/* Base - 仿 Solar Time 风格，各页面通过 body[data-theme] 微调 */
:root {
  --bg: #fff;
  --text: #1a1a1a;
  --text-muted: #555;
  --accent: #e8a319;
  --accent-dark: #c9860f;
  --accent-light: #f5d88a;
  --section-bg: #f8f9fa;
  --card-shadow: 0 4px 20px rgba(0,0,0,.08);
  --header-bg: rgba(255,255,255,.95);
  --footer-bg: #1a1a1a;
  --footer-text: #ccc;
  --radius: 12px;
  --font: "PingFang SC", "Microsoft YaHei", sans-serif;
}

body[data-theme="battery"] { --accent: #2d8f6f; --accent-dark: #1e6b52; --accent-light: #7bc4a8; }
body[data-theme="residential"] { --accent: #d97706; --accent-dark: #b45309; --accent-light: #fcd34d; }
body[data-theme="stories"] { --accent: #7c3aed; --accent-dark: #5b21b6; --accent-light: #c4b5fd; }
body[data-theme="about"] { --accent: #0d9488; --accent-dark: #0f766e; --accent-light: #5eead4; }
body[data-theme="quote"] { --accent: #dc2626; --accent-dark: #b91c1c; --accent-light: #fca5a5; }

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--font); color: var(--text); line-height: 1.6; overflow-x: hidden; }

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--header-bg);
  backdrop-filter: blur(10px);
  box-shadow: 0 1px 0 rgba(0,0,0,.06);
}
.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo { font-size: 1.35rem; font-weight: 700; color: var(--text); text-decoration: none; }
.logo span { color: var(--accent); }
.nav-main { display: flex; gap: 0.5rem; align-items: center; flex-wrap: wrap; }
.nav-main a {
  padding: 0.5rem 0.9rem;
  color: var(--text);
  text-decoration: none;
  font-size: 0.95rem;
  border-radius: 8px;
  transition: background .2s, color .2s;
}
.nav-main a:hover { background: var(--section-bg); color: var(--accent); }
.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.2rem;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  border-radius: 8px;
  font-weight: 600;
  transition: background .2s, transform .15s;
}
.header-cta:hover { background: var(--accent-dark); color: #fff; transform: translateY(-1px); }
.phone-link { font-weight: 700; color: var(--accent); text-decoration: none; }

/* Hero */
.hero {
  min-height: 85vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 8rem 1.5rem 4rem;
  background: linear-gradient(135deg, var(--section-bg) 0%, #fff 50%, var(--accent-light) 100%);
  background-size: 200% 200%;
  animation: heroBg 12s ease infinite;
}
@keyframes heroBg {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}
.hero h1 { font-size: clamp(1.8rem, 4vw, 2.8rem); margin-bottom: 0.5rem; color: var(--text); }
.hero .tagline { font-size: clamp(1rem, 2vw, 1.35rem); color: var(--text-muted); margin-bottom: 1rem; }
.hero .sub { font-size: 0.95rem; color: var(--text-muted); max-width: 520px; margin: 0 auto 1.5rem; }
.hero-btns { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }
.btn {
  display: inline-block;
  padding: 0.85rem 1.8rem;
  border-radius: 8px;
  font-weight: 600;
  text-decoration: none;
  transition: transform .15s, box-shadow .2s;
}
.btn-primary { background: var(--accent); color: #fff; border: none; }
.btn-primary:hover { background: var(--accent-dark); color: #fff; transform: translateY(-2px); box-shadow: 0 8px 25px rgba(0,0,0,.15); }
.btn-outline { background: transparent; color: var(--accent); border: 2px solid var(--accent); }
.btn-outline:hover { background: var(--accent); color: #fff; transform: translateY(-2px); }

/* Section */
section { padding: 4rem 1.5rem; max-width: 1200px; margin: 0 auto; }
.section-title { text-align: center; margin-bottom: 2.5rem; }
.section-title h2 { font-size: clamp(1.5rem, 3vw, 2rem); color: var(--text); margin-bottom: 0.5rem; }
.section-title p { color: var(--text-muted); font-size: 1rem; }
.alt-bg { background: var(--section-bg); }

/* Cards */
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 1.5rem; }
.card {
  background: var(--bg);
  border-radius: var(--radius);
  box-shadow: var(--card-shadow);
  overflow: hidden;
  transition: transform .2s, box-shadow .2s;
}
.card:hover { transform: translateY(-4px); box-shadow: 0 12px 40px rgba(0,0,0,.12); }
.card-img { height: 180px; background: linear-gradient(135deg, var(--accent-light), var(--accent)); display: flex; align-items: center; justify-content: center; font-size: 2.5rem; color: #fff; }
.card-img.card-img-photo { background-size: cover; background-position: center; background-repeat: no-repeat; position: relative; }
.card-img-label { position: absolute; bottom: 0.5rem; left: 0.5rem; background: rgba(0,0,0,.6); color: #fff; padding: 0.25rem 0.5rem; border-radius: 4px; font-size: 0.8rem; font-weight: 600; }
.card-body { padding: 1.5rem; }
.card-body h3 { font-size: 1.2rem; margin-bottom: 0.5rem; color: var(--text); }
.card-body .meta { color: var(--text-muted); font-size: 0.9rem; margin-bottom: 0.75rem; }
.card-body ul { list-style: none; margin-bottom: 1rem; }
.card-body li { padding: 0.25rem 0; padding-left: 1.2rem; position: relative; font-size: 0.9rem; }
.card-body li::before { content: "✓"; position: absolute; left: 0; color: var(--accent); font-weight: 700; }
.card-body .btn { margin-top: 0.5rem; }

/* Why choose */
.reasons { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 2rem; }
.reason { text-align: center; padding: 1rem; }
.reason-icon { font-size: 2.5rem; margin-bottom: 1rem; }
.reason h3 { font-size: 1.1rem; margin-bottom: 0.5rem; }
.reason p { color: var(--text-muted); font-size: 0.95rem; }

/* FAQ */
.faq-list { max-width: 700px; margin: 0 auto; }
.faq-item { border-bottom: 1px solid #eee; }
.faq-item summary { padding: 1rem 0; cursor: pointer; font-weight: 600; list-style: none; display: flex; justify-content: space-between; align-items: center; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "+"; color: var(--accent); font-size: 1.2rem; }
.faq-item[open] summary::after { content: "−"; }
.faq-item p { padding: 0 0 1rem; color: var(--text-muted); font-size: 0.95rem; }

/* Form */
.form-section { max-width: 560px; margin: 0 auto; padding: 2rem; background: var(--bg); border-radius: var(--radius); box-shadow: var(--card-shadow); }
.form-group { margin-bottom: 1rem; }
.form-group label { display: block; margin-bottom: 0.35rem; font-weight: 500; }
.form-group input, .form-group select, .form-group textarea {
  width: 100%;
  padding: 0.7rem 1rem;
  border: 1px solid #ddd;
  border-radius: 8px;
  font: inherit;
}
.form-group textarea { min-height: 100px; resize: vertical; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }

/* Footer */
.site-footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  padding: 3rem 1.5rem 2rem;
  margin-top: 4rem;
}
.footer-inner { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 2rem; }
.footer-inner h4 { color: #fff; font-size: 1rem; margin-bottom: 1rem; }
.footer-inner a { color: var(--footer-text); text-decoration: none; font-size: 0.9rem; }
.footer-inner a:hover { color: var(--accent-light); }
.footer-inner p { font-size: 0.9rem; line-height: 1.7; }
.footer-bottom { max-width: 1200px; margin: 3rem auto 0; padding-top: 1.5rem; border-top: 1px solid #333; text-align: center; font-size: 0.85rem; color: #888; }

/* Util */
.container { max-width: 1200px; margin: 0 auto; padding: 0 1.5rem; }
.page-header { padding: 6rem 1.5rem 3rem; text-align: center; background: linear-gradient(135deg, var(--section-bg), #fff); }
.page-header h1 { font-size: clamp(1.6rem, 3vw, 2.2rem); margin-bottom: 0.5rem; }
.page-header p { color: var(--text-muted); }

/* Mobile nav */
@media (max-width: 768px) {
  .nav-main { display: none; }
  .hero { min-height: 75vh; padding-top: 6rem; }
  .form-row { grid-template-columns: 1fr; }
}