/* ============================================================
   demo-module.css — 智然乐芯 模块展示页面公共样式
   ============================================================ */

:root {
  --brand:      #0f766e;
  --brand-dark: #064e49;
  --brand-2:    #1d4ed8;
  --ink:        #1a2a3a;
  --muted:      #4b6070;
  --line:       #d8e4ee;
  --bg:         #f4f8fc;
  --card:       #ffffff;
  --shadow:     0 8px 28px rgba(15,118,110,.10);
  --shadow-lg:  0 20px 60px rgba(15,118,110,.14);
  --radius:     18px;
  --radius-sm:  10px;
}

*, *::before, *::after { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI Variable", "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
}

/* ── 顶部导航 ── */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}
.topbar-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 20px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand { display: flex; align-items: baseline; gap: 8px; }
.brand-cn { font-size: 20px; font-weight: 700; color: var(--brand); }
.brand-en { font-size: 13px; color: var(--muted); letter-spacing: .06em; }
.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px;
  border: 1px solid var(--line);
  border-radius: 99px;
  background: var(--card);
  color: var(--ink);
  text-decoration: none;
  font-size: 14px;
  transition: background .15s, border-color .15s;
}
.back-btn:hover { background: #f0f6f9; border-color: var(--brand); }

/* ── Hero 区 ── */
.hero {
  background: linear-gradient(135deg, var(--brand-dark) 0%, #0c5682 55%, var(--brand-2) 100%);
  color: #fff;
  padding: 72px 20px 64px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: -40% -20%;
  background: radial-gradient(ellipse at 50% 50%, rgba(255,255,255,.06), transparent 55%);
  pointer-events: none;
}
.hero-badge {
  display: inline-block;
  background: rgba(255,255,255,.15);
  border: 1px solid rgba(255,255,255,.25);
  border-radius: 99px;
  padding: 4px 16px;
  font-size: 12px;
  letter-spacing: .1em;
  text-transform: uppercase;
  margin-bottom: 18px;
}
.hero h1 {
  margin: 0 0 16px;
  font-size: clamp(32px, 6vw, 56px);
  font-weight: 800;
  letter-spacing: -.01em;
  line-height: 1.1;
}
.hero-sub {
  max-width: 680px;
  margin: 0 auto;
  font-size: clamp(15px, 2vw, 18px);
  color: rgba(255,255,255,.88);
  line-height: 1.7;
}
.hero-en {
  margin-top: 10px;
  font-size: 14px;
  color: rgba(255,255,255,.55);
  letter-spacing: .05em;
}

/* ── 通用 Section ── */
.section {
  padding: 64px 20px;
}
.section.bg-soft { background: #eef6f4; }
.section.bg-dark {
  background: linear-gradient(135deg, #0a2740, #0c4a42);
  color: #fff;
}
.container {
  max-width: 1120px;
  margin: 0 auto;
}
.section-label {
  display: inline-block;
  font-size: 12px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--brand);
  font-weight: 700;
  margin-bottom: 10px;
}
.section.bg-dark .section-label { color: #6ee7d9; }
.section-title {
  margin: 0 0 14px;
  font-size: clamp(24px, 4vw, 36px);
  font-weight: 700;
  letter-spacing: -.01em;
  color: var(--ink);
}
.section.bg-dark .section-title { color: #fff; }
.section-desc {
  margin: 0 0 36px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.75;
  max-width: 720px;
}
.section.bg-dark .section-desc { color: rgba(255,255,255,.72); }

/* ── 模块介绍卡片 ── */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  align-items: start;
}
@media (max-width: 768px) { .about-grid { grid-template-columns: 1fr; } }
.about-text { font-size: 15px; color: var(--muted); line-height: 1.85; }
.about-text p { margin: 0 0 14px; }
.about-text p:last-child { margin: 0; }
.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.stat-card {
  background: linear-gradient(135deg, var(--brand), #0c5682);
  color: #fff;
  border-radius: var(--radius-sm);
  padding: 20px;
  text-align: center;
}
.stat-card big { display: block; font-size: 30px; font-weight: 800; }
.stat-card span { font-size: 12px; opacity: .85; }

/* ── 功能特性网格 ── */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 18px;
}
.feature-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px 22px;
  box-shadow: var(--shadow);
  transition: transform .2s, box-shadow .2s;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: linear-gradient(135deg, #e7f7f5, #d0f0ec);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 16px;
}
.feature-card h3 { margin: 0 0 8px; font-size: 17px; color: var(--ink); }
.feature-card p  { margin: 0; font-size: 14px; color: var(--muted); line-height: 1.6; }

/* ── 合作机会 ── */
.coop-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 18px;
}
.coop-card {
  background: rgba(255,255,255,.08);
  border: 1px solid rgba(255,255,255,.15);
  border-radius: var(--radius);
  padding: 24px 22px;
  backdrop-filter: blur(6px);
  transition: background .2s;
}
.coop-card:hover { background: rgba(255,255,255,.14); }
.coop-num {
  font-size: 32px;
  font-weight: 800;
  color: #6ee7d9;
  margin-bottom: 10px;
  line-height: 1;
}
.coop-card h3 { margin: 0 0 8px; font-size: 16px; color: #fff; }
.coop-card p  { margin: 0; font-size: 14px; color: rgba(255,255,255,.68); line-height: 1.65; }

/* ── 留言表单 ── */
.msg-form-wrap {
  max-width: 720px;
  margin: 0 auto;
}
.msg-form {
  background: rgba(255,255,255,.07);
  border: 1px solid rgba(255,255,255,.15);
  border-radius: var(--radius);
  padding: 36px 32px;
  backdrop-filter: blur(6px);
}
@media (max-width: 600px) { .msg-form { padding: 24px 18px; } }
.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-bottom: 14px;
}
@media (max-width: 560px) { .form-row { grid-template-columns: 1fr; } }
.form-group { margin-bottom: 14px; }
.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: rgba(255,255,255,.75);
  margin-bottom: 6px;
}
.form-group label .req { color: #f87171; margin-left: 2px; }
.form-control {
  width: 100%;
  padding: 11px 14px;
  border: 1px solid rgba(255,255,255,.2);
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,.1);
  color: #fff;
  font-size: 14px;
  font-family: inherit;
  outline: none;
  transition: border-color .15s, background .15s;
}
.form-control::placeholder { color: rgba(255,255,255,.38); }
.form-control:focus {
  border-color: #6ee7d9;
  background: rgba(255,255,255,.14);
}
textarea.form-control { resize: vertical; min-height: 120px; }
.submit-btn {
  width: 100%;
  padding: 14px;
  background: linear-gradient(135deg, #0f766e, #1d4ed8);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  transition: opacity .15s, transform .15s;
  margin-top: 6px;
}
.submit-btn:hover:not(:disabled) { opacity: .9; transform: translateY(-1px); }
.submit-btn:disabled { opacity: .55; cursor: not-allowed; transform: none; }
.form-notice {
  text-align: center;
  font-size: 12px;
  color: rgba(255,255,255,.45);
  margin-top: 12px;
}
.msg-result {
  display: none;
  margin-top: 18px;
  padding: 16px 20px;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  text-align: center;
}
.msg-result.ok  { background: rgba(110,231,217,.15); color: #6ee7d9; border: 1px solid rgba(110,231,217,.3); }
.msg-result.err { background: rgba(248,113,113,.12); color: #fca5a5; border: 1px solid rgba(248,113,113,.3); }

/* ── 页脚 ── */
.footer {
  background: #071f2e;
  color: rgba(255,255,255,.45);
  text-align: center;
  padding: 28px 20px;
  font-size: 13px;
}
.footer a { color: rgba(255,255,255,.55); text-decoration: none; }
.footer a:hover { color: #fff; }