/* Pianoesis 官网 — 纯静态，无依赖 */
:root {
  --bg: #faf6ee;
  --bg-soft: #f3ecdf;
  --ink: #3a2f28;
  --ink-soft: #6b5d52;
  --accent: #8b5e3c;
  --accent-deep: #5d3f2a;
  --line: #e5dbc9;
  --card: #fffdf8;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: 860px; margin: 0 auto; padding: 0 24px; }

/* ===== 顶部导航 ===== */
.nav {
  position: sticky; top: 0; z-index: 10;
  background: rgba(250, 246, 238, 0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: 860px; margin: 0 auto; padding: 14px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  flex-wrap: wrap;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--ink); }
.brand:hover { text-decoration: none; }
.brand-glyph {
  width: 26px; height: 26px; border-radius: 50%;
  background: conic-gradient(var(--ink) 0 50%, var(--bg) 50% 100%);
  border: 1.5px solid var(--ink);
  display: inline-block; flex: none;
}
.nav-links { display: flex; gap: 20px; font-size: 15px; flex-wrap: wrap; }
.nav-links a { color: var(--ink-soft); }
.nav-links a:hover { color: var(--accent); text-decoration: none; }

/* ===== 首页 Hero ===== */
.hero { padding: 72px 0 56px; text-align: center; }
.hero h1 { font-size: clamp(34px, 6vw, 52px); font-weight: 800; letter-spacing: 1px; }
.tagline-hero {
  font-size: clamp(15px, 2.2vw, 18px); line-height: 1.9; color: var(--accent-deep);
  letter-spacing: 1.5px; font-weight: 600; margin-top: 16px;
}
.hero .sub { font-size: clamp(17px, 2.6vw, 21px); color: var(--ink-soft); margin-top: 12px; }
.hero .en { font-size: 15px; color: var(--ink-soft); margin-top: 8px; font-style: italic; }
.piano-keys {
  display: inline-flex; gap: 4px; margin-top: 32px; height: 56px;
}
.pk {
  width: 22px; background: var(--card); border: 1.5px solid var(--ink);
  border-radius: 0 0 5px 5px; position: relative;
}
.pk.black { width: 14px; height: 34px; background: var(--ink); margin: 0 -6px; z-index: 1; border-radius: 0 0 4px 4px; }
.pk:nth-child(2) { transform: translateY(6px); }
.pk:nth-child(5) { transform: translateY(-4px); }
.pk:nth-child(8) { transform: translateY(5px); }
.pk:nth-child(11) { transform: translateY(-5px); }

/* ===== 下载入口 ===== */
.cta { padding: 8px 0 64px; text-align: center; }
.badges { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.badge {
  display: inline-flex; align-items: center; gap: 10px;
  border: 1.5px solid var(--ink); border-radius: 12px;
  padding: 12px 22px; font-size: 16px; font-weight: 600; color: var(--ink);
  background: var(--card); transition: transform .15s ease, box-shadow .15s ease;
}
.badge:hover { text-decoration: none; transform: translateY(-2px); box-shadow: 0 6px 18px rgba(93, 63, 42, 0.14); }
.badge.soon { opacity: 0.6; cursor: default; }
.badge.soon:hover { transform: none; box-shadow: none; }
.cta-note { margin-top: 14px; font-size: 14px; color: var(--ink-soft); }

/* ===== 功能卡 ===== */
.features { padding: 24px 0 72px; }
.features h2, .section-title { font-size: 26px; font-weight: 700; margin-bottom: 6px; }
.features .lede, .section-lede { color: var(--ink-soft); margin-bottom: 28px; font-size: 15px; }
.brand-copy {
  font-size: 17px; line-height: 2; color: var(--ink);
  margin: 0 0 22px; text-wrap: balance;
}
.tagline {
  font-size: 15px; line-height: 1.9; color: var(--accent-deep);
  letter-spacing: 1px; margin: 0 0 30px; font-weight: 600;
}
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 18px; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: 14px;
  padding: 22px 22px 18px;
}
.card h3 { font-size: 17px; margin-bottom: 8px; display: flex; align-items: center; gap: 8px; }
.card p { font-size: 14.5px; color: var(--ink-soft); }
.card .ico { font-size: 20px; }

/* ===== 双语区块 ===== */
.lang-section { padding: 40px 0 24px; border-top: 1px solid var(--line); margin-top: 40px; }
.lang-tag {
  display: inline-block; font-size: 13px; font-weight: 700; letter-spacing: 2px;
  color: var(--accent-deep); background: var(--bg-soft);
  border-radius: 999px; padding: 2px 14px; margin-bottom: 18px;
}

/* ===== 法务/文档页 ===== */
.doc { padding: 56px 0 72px; }
.doc h1 { font-size: clamp(26px, 4.5vw, 36px); margin-bottom: 4px; }
.doc .updated { color: var(--ink-soft); font-size: 14px; margin-bottom: 36px; }
.doc h2 { font-size: 21px; margin: 40px 0 12px; padding-top: 18px; border-top: 1px solid var(--line); }
.doc h2:first-of-type { border-top: none; padding-top: 0; }
.doc h3 { font-size: 17px; margin: 26px 0 10px; }
.doc p, .doc li { font-size: 15.5px; color: var(--ink); }
.doc ul { padding-left: 22px; margin: 10px 0; }
.doc li { margin: 6px 0; }
.doc table { width: 100%; border-collapse: collapse; margin: 14px 0; font-size: 14.5px; }
.doc th, .doc td { text-align: left; padding: 9px 12px; border: 1px solid var(--line); }
.doc th { background: var(--bg-soft); font-weight: 600; }
.doc pre {
  background: var(--bg-soft); border: 1px solid var(--line); border-radius: 10px;
  padding: 16px 18px; margin: 12px 0; overflow-x: auto;
  font-size: 12.5px; line-height: 1.6; color: var(--ink);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  white-space: pre-wrap;
}
.doc .muted { color: var(--ink-soft); font-size: 14px; }

/* ===== 页脚 ===== */
footer {
  border-top: 1px solid var(--line);
  padding: 34px 0 44px; margin-top: 40px;
  color: var(--ink-soft); font-size: 14px;
}
footer .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
footer nav { display: flex; gap: 18px; flex-wrap: wrap; }

@media (max-width: 600px) {
  .hero { padding-top: 48px; }
  .doc h2 { margin-top: 32px; }
}