/* ============================================================
   林宇 · 自动化工具站 — 象牙白 · 极简奢华（editorial luxury）
   暖白底 · 墨黑字 · 大留白 · 极少量深绿点缀
   ============================================================ */

:root {
  --bg: #F7F6F3;          /* 象牙 */
  --bg-2: #FFFFFF;        /* 卡片纯白 */
  --fg: #15171A;          /* 墨黑 */
  --muted: #6B6F76;       /* 次文 */
  --muted-2: #9A9DA3;     /* 更淡 */
  --line: #E7E4DD;        /* 发丝描边 */
  --line-2: #D9D5CC;
  --accent: #2F4A3A;      /* 深森绿，仅极少量点缀 */
  --accent-soft: #41614E;
  --radius: 18px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --maxw: 1100px;
  --serif: "Songti SC", "STSong", Georgia, "Times New Roman", "PingFang SC", serif;
  font-synthesis: none;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "Helvetica Neue", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  letter-spacing: -0.011em;
}

a { color: inherit; text-decoration: none; }
code {
  font-family: "SF Mono", ui-monospace, "JetBrains Mono", Menlo, monospace;
  font-size: 0.86em;
  background: #EFEDE7;
  border: 1px solid var(--line);
  padding: 0.12em 0.45em;
  border-radius: 6px;
  color: #3a3d42;
}

/* ---------- 纸质背景层（去掉所有彩色光晕，只留极淡暖光 + 颗粒） ---------- */
.aurora {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  background:
    radial-gradient(1100px 720px at 78% -8%, rgba(47, 74, 58, 0.045), transparent 62%),
    radial-gradient(900px 640px at 6% 102%, rgba(120, 110, 90, 0.05), transparent 60%),
    var(--bg);
}
.orb { display: none; }   /* 彩色球体废弃 */
.grain {
  position: absolute;
  inset: -50%;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.4'/%3E%3C/svg%3E");
  opacity: 0.02;
  pointer-events: none;
}

/* ---------- 导航 ---------- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px clamp(20px, 5vw, 56px);
  backdrop-filter: saturate(160%) blur(16px);
  -webkit-backdrop-filter: saturate(160%) blur(16px);
  background: rgba(247, 246, 243, 0.6);
  border-bottom: 1px solid transparent;
  transition: border-color 0.4s, background 0.4s;
}
.nav.scrolled { border-bottom-color: var(--line); background: rgba(247, 246, 243, 0.82); }
.nav-brand { font-weight: 700; font-size: 1.02rem; letter-spacing: 0.005em; }
.nav-brand span { color: var(--muted); font-weight: 500; margin-left: 5px; }
.nav-links { display: flex; align-items: center; gap: clamp(16px, 3vw, 36px); font-size: 0.93rem; }
.nav-links a { color: var(--muted); transition: color 0.25s; }
.nav-links a:hover { color: var(--fg); }
.nav-cta {
  color: var(--bg) !important;
  background: var(--fg);
  padding: 8px 17px;
  border-radius: 999px;
  transition: transform 0.25s, background 0.25s;
}
.nav-cta:hover { background: #000; transform: translateY(-1px); }

/* ---------- Hero ---------- */
.hero {
  min-height: 100svh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 130px clamp(20px, 5vw, 56px) 90px;
  position: relative;
}
.hero-inner { max-width: 880px; }
.eyebrow {
  font-size: 0.76rem;
  letter-spacing: 0.34em;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 30px;
  text-transform: uppercase;
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.eyebrow::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
}
.hero-title {
  font-family: var(--serif);
  font-size: clamp(2.9rem, 8.2vw, 6rem);
  font-weight: 600;
  line-height: 1.04;
  letter-spacing: -0.015em;
  margin-bottom: 30px;
}
.grad {
  /* 极简奢华不用彩色渐变——点缀色用深绿，克制 */
  color: var(--accent);
  background: none;
  -webkit-text-fill-color: currentColor;
}
.hero-sub {
  font-size: clamp(1.05rem, 2.1vw, 1.32rem);
  color: var(--muted);
  max-width: 600px;
  margin: 0 auto 46px;
  font-weight: 400;
  line-height: 1.7;
}
.hero-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.hero-stat { margin-top: 46px; color: var(--muted-2); font-size: 0.9rem; letter-spacing: 0.04em; }

/* ---------- 按钮 ---------- */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 0.98rem;
  font-weight: 600;
  padding: 14px 30px;
  border-radius: 999px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.3s var(--ease), box-shadow 0.3s, background 0.3s, border-color 0.3s;
  overflow: hidden;
}
.btn-primary {
  color: var(--bg);
  background: var(--fg);
  box-shadow: 0 10px 28px -14px rgba(21, 23, 26, 0.65);
}
.btn-primary::after {
  content: "";
  position: absolute;
  top: 0; left: -120%;
  width: 55%; height: 100%;
  background: linear-gradient(100deg, transparent, rgba(255, 255, 255, 0.22), transparent);
  transform: skewX(-20deg);
  transition: left 0.7s var(--ease);
}
.btn-primary:hover { transform: translateY(-2px); background: #000; box-shadow: 0 16px 36px -14px rgba(21, 23, 26, 0.8); }
.btn-primary:hover::after { left: 130%; }
.btn-ghost {
  color: var(--fg);
  border-color: var(--line-2);
  background: rgba(255, 255, 255, 0.5);
}
.btn-ghost:hover { background: #fff; border-color: var(--fg); transform: translateY(-2px); }

/* ---------- 滚动提示 ---------- */
.scroll-hint {
  position: absolute;
  bottom: 36px; left: 50%;
  transform: translateX(-50%);
  width: 23px; height: 37px;
  border: 1.5px solid var(--line-2);
  border-radius: 14px;
}
.scroll-hint span {
  position: absolute;
  top: 8px; left: 50%;
  width: 3px; height: 7px;
  margin-left: -1.5px;
  background: var(--muted-2);
  border-radius: 2px;
  animation: scroll-dot 1.8s var(--ease) infinite;
}
@keyframes scroll-dot { 0% { opacity: 0; transform: translateY(0); } 40% { opacity: 1; } 80% { opacity: 0; transform: translateY(12px); } }

/* ---------- Section ---------- */
.section { max-width: var(--maxw); margin: 0 auto; padding: clamp(72px, 12vw, 150px) clamp(20px, 5vw, 56px); }
.section-head { max-width: 640px; margin-bottom: 64px; }
.section-head h2 {
  font-family: var(--serif);
  font-size: clamp(2rem, 5vw, 3.1rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 18px;
}
.section-head p { color: var(--muted); font-size: clamp(1rem, 2vw, 1.16rem); line-height: 1.7; }

/* ---------- 卡片网格 ---------- */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(330px, 1fr));
  gap: 24px;
}
.card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 32px;
  border-radius: var(--radius);
  background: var(--bg-2);
  border: 1px solid var(--line);
  box-shadow: 0 1px 2px rgba(21, 23, 26, 0.03);
  transition: transform 0.45s var(--ease), border-color 0.45s, box-shadow 0.45s;
}
.card:hover {
  transform: translateY(-5px);
  border-color: var(--line-2);
  box-shadow: 0 26px 50px -28px rgba(21, 23, 26, 0.28);
}
.card-icon {
  width: 54px; height: 54px;
  display: grid; place-items: center;
  font-size: 1.55rem;
  border-radius: 14px;
  background: var(--fg);
  margin-bottom: 24px;
}
.card-name { font-size: 1.38rem; font-weight: 700; letter-spacing: -0.015em; }
.card-sub { color: var(--accent); font-size: 0.88rem; margin-top: 4px; font-weight: 500; }
.card-desc { color: var(--muted); font-size: 0.96rem; margin: 16px 0 20px; flex-grow: 1; line-height: 1.65; }
.card-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 24px; }
.tag {
  font-size: 0.75rem;
  color: #5a5e66;
  padding: 5px 11px;
  border-radius: 999px;
  background: #F2F0EB;
  border: 1px solid var(--line);
}
.card-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}
.card-meta { font-size: 0.8rem; color: var(--muted-2); display: flex; gap: 12px; }
.card-meta b { color: var(--muted); font-weight: 600; }
.dl {
  display: inline-flex; align-items: center; gap: 7px;
  font-weight: 600; font-size: 0.9rem;
  padding: 10px 18px;
  border-radius: 999px;
  color: var(--bg);
  background: var(--fg);
  transition: transform 0.3s var(--ease), background 0.3s;
  white-space: nowrap;
}
.dl:hover { transform: translateY(-2px); background: #000; }
.dl svg { width: 15px; height: 15px; }

/* ---------- 步骤 ---------- */
.steps {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 22px;
}
.step {
  padding: 34px 30px;
  border-radius: var(--radius);
  background: var(--bg-2);
  border: 1px solid var(--line);
}
.step-no {
  font-family: var(--serif);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--accent);
}
.step h3 { font-size: 1.22rem; margin: 14px 0 10px; font-weight: 650; }
.step p { color: var(--muted); font-size: 0.96rem; line-height: 1.65; }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--line); padding: 64px clamp(20px, 5vw, 56px); }
.footer-inner { max-width: var(--maxw); margin: 0 auto; text-align: center; }
.footer-brand { font-family: var(--serif); font-weight: 600; font-size: 1.1rem; margin-bottom: 8px; }
.footer-note { color: var(--muted-2); font-size: 0.88rem; }

/* ---------- 滚动揭示动画 ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.9s var(--ease), transform 0.9s var(--ease); }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .scroll-hint span { animation: none; }
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

@media (max-width: 640px) {
  .nav-links a:not(.nav-cta) { display: none; }
  .grid { grid-template-columns: 1fr; }
  .card { padding: 26px; }
}