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

:root {
  --color-primary: #1a73e8;
  --color-primary-dark: #1557b0;
  --color-bg: #ffffff;
  --color-surface: #f8f9fa;
  --color-border: #e0e0e0;
  --color-text: #202124;
  --color-text-secondary: #5f6368;
  --color-success: #0d7a3e;
  --color-warning: #e37400;
  --color-danger: #c5221f;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
}

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* Header */
.site-header {
  border-bottom: 1px solid var(--color-border);
  padding: 12px 0;
  position: sticky;
  top: 0;
  background: var(--color-bg);
  z-index: 100;
}
.site-header .container { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.site-logo { font-size: 16px; font-weight: 700; color: var(--color-primary); text-decoration: none; }
.main-nav { display: flex; gap: 12px; flex: 1; }
.main-nav a { color: var(--color-text-secondary); text-decoration: none; font-size: 13px; padding: 4px 8px; border-radius: 4px; }
.main-nav a:hover, .main-nav a.active { color: var(--color-primary); background: #e8f0fe; }
.lang-switch { display: flex; gap: 8px; }
.lang-switch a { font-size: 12px; color: var(--color-text-secondary); text-decoration: none; padding: 2px 6px; border-radius: 3px; }
.lang-switch a.active { color: var(--color-primary); font-weight: 600; }

/* Main */
main { padding: 32px 0 48px; }

/* Hero */
.hero { text-align: center; padding: 40px 0 32px; }
.hero h1 { font-size: 32px; font-weight: 700; margin-bottom: 12px; }
.hero-subtitle { font-size: 15px; color: var(--color-text-secondary); max-width: 720px; margin: 0 auto 24px; }
.btn-hero { font-size: 16px; padding: 14px 32px; }

/* Info overview */
.info-overview { padding: 16px 0 32px; }
.info-overview h2 { font-size: 20px; margin-bottom: 20px; text-align: center; }
.info-cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.info-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px;
}
.info-card h3 { font-size: 15px; font-weight: 700; margin-bottom: 10px; color: var(--color-primary); }
.info-card ul, .info-card ol { padding-left: 18px; margin: 0; }
.info-card li { font-size: 13px; margin-bottom: 5px; line-height: 1.5; }
.info-card ol { counter-reset: step; list-style: none; padding-left: 0; }
.info-card ol li { counter-increment: step; padding-left: 22px; position: relative; }
.info-card ol li::before { content: counter(step); position: absolute; left: 0; width: 17px; height: 17px; background: var(--color-primary); color: #fff; border-radius: 50%; font-size: 11px; text-align: center; line-height: 17px; top: 2px; }
.card-link { margin-top: 10px; font-size: 13px; }
.card-link a { color: var(--color-primary); text-decoration: none; font-weight: 600; }
.card-link a:hover { text-decoration: underline; }

/* Forms */
.assessor-form, .calculator-form {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  margin: 24px 0;
}
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 13px; font-weight: 600; margin-bottom: 4px; }
.form-group select, .form-group input {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  font-size: 14px;
  background: #fff;
}
.form-group small { display: block; margin-top: 4px; font-size: 12px; color: var(--color-text-secondary); }
.btn-primary {
  display: inline-block;
  padding: 10px 24px;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: 4px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
}
.btn-primary:hover { background: var(--color-primary-dark); }

/* Results */
.assessor-result, .calculator-result {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  margin: 24px 0;
}
.result-level { font-size: 18px; font-weight: 700; margin-bottom: 16px; padding: 8px 16px; border-radius: 4px; display: inline-block; }
.result-level.high { background: #e6f4ea; color: var(--color-success); }
.result-level.medium { background: #fef7e0; color: var(--color-warning); }
.result-level.low { background: #fce8e6; color: var(--color-danger); }

.result-section { margin-bottom: 16px; }
.result-section h4 { font-size: 13px; font-weight: 600; color: var(--color-text-secondary); margin-bottom: 4px; }
.result-section p, .result-section ul { font-size: 14px; }
.result-section ul { padding-left: 20px; }

.result-table { width: 100%; border-collapse: collapse; margin: 12px 0; }
.result-table td { padding: 8px 12px; border-bottom: 1px solid var(--color-border); }
.result-table td:last-child { text-align: right; font-weight: 600; }
.total-row td { font-size: 16px; font-weight: 700; border-top: 2px solid var(--color-text); }

/* Info box */
.info-box {
  background: #e8f0fe;
  border-left: 3px solid var(--color-primary);
  padding: 12px 16px;
  border-radius: 0 4px 4px 0;
  margin: 16px 0;
  font-size: 13px;
}

/* City grid */
.city-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 12px; margin: 16px 0; }
.city-grid.large { grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); }
.city-card {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  padding: 16px; background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius); text-decoration: none; color: var(--color-text);
  transition: border-color 0.2s;
}
.city-card:hover { border-color: var(--color-primary); }
.city-card span { font-size: 12px; color: var(--color-text-secondary); margin-top: 4px; }

/* Tool grid */
.tool-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 12px; margin: 16px 0; }
.tool-card {
  padding: 20px; background: var(--color-surface); border: 1px solid var(--color-border);
  border-radius: var(--radius); text-decoration: none; color: var(--color-text);
  font-weight: 600; text-align: center;
}
.tool-card:hover { border-color: var(--color-primary); color: var(--color-primary); }

/* Power grid */
.power-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; margin: 24px 0; }
.power-card { padding: 20px; background: var(--color-surface); border: 1px solid var(--color-border); border-radius: var(--radius); }
.power-card h3 { font-size: 18px; margin-bottom: 4px; }
.power-voltage { font-size: 13px; color: var(--color-text-secondary); margin-bottom: 12px; }
.power-note { font-size: 12px; color: var(--color-text-secondary); margin-top: 8px; font-style: italic; }

/* Compare table */
.table-wrap { overflow-x: auto; margin: 16px 0; }
.compare-table { width: 100%; border-collapse: collapse; margin: 0; min-width: 600px; }
.compare-table th, .compare-table td { padding: 10px 12px; border: 1px solid var(--color-border); text-align: left; font-size: 13px; }
.compare-table th { background: var(--color-surface); font-weight: 600; }

/* Article */
article h1 { font-size: 28px; margin-bottom: 12px; }
article h2 { font-size: 18px; margin: 28px 0 12px; padding-bottom: 8px; border-bottom: 1px solid var(--color-border); }
article h3 { font-size: 15px; margin: 20px 0 8px; }
article p { margin-bottom: 12px; }
article ul { padding-left: 20px; margin-bottom: 12px; }
article li { margin-bottom: 6px; }
article a { color: var(--color-primary); }
.meta { font-size: 12px; color: var(--color-text-secondary); margin-bottom: 20px; }
.disclaimer { font-size: 12px; color: var(--color-text-secondary); font-style: italic; margin-top: 16px; }
.cta-box { text-align: center; padding: 24px; background: var(--color-surface); border-radius: var(--radius); margin: 24px 0; }
.contact-email { font-size: 16px; margin: 16px 0; }

/* FAQ */
.faq details { margin-bottom: 12px; border: 1px solid var(--color-border); border-radius: 4px; }
.faq summary { padding: 12px 16px; cursor: pointer; font-weight: 600; font-size: 14px; }
.faq details p { padding: 0 16px 12px; }

/* Footer */
.site-footer { border-top: 1px solid var(--color-border); padding: 24px 0; margin-top: 48px; }
.footer-links { display: flex; gap: 16px; margin-bottom: 12px; }
.footer-links a { color: var(--color-text-secondary); text-decoration: none; font-size: 13px; }
.footer-links a:hover { color: var(--color-primary); }
.footer-note { font-size: 12px; color: var(--color-text-secondary); margin-bottom: 4px; }
.footer-copy { font-size: 12px; color: var(--color-text-secondary); }

/* Brand grid */
.brand-grid { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
.brand-tag { padding: 6px 14px; background: var(--color-surface); border: 1px solid var(--color-border); border-radius: 20px; font-size: 13px; font-weight: 500; }

/* Home FAQ */
.home-faq { margin: 32px 0; }
.home-faq h2 { font-size: 20px; margin-bottom: 16px; }
.home-brands { margin: 32px 0; }
.home-brands h2 { font-size: 20px; margin-bottom: 8px; }
.home-brands > p { font-size: 14px; color: var(--color-text-secondary); }

/* Responsive */
@media (max-width: 640px) {
  .hero h1 { font-size: 24px; }
  .main-nav { display: none; }
  .power-grid { grid-template-columns: 1fr; }
  .city-grid { grid-template-columns: repeat(2, 1fr); }
  .info-cards { grid-template-columns: 1fr; }
}