/* ============================================================
   站点共享样式（遵循 DESIGN.md 设计准则）
   顺序：设计令牌 → 基础排版 → 组件 → 响应式
   ============================================================ */
:root {
  --blue: #0071e3;
  --ink: #1d1d1f;
  --gray: #86868b;
  --soft: #f5f5f7;
  --hairline: #e8e8ed;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

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

html { font-size: clamp(14px, 0.5vw + 0.7vh, 22px); }

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display",
               "Helvetica Neue", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #ffffff;
  color: var(--ink);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ---------- 基础排版 ---------- */
.eyebrow {
  color: var(--blue);
  font-size: clamp(11px, 1vw + 0.6vh, 16px);
  font-weight: 600;
  letter-spacing: .32em;
  text-transform: uppercase;
  margin-bottom: 1.1rem;
}

.title {
  font-size: clamp(2.1rem, min(7vw, 9vh), 5.2rem);
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.08;
  color: var(--ink);
  text-wrap: balance;
}

.sub {
  font-size: clamp(1rem, 1.4vw + 0.8vh, 1.45rem);
  font-weight: 300;
  color: var(--gray);
  line-height: 1.55;
  margin-top: 1.3rem;
  max-width: 60ch;
  margin-inline: auto;
}

.hl { color: var(--blue); }

/* ---------- 幽灵背景字 ---------- */
.ghost {
  position: absolute;
  z-index: 0;
  font-size: clamp(120px, 24vw, 320px);
  font-weight: 800;
  line-height: .8;
  letter-spacing: -.05em;
  color: var(--ink);
  opacity: .045;
  white-space: nowrap;
  pointer-events: none;
  user-select: none;
}

.g-c { top: 50%; left: 50%; transform: translate(-50%, -50%); }
.g-lb { bottom: -2rem; left: 0; }

/* ---------- 分节 ---------- */
.section, .hero {
  position: relative;
  min-height: 100vh;
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: clamp(3.5rem, 10vh, 7rem) clamp(1.2rem, 6vw, 4rem);
  text-align: center;
  border-bottom: 1px solid var(--hairline);
  overflow: hidden;
}

.inner {
  position: relative;
  z-index: 1;
  width: min(1100px, 100%);
  margin: 0 auto;
}

/* ---------- 教程列表 ---------- */
.rows {
  display: flex;
  flex-direction: column;
  width: min(720px, 100%);
  margin: 3rem auto 0;
  text-align: left;
}

.row {
  display: flex;
  flex-direction: column;
  gap: .25rem;
  border-bottom: 1px solid var(--hairline);
  padding: 1.2rem .4rem;
  text-decoration: none;
  color: var(--ink);
  transition: transform .3s var(--ease);
}

.row:last-child { border-bottom: none; }
.row:hover { transform: translateX(8px); }

.row-head {
  display: flex;
  align-items: center;
  gap: 1.6rem;
  font-size: clamp(1.3rem, 2.4vw + 1.2vh, 2rem);
  font-weight: 600;
  line-height: 1.4;
}

.row-head .ic { flex: none; }

.row .arr {
  margin-left: auto;
  flex: none;
  color: var(--blue);
  opacity: 0;
  transform: translateX(-6px);
  transition: opacity .3s ease, transform .3s var(--ease);
}

.row:hover .arr { opacity: 1; transform: translateX(0); }

.row-sub {
  color: var(--gray);
  font-weight: 300;
  font-size: .95rem;
  padding-left: 2.2rem;
}

/* ---------- 页脚 ---------- */
footer {
  padding: 3rem 1rem;
  text-align: center;
  color: var(--gray);
  font-size: .8rem;
  letter-spacing: .1em;
}

/* ---------- 响应式 ---------- */
@media (max-width: 760px) {
  .ghost { font-size: clamp(90px, 30vw, 180px); }
}

@media (max-height: 640px) {
  .section, .hero { padding-top: 4.5rem; padding-bottom: 4.5rem; }
  .rows { margin-top: 1.8rem; }
}

@media (max-width: 480px) {
  html { font-size: 15px; }
  .title { font-size: 2rem; }
  .ghost { display: none; }
}