/* ============================================================
   FreeCoder 官网宣传页 · 纯静态样式
   深色开发者风格 · 无外部依赖
   ============================================================ */

:root {
  --bg: #070b14;
  --bg-soft: #0b1020;
  --panel: rgba(255, 255, 255, 0.04);
  --panel-strong: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.09);
  --border-strong: rgba(255, 255, 255, 0.16);
  --text: #e8ecf6;
  --text-dim: #9aa4bd;
  --text-faint: #6b7691;
  --indigo: #6366f1;
  --cyan: #22d3ee;
  --violet: #a78bfa;
  --grad: linear-gradient(120deg, #6366f1, #22d3ee);
  --radius: 16px;
  --maxw: 1120px;
  --nav-h: 68px;
}

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

html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei",
    "Noto Sans SC", -apple-system, "Segoe UI", Roboto, sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

::selection { background: rgba(99, 102, 241, 0.45); }

a { color: inherit; text-decoration: none; }

/* ---------- 导航 ---------- */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 50;
  height: var(--nav-h);
  background: rgba(7, 11, 20, 0.78);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav.scrolled { background: rgba(7, 11, 20, 0.92); }

.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  height: 100%;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 28px;
}

.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; letter-spacing: 0.2px; }
.brand-logo { display: inline-flex; filter: drop-shadow(0 0 10px rgba(99, 102, 241, 0.5)); }

.nav-links { display: flex; gap: 26px; margin-left: auto; }
.nav-links a {
  color: var(--text-dim);
  font-size: 15px;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }

.nav-actions { display: flex; align-items: center; gap: 12px; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 9px 10px;
  cursor: pointer;
}
.nav-toggle span { display: block; width: 18px; height: 2px; background: var(--text); border-radius: 2px; transition: 0.25s; }
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.2s, background 0.2s, border-color 0.2s;
  white-space: nowrap;
}
.btn:active { transform: scale(0.97); }

.btn-primary {
  background: var(--grad);
  color: #fff;
  box-shadow: 0 8px 26px rgba(99, 102, 241, 0.35);
}
.btn-primary:hover { box-shadow: 0 10px 34px rgba(99, 102, 241, 0.5); transform: translateY(-1px); }

.btn-ghost {
  background: var(--panel);
  border-color: var(--border-strong);
  color: var(--text);
}
.btn-ghost:hover { background: var(--panel-strong); border-color: rgba(255, 255, 255, 0.28); }

.btn-sm { padding: 8px 16px; font-size: 14px; border-radius: 10px; }
.btn-lg { padding: 14px 30px; font-size: 16px; border-radius: 14px; }

/* ---------- Hero ---------- */
.hero { position: relative; padding: calc(var(--nav-h) + 72px) 24px 40px; overflow: hidden; }

.hero-bg { position: absolute; inset: 0; pointer-events: none; }
.orb { position: absolute; border-radius: 50%; filter: blur(90px); opacity: 0.55; }
.orb-1 { width: 560px; height: 560px; background: rgba(99, 102, 241, 0.4); top: -220px; left: -140px; }
.orb-2 { width: 480px; height: 480px; background: rgba(34, 211, 238, 0.3); top: 60px; right: -180px; }
.grid-lines {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.035) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 90% 70% at 50% 0%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 90% 70% at 50% 0%, #000 30%, transparent 75%);
}

.hero-inner {
  position: relative;
  max-width: var(--maxw);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 48px;
}

.hero-copy {
  text-align: center;
  max-width: 720px;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  max-width: 100%;
  padding: 7px 14px;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  background: var(--panel);
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-dim);
  margin-bottom: 22px;
}
.dot { width: 8px; height: 8px; border-radius: 50%; background: #34d399; box-shadow: 0 0 10px #34d399; animation: pulse 2.2s infinite; }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.35; } }

.hero h1 {
  font-size: clamp(34px, 4.6vw, 54px);
  line-height: 1.22;
  letter-spacing: -0.5px;
  font-weight: 800;
  background: linear-gradient(180deg, #fff 30%, #b9c2dd);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 22px;
}

.lead { font-size: 17px; color: var(--text-dim); max-width: 620px; margin-bottom: 30px; margin-inline: auto; }
.lead strong { color: var(--text); font-weight: 600; }

.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 18px; justify-content: center; }

.hero-meta { font-size: 13.5px; color: var(--text-faint); }

/* ---------- 产品窗口模拟 ---------- */
.mock { position: relative; width: 100%; max-width: 960px; margin: 0 auto; }

.mock-window {
  border: 1px solid var(--border-strong);
  border-radius: 14px;
  background: rgba(13, 18, 33, 0.85);
  box-shadow: 0 40px 90px rgba(0, 0, 0, 0.55), 0 0 0 1px rgba(255,255,255,0.03) inset;
  overflow: hidden;
  backdrop-filter: blur(6px);
  display: flex;
  flex-direction: column;
  aspect-ratio: 16 / 9;
}

.mock-titlebar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 11px 14px;
  background: rgba(255, 255, 255, 0.04);
  border-bottom: 1px solid var(--border);
}
.traffic { display: flex; gap: 6px; }
.traffic i { width: 11px; height: 11px; border-radius: 50%; background: #ff5f57; display: block; }
.traffic i:nth-child(2) { background: #febc2e; }
.traffic i:nth-child(3) { background: #28c840; }
.mock-titlebar .title { font-size: 12.5px; color: var(--text-dim); min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

.mock-body { display: grid; grid-template-columns: 140px 1fr; flex: 1; min-height: 0; }

.mock-main { display: grid; grid-template-columns: 1fr 1fr; min-height: 0; }

.mock-preview {
  border-left: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  background: rgba(255, 255, 255, 0.02);
  overflow: hidden;
}
.preview-bar {
  display: flex; align-items: center; gap: 8px;
  padding: 8px 14px;
  border-bottom: 1px solid var(--border);
  font-size: 11.5px; color: var(--text-faint);
}
.preview-dot { width: 7px; height: 7px; border-radius: 50%; background: #34d399; box-shadow: 0 0 6px #34d399; }
.preview-url { font-family: "SF Mono", "Fira Code", monospace; letter-spacing: 0.3px; }
.preview-content { padding: 14px; display: flex; flex-direction: column; gap: 10px; flex: 1; }
.preview-card {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
}
.preview-card-head { font-size: 12px; font-weight: 700; margin-bottom: 8px; color: var(--text); }
.preview-card-row {
  display: flex; justify-content: space-between; align-items: center;
  font-size: 11.5px; color: var(--text-dim); padding: 4px 0;
}
.preview-card-row.dim { opacity: 0.5; }
.preview-card-row .check { color: #34d399; font-weight: 700; }
.preview-card-sm { flex: 1; }
.preview-bars { display: flex; flex-direction: column; gap: 6px; margin-top: 4px; }
.pbar {
  height: 6px; border-radius: 3px;
  background: linear-gradient(90deg, var(--indigo), var(--cyan));
  width: var(--w);
  opacity: 0.7;
}

.mock-sidebar {
  border-right: 1px solid var(--border);
  padding: 14px 10px;
  font-size: 12.5px;
  color: var(--text-dim);
}
.sb-head { font-size: 11px; color: var(--text-faint); margin-bottom: 10px; padding-left: 8px; letter-spacing: 1px; }
.sb-item {
  display: flex; align-items: center; gap: 7px;
  padding: 7px 8px; border-radius: 8px; margin-bottom: 4px;
  overflow: hidden; white-space: nowrap;
}
.sb-item.active { background: rgba(99, 102, 241, 0.18); color: var(--text); }
.sb-dot { width: 7px; height: 7px; border-radius: 3px; background: var(--indigo); flex-shrink: 0; }
.sb-dot-2 { background: var(--cyan); }
.sb-dot-3 { background: var(--violet); }
.sb-new { padding: 8px; color: var(--cyan); margin-top: 8px; cursor: default; }

.mock-chat { padding: 16px; display: flex; flex-direction: column; gap: 12px; overflow: hidden; }

.msg {
  max-width: 88%;
  padding: 10px 13px;
  border-radius: 12px;
  font-size: 13px;
  line-height: 1.55;
}
.msg.user { align-self: flex-end; background: linear-gradient(120deg, #4f46e5, #6366f1); border-bottom-right-radius: 4px; }
.msg.ai { align-self: flex-start; background: rgba(255, 255, 255, 0.06); border: 1px solid var(--border); border-bottom-left-radius: 4px; }

.chips { display: flex; gap: 6px; margin-top: 9px; flex-wrap: wrap; }
.chips span {
  font-size: 11.5px; padding: 4px 10px; border-radius: 999px;
  background: rgba(34, 211, 238, 0.12); border: 1px solid rgba(34, 211, 238, 0.3);
  color: #7de7f8;
}

.msg.status { font-size: 12.5px; color: var(--text-dim); }
.msg.status .tick { color: #34d399; margin-right: 4px; }
.bar { height: 5px; border-radius: 3px; background: rgba(255, 255, 255, 0.08); margin: 8px 0 6px; overflow: hidden; }
.bar i { display: block; height: 100%; width: 65%; border-radius: 3px; background: var(--grad); animation: slide 1.6s ease-in-out infinite; }
@keyframes slide { 0% { width: 20%; } 60% { width: 80%; } 100% { width: 30%; } }

.mock-toast {
  align-self: center;
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 12.5px; font-weight: 600;
  padding: 8px 16px; border-radius: 999px;
  background: rgba(52, 211, 153, 0.12);
  border: 1px solid rgba(52, 211, 153, 0.35);
  color: #6ee7b7;
  animation: pop 0.4s ease;
}
@keyframes pop { from { transform: scale(0.8); opacity: 0; } to { transform: scale(1); opacity: 1; } }

.typing-slot { min-height: 42px; }

.typing-dots { display: inline-flex; gap: 5px; padding: 12px 14px; }
.typing-dots i { width: 7px; height: 7px; border-radius: 50%; background: var(--text-dim); animation: blink 1.2s infinite; }
.typing-dots i:nth-child(2) { animation-delay: 0.2s; }
.typing-dots i:nth-child(3) { animation-delay: 0.4s; }
@keyframes blink { 0%,80%,100% { opacity: 0.25; transform: translateY(0); } 40% { opacity: 1; transform: translateY(-3px); } }

.mock-float {
  position: absolute;
  background: rgba(15, 20, 36, 0.92);
  border: 1px solid var(--border-strong);
  border-radius: 12px;
  padding: 10px 14px;
  font-size: 12.5px;
  box-shadow: 0 18px 44px rgba(0, 0, 0, 0.5);
  animation: floaty 5s ease-in-out infinite;
}
.mock-float small { color: var(--text-dim); font-size: 11px; }
.float-1 { bottom: -22px; left: -26px; }
.float-2 { top: 44%; right: -30px; color: #7de7f8; animation-delay: 2.4s; }
@keyframes floaty { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }

/* ---------- 实时演示区块（Hero 下方） ---------- */
.demo {
  position: relative;
  padding: 96px 24px 112px;
  background: radial-gradient(760px 420px at 50% 26%, rgba(99, 102, 241, 0.1), transparent 70%);
}

/* ---------- 数据条 ---------- */
.stats { border-block: 1px solid var(--border); background: var(--bg-soft); }
.stats-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 30px 24px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px;
}
.stat { text-align: center; }
.stat b {
  display: block;
  font-size: clamp(28px, 3.4vw, 40px);
  font-weight: 800;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  line-height: 1.25;
}
.stat span { font-size: 14px; color: var(--text-dim); }

/* ---------- 通用章节 ---------- */
.section { padding: 96px 24px; }
.section-alt { background: var(--bg-soft); border-block: 1px solid var(--border); }

.section-head { text-align: center; max-width: 640px; margin: 0 auto 54px; }
.kicker {
  display: inline-block;
  font-size: 13px; font-weight: 600; letter-spacing: 2px;
  color: var(--cyan);
  margin-bottom: 12px;
}
.section-head h2 { font-size: clamp(26px, 3.4vw, 38px); font-weight: 800; letter-spacing: -0.4px; margin-bottom: 12px; }
.section-head p { color: var(--text-dim); font-size: 16px; }

/* ---------- 功能卡片 ---------- */
.cards { max-width: var(--maxw); margin: 0 auto; display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }

.card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px 26px;
  transition: transform 0.25s, border-color 0.25s, background 0.25s;
  position: relative;
  overflow: hidden;
}
.card::before {
  content: "";
  position: absolute; inset: 0 0 auto 0; height: 3px;
  background: var(--grad);
  opacity: 0;
  transition: opacity 0.25s;
}
.card:hover { transform: translateY(-5px); border-color: var(--border-strong); background: var(--panel-strong); }
.card:hover::before { opacity: 1; }

.card-icon {
  width: 52px; height: 52px; border-radius: 14px;
  display: grid; place-items: center;
  background: rgba(130, 140, 180, 0.14); /* 旧浏览器降级 */
  background: color-mix(in srgb, var(--ic) 16%, transparent);
  color: var(--ic);
  margin-bottom: 20px;
}
.card h3 { font-size: 19px; font-weight: 700; margin-bottom: 10px; }
.card > p { color: var(--text-dim); font-size: 14.5px; margin-bottom: 16px; }

.card-list { list-style: none; display: flex; flex-direction: column; gap: 7px; }
.card-list li { font-size: 13.5px; color: var(--text-dim); padding-left: 20px; position: relative; }
.card-list li::before {
  content: "✓";
  position: absolute; left: 0; top: 0;
  color: var(--cyan); font-weight: 700;
}

/* ---------- 步骤 ---------- */
.steps {
  max-width: var(--maxw); margin: 0 auto;
  display: grid; grid-template-columns: repeat(5, 1fr); gap: 18px;
  list-style: none; counter-reset: step;
}
.step {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 20px 24px;
  transition: transform 0.25s, border-color 0.25s;
}
.step:hover { transform: translateY(-4px); border-color: var(--border-strong); }
.step-num {
  display: inline-grid; place-items: center;
  width: 40px; height: 40px; border-radius: 12px;
  background: rgba(99, 102, 241, 0.15);
  border: 1px solid rgba(99, 102, 241, 0.4);
  color: #a5b4fc;
  font-weight: 800; font-size: 14px;
  margin-bottom: 16px;
}
.step h3 { font-size: 16.5px; font-weight: 700; margin-bottom: 8px; }
.step p { font-size: 13.5px; color: var(--text-dim); }

/* ---------- 为什么选择 ---------- */
.why-grid { max-width: var(--maxw); margin: 0 auto; display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.why {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 24px;
  transition: transform 0.25s, border-color 0.25s, background 0.25s;
}
.why:hover { transform: translateY(-4px); border-color: var(--border-strong); background: var(--panel-strong); }
.why-icon { font-size: 26px; display: block; margin-bottom: 14px; }
.why h3 { font-size: 17px; font-weight: 700; margin-bottom: 8px; }
.why p { font-size: 14px; color: var(--text-dim); }

/* ---------- 技术栈 ---------- */
.tech-list {
  max-width: 860px; margin: 0 auto;
  display: flex; flex-wrap: wrap; justify-content: center; gap: 14px;
}
.tech-list span {
  padding: 10px 20px;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  background: var(--panel);
  font-size: 15px; font-weight: 600; color: var(--text);
  transition: border-color 0.2s, background 0.2s;
}
.tech-list span:hover { border-color: rgba(99, 102, 241, 0.6); background: rgba(99, 102, 241, 0.1); }
.tech-list span.tech-chip-featured {
  border-color: rgba(99, 102, 241, 0.75);
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.24), rgba(34, 211, 238, 0.14));
  color: #dfe4ff;
  box-shadow: inset 0 0 0 1px rgba(99, 102, 241, 0.25), 0 6px 24px rgba(99, 102, 241, 0.18);
}

/* 核心引擎卡片（DeepSeek Harness / DSH） */
.engine-card {
  max-width: 860px;
  margin: 28px auto 0;
  display: flex;
  align-items: flex-start;
  gap: 18px;
  padding: 22px 24px;
  border-radius: var(--radius);
  border: 1px solid rgba(99, 102, 241, 0.38);
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.12), rgba(34, 211, 238, 0.05));
  text-align: left;
}
.engine-icon { font-size: 26px; line-height: 1; flex-shrink: 0; }
.engine-card h3 { font-size: 16.5px; font-weight: 700; margin-bottom: 6px; }
.engine-card p { font-size: 14px; color: var(--text-dim); line-height: 1.65; margin-bottom: 14px; }
.engine-card p strong { color: var(--text); }

/* ---------- 安装指南 ---------- */
.guide { max-width: var(--maxw); margin: 0 auto; }

.guide-grid {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  margin-bottom: 28px;
}

.guide-step {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 26px 28px;
  text-align: center;
  transition: transform 0.25s, border-color 0.25s, background 0.25s;
}
.guide-step:hover { transform: translateY(-4px); border-color: var(--border-strong); background: var(--panel-strong); }

.guide-num {
  position: absolute;
  top: 16px; left: 18px;
  display: grid; place-items: center;
  width: 34px; height: 34px; border-radius: 50%;
  background: rgba(99, 102, 241, 0.15);
  border: 1px solid rgba(99, 102, 241, 0.4);
  color: #a5b4fc;
  font-weight: 800; font-size: 15px;
}
.guide-icon { font-size: 34px; display: block; margin-bottom: 14px; }
.guide-step h3 { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.guide-step p { font-size: 14px; color: var(--text-dim); }
.guide-step a { color: var(--cyan); text-decoration: underline; text-underline-offset: 3px; }

.req-card {
  max-width: 760px; margin: 0 auto;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 30px;
}
.req-card strong { display: block; margin-bottom: 12px; font-size: 15px; }
.req-card ul { list-style: none; display: flex; flex-direction: column; gap: 9px; }
.req-card li { font-size: 14px; color: var(--text-dim); }

/* ---------- 跳转链接（无障碍） ---------- */
.skip-link {
  position: fixed;
  top: -48px; left: 16px; z-index: 100;
  padding: 10px 18px; border-radius: 0 0 10px 10px;
  background: var(--indigo); color: #fff;
  font-weight: 600; font-size: 14px;
  transition: top 0.2s;
}
.skip-link:focus { top: 0; }

/* ---------- 常见问题 ---------- */
.faq { max-width: 760px; margin: 0 auto; display: flex; flex-direction: column; gap: 12px; }

.faq-item {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  transition: border-color 0.2s, background 0.2s;
}
.faq-item:hover { border-color: var(--border-strong); }
.faq-item[open] { background: var(--panel-strong); }

.faq-item summary {
  cursor: pointer;
  list-style: none;
  padding: 18px 22px;
  font-size: 16px; font-weight: 600;
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  font-size: 22px; font-weight: 400; color: var(--cyan);
  transition: transform 0.25s;
  flex-shrink: 0; line-height: 1;
}
.faq-item[open] summary::after { transform: rotate(45deg); }

.faq-item p { padding: 0 22px 18px; font-size: 14.5px; color: var(--text-dim); }

/* ---------- 下载 ---------- */
.download { padding-top: 40px; }
.download-card {
  max-width: 860px; margin: 0 auto;
  text-align: center;
  background:
    radial-gradient(600px 300px at 50% 0%, rgba(99, 102, 241, 0.22), transparent 70%),
    var(--panel);
  border: 1px solid var(--border-strong);
  border-radius: 24px;
  padding: 64px 40px;
}
.download-card h2 { font-size: clamp(26px, 3.4vw, 36px); font-weight: 800; margin-bottom: 14px; }
.download-card > p { color: var(--text-dim); font-size: 16px; max-width: 560px; margin: 0 auto 30px; }
.download-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-bottom: 22px; }
.download-note { font-size: 13px; color: var(--text-faint); }

/* ---------- 页脚 ---------- */
.footer { border-top: 1px solid var(--border); padding: 44px 24px; background: var(--bg-soft); }
.footer-inner { max-width: var(--maxw); margin: 0 auto; text-align: center; }
.footer-brand { display: flex; align-items: center; justify-content: center; gap: 10px; font-weight: 700; font-size: 17px; margin-bottom: 10px; }
.footer-tagline { color: var(--text-dim); font-size: 14px; margin-bottom: 18px; }
.footer-links { display: flex; justify-content: center; flex-wrap: wrap; gap: 24px; margin-bottom: 18px; }
.footer-links a { color: var(--text-dim); font-size: 14px; transition: color 0.2s; }
.footer-links a:hover { color: var(--cyan); }
.footer-legal { font-size: 12.5px; color: var(--text-faint); }

/* ---------- 滚动显现动画 ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.visible { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .orb, .mock-float, .bar i, .dot { animation: none; }
}

/* ---------- 响应式 ---------- */
@media (max-width: 980px) {
  .nav-links {
    position: absolute; top: var(--nav-h); left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: rgba(7, 11, 20, 0.97);
    border-bottom: 1px solid var(--border);
    padding: 8px 0;
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 13px 24px; font-size: 16px; }
  .nav-toggle { display: flex; }

  .hero { padding-top: calc(var(--nav-h) + 56px); }
  .hero-copy { text-align: center; }
  .mock { max-width: 560px; }
  .mock-window { aspect-ratio: 4 / 3; }
  .float-1 { left: -10px; }
  .float-2 { right: -8px; }
  .cards { grid-template-columns: 1fr; max-width: 560px; }
  .steps { grid-template-columns: 1fr; max-width: 560px; }
  .guide-grid { grid-template-columns: 1fr; max-width: 560px; }
  .why-grid { grid-template-columns: 1fr; max-width: 560px; }
  .stats-inner { grid-template-columns: repeat(2, 1fr); gap: 26px; }
}

@media (max-width: 760px) {
  .section { padding: 72px 20px; }
  .demo { padding: 72px 20px 96px; }
  .mock-body { grid-template-columns: 1fr; }
  .mock-sidebar { display: none; }
  .mock-main { grid-template-columns: 1fr; }
  .mock-preview { display: none; }
  .mock-window { aspect-ratio: auto; height: 500px; }
  .engine-card { flex-direction: column; }
}

/* 窄屏手机：导航只保留汉堡按钮，CTA 移交给页面内下载区 */
@media (max-width: 480px) {
  .nav-actions .btn { display: none; }
  .download-card { padding: 48px 24px; }
  .footer-links { gap: 14px 22px; }
}