:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #3b82f6;
  --color-accent: #06b6d4;
  --color-bg: #0f172a;
  --color-bg-alt: #1e293b;
  --color-surface: #ffffff;
  --color-text: #1e293b;
  --color-text-muted: #64748b;
  --color-text-light: #94a3b8;
  --color-border: #e2e8f0;
  --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.15);
  --radius: 12px;
  --radius-lg: 20px;
  --transition: 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  line-height: 1.6;
  background: var(--color-surface);
  overflow-x: hidden;
}

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

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: var(--transition);
}

.header--scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--color-text);
}

.nav__logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: #fff;
  font-weight: 700;
  font-size: 18px;
  border-radius: 10px;
}

.nav__logo-text {
  font-weight: 700;
  font-size: 18px;
}

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

.nav__link {
  display: block;
  padding: 8px 16px;
  text-decoration: none;
  color: var(--color-text-muted);
  font-size: 15px;
  font-weight: 500;
  border-radius: 8px;
  transition: var(--transition);
}

.nav__link:hover {
  color: var(--color-primary);
  background: rgba(37, 99, 235, 0.06);
}

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

.nav__link--cta:hover {
  background: var(--color-primary-dark);
}

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav__toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: var(--transition);
}

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 0 80px;
  overflow: hidden;
}

.hero__bg {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #0f172a 100%);
  z-index: 0;
}

.hero__bg::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 80%;
  height: 150%;
  background: radial-gradient(ellipse, rgba(37, 99, 235, 0.25) 0%, transparent 70%);
}

.hero__bg::after {
  content: "";
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 60%;
  height: 100%;
  background: radial-gradient(ellipse, rgba(6, 182, 212, 0.15) 0%, transparent 70%);
}

.hero__content {
  position: relative;
  z-index: 1;
  color: #fff;
}

.hero__badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 50px;
  font-size: 14px;
  letter-spacing: 2px;
  margin-bottom: 24px;
}

.hero__title {
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 24px;
}

.hero__title-accent {
  background: linear-gradient(90deg, #60a5fa, #22d3ee);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__desc {
  font-size: 18px;
  color: var(--color-text-light);
  max-width: 600px;
  margin-bottom: 40px;
  line-height: 1.8;
}

.hero__actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 60px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 16px;
  font-weight: 600;
  text-decoration: none;
  border-radius: 10px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: var(--transition);
}

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

.btn--primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(37, 99, 235, 0.4);
}

.btn--outline {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
}

.btn--outline:hover {
  border-color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.btn--full {
  width: 100%;
}

.hero__stats {
  display: flex;
  gap: 48px;
  flex-wrap: wrap;
}

.hero__stat-num {
  display: block;
  font-size: 36px;
  font-weight: 800;
  color: #fff;
}

.hero__stat-label {
  font-size: 14px;
  color: var(--color-text-light);
}

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

.section--alt {
  background: #f8fafc;
}

.section__header {
  text-align: center;
  margin-bottom: 60px;
}

.section__tag {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(37, 99, 235, 0.08);
  color: var(--color-primary);
  font-size: 14px;
  font-weight: 600;
  border-radius: 50px;
  margin-bottom: 16px;
}

.section__title {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  color: var(--color-text);
}

/* About */
.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}

.about__text {
  font-size: 16px;
  color: var(--color-text-muted);
  margin-bottom: 20px;
  line-height: 1.8;
}

.about__features {
  list-style: none;
  margin-top: 32px;
}

.about__features li {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 0;
  font-size: 15px;
  color: var(--color-text);
}

.about__feature-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: rgba(37, 99, 235, 0.1);
  color: var(--color-primary);
  border-radius: 50%;
  font-size: 14px;
  font-weight: 700;
  flex-shrink: 0;
}

.about__visual {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.about__card {
  padding: 28px;
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  transition: var(--transition);
}

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

.about__card-icon {
  font-size: 32px;
  margin-bottom: 12px;
}

.about__card h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.about__card p {
  font-size: 14px;
  color: var(--color-text-muted);
}

/* Services */
.services__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.service-card {
  padding: 36px 28px;
  background: #fff;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  transition: var(--transition);
}

.service-card:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-lg);
  transform: translateY(-6px);
}

.service-card__icon {
  font-size: 40px;
  margin-bottom: 20px;
}

.service-card__title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

.service-card__desc {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* Tech */
.tech__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.tech__group {
  padding: 32px;
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
}

.tech__group-title {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-primary);
  display: inline-block;
}

.tech__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tech__tag {
  padding: 8px 16px;
  background: #f1f5f9;
  color: var(--color-text);
  font-size: 14px;
  font-weight: 500;
  border-radius: 8px;
  transition: var(--transition);
}

.tech__tag:hover {
  background: rgba(37, 99, 235, 0.1);
  color: var(--color-primary);
}

/* Process */
.process__timeline {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 24px;
}

.process__step {
  text-align: center;
  padding: 32px 20px;
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  position: relative;
  transition: var(--transition);
}

.process__step:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-primary-light);
}

.process__step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: #fff;
  font-size: 18px;
  font-weight: 800;
  border-radius: 50%;
  margin-bottom: 16px;
}

.process__step-title {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 8px;
}

.process__step-desc {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.6;
}

/* Contact */
.contact__wrapper {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
}

.contact__desc {
  font-size: 16px;
  color: var(--color-text-muted);
  margin: 20px 0 32px;
  line-height: 1.8;
}

.contact__list {
  list-style: none;
}

.contact__list li {
  display: flex;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}

.contact__list-icon {
  font-size: 24px;
  flex-shrink: 0;
}

.contact__list strong {
  display: block;
  font-size: 14px;
  color: var(--color-text-muted);
  margin-bottom: 4px;
}

.contact__list p {
  font-size: 16px;
  color: var(--color-text);
}

.contact__form {
  padding: 40px;
  background: #fff;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
}

.form__group {
  margin-bottom: 20px;
}

.form__group label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--color-text);
}

.form__group input,
.form__group textarea {
  width: 100%;
  padding: 12px 16px;
  font-size: 15px;
  font-family: inherit;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  transition: var(--transition);
  background: #f8fafc;
}

.form__group input:focus,
.form__group textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  background: #fff;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form__group textarea {
  resize: vertical;
}

/* Footer */
.footer {
  background: var(--color-bg);
  color: #fff;
  padding: 48px 0;
}

.footer__content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

.footer__logo {
  font-size: 20px;
  font-weight: 700;
}

.footer__brand p {
  font-size: 14px;
  color: var(--color-text-light);
  margin-top: 4px;
}

.footer__copy {
  font-size: 14px;
  color: var(--color-text-light);
}

/* Toast */
.toast {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  padding: 16px 32px;
  background: var(--color-bg);
  color: #fff;
  border-radius: 10px;
  font-size: 15px;
  box-shadow: var(--shadow-lg);
  z-index: 2000;
  opacity: 0;
  transition: var(--transition);
}

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

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

  .process__timeline {
    grid-template-columns: repeat(3, 1fr);
  }
}

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

  .nav__menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: #fff;
    padding: 16px;
    gap: 4px;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
  }

  .nav__menu--open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav__link {
    width: 100%;
    text-align: center;
    padding: 12px;
  }

  .about__grid,
  .contact__wrapper {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .services__grid {
    grid-template-columns: 1fr;
  }

  .tech__grid {
    grid-template-columns: 1fr;
  }

  .process__timeline {
    grid-template-columns: 1fr;
  }

  .hero__stats {
    gap: 32px;
  }

  .footer__content {
    flex-direction: column;
    text-align: center;
  }
}