/* ========================================
   苏青青 · 高级门户
   ======================================== */

/* ===== CSS Variables ===== */
:root {
  --bg: #0b0a0f;
  --bg-alt: #111015;
  --surface: rgba(18,17,24,0.6);
  --surface-hover: rgba(30,28,40,0.8);
  --border: rgba(139,127,214,0.12);
  --border-hover: rgba(139,127,214,0.25);
  --primary: #8B7FD6;
  --primary-light: #b096e8;
  --accent: #7EC8E3;
  --text: rgba(255,255,255,0.85);
  --text-sub: rgba(255,255,255,0.55);
  --text-dim: rgba(255,255,255,0.3);
  --radius: 14px;
  --radius-lg: 20px;
  --transition: all 0.3s cubic-bezier(0.22, 1, 0.36, 1);
}

/* ===== Reset ===== */
*, *::before, *::after {
  margin: 0; padding: 0;
  box-sizing: border-box;
}
html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  min-height: 100vh;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* ===== Particle Canvas ===== */
#particleCanvas {
  position: fixed; inset: 0;
  z-index: 0;
  pointer-events: none;
}
.bg-gradient {
  position: fixed; inset: 0;
  z-index: 0;
  background:
    radial-gradient(ellipse 80% 60% at 20% 20%, rgba(139,127,214,0.04) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 80% 70%, rgba(126,200,227,0.03) 0%, transparent 60%),
    radial-gradient(ellipse 50% 50% at 50% 100%, rgba(192,132,252,0.02) 0%, transparent 50%);
  pointer-events: none;
}

/* ===== Loader ===== */
.loader {
  position: fixed; inset: 0;
  z-index: 999;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
  background: var(--bg);
  transition: opacity 0.6s ease, visibility 0.6s ease;
}
.loader.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}
.loader-ring {
  width: 48px; height: 48px;
  border: 2px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
.loader-text {
  font-size: 13px;
  color: var(--text-sub);
  letter-spacing: 1px;
}
@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ===== Nav ===== */
.nav {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 100;
  padding: 0 24px;
  transition: var(--transition);
}
.nav.scrolled {
  background: rgba(11,10,15,0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.5px;
  transition: var(--transition);
}
.nav-brand:hover { color: var(--primary); }
.nav-brand-icon { font-size: 18px; }
.nav-links {
  display: flex;
  gap: 32px;
}
.nav-link {
  font-size: 13px;
  color: var(--text-sub);
  letter-spacing: 0.5px;
  transition: var(--transition);
  position: relative;
}
.nav-link::after {
  content: '';
  position: absolute; bottom: -4px; left: 0; right: 0;
  height: 1.5px;
  background: var(--primary);
  transform: scaleX(0);
  transition: transform 0.3s ease;
}
.nav-link:hover { color: var(--text); }
.nav-link:hover::after { transform: scaleX(1); }
.nav-link.active { color: var(--text); }
.nav-link.active::after { transform: scaleX(1); }

.nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
}
.nav-cta {
  font-size: 12px;
  padding: 8px 18px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: white;
  font-weight: 500;
  letter-spacing: 0.3px;
  transition: var(--transition);
}
.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(139,127,214,0.25);
}

.nav-hamburger {
  display: none;
  background: none;
  border: none;
  width: 24px; height: 18px;
  flex-direction: column;
  justify-content: space-between;
  cursor: pointer;
  padding: 0;
}
.nav-hamburger span {
  display: block;
  width: 100%; height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: var(--transition);
}

@media (max-width: 768px) {
  .nav-links {
    position: fixed; top: 60px; left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: rgba(11,10,15,0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    padding: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
  }
  .nav-links.open { max-height: 300px; }
  .nav-link {
    padding: 16px 24px;
    border-bottom: 1px solid var(--border);
  }
  .nav-link::after { display: none; }
  .nav-hamburger { display: flex; }
  .nav-hamburger.open span:nth-child(1) { transform: rotate(45deg) translate(5px,6px); }
  .nav-hamburger.open span:nth-child(2) { opacity: 0; }
  .nav-hamburger.open span:nth-child(3) { transform: rotate(-45deg) translate(5px,-6px); }
}

/* ===== Hero ===== */
.hero {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 100px 24px 80px;
}
.hero-inner {
  max-width: 520px;
  opacity: 0;
  transform: translateY(30px);
  animation: heroIn 1s ease 0.2s forwards;
}
@keyframes heroIn {
  to { opacity: 1; transform: translateY(0); }
}
.hero-badge {
  display: inline-block;
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 11px;
  letter-spacing: 1px;
  background: rgba(139,127,214,0.1);
  border: 1px solid rgba(139,127,214,0.15);
  color: var(--primary-light);
  margin-bottom: 24px;
}
.hero-avatar {
  position: relative;
  width: 100px; height: 100px;
  margin: 0 auto 24px;
}
.hero-avatar-inner {
  width: 100%; height: 100%;
  border-radius: 50%;
  overflow: hidden;
  position: relative;
  z-index: 1;
}
.hero-avatar-inner img {
  width: 100%; height: 100%;
  object-fit: cover;
}
.hero-avatar-ring {
  position: absolute; inset: -4px;
  border-radius: 50%;
  border: 1.5px solid transparent;
  background: linear-gradient(135deg, var(--primary), var(--accent), var(--primary-light)) border-box;
  -webkit-mask: linear-gradient(#fff 0 0) padding-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  animation: rotateRing 4s linear infinite;
}
@keyframes rotateRing {
  to { transform: rotate(360deg); }
}
.hero-title-main {
  display: block;
  font-size: 44px;
  font-weight: 700;
  background: linear-gradient(135deg, #fff 0%, var(--primary-light) 50%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -1px;
}
.hero-title-sub {
  display: block;
  font-size: 16px;
  color: var(--text-sub);
  font-weight: 400;
  margin-top: 4px;
}
.hero-desc {
  font-size: 14px;
  color: var(--text-sub);
  line-height: 1.8;
  margin: 16px 0 32px;
}
.hero-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}
.hero-scroll-hint {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-dim);
  font-size: 11px;
  letter-spacing: 1px;
  opacity: 0;
  animation: fadeIn 1s ease 1.5s forwards;
}
.scroll-arrow {
  width: 16px; height: 16px;
  border-right: 1.5px solid var(--text-dim);
  border-bottom: 1.5px solid var(--text-dim);
  transform: rotate(45deg);
  animation: bounceArrow 2s ease infinite;
}
@keyframes bounceArrow {
  0%, 100% { transform: rotate(45deg) translate(0,0); opacity: 0.4; }
  50% { transform: rotate(45deg) translate(0,4px); opacity: 1; }
}
@keyframes fadeIn {
  to { opacity: 1; }
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 12px 26px;
  border-radius: 10px;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.3px;
  cursor: pointer;
  border: none;
  transition: var(--transition);
}
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: white;
  box-shadow: 0 4px 20px rgba(139,127,214,0.2);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 28px rgba(139,127,214,0.3);
}
.btn-arrow {
  display: inline-block;
  transition: transform 0.3s ease;
}
.btn-primary:hover .btn-arrow {
  transform: translateX(4px);
}
.btn-ghost {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-sub);
}
.btn-ghost:hover {
  border-color: var(--border-hover);
  color: var(--text);
}
.btn-lg {
  padding: 14px 32px;
  font-size: 14px;
}

/* ===== Sections ===== */
.section {
  position: relative;
  z-index: 1;
  padding: 100px 24px;
}
.section.features-section { background: var(--bg-alt); }
.section-inner {
  max-width: 1000px;
  margin: 0 auto;
}
.section-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 48px;
}
.section-number {
  font-size: 14px;
  font-weight: 500;
  color: var(--primary);
  opacity: 0.6;
  font-family: monospace;
}
.section-title {
  font-size: 28px;
  font-weight: 600;
  letter-spacing: -0.3px;
}
.section-line {
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, var(--border), transparent);
}

/* ===== About ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}
.about-text p {
  font-size: 14px;
  color: var(--text-sub);
  margin-bottom: 14px;
  line-height: 1.9;
}
.about-text p em {
  color: var(--primary-light);
  font-style: normal;
}
.about-stats {
  display: flex;
  gap: 28px;
  margin-top: 24px;
}
.stat {
  text-align: center;
}
.stat-num {
  display: block;
  font-size: 28px;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.stat-label {
  font-size: 11px;
  color: var(--text-dim);
  letter-spacing: 0.5px;
}
.about-card-glow {
  position: relative;
  padding: 1px;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--border), transparent);
}
.about-card-inner {
  background: var(--surface);
  border-radius: calc(var(--radius-lg) - 1px);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}
.ac-item {
  display: flex;
  align-items: center;
  gap: 14px;
}
.ac-icon { font-size: 20px; }
.ac-item strong {
  display: block;
  font-size: 13px;
  font-weight: 500;
}
.ac-item span {
  font-size: 12px;
  color: var(--text-dim);
}

/* ===== Features ===== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: var(--transition);
  animation: cardIn 0.6s ease calc(var(--i) * 0.08s) both;
}
@keyframes cardIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
.feature-card:hover {
  background: var(--surface-hover);
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0,0,0,0.2);
}
.fc-icon {
  font-size: 26px;
  margin-bottom: 14px;
}
.feature-card h3 {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 8px;
}
.feature-card p {
  font-size: 12.5px;
  color: var(--text-sub);
  line-height: 1.8;
}

/* ===== Showcase ===== */
.showcase-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.showcase-card {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  display: block;
  animation: cardIn 0.6s ease calc(var(--i) * 0.1s) both;
  transition: var(--transition);
}
.showcase-card:hover {
  transform: translateY(-4px);
}
.sc-bg {
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(139,127,214,0.1), rgba(126,200,227,0.05));
  transition: var(--transition);
}
.showcase-card:hover .sc-bg {
  opacity: 0.7;
}
.sc-content {
  position: relative;
  padding: 36px 24px;
  text-align: center;
}
.sc-icon {
  font-size: 30px;
  display: block;
  margin-bottom: 12px;
}
.sc-content h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 4px;
}
.sc-content p {
  font-size: 12px;
  color: var(--text-sub);
  margin-bottom: 12px;
}
.sc-link {
  font-size: 12px;
  color: var(--primary);
  font-weight: 500;
  opacity: 0;
  transform: translateY(4px);
  transition: var(--transition);
  display: inline-block;
}
.showcase-card:hover .sc-link {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Contact ===== */
.contact-section {
  text-align: center;
}
.contact-text {
  font-size: 16px;
  color: var(--text-sub);
  line-height: 2;
  margin-bottom: 28px;
}

/* ===== Footer ===== */
.footer {
  position: relative;
  z-index: 1;
  padding: 48px 24px;
  text-align: center;
  border-top: 1px solid var(--border);
}
.footer-brand {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}
.footer-sub {
  font-size: 12px;
  color: var(--text-dim);
  margin-bottom: 3px;
}
.footer-sub a {
  color: var(--primary);
}
.footer-sub a:hover { text-decoration: underline; }
.footer-copy {
  font-size: 11px;
  color: var(--text-dim);
  opacity: 0.6;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .about-grid { grid-template-columns: 1fr; gap: 32px; }
  .features-grid { grid-template-columns: 1fr 1fr; }
  .showcase-grid { grid-template-columns: 1fr; }
  .hero-title-main { font-size: 34px; }
  .section { padding: 60px 20px; }
  .hide-mobile { display: none; }
}
@media (max-width: 480px) {
  .features-grid { grid-template-columns: 1fr; }
  .about-stats { gap: 20px; }
  .about-stats { justify-content: center; }
}