); font-size: 14px; font-weight: 600; }
.price-card .pc-date { color: var(--faint); font-size: 12px; letter-spacing: .3px; white-space: nowrap; }
.price-card .pc-legend b.up { color: var(--up); }
.price-card .pc-legend b.down { color: var(--down); }
.price-card .pc-legend b.flat { color: var(--faint); }

/* ---------- 文章正文 ---------- */
.article { max-width: var(--readw); margin: 0 auto; }
.back-link {
  display: inline-flex; align-items: center; gap: 6px; margin-bottom: 24px;
  font-size: 12px; letter-spacing: 2px; text-transform: uppercase; color: var(--muted);
}
.back-link:hover { color: var(--olive-ink); }
.article .a-date {
  display: block; font-size: 12px; letter-spacing: 2px; text-transform: uppercase;
  color: var(--olive-ink); font-weight: 600; margin-bottom: 14px;
}
.article-body { font-size: 16.5px; color: var(--ink-soft); }
.article-body > *:first-child { margin-top: 0; }
.article-body h1 { font-family: var(--serif); font-weight: 400; font-size: 30px; margin: 32px 0 16px; color: var(--ink); line-height: 1.25; }
.article-body h2 { font-family: var(--serif); font-weight: 400; font-size: 24px; margin: 32px 0 12px; color: var(--ink); padding-bottom: 8px; border-bottom: 1px solid var(--line); }
.article-body h3 { font-family: var(--serif); font-weight: 400; font-size: 20px; margin: 24px 0 8px; color: var(--ink); }
.article-body p { margin: 15px 0; }
.article-body ul, .article-body ol { margin: 15px 0; padding-left: 24px; }
.article-body li { margin: 7px 0; }
.article-body li::marker { color: var(--olive); }
.article-body blockquote {
  margin: 18px 0; padding: 12px 20px; border-left: 3px solid var(--olive);
  background: var(--panel-warm-2); color: var(--ink-soft); border-radius: 0 6px 6px 0;
}
.article-body blockquote p { margin: 8px 0; }
.article-body code { background: var(--panel-warm-2); padding: 2px 7px; border-radius: 3px; font-family: Consolas, monospace; font-size: .9em; color: var(--olive-ink); }
.article-body pre { background: #33302a; color: #f1ece1; padding: 16px 18px; border-radius: 4px; overflow-x: auto; }
.article-body pre code { background: none; padding: 0; color: inherit; }
.article-body img { border-radius: 4px; }
.article-body table { border-collapse: collapse; width: 100%; margin: 20px 0; font-size: 15px; }
.article-body th, .article-body td { border-bottom: 1px solid var(--line); padding: 10px 12px; text-align: left; }
.article-body th { font-family: var(--serif); font-weight: 400; color: var(--ink); border-bottom: 2px solid var(--olive); }
.article-body hr { border: none; border-top: 1px solid var(--line); margin: 30px 0; }

/* ---------- 关于我 ---------- */
.about-card { max-width: var(--readw); margin: 0 auto; font-size: 16.5px; color: var(--ink-soft); }
.about-card h2 { font-family: var(--serif); font-weight: 400; font-size: 22px; color: var(--ink); margin-top: 34px; }
.about-card ul { padding-left: 22px; }
.about-card li { margin: 7px 0; }
.about-card li::marker { color: var(--olive); }

/* ---------- 页脚 ---------- */
.foot {
  max-width: var(--maxw); margin: 40px auto 0; padding: 28px 24px; color: var(--faint);
  font-size: 12px; letter-spacing: 1px; border-top: 1px solid var(--line); text-align: center;
}

/* ---------- 响应式 ---------- */
@media (max-width: 720px) {
  .masthead { height: 150px; } .masthead.home { height: 220px; }
  .wrap { padding: 40px 18px 56px; }
  .feature { flex-direction: column; }
  .feature-media { flex-basis: 6px; width: 100%; }
  .sitenav { gap: 0; padding: 10px 66px 10px 8px; }
  .sitenav a { padding: 6px 9px; letter-spacing: .5px; font-size: 13px; }
  .lang-toggle { right: 8px; font-size: 13px; padding: 6px 12px; min-width: 0; }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; scroll-behavior: auto; } }