/**
 * Yiwu Sourcing Partner - Styles
 * 现代化咨询公司风格，绿色系品牌主色调
 */

/* ============================================
   CSS Variables - Design Tokens
   ============================================ */
:root {
  /* Brand Colors - 绿色系 */
  --color-primary: #1F6B4F;
  --color-primary-dark: #185842;
  --color-primary-light: #3E8E6F;
  --color-secondary: #3E8E6F;

  /* Neutral Colors */
  --color-dark: #222222;
  --color-text: #333333;
  --color-text-light: #666666;
  --color-light-bg: #F8F9F8;
  --color-white: #FFFFFF;
  --color-border: #E5E7EB;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-family-heading: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  --spacing-4xl: 6rem;

  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;

  /* Shadows */
  --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 15px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1);

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-base: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* Container */
  --container-max: 1200px;
  --container-padding: 1.5rem;
}

/* ============================================
   Base Styles
   ============================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
}

ul, ol {
  list-style: none;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-family-heading);
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-dark);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

/* ============================================
   Container & Layout
   ============================================ */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.section {
  padding: var(--spacing-4xl) 0;
}

.section--light {
  background-color: var(--color-light-bg);
}

.section--primary {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.section--primary h2,
.section--primary h3,
.section--primary p {
  color: var(--color-white);
}

/* ============================================
   Header & Navigation
   ============================================ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background-color: var(--color-white);
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base);
}

.header.scrolled {
  box-shadow: var(--shadow-md);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.header__logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.header__logo img {
  height: 40px;
  width: auto;
}

.header__logo-text {
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--color-dark);
}

.header__nav {
  display: none;
}

.nav__list {
  display: flex;
  gap: var(--spacing-xl);
}

.nav__link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text);
  padding: var(--spacing-sm) 0;
  position: relative;
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-primary);
  transition: width var(--transition-base);
}

.nav__link:hover::after,
.nav__link.active::after {
  width: 100%;
}

.nav__link:hover,
.nav__link.active {
  color: var(--color-primary);
}

/* Language Selector */
.lang-selector {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-md);
  background-color: var(--color-light-bg);
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-sm);
  border: none;
  border-radius: var(--radius-sm);
  background-color: transparent;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-text-light);
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.lang-btn.active {
  background-color: var(--color-primary);
  color: var(--color-white);
}

.lang-btn__flag {
  font-size: 1.1rem;
}

/* Mobile Menu Button */
.mobile-menu-btn {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: var(--spacing-sm);
  border: none;
  background-color: transparent;
  cursor: pointer;
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-dark);
  transition: all var(--transition-fast);
}

.mobile-menu-btn.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-btn.active span:nth-child(2) {
  opacity: 0;
}

.mobile-menu-btn.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Navigation */
.mobile-nav {
  display: none;
  position: absolute;
  top: 70px;
  left: 0;
  right: 0;
  background-color: var(--color-white);
  box-shadow: var(--shadow-lg);
  padding: var(--spacing-md);
}

.mobile-nav.active {
  display: block;
}

.mobile-nav__list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.mobile-nav__link {
  display: block;
  padding: var(--spacing-md);
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.mobile-nav__link:hover,
.mobile-nav__link.active {
  background-color: var(--color-light-bg);
  color: var(--color-primary);
}

.mobile-nav__lang {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--color-border);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 70px;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  overflow: hidden;
}

.hero__bg {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  opacity: 0.1;
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='1'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: 700px;
  color: var(--color-white);
}

.hero__subtitle {
  display: inline-block;
  font-size: 0.9rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: var(--spacing-md);
  opacity: 0.9;
}

.hero__title {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: var(--spacing-lg);
  line-height: 1.2;
}

.hero__description {
  font-size: 1.1rem;
  line-height: 1.8;
  margin-bottom: var(--spacing-xl);
  opacity: 0.95;
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

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

.btn--primary:hover {
  background-color: var(--color-light-bg);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn--secondary {
  background-color: transparent;
  color: var(--color-white);
  border: 2px solid var(--color-white);
}

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

.btn--outline {
  background-color: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

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

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

.btn--green:hover {
  background-color: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn__icon {
  font-size: 1.2rem;
}

/* ============================================
   About Section
   ============================================ */
.about__content {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.about__subtitle {
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: var(--spacing-md);
}

.about__title {
  font-size: 2rem;
  margin-bottom: var(--spacing-lg);
}

.about__description {
  font-size: 1.1rem;
  color: var(--color-text-light);
  line-height: 1.8;
}

/* ============================================
   Team Section
   ============================================ */
.team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-xl);
  margin-top: var(--spacing-3xl);
}

.team-card {
  background-color: var(--color-white);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.team-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
}

.team-card__image {
  width: 100%;
  height: 300px;
  object-fit: cover;
  object-position: center 15%;
}

.team-card__content {
  padding: var(--spacing-xl);
}

.team-card__name {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-xs);
}

.team-card__role {
  font-size: 0.95rem;
  color: var(--color-primary);
  font-weight: 500;
  margin-bottom: var(--spacing-md);
}

.team-card__exp-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-light);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: var(--spacing-sm);
}

.team-card__exp-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.team-card__exp-item {
  font-size: 0.95rem;
  color: var(--color-text);
  padding-left: var(--spacing-md);
  position: relative;
}

.team-card__exp-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 6px;
  height: 6px;
  background-color: var(--color-primary);
  border-radius: 50%;
}

.team__quote {
  text-align: center;
  max-width: 700px;
  margin: var(--spacing-3xl) auto 0;
  padding: var(--spacing-xl);
  background-color: var(--color-light-bg);
  border-radius: var(--radius-lg);
  border-left: 4px solid var(--color-primary);
}

.team__quote p {
  font-size: 1.05rem;
  font-style: italic;
  color: var(--color-text);
  line-height: 1.8;
}

/* ============================================
   Services Section
   ============================================ */
.services__header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto;
}

.services__subtitle {
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: var(--spacing-md);
}

.section--light .services__subtitle {
  color: var(--color-primary);
}

.services__title {
  font-size: 2rem;
  margin-bottom: var(--spacing-lg);
}

.section--light .services__title {
  color: var(--color-dark);
}

.services__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-xl);
  margin-top: var(--spacing-3xl);
}

.service-card {
  background-color: var(--color-white);
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  transition: all var(--transition-base);
}

.service-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
}

.service-card__icon {
  width: 60px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-light-bg);
  border-radius: var(--radius-md);
  margin-bottom: var(--spacing-lg);
  font-size: 1.8rem;
}

.service-card__title {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-sm);
}

.service-card__desc {
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.7;
}

/* ============================================
   Why Us Section
   ============================================ */
.why__header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto;
}

.why__subtitle {
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: var(--spacing-md);
}

.why__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-xl);
  margin-top: var(--spacing-3xl);
}

.why-card {
  text-align: center;
  padding: var(--spacing-xl);
}

.why-card__icon {
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  margin: 0 auto var(--spacing-lg);
  font-size: 2rem;
}

.why-card__title {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-sm);
  color: var(--color-white);
}

.why-card__desc {
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.85);
  line-height: 1.7;
}

/* ============================================
   Contact Section
   ============================================ */
.contact__header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto;
}

.contact__subtitle {
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: var(--spacing-md);
}

.section--light .contact__subtitle {
  color: var(--color-primary);
}

.contact__title {
  font-size: 2rem;
  margin-bottom: var(--spacing-lg);
}

.contact__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-xl);
  margin-top: var(--spacing-3xl);
}

.contact-card {
  background-color: var(--color-white);
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  text-align: center;
}

.contact-card__name {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-md);
}

.contact-card__image {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  object-position: center 15%;
  margin: 0 auto var(--spacing-lg);
  border: 4px solid var(--color-light-bg);
}

.contact-card__info {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.contact-card__item {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  font-size: 1rem;
}

.contact-card__item-icon {
  font-size: 1.2rem;
}

.contact-card__item-link {
  color: var(--color-primary);
  font-weight: 500;
}

.contact-card__item-link:hover {
  text-decoration: underline;
}

/* CTA Box */
.cta-box {
  max-width: 600px;
  margin: var(--spacing-3xl) auto 0;
  padding: var(--spacing-2xl);
  background-color: var(--color-white);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  text-align: center;
}

.cta-box__title {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-lg);
}

.cta-box__desc {
  font-size: 0.95rem;
  color: var(--color-text-light);
  margin-bottom: var(--spacing-lg);
}

.cta-box__list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  text-align: left;
  max-width: 300px;
  margin-left: auto;
  margin-right: auto;
}

.cta-box__list-item {
  font-size: 0.95rem;
  color: var(--color-text);
  padding-left: var(--spacing-md);
  position: relative;
}

.cta-box__list-item::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: bold;
}

.cta-box__note {
  font-size: 0.9rem;
  color: var(--color-text-light);
  font-style: italic;
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background-color: var(--color-dark);
  color: var(--color-white);
  padding: var(--spacing-3xl) 0 var(--spacing-xl);
}

.footer__content {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.footer__brand {
  text-align: center;
}

.footer__logo {
  height: 50px;
  margin-bottom: var(--spacing-md);
}

.footer__slogan {
  font-size: 0.95rem;
  opacity: 0.9;
  margin-bottom: var(--spacing-sm);
}

.footer__location {
  font-size: 0.9rem;
  opacity: 0.7;
}

.footer__contact {
  text-align: center;
}

.footer__contact-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.footer__contact-item {
  font-size: 0.9rem;
  margin-bottom: var(--spacing-xs);
  opacity: 0.9;
}

.footer__contact-link {
  color: var(--color-white);
  opacity: 0.9;
}

.footer__contact-link:hover {
  opacity: 1;
  text-decoration: underline;
}

.footer__bottom {
  text-align: center;
  padding-top: var(--spacing-xl);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer__rights {
  font-size: 0.85rem;
  opacity: 0.7;
}

/* ============================================
   Responsive Styles
   ============================================ */

/* Tablet - 768px and up */
@media (min-width: 768px) {
  h1 { font-size: 3rem; }
  h2 { font-size: 2.25rem; }

  .hero__title {
    font-size: 3rem;
  }

  .team__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .services__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .why__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .contact__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer__content {
    grid-template-columns: repeat(2, 1fr);
    text-align: left;
  }

  .footer__brand {
    text-align: left;
  }

  .footer__contact {
    text-align: right;
  }
}

/* Desktop - 1024px and up */
@media (min-width: 1024px) {
  :root {
    --container-padding: 2rem;
  }

  h1 { font-size: 3.5rem; }
  h2 { font-size: 2.5rem; }

  .header__nav {
    display: block;
  }

  .mobile-menu-btn {
    display: none;
  }

  .hero__title {
    font-size: 3.5rem;
  }

  .hero__description {
    font-size: 1.2rem;
  }

  .team__grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .why__grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .footer__content {
    grid-template-columns: 2fr 1fr 1fr;
  }
}

/* Large Desktop - 1280px and up */
@media (min-width: 1280px) {
  .container {
    padding: 0 2rem;
  }
}

/* Print Styles */
@media print {
  .header,
  .mobile-menu-btn,
  .mobile-nav,
  .hero__cta,
  .btn {
    display: none !important;
  }

  .hero {
    min-height: auto;
    padding: 2rem 0;
  }

  .section {
    padding: 2rem 0;
  }
}

/* Accessibility - Focus Styles */
a:focus,
button:focus,
.nav__link:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Accessibility - Skip Link */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-primary);
  color: var(--color-white);
  padding: var(--spacing-sm) var(--spacing-md);
  z-index: 10000;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 0;
}