/* ============================================
   ErgoOptimize - Modern American Style Design
   ============================================ */

/* 全局重置与基础样式 */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* 现代配色方案 */
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #3b82f6;
  --color-secondary: #0f172a;
  --color-accent: #f59e0b;
  --color-success: #10b981;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-bg: #f8fafc;
  --color-bg-alt: #ffffff;
  --color-border: #e2e8f0;
  --color-shadow: rgba(0, 0, 0, 0.08);
  --color-shadow-strong: rgba(0, 0, 0, 0.15);

  /* 间距系统 */
  --spacing-xs: 0.5rem;
  --spacing-sm: 0.75rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  --spacing-4xl: 6rem;

  /* 圆角 */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;

  /* 字体 */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* ============================================
   HEADER & NAVIGATION
   ============================================ */

header {
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(10px);
  background: rgba(255, 255, 255, 0.95);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-md) var(--spacing-lg);
  max-width: 1280px;
  margin: 0 auto;
  position: relative;
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  text-decoration: none;
  color: var(--color-secondary);
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.logo::before {
  content: '⚡';
  font-size: 1.8rem;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
  z-index: 1002;
}

.mobile-menu-toggle span {
  display: block;
  width: 25px;
  height: 2px;
  background: var(--color-text);
  transition: all 0.3s ease;
  border-radius: 2px;
}

.mobile-menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(6px, 6px);
}

.mobile-menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}

nav ul {
  display: flex;
  list-style: none;
  gap: var(--spacing-lg);
}

nav a {
  text-decoration: none;
  color: var(--color-text);
  font-weight: 500;
  font-size: 0.9375rem;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  transition: all 0.2s ease;
}

nav a:hover {
  color: var(--color-primary);
  background: rgba(37, 99, 235, 0.08);
}

/* 增大触摸区域（针对移动设备） */
@media (hover: none) and (pointer: coarse) {
  nav a {
    padding: var(--spacing-md) var(--spacing-lg);
    min-height: 44px;
    display: inline-flex;
    align-items: center;
  }

  .btn {
    min-height: 48px;
  }

  .toggle-switch {
    min-width: 56px;
    min-height: 56px;
  }

  .toggle-switch::after {
    width: 28px;
    height: 28px;
  }
}

/* ============================================
   HERO SECTION
   ============================================ */

.hero {
  background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #334155 100%);
  color: white;
  padding: var(--spacing-4xl) var(--spacing-lg);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1200 600"><path d="M0,300 C300,0 600,600 900,300 C1200,0 1500,600 1800,300 L1800,600 L0,600 Z" fill="rgba(255,255,255,0.03)"/></svg>') center/cover no-repeat;
  opacity: 0.5;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: var(--spacing-xl);
  letter-spacing: -0.03em;
}

.hero-subtitle {
  font-size: clamp(1.125rem, 2vw, 1.5rem);
  opacity: 0.9;
  margin-bottom: var(--spacing-2xl);
  line-height: 1.6;
}

.hero-cta {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
}

/* ============================================
   BUTTONS
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all 0.3s ease;
  white-space: nowrap;
}

.btn-primary {
  background: var(--color-primary);
  color: white;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.4);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.5);
}

.btn-secondary {
  background: white;
  color: var(--color-secondary);
  border: 2px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: white;
}

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-outline:hover {
  background: var(--color-primary);
  color: white;
}

.btn-lg {
  padding: var(--spacing-lg) var(--spacing-2xl);
  font-size: 1.125rem;
}

.btn-sm {
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: 0.875rem;
}

/* ============================================
   CARDS
   ============================================ */

.card {
  background: var(--color-bg-alt);
  border-radius: var(--radius-xl);
  box-shadow: 0 1px 3px var(--color-shadow);
  padding: var(--spacing-xl);
  border: 1px solid var(--color-border);
  transition: all 0.3s ease;
}

.card:hover {
  box-shadow: 0 10px 30px var(--color-shadow-strong);
  transform: translateY(-2px);
}

/* ============================================
   SECTIONS
   ============================================ */

section {
  padding: var(--spacing-4xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.section-title {
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 700;
  color: var(--color-secondary);
  margin-bottom: var(--spacing-md);
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* ============================================
   FEATURE CARDS
   ============================================ */

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-xl);
}

.feature-card {
  background: var(--color-bg-alt);
  border-radius: var(--radius-xl);
  padding: var(--spacing-2xl);
  text-align: center;
  border: 1px solid var(--color-border);
  transition: all 0.3s ease;
}

.feature-card:hover {
  border-color: var(--color-primary);
  box-shadow: 0 20px 40px var(--color-shadow-strong);
  transform: translateY(-4px);
}

.feature-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-lg);
  display: block;
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-secondary);
  margin-bottom: var(--spacing-sm);
}

.feature-card p {
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-lg);
}

/* ============================================
   PRODUCT CARDS
   ============================================ */

.product-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--spacing-xl);
}

.product-card {
  background: var(--color-bg-alt);
  border-radius: var(--radius-xl);
  overflow: hidden;
  border: 1px solid var(--color-border);
  transition: all 0.3s ease;
}

.product-card:hover {
  box-shadow: 0 20px 40px var(--color-shadow-strong);
  transform: translateY(-4px);
}

.product-image {
  width: 100%;
  height: 240px;
  object-fit: cover;
  background: linear-gradient(135deg, #f1f5f9 0%, #e2e8f0 100%);
}

.product-badge {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  background: var(--color-accent);
  color: white;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-md);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
}

.product-content {
  padding: var(--spacing-xl);
}

.product-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-secondary);
  margin-bottom: var(--spacing-sm);
}

.product-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-md);
}

.product-rating {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  color: var(--color-accent);
  font-weight: 600;
}

.product-price {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
}

.product-specs {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-md);
  flex-wrap: wrap;
}

.spec-tag {
  background: var(--color-bg);
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.match-score {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  background: linear-gradient(135deg, var(--color-success), #059669);
  color: white;
  padding: var(--spacing-sm) var(--spacing-lg);
  border-radius: var(--radius-lg);
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: var(--spacing-md);
}

.match-score::before {
  content: '✓';
}

/* ============================================
   CALCULATOR FORM
   ============================================ */

.calculator-form {
  background: var(--color-bg-alt);
  border-radius: var(--radius-2xl);
  padding: var(--spacing-3xl);
  border: 1px solid var(--color-border);
  box-shadow: 0 20px 40px var(--color-shadow-strong);
  max-width: 700px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: var(--spacing-xl);
}

.form-group label {
  display: block;
  margin-bottom: var(--spacing-sm);
  font-weight: 600;
  color: var(--color-text);
  font-size: 0.9375rem;
}

.form-group input,
.form-group select {
  width: 100%;
  padding: var(--spacing-md);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  font-size: 1rem;
  font-family: inherit;
  transition: all 0.2s ease;
  background: var(--color-bg);
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
}

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-lg);
}

.toggle-group {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.toggle-switch {
  position: relative;
  width: 56px;
  height: 30px;
  background: var(--color-border);
  border-radius: 30px;
  cursor: pointer;
  transition: background 0.3s ease;
}

.toggle-switch.active {
  background: var(--color-primary);
}

.toggle-switch::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 24px;
  height: 24px;
  background: white;
  border-radius: 50%;
  transition: transform 0.3s ease;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.toggle-switch.active::after {
  transform: translateX(26px);
}

/* ============================================
   RESULTS DISPLAY
   ============================================ */

.results-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-xl);
  margin: var(--spacing-3xl) 0;
}

.result-box {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: white;
  padding: var(--spacing-2xl);
  border-radius: var(--radius-xl);
  text-align: center;
  box-shadow: 0 10px 30px rgba(37, 99, 235, 0.3);
}

.result-value {
  font-size: 3.5rem;
  font-weight: 800;
  line-height: 1;
  margin-bottom: var(--spacing-sm);
}

.result-label {
  font-size: 1rem;
  opacity: 0.9;
}

.result-icon {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-md);
}

/* ============================================
   COMPARISON TABLE
   ============================================ */

.comparison-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-xl);
  box-shadow: 0 4px 12px var(--color-shadow);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--color-bg-alt);
}

.comparison-table th,
.comparison-table td {
  padding: var(--spacing-lg);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.comparison-table th {
  background: linear-gradient(135deg, var(--color-secondary), #334155);
  color: white;
  font-weight: 600;
  font-size: 0.9375rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.comparison-table tr:hover {
  background: var(--color-bg);
}

.comparison-table td:first-child {
  font-weight: 600;
  color: var(--color-text);
}

/* ============================================
   FAQ SECTION
   ============================================ */

.faq-section {
  background: var(--color-bg-alt);
  border-radius: var(--radius-xl);
  padding: var(--spacing-3xl);
  border: 1px solid var(--color-border);
}

.faq-item {
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-xl) 0;
}

.faq-item:last-child {
  border-bottom: none;
}

.faq-question {
  font-weight: 600;
  font-size: 1.125rem;
  color: var(--color-text);
  margin-bottom: var(--spacing-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.faq-question::after {
  content: '+';
  font-size: 1.5rem;
  color: var(--color-primary);
  transition: transform 0.3s ease;
}

.faq-item.active .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  color: var(--color-text-muted);
  line-height: 1.7;
  max-height: 0;
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding-top: var(--spacing-md);
}

/* ============================================
   FOOTER
   ============================================ */

footer {
  background: var(--color-secondary);
  color: white;
  padding: var(--spacing-4xl) 0 var(--spacing-xl);
  margin-top: var(--spacing-4xl);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

.footer-column h4 {
  font-size: 0.9375rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--spacing-lg);
  color: rgba(255, 255, 255, 0.7);
}

.footer-column ul {
  list-style: none;
}

.footer-column li {
  margin-bottom: var(--spacing-sm);
}

.footer-column a {
  color: rgba(255, 255, 255, 0.8);
  text-decoration: none;
  transition: color 0.2s ease;
  font-size: 0.9375rem;
}

.footer-column a:hover {
  color: white;
}

.copyright {
  text-align: center;
  padding-top: var(--spacing-xl);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.875rem;
}

.affiliate-disclosure {
  background: rgba(255, 255, 255, 0.05);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.6);
  text-align: center;
  margin-top: var(--spacing-xl);
}

/* ============================================
   UTILITY CLASSES
   ============================================ */

.text-center { text-align: center; }
.text-primary { color: var(--color-primary); }
.text-muted { color: var(--color-text-muted); }
.mt-lg { margin-top: var(--spacing-xl); }
.mb-lg { margin-bottom: var(--spacing-xl); }

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */

@media (max-width: 768px) {
  :root {
    --spacing-4xl: 3rem;
    --spacing-3xl: 2.5rem;
    --spacing-2xl: 2rem;
  }

  /* Mobile Navigation */
  .mobile-menu-toggle {
    display: flex;
  }

  nav {
    position: fixed;
    top: 0;
    right: -100%;
    width: 75%;
    max-width: 300px;
    height: 100vh;
    background: var(--color-bg-alt);
    box-shadow: -5px 0 30px rgba(0, 0, 0, 0.15);
    transition: right 0.3s ease;
    z-index: 1001;
    padding: var(--spacing-2xl) var(--spacing-xl);
    overflow-y: auto;
  }

  nav.active {
    right: 0;
  }

  nav ul {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  nav a {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
    font-size: 1.0625rem;
  }

  /* Overlay when menu is open */
  .nav-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    opacity: 0;
    transition: opacity 0.3s ease;
  }

  .nav-overlay.active {
    display: block;
    opacity: 1;
  }

  /* Prevent body scroll when menu is open */
  body.menu-open {
    overflow: hidden;
  }

  .hero h1 {
    font-size: 2rem;
    line-height: 1.2;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .hero-cta {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .hero-cta .btn {
    width: 100%;
  }

  .btn {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
  }

  .btn-lg {
    padding: var(--spacing-lg) var(--spacing-xl);
    font-size: 1rem;
  }

  /* Make sure standalone buttons outside hero-cta also work well */
  .btn:not(.hero-cta .btn) {
    width: auto;
  }

  .container {
    padding: 0 var(--spacing-md);
  }

  .header-content {
    padding: var(--spacing-sm) var(--spacing-md);
  }

  .feature-grid,
  .product-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }

  .calculator-form {
    padding: var(--spacing-lg);
  }

  .form-row {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }

  .comparison-table {
    font-size: 0.8125rem;
  }

  .comparison-table th,
  .comparison-table td {
    padding: var(--spacing-sm) var(--spacing-md);
  }

  .comparison-table th:first-child,
  .comparison-table td:first-child {
    position: sticky;
    left: 0;
    background: inherit;
    z-index: 1;
  }

  .results-container {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }

  .result-box {
    padding: var(--spacing-lg);
  }

  .result-value {
    font-size: 2.5rem;
  }

  .section-header {
    margin-bottom: var(--spacing-xl);
  }

  .section-title {
    font-size: 1.75rem;
  }

  section {
    padding: var(--spacing-2xl) 0;
  }

  .hero {
    padding: var(--spacing-2xl) var(--spacing-md);
  }

  .faq-section {
    padding: var(--spacing-xl);
  }

  .footer-content {
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
  }

  /* Product card adjustments */
  .product-content {
    padding: var(--spacing-lg);
  }

  .product-image {
    height: 200px;
  }

  /* Match score size */
  .match-score {
    font-size: 1rem;
    padding: var(--spacing-sm) var(--spacing-md);
  }

  /* Form inputs better touch targets */
  .form-group input,
  .form-group select {
    padding: var(--spacing-md);
    font-size: 16px; /* Prevents zoom on iOS */
  }
}

@media (max-width: 480px) {
  :root {
    --spacing-4xl: 2.5rem;
    --spacing-3xl: 2rem;
    --spacing-2xl: 1.5rem;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .calculator-form {
    padding: var(--spacing-md);
  }

  .feature-card,
  .card {
    padding: var(--spacing-lg);
  }

  .product-card {
    border-radius: var(--radius-lg);
  }

  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }

  .result-value {
    font-size: 2rem;
  }

  .feature-icon {
    font-size: 2.5rem;
  }

  /* Very small screens - adjust button text */
  .btn {
    font-size: 0.9375rem;
    padding: var(--spacing-sm) var(--spacing-md);
  }

  /* Ensure links don't overflow */
  nav a {
    font-size: 1rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
}

/* Landscape mobile optimizations */
@media (max-height: 500px) and (orientation: landscape) {
  .hero {
    padding: var(--spacing-lg) var(--spacing-md);
  }

  .hero h1 {
    font-size: 1.5rem;
  }

  .hero-subtitle {
    font-size: 0.9375rem;
    margin-bottom: var(--spacing-md);
  }

  section {
    padding: var(--spacing-lg) 0;
  }

  nav {
    padding: var(--spacing-lg);
  }
}

/* ============================================
   ANIMATIONS
   ============================================ */

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-fade-in {
  animation: fadeInUp 0.6s ease-out;
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.8;
  }
}

.animate-pulse {
  animation: pulse 2s ease-in-out infinite;
}

/* ============================================
   PRINT STYLES
   ============================================ */

@media print {
  header,
  footer,
  .btn {
    display: none;
  }

  .card {
    box-shadow: none;
    border: 1px solid #ddd;
  }
}