:root {
  --primary: #2BA8A8;
  --primary-dark: #238E8E;
  --primary-light: #E8F7F7;
  --accent: #FF8C42;
  --accent-light: #FFF0E6;
  --text: #1F2937;
  --text-light: #6B7280;
  --bg: #FFFFFF;
  --bg-soft: #F8FAFB;
  --bg-warm: #FFFBF7;
  --shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
  --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.05);
  --radius: 16px;
  --radius-sm: 12px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  line-height: 1.6;
  background: var(--bg);
  overflow-x: hidden;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  padding: 16px 0;
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-sm);
  padding: 12px 0;
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: #fff;
  font-weight: 700;
  font-size: 1.1rem;
  transition: var(--transition);
}

.navbar.scrolled .nav-logo {
  color: var(--text);
}

.nav-logo img {
  width: 40px;
  height: 40px;
  object-fit: contain;
  border-radius: 50%;
  background: #fff;
  padding: 3px;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
}

.nav-menu a {
  display: block;
  padding: 8px 14px;
  text-decoration: none;
  color: rgba(255, 255, 255, 0.9);
  font-size: 0.95rem;
  font-weight: 500;
  border-radius: 100px;
  transition: var(--transition);
}

.navbar.scrolled .nav-menu a {
  color: var(--text);
}

.nav-menu a:hover {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
}

.navbar.scrolled .nav-menu a:hover {
  background: var(--primary-light);
  color: var(--primary-dark);
}

.nav-cta {
  background: var(--accent) !important;
  color: #fff !important;
  box-shadow: 0 4px 14px rgba(255, 140, 66, 0.35);
}

.nav-cta:hover {
  background: #FF7A2F !important;
  color: #fff !important;
  transform: translateY(-1px);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: var(--transition);
}

.navbar.scrolled .nav-toggle span {
  background: var(--text);
}

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: #fff;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: -2;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  animation: slowZoom 20s ease-in-out infinite alternate;
}

@keyframes slowZoom {
  0% { transform: scale(1); }
  100% { transform: scale(1.08); }
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(43, 168, 168, 0.85) 0%, rgba(35, 142, 142, 0.75) 50%, rgba(255, 140, 66, 0.55) 100%);
  z-index: -1;
}

.hero-content {
  position: relative;
  z-index: 1;
  padding-top: 80px;
}

.hero-logo {
  margin-bottom: 24px;
}

.hero-logo img {
  width: 120px;
  height: 120px;
  object-fit: contain;
  background: #fff;
  border-radius: 50%;
  padding: 10px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
  animation: float 4s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.hero-title {
  font-size: clamp(2.5rem, 7vw, 4.5rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 16px;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  font-weight: 500;
  opacity: 0.95;
  margin-bottom: 8px;
}

.hero-desc {
  font-size: clamp(1rem, 2vw, 1.25rem);
  opacity: 0.9;
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  margin-bottom: 60px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  border-radius: 100px;
  font-weight: 600;
  font-size: 1rem;
  text-decoration: none;
  cursor: pointer;
  border: 2px solid transparent;
  transition: var(--transition);
}

.btn-primary {
  background: #fff;
  color: var(--primary-dark);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.6);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: #fff;
}

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

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

.btn-large {
  padding: 16px 40px;
  font-size: 1.1rem;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
}

.stat-item {
  text-align: center;
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 2px;
  flex-wrap: wrap;
}

.stat-number,
.stat-suffix {
  font-size: 2.5rem;
  font-weight: 800;
}

.stat-label {
  display: block;
  width: 100%;
  font-size: 0.95rem;
  opacity: 0.9;
  margin-top: 4px;
}

.scroll-down {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  width: 40px;
  height: 60px;
  border: 2px solid rgba(255, 255, 255, 0.6);
  border-radius: 24px;
  display: flex;
  justify-content: center;
  padding-top: 10px;
  transition: var(--transition);
}

.scroll-down:hover {
  border-color: #fff;
}

.scroll-down span {
  width: 6px;
  height: 12px;
  background: #fff;
  border-radius: 3px;
  animation: scrollBounce 1.8s infinite;
}

@keyframes scrollBounce {
  0%, 100% { transform: translateY(0); opacity: 1; }
  50% { transform: translateY(10px); opacity: 0.5; }
}

/* Sections */
.section {
  padding: 100px 0;
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 64px;
}

.section-header.light {
  color: #fff;
}

.section-tag {
  display: inline-block;
  padding: 6px 16px;
  background: var(--primary-light);
  color: var(--primary-dark);
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: 100px;
  margin-bottom: 16px;
}

.section-header.light .section-tag {
  background: rgba(255, 255, 255, 0.2);
  color: #fff;
}

.section-header h2 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 16px;
  line-height: 1.3;
}

.section-header p {
  font-size: 1.1rem;
  color: var(--text-light);
}

.section-header.light p {
  color: rgba(255, 255, 255, 0.85);
}

/* About */
.about {
  background: var(--bg-soft);
}

.problems-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 64px;
}

.problem-card {
  background: #fff;
  padding: 36px 28px;
  border-radius: var(--radius);
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.problem-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow);
}

.problem-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.problem-card h3 {
  font-size: 1.25rem;
  margin-bottom: 10px;
  color: var(--text);
}

.problem-card p {
  color: var(--text-light);
  font-size: 0.95rem;
}

.about-solution {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  background: #fff;
  border-radius: var(--radius);
  padding: 48px;
  box-shadow: var(--shadow-sm);
}

.solution-text h3 {
  font-size: 1.75rem;
  margin-bottom: 20px;
  color: var(--primary-dark);
}

.solution-text p {
  font-size: 1.05rem;
  color: var(--text-light);
  margin-bottom: 24px;
  line-height: 1.8;
}

.solution-text ul {
  list-style: none;
}

.solution-text li {
  position: relative;
  padding-left: 28px;
  margin-bottom: 14px;
  color: var(--text);
}

.solution-text li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--primary);
  font-weight: 700;
}

.solution-image {
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.solution-image img {
  width: 100%;
  height: auto;
  display: block;
  transition: var(--transition);
}

.solution-image:hover img {
  transform: scale(1.03);
}

/* Values */
.values {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  position: relative;
  overflow: hidden;
}

.values::before {
  content: "";
  position: absolute;
  top: -100px;
  right: -100px;
  width: 400px;
  height: 400px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 50%;
}

.values::after {
  content: "";
  position: absolute;
  bottom: -150px;
  left: -150px;
  width: 500px;
  height: 500px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: 50%;
}

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

.values-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.value-card {
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius);
  padding: 40px 28px;
  color: #fff;
  transition: var(--transition);
}

.value-card:hover {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-8px);
}

.value-number {
  font-size: 3rem;
  font-weight: 800;
  opacity: 0.3;
  margin-bottom: 16px;
  line-height: 1;
}

.value-card h3 {
  font-size: 1.4rem;
  margin-bottom: 14px;
}

.value-card p {
  opacity: 0.9;
  line-height: 1.7;
}

/* Activities */
.activities {
  background: var(--bg-warm);
}

.activities-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-bottom: 40px;
}

.activity-card {
  background: #fff;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.activity-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow);
}

.activity-image {
  height: 200px;
  background-size: cover;
  background-position: center;
  position: relative;
}

.activity-content {
  padding: 24px;
}

.activity-badge {
  display: inline-block;
  padding: 4px 12px;
  background: var(--accent-light);
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: 100px;
  margin-bottom: 12px;
}

.activity-content h3 {
  font-size: 1.25rem;
  margin-bottom: 10px;
}

.activity-content p {
  color: var(--text-light);
  font-size: 0.95rem;
}

.activities-extra {
  text-align: center;
  background: #fff;
  padding: 32px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  color: var(--text-light);
}

.activities-extra strong {
  color: var(--primary-dark);
}

/* Goal */
.goal {
  background: var(--bg);
}

.goal-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.goal-text h2 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 20px;
  line-height: 1.3;
  color: var(--text);
}

.goal-text > p {
  color: var(--text-light);
  font-size: 1.1rem;
  margin-bottom: 36px;
  line-height: 1.8;
}

.goal-metrics {
  display: flex;
  gap: 32px;
  flex-wrap: wrap;
}

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

.goal-number,
.goal-suffix {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--primary);
}

.goal-suffix {
  font-size: 1.25rem;
  color: var(--text);
  margin-left: 2px;
}

.goal-label {
  display: block;
  color: var(--text-light);
  font-size: 0.9rem;
  margin-top: 4px;
}

.goal-image {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.goal-image img {
  width: 100%;
  height: auto;
  display: block;
}

.goal-badge {
  position: absolute;
  bottom: 24px;
  right: 24px;
  background: var(--accent);
  color: #fff;
  padding: 10px 20px;
  border-radius: 100px;
  font-weight: 700;
  box-shadow: 0 4px 16px rgba(255, 140, 66, 0.35);
}

/* Join */
.join {
  background: linear-gradient(135deg, var(--primary-light) 0%, #fff 100%);
  text-align: center;
}

.join-content {
  max-width: 680px;
  margin: 0 auto;
}

.join-logo img {
  width: 100px;
  height: 100px;
  object-fit: contain;
  background: #fff;
  border-radius: 50%;
  padding: 8px;
  box-shadow: var(--shadow);
  margin-bottom: 24px;
}

.join-content h2 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  margin-bottom: 16px;
  color: var(--text);
}

.join-content > p {
  color: var(--text-light);
  font-size: 1.1rem;
  margin-bottom: 32px;
}

.join-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.join-note {
  font-size: 0.95rem;
  color: var(--text-light);
  font-style: italic;
}

/* Footer */
.footer {
  background: var(--text);
  color: rgba(255, 255, 255, 0.7);
  padding: 48px 0;
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 12px;
  color: #fff;
  font-weight: 700;
  font-size: 1.1rem;
}

.footer-brand img {
  width: 40px;
  height: 40px;
  object-fit: contain;
  background: #fff;
  border-radius: 50%;
  padding: 4px;
}

.footer-slogan {
  margin-bottom: 16px;
  color: rgba(255, 255, 255, 0.85);
}

.footer-copy {
  font-size: 0.85rem;
}

/* Toast */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text);
  color: #fff;
  padding: 14px 28px;
  border-radius: 100px;
  font-weight: 500;
  z-index: 3000;
  opacity: 0;
  transition: var(--transition);
  box-shadow: var(--shadow);
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* Reveal animations */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 1024px) {
  .problems-grid,
  .values-grid,
  .activities-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    flex-direction: column;
    background: rgba(255, 255, 255, 0.98);
    padding: 16px;
    gap: 4px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
  }

  .nav-menu.open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav-menu a {
    color: var(--text) !important;
    width: 100%;
    text-align: center;
  }

  .nav-cta {
    background: var(--accent) !important;
    color: #fff !important;
  }

  .hero-stats {
    gap: 24px;
  }

  .stat-number,
  .stat-suffix {
    font-size: 2rem;
  }

  .values-grid,
  .activities-grid,
  .about-solution,
  .goal-content {
    grid-template-columns: 1fr;
  }

  .problems-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .problem-card {
    padding: 28px 24px;
  }

  .problem-icon {
    font-size: 2.25rem;
  }

  .goal-metrics {
    justify-content: center;
  }

  .about-solution,
  .goal-text {
    text-align: center;
  }

  .solution-text ul {
    display: inline-block;
    text-align: left;
  }

  .section {
    padding: 72px 0;
  }

  .about-solution {
    padding: 32px;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
    width: 100%;
    padding: 0 24px;
  }

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

  .join-actions {
    flex-direction: column;
  }

  .join-actions .btn {
    width: 100%;
  }

  .goal-badge {
    font-size: 0.8rem;
    padding: 8px 14px;
  }
}