/* ============================================================
   AI 提效笔记 · 温暖纸质风（mobile-first）
   零外链、零脚本依赖、移动端优先
   ============================================================ */

:root {
  --paper:      #f7f1e3;   /* 米白纸底 */
  --paper-deep: #efe6d2;   /* 纸面加深 */
  --ink:        #3a332b;   /* 墨色正文 */
  --ink-soft:   #6b6153;   /* 次级文字 */
  --line:       #d9cdb4;   /* 纸线/描边 */
  --accent:     #a4652f;   /* 牛皮纸棕（强调） */
  --accent-soft:#c98d55;
  --tape:       rgba(214, 193, 160, .55);
  --radius:     14px;
}

* { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Hiragino Sans GB", system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.75;
  color: var(--ink);
  background-color: var(--paper);
  /* 纸纹：细微噪点，纯 CSS，零图片 */
  background-image:
    radial-gradient(rgba(120, 100, 70, .045) 1px, transparent 1px);
  background-size: 6px 6px;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.page {
  max-width: 640px;          /* 移动端全宽；桌面端居中限宽 */
  margin: 0 auto;
  padding: 0 20px 48px;
  padding-bottom: calc(48px + env(safe-area-inset-bottom));
}

/* ---------- Hero ---------- */
.hero {
  text-align: center;
  padding: 56px 0 40px;
}
.hero-badge {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 2px;
  color: var(--accent);
  border: 1px solid var(--accent-soft);
  border-radius: 999px;
  padding: 4px 14px;
  margin-bottom: 22px;
  opacity: .85;
}
.hero-title {
  font-size: clamp(44px, 12vw, 68px);
  font-weight: 800;
  letter-spacing: 4px;
  line-height: 1.15;
  color: var(--ink);
}
.hero-sub {
  margin-top: 16px;
  font-size: clamp(18px, 4.6vw, 24px);
  font-weight: 600;
  color: var(--accent);
}
.hero-lead {
  margin: 24px auto 0;
  max-width: 30em;
  font-size: 16px;
  color: var(--ink-soft);
}
.hero-tape {
  position: relative;
  margin: 32px auto 0;
  max-width: 26em;
  background: var(--tape);
  padding: 18px 20px;
  border-radius: 4px;
  transform: rotate(-1deg);
  box-shadow: 0 2px 6px rgba(90, 70, 40, .12);
}
.tape-pin {
  position: absolute;
  top: -10px;
  left: 50%;
  width: 26px; height: 26px;
  margin-left: -13px;
  background: rgba(214, 193, 160, .9);
  border-radius: 4px;
  box-shadow: 0 1px 3px rgba(90, 70, 40, .25);
  transform: rotate(8deg);
}
.tape-text {
  font-size: 15px;
  color: var(--ink);
  font-weight: 500;
}

/* ---------- Section ---------- */
.section { margin-top: 44px; }
.section-title {
  font-size: 22px;
  font-weight: 700;
  text-align: center;
  position: relative;
  padding-bottom: 12px;
}
.section-title::after {
  content: "";
  position: absolute;
  left: 50%; bottom: 0;
  width: 36px; height: 3px;
  margin-left: -18px;
  border-radius: 2px;
  background: var(--accent-soft);
}
.section-note {
  text-align: center;
  font-size: 15px;
  color: var(--ink-soft);
  margin-top: 14px;
}

/* ---------- Cards（三路口） ---------- */
.cards { margin-top: 22px; display: flex; flex-direction: column; gap: 14px; }
.card {
  background: var(--paper-deep);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 18px 16px;
  box-shadow: 0 1px 4px rgba(90, 70, 40, .08);
}
.card-head { margin-bottom: 8px; }
.card-tag {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  padding: 2px 12px;
  border-radius: 999px;
  color: #fff;
}
.tag-tool   { background: #b0713f; }
.tag-howto  { background: #6d8a6a; }
.tag-script { background: #7a6a8f; }
.tag-ai     { background: #8a6d3b; }
.card-body { font-size: 16px; color: var(--ink); }
.card-body strong { color: var(--accent); }

/* ---------- 手写便签（信任背书） ---------- */
.note {
  position: relative;
  background: #fffdf4;
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 26px 22px 22px;
  box-shadow: 0 3px 10px rgba(90, 70, 40, .10);
  transform: rotate(.5deg);
}
.note::before {
  content: "";
  position: absolute;
  top: -12px; left: 50%;
  width: 90px; height: 24px;
  margin-left: -45px;
  background: rgba(233, 215, 176, .8);
  box-shadow: 0 1px 3px rgba(90, 70, 40, .18);
  transform: rotate(-2deg);
  border-radius: 2px;
}
.note-title { font-size: 20px; font-weight: 700; margin-bottom: 10px; }
.note-body { font-size: 16px; color: var(--ink); margin-bottom: 10px; }
.note-body strong { color: var(--accent); }
.note-sign { text-align: right; font-size: 15px; color: var(--ink-soft); margin-top: 6px; }

/* ---------- 404 ---------- */
.notfound { text-align: center; padding: 80px 0 60px; }
.nf-code { font-size: 72px; font-weight: 800; color: var(--accent); line-height: 1; }
.nf-title { font-size: 22px; font-weight: 700; margin-top: 14px; color: var(--ink); }
.nf-text { margin-top: 10px; font-size: 15px; color: var(--ink-soft); }
.nf-btn {
  display: inline-block;
  margin-top: 24px;
  padding: 12px 28px;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  min-height: 48px;
  line-height: 24px;
}

/* ---------- 文章列表 ---------- */
.article-list { margin-top: 22px; display: flex; flex-direction: column; gap: 14px; }
.article-item {
  display: block;
  background: #fffdf4;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 18px 16px;
  box-shadow: 0 1px 4px rgba(90, 70, 40, .08);
  text-decoration: none;
  color: var(--ink);
  transition: transform .15s ease;
}
.article-item:active { transform: scale(.97); }
.article-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 8px;
}
.article-cat {
  font-size: 12px;
  font-weight: 700;
  padding: 2px 10px;
  border-radius: 999px;
  background: #7a6a8f;
  color: #fff;
}
.article-meta time { font-size: 12.5px; color: var(--ink-soft); }
.article-title { font-size: 17px; font-weight: 700; color: var(--ink); }
.article-excerpt {
  margin-top: 8px;
  font-size: 14.5px;
  color: var(--ink-soft);
  line-height: 1.7;
}

/* ---------- Footer ---------- */
.footer {
  margin-top: 56px;
  text-align: center;
  padding-top: 28px;
  border-top: 1px dashed var(--line);
}
.footer-slogan {
  font-size: 20px;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: 1px;
}
.footer-icp { margin-top: 12px; font-size: 12.5px; color: var(--ink-soft); }
.icp-link { color: var(--ink-soft); text-decoration: none; border-bottom: 1px dashed rgba(107,97,83,.5); }
.icp-link:active { color: var(--accent); }
.footer-copy { margin-top: 6px; font-size: 12.5px; color: var(--ink-soft); }

/* 触控目标安全区 */
a { min-height: 48px; }