/* ============================================================
   专业开发微信小程序 - 品牌网站 全局样式
   基于 PRD V1.0 设计规范
   ============================================================ */

/* === CSS Variables (Design Tokens) === */
:root {
  --color-primary:        #1E40AF;
  --color-primary-light:  #3B82F6;
  --color-primary-dark:   #152C7A;
  --color-accent:         #F97316;
  --color-accent-hover:   #EA580C;
  --color-bg:             #FFFFFF;
  --color-bg-alt:         #F8FAFC;
  --color-bg-highlight:   #EFF6FF;
  --color-text:           #1E293B;
  --color-text-inverse:   #FFFFFF;
  --color-text-muted:     #64748B;
  --color-border:         #E2E8F0;
  --color-success:        #10B981;
  --color-error:          #EF4444;
  --color-warning:        #F59E0B;

  --font-family: "PingFang SC", "Microsoft YaHei", "Source Han Sans CN", -apple-system, sans-serif;
  --font-size-h1: 56px;
  --font-size-h2: 40px;
  --font-size-h3: 28px;
  --font-size-h4: 20px;
  --font-size-body: 16px;
  --font-size-small: 14px;
  --font-size-caption: 12px;
  --font-weight-bold: 700;
  --font-weight-semibold: 600;
  --font-weight-regular: 400;
  --line-height-heading: 1.3;
  --line-height-body: 1.7;

  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 40px;
  --space-6: 48px;
  --space-8: 64px;
  --space-10: 80px;
  --space-12: 96px;
  --section-padding: 120px;

  --container-max: 1200px;
  --container-padding: 24px;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.10);
  --shadow-xl: 0 20px 50px rgba(0,0,0,0.15);
  --shadow-card-hover: 0 8px 30px rgba(30,64,175,0.12);

  --transition-fast: 200ms cubic-bezier(0.4,0,0.2,1);
  --transition-normal: 300ms cubic-bezier(0.4,0,0.2,1);
  --transition-slow: 500ms cubic-bezier(0.4,0,0.2,1);

  --z-header: 100;
  --z-modal: 200;
  --z-toast: 300;
}

/* === Reset === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font-family);
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; height: auto; display: block; }
button { cursor: pointer; font-family: inherit; border: none; background: none; }
input, select, textarea { font-family: inherit; font-size: inherit; }

/* === Container === */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* === Section Spacing === */
.section {
  padding: var(--section-padding) 0;
}
.section-alt {
  background: var(--color-bg-alt);
  padding: var(--section-padding) 0;
}

/* === Typography === */
h1, h2, h3, h4 { font-weight: var(--font-weight-bold); line-height: var(--line-height-heading); }
h1 { font-size: var(--font-size-h1); }
h2 { font-size: var(--font-size-h2); }
h3 { font-size: var(--font-size-h3); }
h4 { font-size: var(--font-size-h4); }

/* === Section Title Component === */
.section-title {
  text-align: center;
  margin-bottom: var(--space-6);
}
.section-title .badge {
  display: inline-block;
  background: var(--color-bg-highlight);
  color: var(--color-primary);
  font-size: var(--font-size-small);
  font-weight: var(--font-weight-semibold);
  padding: 4px 16px;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-2);
}
.section-title h2 {
  color: var(--color-text);
}
.section-title p {
  color: var(--color-text-muted);
  font-size: var(--font-size-body);
  max-width: 600px;
  margin: var(--space-2) auto 0;
}
.section-title.left { text-align: left; }
.section-title.left p { margin-left: 0; }

/* === Buttons === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  font-weight: var(--font-weight-semibold);
  font-size: var(--font-size-body);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  white-space: nowrap;
}
.btn:active { transform: scale(0.98); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

.btn-sm  { height: 36px; padding: 0 16px; font-size: var(--font-size-small); }
.btn-md  { height: 44px; padding: 0 24px; }
.btn-lg  { height: 52px; padding: 0 32px; font-size: 18px; }

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

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

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border: 1.5px solid var(--color-primary);
}
.btn-outline:hover { background: var(--color-bg-highlight); }

.btn-outline-white {
  background: transparent;
  color: white;
  border: 1.5px solid rgba(255,255,255,0.5);
}
.btn-outline-white:hover { background: rgba(255,255,255,0.1); border-color: white; }

.btn-ghost {
  background: transparent;
  color: var(--color-primary);
}
.btn-ghost:hover { background: var(--color-bg-highlight); }

/* === Header === */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: var(--z-header);
  background: white;
  border-bottom: 1px solid transparent;
  transition: all var(--transition-normal);
  height: 72px;
}
.header.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
  height: 64px;
}
.header .container {
  display: flex;
  align-items: center;
  height: 100%;
  gap: var(--space-4);
}
.header-logo {
  font-size: 20px;
  font-weight: var(--font-weight-bold);
  color: var(--color-primary);
  white-space: nowrap;
  flex-shrink: 0;
}
.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-left: auto;
}
.header-nav a {
  font-size: var(--font-size-body);
  color: var(--color-text);
  position: relative;
  padding: 4px 0;
  transition: color var(--transition-fast);
}
.header-nav a::after {
  content: '';
  position: absolute;
  bottom: -2px; left: 50%; transform: translateX(-50%);
  width: 0; height: 2px;
  background: var(--color-primary);
  border-radius: 1px;
  transition: width var(--transition-fast);
}
.header-nav a:hover,
.header-nav a.active { color: var(--color-primary); }
.header-nav a:hover::after,
.header-nav a.active::after { width: 20px; }
.header-phone {
  color: var(--color-text-muted);
  font-size: var(--font-size-small);
  white-space: nowrap;
  flex-shrink: 0;
}
.header-phone .icon { vertical-align: middle; margin-right: 4px; }
.header-cta { flex-shrink: 0; }

/* Hamburger */
.hamburger {
  display: none;
  width: 40px; height: 40px;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  color: var(--color-text);
  flex-shrink: 0;
}
.hamburger.active { color: var(--color-primary); }

/* Mobile Drawer */
.drawer-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: calc(var(--z-header) + 1);
  opacity: 0;
  transition: opacity var(--transition-normal);
}
.drawer-overlay.open {
  display: block;
  opacity: 1;
}
.drawer {
  position: fixed;
  top: 0; right: 0; bottom: 0;
  width: 280px;
  background: white;
  z-index: calc(var(--z-header) + 2);
  transform: translateX(100%);
  transition: transform var(--transition-normal);
  padding: var(--space-3);
  display: flex;
  flex-direction: column;
}
.drawer.open { transform: translateX(0); }
.drawer-close {
  align-self: flex-end;
  font-size: 24px;
  color: var(--color-text);
  width: 40px; height: 40px;
  display: flex; align-items: center; justify-content: center;
}
.drawer-nav { margin-top: var(--space-4); flex: 1; }
.drawer-nav a {
  display: flex;
  align-items: center;
  height: 48px;
  padding-left: var(--space-3);
  font-size: var(--font-size-body);
  color: var(--color-text);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}
.drawer-nav a:hover,
.drawer-nav a.active { background: var(--color-bg-highlight); color: var(--color-primary); }
.drawer-info {
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-3);
  margin-top: var(--space-3);
}
.drawer-info .phone {
  font-size: 18px;
  font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}
.drawer-info .btn { width: 100%; }

/* === Hero === */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 600px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: linear-gradient(135deg, #0F172A 0%, #1E3A8A 50%, #1E40AF 100%);
  overflow: hidden;
  padding-top: 72px;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 50%, rgba(59,130,246,0.15) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(249,115,22,0.08) 0%, transparent 50%);
}
.hero-particles {
  position: absolute;
  inset: 0;
  opacity: 0.3;
  background-image:
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 60px 60px;
}
.hero-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  padding: 0 var(--container-padding);
}
.hero h1 {
  color: white;
  font-size: var(--font-size-h1);
  margin-bottom: var(--space-3);
}
.hero p {
  color: rgba(255,255,255,0.8);
  font-size: 18px;
  margin-bottom: var(--space-6);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}
.hero-stats {
  display: flex;
  justify-content: center;
  gap: var(--space-6);
  margin-bottom: var(--space-5);
  flex-wrap: wrap;
}
.hero-stat {
  text-align: center;
}
.hero-stat .num {
  font-size: 36px;
  font-weight: var(--font-weight-bold);
  color: var(--color-accent);
}
.hero-stat .label {
  font-size: var(--font-size-small);
  color: rgba(255,255,255,0.7);
  margin-top: 4px;
}
.hero-btns {
  display: flex;
  justify-content: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}

/* === Trust === */
.trust-logos {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--space-6);
  flex-wrap: wrap;
  margin-bottom: var(--space-6);
}
.trust-logo-placeholder {
  height: 40px;
  width: 120px;
  background: var(--color-border);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-caption);
  color: var(--color-text-muted);
  opacity: 0.6;
}
.trust-numbers {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-4);
}
.trust-number {
  text-align: center;
  padding: var(--space-4);
}
.trust-number .num {
  font-size: 36px;
  font-weight: var(--font-weight-bold);
  color: var(--color-primary);
}
.trust-number .label {
  font-size: var(--font-size-small);
  color: var(--color-text-muted);
  margin-top: var(--space-1);
}

/* === Value Cards === */
.cards-grid { display: grid; gap: var(--space-3); }
.cards-4 { grid-template-columns: repeat(4, 1fr); }
.cards-3 { grid-template-columns: repeat(3, 1fr); }
.cards-2 { grid-template-columns: repeat(2, 1fr); }

.info-card {
  background: var(--color-bg-alt);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  text-align: center;
  transition: all var(--transition-normal);
  border: 1px solid transparent;
}
.info-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
  background: white;
  border-color: var(--color-border);
}
.info-card .icon-box {
  width: 64px; height: 64px;
  margin: 0 auto var(--space-3);
  background: var(--color-bg-highlight);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  color: var(--color-primary);
}
.info-card h4 {
  margin-bottom: var(--space-1);
  font-size: var(--font-size-h4);
}
.info-card p {
  color: var(--color-text-muted);
  font-size: var(--font-size-small);
  line-height: 1.6;
}

/* === Case Cards === */
.case-card {
  background: white;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
  cursor: pointer;
}
.case-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}
.case-card-img {
  position: relative;
  aspect-ratio: 4 / 3;
  background: var(--color-bg-alt);
  overflow: hidden;
}
.case-card-img img {
  width: 100%; height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}
.case-card:hover .case-card-img img { transform: scale(1.03); }
.case-card-img .badge {
  position: absolute;
  top: 12px; left: 12px;
  background: var(--color-primary);
  color: white;
  font-size: var(--font-size-caption);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-weight: var(--font-weight-semibold);
}
.case-card-body {
  padding: var(--space-3);
}
.case-card-body h4 {
  font-size: var(--font-size-h4);
  margin-bottom: var(--space-1);
}
.case-card-body p {
  color: var(--color-text-muted);
  font-size: var(--font-size-small);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: var(--space-2);
}
.case-card-tags {
  display: flex;
  gap: var(--space-1);
  flex-wrap: wrap;
}
.case-card-tags span {
  background: var(--color-bg-highlight);
  color: var(--color-primary);
  font-size: var(--font-size-caption);
  padding: 2px 10px;
  border-radius: var(--radius-full);
  font-weight: var(--font-weight-semibold);
}

/* === Process Steps === */
.process-steps {
  display: flex;
  justify-content: space-between;
  position: relative;
}
.process-steps::before {
  content: '';
  position: absolute;
  top: 28px; left: 40px; right: 40px;
  height: 2px;
  background: var(--color-border);
}
.process-step {
  position: relative;
  z-index: 1;
  text-align: center;
  flex: 1;
  max-width: 160px;
}
.process-step .circle {
  width: 56px; height: 56px;
  border-radius: 50%;
  background: var(--color-primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: var(--font-weight-bold);
  margin: 0 auto var(--space-2);
  position: relative;
  z-index: 1;
}
.process-step h4 {
  font-size: var(--font-size-body);
  margin-bottom: 4px;
}
.process-step p {
  color: var(--color-text-muted);
  font-size: var(--font-size-small);
  line-height: 1.5;
}

/* === CTA Section === */
.cta-section {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  padding: 100px 0;
  text-align: center;
}
.cta-section h2 {
  color: white;
  font-size: var(--font-size-h3);
  margin-bottom: var(--space-2);
}
.cta-section p {
  color: rgba(255,255,255,0.8);
  font-size: var(--font-size-body);
  max-width: 500px;
  margin: 0 auto var(--space-5);
}

/* === Page Header === */
.page-header {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  padding: 120px 0 var(--space-4);
  text-align: center;
}
.page-header h1 {
  color: white;
  font-size: var(--font-size-h2);
}
.page-header p {
  color: rgba(255,255,255,0.8);
  font-size: 18px;
  margin-top: var(--space-2);
}

/* === Filter Bar === */
.filter-bar {
  display: flex;
  justify-content: center;
  gap: var(--space-1);
  flex-wrap: wrap;
  margin-bottom: var(--space-5);
}
.filter-tag {
  height: 36px;
  padding: 0 16px;
  border-radius: var(--radius-full);
  font-size: var(--font-size-small);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  background: white;
  transition: all var(--transition-fast);
}
.filter-tag:hover { border-color: var(--color-primary-light); color: var(--color-primary); }
.filter-tag.active {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
}

/* === Modal === */
.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: var(--z-modal);
  align-items: center;
  justify-content: center;
}
.modal-overlay.open { display: flex; }
.modal {
  background: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  width: 560px;
  max-width: 90vw;
  max-height: 80vh;
  overflow-y: auto;
  animation: modalIn var(--transition-normal) ease-out;
}
@keyframes modalIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}
.modal-close {
  position: sticky;
  top: 16px; right: 16px;
  width: 36px; height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  color: var(--color-text-muted);
  border-radius: 50%;
  background: var(--color-bg-alt);
  float: right;
  z-index: 1;
  transition: all var(--transition-fast);
}
.modal-close:hover { color: var(--color-text); background: var(--color-border); }
.modal-body { padding: var(--space-6); clear: both; }
.modal-body h3 { font-size: var(--font-size-h4); margin-bottom: var(--space-3); }
.modal-body h4 { font-size: var(--font-size-body); color: var(--color-text-muted); margin-bottom: var(--space-2); margin-top: var(--space-4); }
.modal-body p { color: var(--color-text-muted); font-size: var(--font-size-small); line-height: 1.7; margin-bottom: var(--space-2); }
.modal-body ul { list-style: none; padding: 0; }
.modal-body ul li {
  padding: var(--space-1) 0;
  padding-left: 24px;
  position: relative;
  font-size: var(--font-size-small);
  color: var(--color-text-muted);
}
.modal-body ul li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-success);
  font-weight: var(--font-weight-bold);
}
.modal-img { width: 100%; border-radius: var(--radius-md); margin-bottom: var(--space-4); }
.modal-tags { display: flex; gap: var(--space-1); flex-wrap: wrap; margin-bottom: var(--space-4); }
.modal-tags span {
  background: var(--color-bg-highlight);
  color: var(--color-primary);
  font-size: var(--font-size-caption);
  padding: 4px 12px;
  border-radius: var(--radius-full);
}
.modal-cta {
  text-align: center;
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-3);
  margin-top: var(--space-4);
}

/* === Contact Page Layout === */
.contact-grid {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: var(--space-6);
}
.contact-cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-2);
}
.contact-card {
  background: var(--color-bg-alt);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
  transition: all var(--transition-fast);
}
.contact-card:hover { background: white; box-shadow: var(--shadow-md); }
.contact-card .icon-circle {
  width: 48px; height: 48px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  color: white;
  flex-shrink: 0;
}
.icon-phone   { background: var(--color-primary-light); }
.icon-wechat  { background: var(--color-success); }
.icon-mail    { background: var(--color-warning); }
.icon-address { background: var(--color-accent); }
.contact-card .info h4 {
  font-size: var(--font-size-body);
  margin-bottom: 2px;
}
.contact-card .info p {
  font-size: var(--font-size-small);
  color: var(--color-text-muted);
}

/* === Form === */
.form-group {
  margin-bottom: var(--space-3);
}
.form-group label {
  display: block;
  font-size: var(--font-size-small);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-1);
  color: var(--color-text);
}
.form-group label .required {
  color: var(--color-error);
  margin-left: 2px;
}
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  height: 44px;
  padding: 0 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: white;
  color: var(--color-text);
  transition: all var(--transition-fast);
  outline: none;
}
.form-group textarea {
  height: 120px;
  padding: 12px;
  resize: vertical;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--color-primary-light);
  box-shadow: 0 0 0 3px rgba(59,130,246,0.15);
}
.form-group.error input,
.form-group.error select,
.form-group.error textarea {
  border-color: var(--color-error);
}
.form-group .error-msg {
  display: none;
  color: var(--color-error);
  font-size: var(--font-size-caption);
  margin-top: 4px;
}
.form-group.error .error-msg {
  display: block;
}
.form-group .char-count {
  text-align: right;
  font-size: var(--font-size-caption);
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* Radio group */
.radio-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
}
.radio-option {
  position: relative;
}
.radio-option input { display: none; }
.radio-option label {
  display: block;
  height: 36px;
  line-height: 36px;
  padding: 0 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: var(--font-size-small);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
}
.radio-option input:checked + label {
  background: var(--color-bg-highlight);
  border-color: var(--color-primary-light);
  color: var(--color-primary);
}
.radio-option label:hover { border-color: var(--color-primary-light); }

/* === Success Message === */
.success-msg {
  display: none;
  background: #ECFDF5;
  border: 1px solid var(--color-success);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  margin-bottom: var(--space-3);
  color: #065F46;
  font-size: var(--font-size-small);
}
.success-msg.show { display: flex; align-items: center; gap: var(--space-2); }
.success-msg .icon { font-size: 20px; }

/* === Map Placeholder === */
.map-placeholder {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  height: 100%;
  min-height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: var(--font-size-small);
}

/* === Working Hours === */
.working-hours {
  text-align: center;
  padding: var(--space-5) 0;
  background: var(--color-bg-alt);
  color: var(--color-text-muted);
  font-size: var(--font-size-small);
}
.working-hours .icon { vertical-align: middle; margin-right: var(--space-1); }

/* === Accordion (FAQ) === */
.accordion { max-width: 800px; margin: 0 auto; }
.accordion-item {
  background: white;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-1);
  overflow: hidden;
}
.accordion-header {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  cursor: pointer;
  transition: background var(--transition-fast);
}
.accordion-header:hover { background: var(--color-bg-alt); }
.accordion-header .arrow {
  font-size: 14px;
  transition: transform var(--transition-fast);
  color: var(--color-text-muted);
  flex-shrink: 0;
}
.accordion-item.open .accordion-header .arrow {
  transform: rotate(180deg);
}
.accordion-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-normal);
}
.accordion-item.open .accordion-body {
  max-height: 500px;
}
.accordion-body p {
  padding: 0 var(--space-3) var(--space-3);
  color: var(--color-text-muted);
  font-size: var(--font-size-small);
  line-height: 1.7;
}

/* === SLA Table === */
.sla-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--font-size-small);
}
.sla-table th {
  background: var(--color-bg-alt);
  padding: var(--space-2);
  text-align: left;
  font-weight: var(--font-weight-semibold);
  border-bottom: 2px solid var(--color-border);
}
.sla-table td {
  padding: var(--space-2);
  border-bottom: 1px solid var(--color-border);
}
.sla-table tr:nth-child(even) td { background: var(--color-bg-alt); }
.sla-dot {
  display: inline-block;
  width: 8px; height: 8px;
  border-radius: 50%;
  margin-right: var(--space-1);
}
.sla-dot.urgent { background: var(--color-error); }
.sla-dot.important { background: var(--color-warning); }
.sla-dot.normal { background: var(--color-primary-light); }
.sla-dot.advice { background: var(--color-text-muted); }

/* === Scope Cards === */
.scope-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-3);
}
.scope-card {
  border-radius: var(--radius-md);
  padding: var(--space-5);
  border: 1px solid var(--color-border);
}
.scope-card.free { border-top: 4px solid var(--color-success); }
.scope-card.paid { border-top: 4px solid var(--color-accent); }
.scope-card .icon-circle-lg {
  width: 56px; height: 56px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 26px;
  color: white;
  margin-bottom: var(--space-3);
}
.scope-card.free .icon-circle-lg { background: var(--color-success); }
.scope-card.paid .icon-circle-lg { background: var(--color-accent); }
.scope-card h3 { margin-bottom: var(--space-3); }
.scope-card ul li {
  padding: var(--space-1) 0;
  padding-left: 24px;
  position: relative;
  font-size: var(--font-size-small);
  color: var(--color-text-muted);
}
.scope-card.free ul li::before {
  content: '✓'; position: absolute; left: 0; color: var(--color-success); font-weight: var(--font-weight-bold);
}
.scope-card.paid ul li::before {
  content: '+'; position: absolute; left: 0; color: var(--color-accent); font-weight: var(--font-weight-bold);
}

/* === Dev Advantage === */
.advantage-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  max-width: 900px;
}
.advantage-item {
  display: flex;
  gap: var(--space-3);
  align-items: flex-start;
}
.advantage-item .icon-circle-lg {
  width: 56px; height: 56px;
  border-radius: 50%;
  background: var(--color-primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  flex-shrink: 0;
}
.advantage-item h4 { font-size: var(--font-size-h4); margin-bottom: 4px; }
.advantage-item p { color: var(--color-text-muted); font-size: var(--font-size-small); line-height: 1.6; }

/* === Promise Cards (Warranty) === */
.promise-cards { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-3); }
.promise-card {
  text-align: center;
  padding: var(--space-4);
  background: white;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
}
.promise-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-card-hover); }
.promise-card .num {
  font-size: 28px;
  font-weight: var(--font-weight-bold);
  color: var(--color-accent);
  margin-bottom: var(--space-1);
}
.promise-card h4 { font-size: var(--font-size-body); margin-bottom: 4px; }
.promise-card p { font-size: var(--font-size-small); color: var(--color-text-muted); }

/* === Back to Top === */
.back-to-top {
  position: fixed;
  bottom: 32px; right: 32px;
  width: 44px; height: 44px;
  border-radius: 50%;
  background: var(--color-primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  box-shadow: var(--shadow-md);
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  transition: all var(--transition-fast);
  z-index: 50;
}
.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.back-to-top:hover { background: var(--color-primary-dark); box-shadow: var(--shadow-lg); }

/* === Footer === */
.footer {
  background: #0F172A;
  color: rgba(255,255,255,0.7);
  padding: var(--space-8) 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: var(--space-5);
}
.footer h4 {
  color: white;
  font-size: 18px;
  margin-bottom: var(--space-3);
}
.footer-contact p {
  font-size: var(--font-size-small);
  margin-bottom: var(--space-1);
  display: flex;
  align-items: center;
  gap: var(--space-1);
}
.footer-links a {
  display: block;
  font-size: var(--font-size-small);
  padding: 4px 0;
  transition: all var(--transition-fast);
}
.footer-links a:hover { color: white; padding-left: 4px; }
.footer-services p {
  font-size: var(--font-size-small);
  margin-bottom: var(--space-1);
}
.footer-qr {
  width: 120px; height: 120px;
  background: white;
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: var(--space-1);
}
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  margin-top: var(--space-6);
  padding-top: var(--space-3);
  text-align: center;
  font-size: var(--font-size-caption);
  color: rgba(255,255,255,0.4);
}

/* === Animations === */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 600ms ease-out, transform 600ms ease-out;
}
.animate-on-scroll.animated {
  opacity: 1;
  transform: translateY(0);
}

/* === Case Grid Filter Animation === */
.case-card.filtering-out {
  opacity: 0;
  transform: scale(0.95);
  transition: all var(--transition-normal);
}

/* === QR Code (Contact Page) === */
.contact-card-wechat { position: relative; }
.qr-thumb-wrap { flex-shrink: 0; text-align: center; }
.qr-thumb {
  width: 56px; height: 56px;
  border-radius: var(--radius-sm);
  border: 2px solid var(--color-border);
  cursor: pointer;
  transition: all var(--transition-fast);
  object-fit: cover;
}
.qr-thumb:hover {
  border-color: var(--color-success);
  transform: scale(1.05);
  box-shadow: 0 2px 12px rgba(16,185,129,0.2);
}
.qr-tip {
  font-size: 11px;
  color: var(--color-success);
  margin-top: 4px;
}
.qr-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  z-index: var(--z-modal);
  justify-content: center;
  align-items: center;
  backdrop-filter: blur(2px);
}
.qr-overlay.show { display: flex; }
.qr-popup {
  background: white;
  border-radius: var(--radius-xl);
  padding: 40px;
  text-align: center;
  animation: qrPopIn var(--transition-normal) ease-out;
  box-shadow: var(--shadow-xl);
}
@keyframes qrPopIn {
  from { opacity: 0; transform: scale(0.9); }
  to   { opacity: 1; transform: scale(1); }
}
.qr-popup img {
  width: 220px; height: 220px;
  border-radius: var(--radius-md);
}
.qr-popup h3 {
  margin: var(--space-2) 0 4px;
  color: var(--color-text);
  font-size: 18px;
}
.qr-popup p {
  color: var(--color-text-muted);
  font-size: var(--font-size-small);
  margin-bottom: var(--space-2);
}
@media (max-width: 500px) {
  .qr-popup { padding: 24px; margin: 0 16px; }
  .qr-popup img { width: 180px; height: 180px; }
}

/* === Responsive === */
@media (max-width: 1023px) {
  :root {
    --font-size-h1: 40px;
    --font-size-h2: 32px;
    --font-size-h3: 24px;
    --section-padding: 80px;
  }
  .header-nav, .header-phone { display: none; }
  .hamburger { display: flex; margin-left: auto; }
  .cards-4, .cards-3 { grid-template-columns: repeat(2, 1fr); }
  .promise-cards { grid-template-columns: repeat(2, 1fr); }
  .process-steps { flex-wrap: wrap; gap: var(--space-2); }
  .process-steps::before { display: none; }
  .process-step { max-width: none; flex: 0 0 calc(33.33% - 16px); }
  .contact-grid { grid-template-columns: 1fr; }
  .contact-cards { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .scope-cards { grid-template-columns: 1fr; }
  .trust-numbers { grid-template-columns: repeat(2, 1fr); }
  .sla-table { font-size: var(--font-size-caption); }
}

@media (max-width: 767px) {
  :root {
    --font-size-h1: 32px;
    --font-size-h2: 26px;
    --font-size-h3: 20px;
    --font-size-h4: 18px;
    --section-padding: 64px;
  }
  .cards-4, .cards-3, .cards-2 { grid-template-columns: 1fr; }
  .promise-cards { grid-template-columns: 1fr; }
  .hero-stats { gap: var(--space-3); }
  .hero-stat .num { font-size: 24px; }
  .hero-btns { flex-direction: column; align-items: center; }
  .hero-btns .btn { width: 100%; max-width: 280px; }
  .process-steps { flex-direction: column; gap: var(--space-3); }
  .process-step { max-width: none; flex: none; display: flex; align-items: flex-start; text-align: left; gap: var(--space-2); }
  .process-step .circle { margin: 0; flex-shrink: 0; }
  .trust-numbers { grid-template-columns: repeat(2, 1fr); gap: var(--space-2); }
  .trust-number { padding: var(--space-2); }
  .trust-number .num { font-size: 28px; }
  .contact-cards { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .map-placeholder { min-height: 250px; }
  .footer-grid { grid-template-columns: 1fr; gap: var(--space-4); }
  .scope-cards { grid-template-columns: 1fr; }
  .advantage-item { flex-direction: column; align-items: flex-start; }
  .filter-bar { justify-content: flex-start; flex-wrap: nowrap; overflow-x: auto; padding-bottom: var(--space-1); }
  .filter-bar::-webkit-scrollbar { display: none; }
  .filter-tag { flex-shrink: 0; }
  .page-header { padding: 100px 0 var(--space-3); }
  .page-header h1 { font-size: 28px; }
  .sla-table { font-size: var(--font-size-caption); }
  .sla-table th, .sla-table td { padding: var(--space-1); }
}