/* ============================================
   银联商务电签机 — 深翠绿低送风
   UMS E-Sign Terminal Product Website
   ============================================ */

/* --- CSS Variables --- */
:root {
  --ums-emerald: #14532D;
  --ums-emerald-light: #166534;
  --lowrate-orange: #F97316;
  --free-green: #10B981;
  --bg-page: #ECFDF5;
  --text-dark: #052E16;
  --text-body: #334155;
  --text-muted: #64748B;
  --white: #FFFFFF;
  --border-light: rgba(20, 83, 45, 0.12);
  --shadow-sm: 0 1px 3px rgba(20, 83, 45, 0.08);
  --shadow-md: 0 4px 12px rgba(20, 83, 45, 0.10);
  --shadow-lg: 0 8px 30px rgba(20, 83, 45, 0.12);
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-pill: 9999px;
  --font-cn: 'Noto Sans SC', sans-serif;
  --font-en: 'DM Sans', sans-serif;
  --transition: 0.3s ease;
  --max-width: 1200px;
}

/* --- Reset & Base --- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-cn);
  color: var(--text-body);
  background: var(--white);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color var(--transition);
}

ul, ol { list-style: none; }

img {
  max-width: 100%;
  display: block;
}

/* --- Utility --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.highlight-orange {
  color: var(--lowrate-orange);
  font-weight: 700;
}

.highlight-green {
  color: var(--free-green);
  font-weight: 700;
}

.highlight-emerald {
  color: var(--ums-emerald);
  font-weight: 700;
}

.text-center { text-align: center; }

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-cn);
  font-size: 16px;
  font-weight: 600;
  padding: 14px 32px;
  border-radius: var(--radius-pill);
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn:hover {
  transform: scale(1.05);
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: linear-gradient(135deg, var(--lowrate-orange), #FB923C);
  color: var(--white);
  box-shadow: 0 4px 16px rgba(249, 115, 22, 0.35);
}

.btn-primary:hover {
  box-shadow: 0 6px 24px rgba(249, 115, 22, 0.45);
}

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

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.12);
}

.btn-emerald {
  background: linear-gradient(135deg, var(--ums-emerald), var(--ums-emerald-light));
  color: var(--white);
  box-shadow: 0 4px 16px rgba(20, 83, 45, 0.35);
}

.btn-free {
  background: linear-gradient(135deg, var(--free-green), #34D399);
  color: var(--white);
  box-shadow: 0 4px 16px rgba(16, 185, 129, 0.35);
}

/* --- Navigation --- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--white);
  transition: box-shadow var(--transition), background var(--transition);
  height: 64px;
}

.navbar.scrolled {
  box-shadow: 0 2px 20px rgba(20, 83, 45, 0.12);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-cn);
  font-weight: 700;
  font-size: 18px;
  color: var(--ums-emerald);
}

.nav-logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--ums-emerald), var(--ums-emerald-light));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 14px;
  font-weight: 900;
  font-family: var(--font-en);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-body);
  position: relative;
  padding: 4px 0;
  transition: color var(--transition);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--lowrate-orange);
  transition: width var(--transition);
  border-radius: 1px;
}

.nav-links a:hover {
  color: var(--ums-emerald);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-links a.active {
  color: var(--ums-emerald);
}

.nav-cta {
  padding: 10px 24px;
  font-size: 14px;
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
  border: none;
  background: none;
}

.hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--ums-emerald);
  border-radius: 2px;
  transition: all var(--transition);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* --- Hero Section --- */
.hero {
  background: linear-gradient(135deg, var(--ums-emerald) 0%, var(--ums-emerald-light) 100%);
  color: var(--white);
  padding: 140px 0 80px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(249, 115, 22, 0.08) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(16, 185, 129, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero .container {
  position: relative;
  z-index: 1;
}

.hero-tag {
  display: inline-block;
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.25);
  padding: 6px 18px;
  border-radius: var(--radius-pill);
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 24px;
  backdrop-filter: blur(4px);
}

.hero-title {
  font-size: 52px;
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}

.hero-title .accent-orange {
  color: var(--lowrate-orange);
}

.hero-title .accent-green {
  color: var(--free-green);
}

.hero-subtitle {
  font-size: 20px;
  font-weight: 400;
  opacity: 0.9;
  margin-bottom: 36px;
  max-width: 560px;
  line-height: 1.6;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

/* --- Section Common --- */
.section {
  padding: 80px 0;
}

.section-alt {
  background: var(--bg-page);
}

.section-title {
  font-size: 36px;
  font-weight: 800;
  color: var(--text-dark);
  margin-bottom: 12px;
  line-height: 1.25;
}

.section-subtitle {
  font-size: 18px;
  color: var(--text-muted);
  margin-bottom: 48px;
  line-height: 1.6;
}

/* --- Low-Rate Cards (Staggered) --- */
.rate-cards {
  display: flex;
  gap: 20px;
  align-items: stretch;
}

.rate-card {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 36px 32px;
  border: 1px solid var(--border-light);
  transition: transform var(--transition), box-shadow var(--transition);
}

.rate-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.rate-card-wide {
  flex: 0 0 55%;
}

.rate-card-narrow {
  flex: 0 0 43%;
}

.rate-card .card-number {
  font-family: var(--font-en);
  font-size: 56px;
  font-weight: 700;
  color: var(--lowrate-orange);
  line-height: 1;
  margin-bottom: 12px;
}

.rate-card .card-label {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 8px;
}

.rate-card .card-desc {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* --- Free Section --- */
.free-block {
  padding: 60px 0;
}

.free-highlight {
  font-size: 36px;
  font-weight: 800;
  color: var(--free-green);
  margin-bottom: 16px;
  line-height: 1.3;
}

.free-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 32px;
}

.free-list-item {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 18px;
  color: var(--text-body);
}

.free-list-item .check {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--free-green), #34D399);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 14px;
  flex-shrink: 0;
}

/* --- Compare Table --- */
.compare-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
  background: var(--white);
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
}

.compare-table th {
  background: linear-gradient(135deg, var(--ums-emerald), var(--ums-emerald-light));
  color: var(--white);
  font-weight: 700;
  padding: 16px 24px;
  text-align: center;
  white-space: nowrap;
  font-size: 16px;
}

.compare-table th:first-child {
  text-align: left;
}

.compare-table td {
  padding: 14px 24px;
  text-align: center;
  border-bottom: 1px solid var(--border-light);
  color: var(--text-body);
}

.compare-table td:first-child {
  text-align: left;
  font-weight: 600;
  color: var(--text-dark);
}

.compare-table tr:last-child td {
  border-bottom: none;
}

.compare-table .check-yes {
  color: var(--free-green);
  font-size: 20px;
}

.compare-table .check-no {
  color: #CBD5E1;
  font-size: 20px;
}

.compare-table .highlight-row td {
  background: rgba(16, 185, 129, 0.05);
  font-weight: 500;
}

/* --- FAQ Accordion --- */
.faq-list {
  max-width: 760px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  overflow: hidden;
  background: var(--white);
  transition: box-shadow var(--transition);
}

.faq-item:hover {
  box-shadow: var(--shadow-sm);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  cursor: pointer;
  font-size: 16px;
  font-weight: 600;
  color: var(--text-dark);
  user-select: none;
  transition: background var(--transition);
}

.faq-question:hover {
  background: rgba(20, 83, 45, 0.03);
}

.faq-question .arrow {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition);
  color: var(--text-muted);
  flex-shrink: 0;
}

.faq-item.active .faq-question .arrow {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
}

.faq-item.active .faq-answer {
  max-height: 300px;
}

.faq-answer-inner {
  padding: 0 24px 18px;
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.7;
}

/* --- Bottom CTA --- */
.bottom-cta {
  background: linear-gradient(135deg, var(--ums-emerald), var(--ums-emerald-light));
  color: var(--white);
  padding: 80px 0;
  text-align: center;
}

.bottom-cta-title {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 12px;
  line-height: 1.3;
}

.bottom-cta-subtitle {
  font-size: 18px;
  opacity: 0.85;
  margin-bottom: 32px;
}

/* --- Footer --- */
.footer {
  background: linear-gradient(135deg, var(--ums-emerald) 0%, var(--ums-emerald-light) 100%);
  color: var(--white);
  padding: 48px 0 24px;
}

.footer-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  margin-bottom: 36px;
}

.footer-col h4 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 16px;
  color: rgba(255, 255, 255, 0.95);
}

.footer-col a {
  display: block;
  font-size: 14px;
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: 10px;
  transition: color var(--transition);
}

.footer-col a:hover {
  color: var(--white);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding-top: 20px;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.5);
  text-align: center;
  line-height: 1.8;
}

/* --- Low-Rate Page Specifics --- */
.hero-orange {
  background: linear-gradient(135deg, var(--lowrate-orange) 0%, #FB923C 100%);
  padding: 120px 0 60px;
  color: var(--white);
  position: relative;
  overflow: hidden;
}

.hero-orange::before {
  content: '';
  position: absolute;
  top: -40%;
  right: -15%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.rate-features {
  display: flex;
  flex-direction: column;
  gap: 40px;
}

.rate-feature-row {
  display: flex;
  gap: 24px;
  align-items: stretch;
}

.rate-feature-card {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 36px 32px;
  border: 1px solid var(--border-light);
  transition: transform var(--transition), box-shadow var(--transition);
}

.rate-feature-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.rate-feature-card.card-wide {
  flex: 1.4;
}

.rate-feature-card.card-regular {
  flex: 1;
}

.rate-feature-card.card-bg {
  background: linear-gradient(135deg, #FFF7ED, #FFEDD5);
  border-color: rgba(249, 115, 22, 0.15);
}

.rate-feature-card .feat-number {
  font-family: var(--font-en);
  font-size: 48px;
  font-weight: 700;
  color: var(--lowrate-orange);
  line-height: 1;
  margin-bottom: 10px;
}

.rate-feature-card .feat-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 8px;
}

.rate-feature-card .feat-desc {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* --- Free Page Specifics --- */
.hero-green {
  background: linear-gradient(135deg, var(--free-green) 0%, #34D399 100%);
  padding: 120px 0 60px;
  color: var(--white);
  position: relative;
  overflow: hidden;
}

.hero-green::before {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.free-features {
  display: flex;
  flex-direction: column;
  gap: 40px;
}

.free-feature-row {
  display: flex;
  gap: 24px;
  align-items: stretch;
}

.free-feature-card {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 36px 32px;
  border: 1px solid var(--border-light);
  transition: transform var(--transition), box-shadow var(--transition);
}

.free-feature-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.free-feature-card.card-wide {
  flex: 1.3;
}

.free-feature-card.card-regular {
  flex: 1;
}

.free-feature-card .feat-number {
  font-family: var(--font-en);
  font-size: 48px;
  font-weight: 700;
  color: var(--free-green);
  line-height: 1;
  margin-bottom: 10px;
}

.free-feature-card .feat-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 8px;
}

.free-feature-card .feat-desc {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Free Rules Box */
.free-rules-box {
  background: linear-gradient(135deg, #ECFDF5, #D1FAE5);
  border: 2px solid rgba(16, 185, 129, 0.2);
  border-radius: var(--radius-md);
  padding: 40px 36px;
}

.free-rules-box h3 {
  font-size: 24px;
  font-weight: 800;
  color: var(--free-green);
  margin-bottom: 20px;
}

.free-rules-box .rule-item {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 16px;
}

.free-rules-box .rule-num {
  font-family: var(--font-en);
  font-size: 20px;
  font-weight: 700;
  color: var(--free-green);
  flex-shrink: 0;
  width: 32px;
}

.free-rules-box .rule-text {
  font-size: 16px;
  color: var(--text-body);
  line-height: 1.7;
}

/* --- Compare Page Specifics --- */
.hero-emerald {
  background: linear-gradient(135deg, var(--ums-emerald) 0%, var(--ums-emerald-light) 100%);
  padding: 120px 0 60px;
  color: var(--white);
  position: relative;
  overflow: hidden;
}

.hero-emerald::before {
  content: '';
  position: absolute;
  top: -30%;
  right: -10%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(249, 115, 22, 0.06) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.compare-dimension {
  margin-bottom: 48px;
}

.compare-dimension h3 {
  font-size: 22px;
  font-weight: 700;
  color: var(--text-dark);
  margin-bottom: 16px;
  padding-left: 16px;
  border-left: 4px solid var(--lowrate-orange);
}

/* --- Low-Rate Compare Section (Home) --- */
.lowrate-compare {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .hero-title {
    font-size: 40px;
  }

  .rate-cards {
    flex-direction: column;
  }

  .rate-card-wide,
  .rate-card-narrow {
    flex: 1;
  }

  .rate-feature-row,
  .free-feature-row {
    flex-direction: column;
  }

  .rate-feature-card.card-wide,
  .rate-feature-card.card-regular,
  .free-feature-card.card-wide,
  .free-feature-card.card-regular {
    flex: 1;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: 20px 24px;
    gap: 16px;
    box-shadow: var(--shadow-md);
    border-top: 1px solid var(--border-light);
  }

  .nav-links.open {
    display: flex;
  }

  .hamburger {
    display: flex;
  }

  .hero {
    padding: 120px 0 60px;
  }

  .hero-title {
    font-size: 32px;
  }

  .hero-subtitle {
    font-size: 17px;
  }

  .section {
    padding: 56px 0;
  }

  .section-title {
    font-size: 28px;
  }

  .footer-content {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .compare-table th,
  .compare-table td {
    padding: 10px 14px;
    font-size: 14px;
  }

  .bottom-cta-title {
    font-size: 28px;
  }

  .free-highlight {
    font-size: 28px;
  }

  .rate-card .card-number {
    font-size: 42px;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 28px;
  }

  .hero-buttons {
    flex-direction: column;
  }

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

  .btn {
    padding: 12px 24px;
    font-size: 15px;
  }
}