:root {
  --white: #ffffff;
  --bg: #ffffff;
  --bg-alt: #fafafa;
  --bg-dark: #0a0a0a;
  --text-primary: #0a0a0a;
  --text-secondary: #555555;
  --text-muted: #999999;
  --text-light: #cccccc;
  --border: #e5e5e5;
  --border-light: #dddddd;
  --accent: #2a2a2a;
  --overlay: rgba(0, 0, 0, 0.55);
  --font-en: 'Space Grotesk', sans-serif;
  --font-cn: 'Noto Sans SC', sans-serif;
  --container: 1200px;
  --nav-height: 72px;
  --section-pad: 140px;
  --grid-gap: 48px;
  --radius: 3px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 40px rgba(0,0,0,0.12);
  --transition: 0.35s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

*, *::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-primary); background: var(--bg);
  line-height: 1.7; font-weight: 400;
  -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
button { border: none; background: none; cursor: pointer; font-family: inherit; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 32px; }

/* ==================== Typography ==================== */
.overline {
  font-family: var(--font-en); font-size: 11px; font-weight: 600;
  letter-spacing: 0.2em; text-transform: uppercase; color: var(--text-muted);
}
.section-label {
  font-family: var(--font-en); font-size: 13px; font-weight: 500;
  letter-spacing: 0.15em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 12px;
}
.section-number {
  font-family: var(--font-en); font-size: 80px; font-weight: 700;
  color: rgba(255,255,255,0.1); line-height: 1; margin-bottom: 12px; letter-spacing: -0.04em;
}
.section-title {
  font-size: 42px; font-weight: 700; letter-spacing: -0.02em;
  line-height: 1.2; margin-bottom: 20px;
}
.section-desc { font-size: 17px; color: var(--text-secondary); line-height: 1.8; max-width: 560px; }

/* ==================== Buttons ==================== */
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 14px 32px;
  font-size: 14px; font-weight: 500; letter-spacing: 0.02em;
  border-radius: var(--radius); transition: all var(--transition); cursor: pointer;
}
.btn-primary { background: var(--text-primary); color: var(--white); }
.btn-primary:hover { background: var(--accent); transform: translateY(-1px); box-shadow: var(--shadow-md); }
.btn-outline { background: transparent; color: var(--text-primary); border: 1.5px solid var(--text-primary); }
.btn-outline:hover { background: var(--text-primary); color: var(--white); }
.btn-white { background: var(--white); color: var(--text-primary); }
.btn-white:hover { background: var(--bg-alt); transform: translateY(-1px); }
.btn-sm { padding: 10px 24px; font-size: 13px; }
.btn-icon { width: 20px; height: 20px; }

/* ==================== Navigation ==================== */
.nav {
  position: fixed; top: 0; left: 0; right: 0;
  height: var(--nav-height); z-index: 1000;
  background: transparent;
  transition: all var(--transition);
}
.nav.scrolled {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 1px 0 var(--border);
}
.nav-inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 100%; max-width: var(--container); margin: 0 auto; padding: 0 32px;
}
.nav-logo {
  font-family: var(--font-en); font-size: 20px; font-weight: 700;
  letter-spacing: -0.02em; color: var(--white);
  display: flex; align-items: center; gap: 10px;
  transition: color var(--transition);
}
.nav-logo .logo-mark {
  width: 32px; height: 32px; background: var(--white); border-radius: 6px;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; font-weight: 700; color: var(--bg-dark);
  transition: all var(--transition);
}
.nav-links { display: flex; align-items: center; gap: 36px; }
.nav-links a {
  font-size: 14px; font-weight: 400; color: rgba(255,255,255,0.8);
  transition: color var(--transition); position: relative;
}
.nav-links a::after {
  content: ''; position: absolute; bottom: -4px; left: 0;
  width: 0; height: 1.5px; background: var(--white);
  transition: width var(--transition);
}
.nav-links a:hover { color: var(--white); }
.nav-links a:hover::after { width: 100%; }
.nav-links a.active { color: var(--white); font-weight: 500; }
.nav-links a.active::after { width: 100%; }
.nav.scrolled .nav-logo { color: var(--text-primary); }
.nav.scrolled .nav-logo .logo-mark { background: var(--bg-dark); color: var(--white); }
.nav.scrolled .nav-links a { color: var(--text-secondary); }
.nav.scrolled .nav-links a:hover, .nav.scrolled .nav-links a.active { color: var(--text-primary); }
.nav.scrolled .nav-links a::after { background: var(--text-primary); }
.nav-cta .btn { padding: 10px 24px; font-size: 13px; }
.nav-menu-btn { display: none; color: var(--white); transition: color var(--transition); }
.nav.scrolled .nav-menu-btn { color: var(--text-primary); }

/* Mobile Menu */
.mobile-menu {
  display: none; position: fixed; inset: 0; background: var(--white);
  z-index: 1100; flex-direction: column; align-items: center; justify-content: center; gap: 32px;
  opacity: 0; pointer-events: none; transition: opacity 0.4s ease;
}
.mobile-menu.open { opacity: 1; pointer-events: all; }
.mobile-menu a { font-size: 28px; font-weight: 500; color: var(--text-primary); }
.mobile-menu-close {
  position: absolute; top: 24px; right: 32px;
  color: var(--text-primary); z-index: 2;
}

/* ==================== Page Hero ==================== */
.page-hero {
  position: relative; height: 52vh; min-height: 380px; max-height: 560px;
  overflow: hidden; display: flex; align-items: flex-end;
}
.page-hero-bg {
  position: absolute; inset: 0; background-size: cover; background-position: center;
}
.page-hero-overlay {
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(0,0,0,0.65) 0%, rgba(0,0,0,0.35) 100%);
}
.page-hero-content {
  position: relative; z-index: 10;
  padding: 0 0 80px calc((100vw - var(--container)) / 2 + 32px);
  max-width: var(--container);
}
.page-hero-content h1 {
  font-size: 52px; font-weight: 700; color: var(--white);
  line-height: 1.15; letter-spacing: -0.02em; margin-bottom: 20px;
}
.page-hero-content p {
  font-size: 18px; color: rgba(255,255,255,0.75); max-width: 520px;
}

/* ==================== Stats Bar ==================== */
.stats-bar { padding: 80px 0; border-bottom: 1px solid var(--border); }
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; }
.stat-item { text-align: center; padding: 0 32px; }
.stat-number {
  font-family: var(--font-en); font-size: 48px; font-weight: 700;
  letter-spacing: -0.03em; line-height: 1; margin-bottom: 12px; color: var(--text-primary);
}
.stat-number .suffix { font-size: 28px; font-weight: 400; color: var(--text-muted); }
.stat-label { font-size: 14px; color: var(--text-muted); font-weight: 400; }

/* ==================== Filter ==================== */
.filter-section { padding: var(--section-pad) 0; }
.filter-section-header { margin-bottom: 64px; }
.filter-tabs { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 56px; }
.filter-btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 20px; font-size: 13px; font-weight: 500;
  border-radius: var(--radius); border: 1px solid var(--border);
  color: var(--text-secondary); background: var(--bg);
  cursor: pointer; transition: all var(--transition);
}
.filter-btn:hover { border-color: var(--text-primary); color: var(--text-primary); }
.filter-btn.active { background: var(--text-primary); color: var(--white); border-color: var(--text-primary); }

/* ==================== Cases Grid ==================== */
.cases-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.case-card {
  border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--border); transition: all var(--transition); cursor: pointer;
}
.case-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.case-card-img {
  width: 100%; height: 240px; background-size: cover; background-position: center;
  position: relative;
}
.case-card-img::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.5) 0%, transparent 50%);
  opacity: 0; transition: opacity var(--transition);
}
.case-card:hover .case-card-img::after { opacity: 1; }
.case-card-tag {
  position: absolute; top: 16px; left: 16px; z-index: 2;
  font-size: 11px; padding: 3px 10px; background: rgba(255,255,255,0.95);
  border-radius: 20px; color: var(--text-muted); font-weight: 500;
  backdrop-filter: blur(8px);
}
.case-card-body { padding: 28px; }
.case-client {
  font-family: var(--font-en); font-size: 12px; font-weight: 500;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 10px;
}
.case-card-body h3 {
  font-size: 19px; font-weight: 600; margin-bottom: 12px; line-height: 1.4;
}
.case-card-body p {
  font-size: 14px; color: var(--text-secondary); margin-bottom: 20px; line-height: 1.7;
}
.case-metrics {
  display: flex; gap: 24px; padding-top: 20px; border-top: 1px solid var(--border-light);
}
.case-metric-value {
  font-family: var(--font-en); font-size: 22px; font-weight: 700; color: var(--text-primary);
}
.case-metric-label { font-size: 12px; color: var(--text-muted); }

/* ==================== Featured Case ==================== */
.featured-section { padding: var(--section-pad) 0; background: var(--bg-alt); }
.featured-header { margin-bottom: 64px; }
.featured-img {
  width: 100%; height: 440px; background-size: cover; background-position: center;
  border-radius: var(--radius); margin-bottom: 120px; overflow: hidden;
}

.featured-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 80px; margin-bottom: 120px;
}
.featured-label {
  font-family: var(--font-en); font-size: 11px; font-weight: 600;
  letter-spacing: 0.2em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 16px;
}
.featured-subtitle {
  font-size: 24px; font-weight: 700; margin-bottom: 20px;
}
.featured-text { font-size: 15px; color: var(--text-secondary); line-height: 1.8; margin-bottom: 16px; }

.pain-points-list { display: flex; flex-direction: column; gap: 20px; }
.pain-point-card {
  display: flex; align-items: flex-start; gap: 16px;
  padding: 20px; background: var(--white); border-radius: var(--radius);
  border: 1px solid var(--border);
}
.pain-point-icon {
  width: 40px; height: 40px; background: var(--bg-alt); border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0; color: var(--text-primary);
}
.pain-point-card h4 { font-size: 14px; font-weight: 600; margin-bottom: 4px; }
.pain-point-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.6; }

/* Architecture */
.arch-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-bottom: 120px; }
.arch-card {
  background: var(--white); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 32px; text-align: center; transition: all var(--transition);
}
.arch-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.arch-icon {
  width: 56px; height: 56px; margin: 0 auto 20px; background: var(--bg-alt);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  color: var(--text-primary);
}
.arch-card h4 { font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.arch-card p { font-size: 13px; color: var(--text-secondary); line-height: 1.7; }

/* Timeline */
.timeline-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 80px; margin-bottom: 120px;
}
.timeline { display: flex; flex-direction: column; }
.timeline-item {
  position: relative; padding-left: 48px; padding-bottom: 40px;
}
.timeline-item::before {
  content: ''; position: absolute; left: 15px; top: 40px; bottom: -24px; width: 1px;
  background: var(--border);
}
.timeline-item:last-child::before { display: none; }
.timeline-number {
  position: absolute; left: 0; top: 0; width: 32px; height: 32px;
  background: var(--bg-dark); color: var(--white); border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-en); font-size: 14px; font-weight: 700; z-index: 1;
}
.timeline-item h4 { font-size: 16px; font-weight: 600; margin-bottom: 6px; }
.timeline-item p { font-size: 14px; color: var(--text-secondary); line-height: 1.7; }

/* Tech Stack */
.tech-list { display: flex; flex-direction: column; gap: 16px; }
.tech-item {
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px; background: var(--white); border-radius: var(--radius);
  border: 1px solid var(--border);
}
.tech-item-left { display: flex; align-items: center; gap: 12px; }
.tech-item-left span { font-size: 14px; font-weight: 500; }
.tech-item-right { font-size: 14px; color: var(--text-secondary); }

/* Results */
.results-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-bottom: 120px; }
.result-card {
  background: var(--white); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 32px; text-align: center; transition: all var(--transition);
}
.result-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.result-value {
  font-family: var(--font-en); font-size: 52px; font-weight: 700;
  letter-spacing: -0.03em; line-height: 1; margin-bottom: 12px;
}
.result-label { font-size: 14px; color: var(--text-muted); margin-bottom: 8px; }
.result-change { font-size: 12px; color: #16a34a; font-weight: 500; }

/* Testimonial */
.testimonial {
  background: var(--bg-dark); color: var(--white); border-radius: var(--radius);
  padding: 64px; position: relative; overflow: hidden;
}
.testimonial-quote-mark {
  position: absolute; top: 24px; left: 32px;
  font-family: var(--font-en); font-size: 120px; font-weight: 700;
  color: rgba(255,255,255,0.04); line-height: 1; letter-spacing: -0.04em;
}
.testimonial-inner { position: relative; z-index: 1; }
.testimonial-text {
  font-size: 22px; color: rgba(255,255,255,0.85); line-height: 1.8;
  margin-bottom: 32px; max-width: 800px;
}
.testimonial-author { display: flex; align-items: center; gap: 16px; }
.testimonial-avatar {
  width: 48px; height: 48px; border-radius: 50%;
  background: rgba(255,255,255,0.1); display: flex; align-items: center;
  justify-content: center; color: rgba(255,255,255,0.6);
  font-family: var(--font-en); font-size: 18px; font-weight: 700;
}
.testimonial-name { font-size: 14px; font-weight: 600; color: var(--white); }
.testimonial-role { font-size: 12px; color: rgba(255,255,255,0.5); }

/* ==================== CTA ==================== */
.cta-section { padding: 100px 0; text-align: center; }
.cta-section .section-title { margin-bottom: 24px; }
.cta-section .section-desc { margin: 0 auto 48px; text-align: center; }
.cta-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* ==================== Footer ==================== */
.footer { background: var(--bg-dark); color: var(--white); padding: 80px 0 0; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 64px; margin-bottom: 64px; }
.footer-brand h3 { font-family: var(--font-en); font-size: 22px; font-weight: 700; margin-bottom: 16px; letter-spacing: -0.02em; }
.footer-brand p { font-size: 14px; color: rgba(255,255,255,0.5); line-height: 1.7; max-width: 320px; }
.footer-col h4 { font-size: 14px; font-weight: 600; margin-bottom: 24px; letter-spacing: 0.02em; }
.footer-col ul li { margin-bottom: 14px; }
.footer-col ul li a { font-size: 14px; color: rgba(255,255,255,0.5); transition: color var(--transition); }
.footer-col ul li a:hover { color: var(--white); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1); padding: 24px 0;
  display: flex; justify-content: space-between; align-items: center;
}
.footer-bottom p { font-size: 13px; color: rgba(255,255,255,0.35); }
.footer-bottom-links { display: flex; gap: 24px; }
.footer-bottom-links a { font-size: 13px; color: rgba(255,255,255,0.35); transition: color var(--transition); }
.footer-bottom-links a:hover { color: rgba(255,255,255,0.7); }

/* ==================== Back to Top ==================== */
.back-to-top {
  position: fixed; bottom: 32px; right: 32px;
  width: 48px; height: 48px; background: var(--text-primary); color: var(--white);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  z-index: 100; opacity: 0; pointer-events: none;
  transform: translateY(12px); transition: all var(--transition); box-shadow: var(--shadow-md);
}
.back-to-top.visible { opacity: 1; pointer-events: all; transform: translateY(0); }
.back-to-top:hover { transform: translateY(-2px); }

/* ==================== Quote Modal ==================== */
.quote-modal {
  position: fixed; inset: 0; z-index: 3000;
  display: flex; align-items: center; justify-content: center;
  opacity: 0; pointer-events: none; transition: opacity 0.4s ease;
}
.quote-modal.open { opacity: 1; pointer-events: all; }
.quote-modal-overlay { position: absolute; inset: 0; background: rgba(0,0,0,0.6); backdrop-filter: blur(4px); }
.quote-modal-content {
  position: relative; background: var(--white); width: 92%; max-width: 860px;
  max-height: 90vh; overflow-y: auto; border-radius: var(--radius); z-index: 1;
  transform: translateY(30px) scale(0.97);
  transition: transform 0.45s cubic-bezier(0.25, 0.46, 0.45, 0.94);
  overflow: hidden; box-shadow: 0 24px 80px rgba(0,0,0,0.18);
}
.quote-modal.open .quote-modal-content { transform: translateY(0) scale(1); }
.quote-modal-inner { display: grid; grid-template-columns: 1fr 1fr; min-height: 460px; }
.quote-modal-left {
  background: var(--bg-dark); color: var(--white); padding: 52px 44px;
  display: flex; flex-direction: column; justify-content: space-between;
}
.quote-modal-left .overline { color: rgba(255,255,255,0.45); margin-bottom: 24px; }
.quote-modal-left h2 { font-size: 30px; font-weight: 700; line-height: 1.25; letter-spacing: -0.02em; margin-bottom: 20px; }
.quote-modal-left > p { font-size: 15px; color: rgba(255,255,255,0.6); line-height: 1.8; margin-bottom: 40px; }
.quote-modal-contact-info { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 28px; }
.quote-modal-contact-item { display: flex; align-items: center; gap: 14px; margin-bottom: 16px; }
.quote-modal-contact-item:last-child { margin-bottom: 0; }
.quote-modal-contact-icon {
  width: 36px; height: 36px; border: 1px solid rgba(255,255,255,0.15); border-radius: 50%;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0; color: rgba(255,255,255,0.7);
}
.quote-modal-contact-item span { font-size: 15px; color: rgba(255,255,255,0.85); }
.quote-modal-right { padding: 52px 44px; display: flex; flex-direction: column; justify-content: center; }
.quote-modal-right h3 { font-size: 22px; font-weight: 700; margin-bottom: 8px; letter-spacing: -0.01em; }
.quote-modal-right > p { font-size: 14px; color: var(--text-muted); margin-bottom: 32px; }
.quote-form .form-group { margin-bottom: 20px; }
.quote-form label { display: block; font-size: 13px; font-weight: 500; margin-bottom: 8px; color: var(--text-primary); }
.quote-form label .required { color: #e53e3e; }
.quote-form input, .quote-form textarea {
  width: 100%; padding: 14px 16px; border: 1px solid var(--border); border-radius: var(--radius);
  background: var(--white); color: var(--text-primary); font-size: 15px;
  transition: border-color var(--transition); outline: none; font-family: inherit;
}
.quote-form input:focus, .quote-form textarea:focus { border-color: var(--text-primary); }
.quote-form textarea { resize: vertical; min-height: 64px; }
.quote-form .btn { width: 100%; justify-content: center; margin-top: 4px; }
.quote-modal-close {
  position: absolute; top: 20px; right: 20px; width: 40px; height: 40px;
  display: flex; align-items: center; justify-content: center;
  background: rgba(0,0,0,0.06); border-radius: 50%; z-index: 2;
  color: var(--text-muted); transition: all var(--transition); cursor: pointer;
}
.quote-modal-close:hover { background: rgba(0,0,0,0.12); color: var(--text-primary); }
.quote-modal-success { display: none; text-align: center; padding: 60px 44px; }
.quote-modal-success.show { display: flex; flex-direction: column; align-items: center; justify-content: center; min-height: 460px; }
.quote-modal-success .success-icon { width: 72px; height: 72px; margin-bottom: 24px; color: #22c55e; }
.quote-modal-success h3 { font-size: 24px; font-weight: 700; margin-bottom: 10px; }
.quote-modal-success p { font-size: 15px; color: var(--text-secondary); line-height: 1.7; }

/* ==================== Case Detail Modal ==================== */
.case-modal {
  position: fixed; inset: 0; z-index: 2000;
  display: flex; align-items: center; justify-content: center;
  opacity: 0; pointer-events: none; transition: opacity 0.4s ease;
}
.case-modal.open { opacity: 1; pointer-events: all; }
.case-modal-overlay { position: absolute; inset: 0; background: rgba(0,0,0,0.6); backdrop-filter: blur(4px); }
.case-modal-content {
  position: relative; background: var(--white); width: 92%; max-width: 860px;
  max-height: 85vh; overflow-y: auto; border-radius: var(--radius); z-index: 1;
  transform: translateY(20px); transition: transform 0.4s ease;
}
.case-modal.open .case-modal-content { transform: translateY(0); }
.case-modal-close {
  position: absolute; top: 20px; right: 20px; width: 40px; height: 40px;
  display: flex; align-items: center; justify-content: center;
  background: var(--bg-alt); border-radius: 50%; z-index: 2;
  color: var(--text-primary); cursor: pointer; transition: all var(--transition);
}
.case-modal-close:hover { background: var(--border); }
.case-modal-img { width: 100%; height: 300px; background-size: cover; background-position: center; }
.case-modal-body { padding: 48px; }
.case-modal-body .modal-tag {
  font-family: var(--font-en); font-size: 11px; font-weight: 600;
  letter-spacing: 0.2em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 12px; display: block;
}
.case-modal-body h2 { font-size: 32px; font-weight: 700; line-height: 1.3; margin-bottom: 16px; }
.case-modal-body .modal-desc { font-size: 14px; color: var(--text-secondary); line-height: 1.8; margin-bottom: 32px; }
.case-modal-metrics {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
  padding-top: 24px; border-top: 1px solid var(--border);
}
.case-modal-metric { text-align: center; }
.case-modal-metric .value {
  font-family: var(--font-en); font-size: 22px; font-weight: 700;
  color: var(--text-primary); margin-bottom: 4px;
}
.case-modal-metric .label { font-size: 12px; color: var(--text-muted); }

/* ==================== Side Tools ==================== */
.side-tools {
  position: fixed; right: 28px; top: 50%; transform: translateY(-50%);
  z-index: 950; display: flex; flex-direction: column; gap: 6px;
}
.side-tool-btn {
  width: 52px; height: 52px; background: var(--white); border: 1px solid var(--border);
  border-radius: 50%; display: flex; align-items: center; justify-content: center;
  cursor: pointer; transition: all var(--transition); color: var(--text-primary);
  position: relative; box-shadow: var(--shadow-sm); padding: 0;
}
.side-tool-btn:hover {
  background: var(--text-primary); color: var(--white); border-color: var(--text-primary);
  transform: scale(1.08); box-shadow: var(--shadow-md);
}
.side-tool-label {
  position: absolute; right: 62px; white-space: nowrap;
  background: var(--text-primary); color: var(--white);
  padding: 6px 14px; border-radius: var(--radius);
  font-size: 13px; font-weight: 500; opacity: 0; pointer-events: none;
  transform: translateX(8px); transition: all var(--transition); box-shadow: var(--shadow-sm);
}
.side-tool-label::after {
  content: ''; position: absolute; right: -6px; top: 50%; transform: translateY(-50%);
  width: 0; height: 0;
  border-top: 6px solid transparent; border-bottom: 6px solid transparent;
  border-left: 6px solid var(--text-primary);
}
.side-tool-btn:hover .side-tool-label { opacity: 1; transform: translateX(0); }

/* ==================== Mobile Bottom Tools ==================== */
.mobile-tools {
  display: none; position: fixed; bottom: 0; left: 0; right: 0;
  z-index: 950; background: var(--white);
  border-top: 1px solid var(--border); box-shadow: 0 -2px 20px rgba(0,0,0,0.06);
}
.mobile-tools-inner { display: grid; grid-template-columns: repeat(3, 1fr); height: 56px; }
.mobile-tool-btn {
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 2px; cursor: pointer; transition: all var(--transition);
  color: var(--text-secondary); padding: 0; font-size: 11px; font-weight: 500; font-family: var(--font-cn);
}
.mobile-tool-btn:hover { color: var(--text-primary); background: var(--bg-alt); }

/* ==================== Animations ==================== */
.reveal { opacity: 0; transform: translateY(32px); transition: opacity 0.8s ease, transform 0.8s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }
.reveal-left { opacity: 0; transform: translateX(-32px); transition: opacity 0.8s ease, transform 0.8s ease; }
.reveal-left.visible { opacity: 1; transform: translateX(0); }
.reveal-right { opacity: 0; transform: translateX(32px); transition: opacity 0.8s ease, transform 0.8s ease; }
.reveal-right.visible { opacity: 1; transform: translateX(0); }

.stagger-children > * { opacity: 0; transform: translateY(24px); transition: opacity 0.6s ease, transform 0.6s ease; }
.stagger-children.visible > *:nth-child(1) { transition-delay: 0s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(2) { transition-delay: 0.08s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(3) { transition-delay: 0.16s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(4) { transition-delay: 0.24s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(5) { transition-delay: 0.32s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(6) { transition-delay: 0.4s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(7) { transition-delay: 0.48s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(8) { transition-delay: 0.56s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(9) { transition-delay: 0.64s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(10) { transition-delay: 0.72s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(11) { transition-delay: 0.8s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(12) { transition-delay: 0.88s; opacity: 1; transform: translateY(0); }
.stagger-children.visible > * { opacity: 1; transform: translateY(0); }

.detail-metric { opacity: 0; transform: translateY(20px); transition: opacity 0.5s ease, transform 0.5s ease; }
.detail-metric.visible { opacity: 1; transform: translateY(0); }
.detail-metric:nth-child(1) { transition-delay: 0s; }
.detail-metric:nth-child(2) { transition-delay: 0.1s; }
.detail-metric:nth-child(3) { transition-delay: 0.2s; }
.detail-metric:nth-child(4) { transition-delay: 0.3s; }

/* ==================== Responsive ==================== */
@media (max-width: 1024px) {
  :root { --section-pad: 100px; --grid-gap: 32px; }
  .section-title { font-size: 34px; }
  .section-number { font-size: 60px; }
  .cases-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { gap: 32px; }
  .arch-grid { grid-template-columns: repeat(2, 1fr); }
  .results-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  :root { --section-pad: 80px; --nav-height: 60px; }
  .nav-links, .nav-cta { display: none; }
  .nav-menu-btn { display: flex; }
  .mobile-menu { display: flex; }
  .section-title { font-size: 28px; }
  .section-number { font-size: 48px; }
  .cases-grid { grid-template-columns: 1fr; }
  .featured-grid { grid-template-columns: 1fr; gap: 40px; }
  .timeline-grid { grid-template-columns: 1fr; gap: 40px; }
  .arch-grid { grid-template-columns: 1fr; }
  .results-grid { grid-template-columns: 1fr 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .page-hero-bg { height: 420px; }
  .page-hero-content h1 { font-size: 36px; }
  .featured-img { height: 300px; }
  .side-tools { display: none !important; }
  .mobile-tools { display: block; }
  .footer-grid { grid-template-columns: 1fr; gap: 40px; }
  .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
  .quote-modal-inner { grid-template-columns: 1fr; }
  .quote-modal-left { padding: 40px 32px 32px; }
  .quote-modal-right { padding: 32px; }
  .case-modal-metrics { grid-template-columns: 1fr; gap: 16px; }
  .case-modal-body { padding: 32px; }
  .testimonial { padding: 40px 24px; }
  .testimonial-text { font-size: 18px; }
}

@media (max-width: 480px) {
  .container { padding: 0 20px; }
  .page-hero-content h1 { font-size: 30px; }
  .stat-number { font-size: 40px; }
  .results-grid { grid-template-columns: 1fr; }
  .cta-actions { flex-direction: column; align-items: center; }
}