/* ============================================================
 * 极客实验室 GeekLab 产品展示站 - 全局样式
 * 风格：深色科技风（与 board.geekrobot.com.cn 同设计语言）
 * 页面：index.html（单页展示站）
 * 内容：导航 / Hero / 特性 / 流程 / 案例 / 画廊 / 积木分类 / CTA / 页脚 / 灯箱
 * ============================================================ */

/* ---------- 设计变量 ---------- */
:root {
  --bg: #0a0f1e;              /* 页面底色：深海军蓝 */
  --bg-soft: #101830;         /* 稍浅的区块底色 */
  --card: #141d38;            /* 卡片底色 */
  --card-hover: #1a2444;      /* 卡片悬停底色 */
  --border: #243156;          /* 卡片描边 */
  --primary: #22d3ee;         /* 主色：青 */
  --primary-deep: #0e9db8;    /* 主色加深（悬停） */
  --accent: #818cf8;          /* 点缀色：靛紫 */
  --text: #e8edf7;            /* 主文字 */
  --text-sub: #93a0bd;        /* 次要文字 */
  --text-dim: #5c6a8a;        /* 弱化文字 */
  --ok: #34d399;              /* 成功绿 */
  --warn: #fbbf24;            /* 警告黄 */
  --danger: #f87171;          /* 危险红 */
  --radius: 14px;             /* 卡片圆角 */
  --maxw: 1120px;             /* 内容最大宽度 */
}

/* ---------- 基础重置 ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: "Microsoft YaHei", "PingFang SC", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-deep); }

/* ---------- 顶部导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(10, 15, 30, .88);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--maxw); margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 20px; height: 60px;
}
.nav-logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 18px; font-weight: 700; color: var(--text);
}
/* 2026-09-21：logo 可见性——logo.png 是黑色图标+透明底，深蓝页面上
   几乎不可见 → filter:invert(1) 把黑色反转成白色（透明区不受影响），
   白色徽章图案落在深蓝底上对比清晰，与整站深色风格融为一体 */
.nav-logo img {
  width: 38px; height: 38px;
  filter: invert(1);
  transition: filter .2s;
}
.nav-logo:hover img { filter: invert(1) brightness(1.25); }
.nav-logo small { font-size: 12px; color: var(--text-sub); font-weight: 400; }
.nav-links { display: flex; gap: 6px; align-items: center; }
.nav-links a {
  color: var(--text-sub); font-size: 14px;
  padding: 7px 14px; border-radius: 8px;
  transition: .2s;
}
.nav-links a:hover { color: var(--text); background: var(--card); }
.nav-links a.active { color: var(--primary); background: rgba(34, 211, 238, .1); }
.nav-cta {
  background: var(--primary); color: #06222a !important;
  font-weight: 600;
}
.nav-cta:hover { background: var(--primary-deep); }
/* 移动端菜单按钮 */
.nav-toggle {
  display: none; background: none; border: 1px solid var(--border);
  color: var(--text); font-size: 20px; border-radius: 8px;
  width: 40px; height: 40px; cursor: pointer;
}
@media (max-width: 720px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none; position: absolute; top: 60px; left: 0; right: 0;
    flex-direction: column; background: var(--bg-soft);
    border-bottom: 1px solid var(--border); padding: 10px;
  }
  .nav-links.open { display: flex; }
  .nav-links a { width: 100%; text-align: center; }
}

/* ---------- Hero 首屏 ---------- */
.hero {
  position: relative; overflow: hidden;
  padding: 90px 20px 70px; text-align: center;
  background:
    radial-gradient(ellipse 60% 50% at 50% -10%, rgba(34, 211, 238, .16), transparent),
    radial-gradient(ellipse 40% 40% at 85% 30%, rgba(129, 140, 248, .12), transparent);
}
.hero-badge {
  display: inline-block; font-size: 13px; color: var(--primary);
  border: 1px solid rgba(34, 211, 238, .4); border-radius: 999px;
  padding: 4px 16px; margin-bottom: 22px;
  background: rgba(34, 211, 238, .08);
}
.hero h1 { font-size: 44px; letter-spacing: 2px; margin-bottom: 14px; }
.hero h1 .grad {
  background: linear-gradient(90deg, var(--primary), var(--accent));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-sub {
  font-size: 17px; color: var(--text-sub);
  max-width: 640px; margin: 0 auto 34px;
}
.hero-btns { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 12px 30px; border-radius: 10px;
  font-size: 15px; font-weight: 600; transition: .2s; cursor: pointer;
  border: 1px solid transparent;
}
.btn-primary { background: var(--primary); color: #06222a; }
.btn-primary:hover { background: var(--primary-deep); color: #06222a; }
.btn-ghost { border-color: var(--border); color: var(--text); background: var(--card); }
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); }

/* Hero 下的主视觉截图 */
.hero-img { max-width: 960px; margin: 50px auto 0; }

/* ---------- 截图框架（真实截图展示容器） ---------- */
.shot-frame {
  border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--card); overflow: hidden;
  box-shadow: 0 18px 50px rgba(0, 0, 0, .45);
}
.shot-frame img { width: 100%; height: auto; }
.shot-frame figcaption {
  padding: 12px 16px; font-size: 13px; color: var(--text-sub);
  border-top: 1px solid var(--border); text-align: center;
}

/* ---------- 通用区块 ---------- */
.section { padding: 72px 20px; }
/* 锚点跳转时为 sticky 导航（60px）预留偏移，避免标题被遮挡 */
section[id] { scroll-margin-top: 76px; }
.section:nth-of-type(even) { background: var(--bg-soft); }
.container { max-width: var(--maxw); margin: 0 auto; }
.sec-head { text-align: center; margin-bottom: 46px; }
.sec-title { font-size: 30px; margin-bottom: 10px; }
.sec-title::after {
  content: ""; display: block; width: 48px; height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  margin: 12px auto 0; border-radius: 2px;
}
.sec-sub { color: var(--text-sub); font-size: 15px; }

/* ---------- 特性卡片网格 ---------- */
.grid { display: grid; gap: 18px; }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 900px) { .grid-4 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .grid-4 { grid-template-columns: 1fr; } }

/* 三列卡片网格（2026-09-21 作品馆 tab 展示页） */
.grid-3 { grid-template-columns: repeat(3, 1fr); }
@media (max-width: 900px) { .grid-3 { grid-template-columns: 1fr; } }

.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 26px 22px;
  transition: .25s;
}
.card:hover {
  background: var(--card-hover);
  border-color: rgba(34, 211, 238, .45);
  transform: translateY(-3px);
}
.card .ico {
  width: 46px; height: 46px; border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(34, 211, 238, .12); color: var(--primary);
  margin-bottom: 16px;
}
.card .ico svg { width: 24px; height: 24px; }
.card h3 { font-size: 17px; margin-bottom: 8px; }
.card p { font-size: 14px; color: var(--text-sub); }

/* ---------- 步骤列表（工作流程） ---------- */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; counter-reset: step; }
@media (max-width: 900px) { .steps { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .steps { grid-template-columns: 1fr; } }
.step {
  position: relative; background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 24px 20px 20px;
}
.step::before {
  counter-increment: step; content: counter(step);
  position: absolute; top: -14px; left: 20px;
  width: 28px; height: 28px; border-radius: 50%;
  background: var(--primary); color: #06222a;
  font-weight: 700; font-size: 14px;
  display: flex; align-items: center; justify-content: center;
}
.step h3 { font-size: 16px; margin: 6px 0 8px; }
.step p { font-size: 13.5px; color: var(--text-sub); }

/* ---------- 案例展示（图文交替行） ---------- */
.case-row {
  display: grid; grid-template-columns: 1.25fr 1fr; gap: 40px;
  align-items: center; margin-bottom: 64px;
}
.case-row:last-child { margin-bottom: 0; }
.case-reverse .case-shot { order: 2; }
.case-reverse .case-info { order: 1; }
@media (max-width: 860px) {
  .case-row { grid-template-columns: 1fr; gap: 22px; }
  .case-reverse .case-shot { order: 0; }
  .case-reverse .case-info { order: 1; }
}
.case-shot {
  border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; background: var(--card);
  box-shadow: 0 12px 36px rgba(0, 0, 0, .35);
  cursor: zoom-in;
  transition: .25s;
}
.case-shot:hover { border-color: rgba(34, 211, 238, .45); transform: translateY(-3px); }
.case-shot img { width: 100%; height: auto; }
.case-tag {
  display: inline-block; font-size: 12.5px; color: var(--primary);
  border: 1px solid rgba(34, 211, 238, .4); border-radius: 999px;
  padding: 3px 12px; margin-bottom: 12px;
  background: rgba(34, 211, 238, .08);
}
.case-info h3 { font-size: 24px; margin-bottom: 10px; }
.case-info > p { font-size: 14.5px; color: var(--text-sub); margin-bottom: 14px; }
.case-points { list-style: none; }
.case-points li {
  position: relative; font-size: 14px; color: var(--text-sub);
  padding-left: 22px; margin-bottom: 8px;
}
.case-points li::before {
  content: ""; position: absolute; left: 0; top: 9px;
  width: 8px; height: 8px; border-radius: 2px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
}

/* ---------- 界面预览画廊 ---------- */
.gallery-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px;
}
@media (max-width: 900px) { .gallery-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .gallery-grid { grid-template-columns: 1fr; } }
.g-item {
  border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; background: var(--card);
  cursor: zoom-in; transition: .25s;
}
.g-item:hover { border-color: rgba(34, 211, 238, .45); transform: translateY(-3px); }
.g-item img { width: 100%; aspect-ratio: 16 / 10; object-fit: cover; object-position: top; }
.g-item figcaption {
  padding: 10px 14px; font-size: 13px; color: var(--text-sub);
  border-top: 1px solid var(--border);
}

/* ---------- 积木分类标签云 ---------- */
.block-tags {
  display: flex; flex-wrap: wrap; gap: 12px; justify-content: center;
  max-width: 860px; margin: 0 auto;
}
.btag {
  font-size: 14px; padding: 8px 18px; border-radius: 999px;
  border: 1px solid var(--border); background: var(--card);
  color: var(--text-sub); transition: .2s;
}
.btag:hover { transform: translateY(-2px); color: var(--text); }
/* 各分类配色取自软件内积木实际配色 */
.bt-net    { border-color: rgba(34, 211, 238, .5); }
.bt-evt    { border-color: rgba(251, 191, 36, .5); }
.bt-led    { border-color: rgba(244, 114, 182, .5); }
.bt-io     { border-color: rgba(52, 211, 153, .5); }
.bt-motor  { border-color: rgba(96, 165, 250, .5); }
.bt-voice  { border-color: rgba(167, 139, 250, .6); }
.bt-lcd    { border-color: rgba(45, 212, 191, .5); }
.bt-sensor { border-color: rgba(251, 146, 60, .5); }
.bt-sys    { border-color: rgba(148, 163, 184, .5); }
.bt-ctrl   { border-color: rgba(59, 130, 246, .5); }
.bt-math   { border-color: rgba(34, 197, 94, .5); }
.bt-var    { border-color: rgba(232, 121, 249, .5); }
.bt-text   { border-color: rgba(20, 184, 166, .5); }
.bt-conv   { border-color: rgba(100, 116, 139, .5); }
.bt-list   { border-color: rgba(59, 130, 246, .5); }
.bt-func   { border-color: rgba(168, 85, 247, .5); }

/* ---------- 灯箱（点击查看大图） ---------- */
.lightbox {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(5, 8, 18, .92);
  display: none; align-items: center; justify-content: center;
  padding: 40px 20px;
}
.lightbox.open { display: flex; }
.lightbox img {
  max-width: 94vw; max-height: 90vh;
  border-radius: 10px; border: 1px solid var(--border);
  box-shadow: 0 24px 80px rgba(0, 0, 0, .6);
}
.lightbox-close {
  position: absolute; top: 18px; right: 24px;
  width: 44px; height: 44px; border-radius: 50%;
  background: var(--card); border: 1px solid var(--border);
  color: var(--text); font-size: 24px; cursor: pointer;
  transition: .2s;
}
.lightbox-close:hover { border-color: var(--primary); color: var(--primary); }

/* ---------- 页脚 ---------- */
.footer {
  border-top: 1px solid var(--border);
  padding: 36px 20px 30px; text-align: center;
  color: var(--text-dim); font-size: 13px;
}
.footer .foot-links { margin-bottom: 12px; display: flex; gap: 20px; justify-content: center; flex-wrap: wrap; }
.footer a { color: var(--text-sub); }
.footer a:hover { color: var(--primary); }

/* ---------- 滚动出现动画 ---------- */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .6s, transform .6s; }
.reveal.visible { opacity: 1; transform: none; }

/* 移动端 Hero 字号收紧 */
@media (max-width: 560px) {
  .hero h1 { font-size: 32px; }
  .hero-sub { font-size: 15px; }
  .sec-title { font-size: 24px; }
}