/* 
 * SynBioXTech - Main Stylesheet
 * 现代化设计，灵感来自Product Hunt但有自己的独特风格
 */

:root {
  /* 主色调 */
  --primary-color: #ff6154;
  --primary-dark: #e04a3f;
  --primary-light: #ff8a7f;
  
  /* 辅助色调 */
  --secondary-color: #4b8eff;
  --secondary-dark: #3a70cc;
  --secondary-light: #7cacff;
  
  /* 中性色调 */
  --dark: #222222;
  --medium-dark: #555555;
  --medium: #888888;
  --medium-light: #cccccc;
  --light: #f5f5f5;
  --white: #ffffff;
  
  /* 功能色调 */
  --success: #28a745;
  --warning: #ffc107;
  --danger: #dc3545;
  --info: #17a2b8;
  
  /* 字体 */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  --font-secondary: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  
  /* 尺寸 */
  --header-height: 70px;
  --footer-height: 300px;
  --container-max-width: 1200px;
  --container-padding: 20px;
  
  /* 圆角 */
  --border-radius-sm: 4px;
  --border-radius-md: 8px;
  --border-radius-lg: 16px;
  
  /* 阴影 */
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.15);
  
  /* 过渡 */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* 基础样式重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-primary);
  color: var(--dark);
  background-color: var(--white);
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-secondary);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 1rem;
}

h1 {
  font-size: 2.5rem;
}

h2 {
  font-size: 2rem;
}

h3 {
  font-size: 1.75rem;
}

h4 {
  font-size: 1.5rem;
}

h5 {
  font-size: 1.25rem;
}

h6 {
  font-size: 1rem;
}

p {
  margin-bottom: 1.5rem;
}

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

ul, ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
}

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

/* 按钮 */
.btn {
  display: inline-block;
  font-weight: 600;
  text-align: center;
  white-space: nowrap;
  vertical-align: middle;
  user-select: none;
  border: 2px solid transparent;
  padding: 0.75rem 1.5rem;
  font-size: 1rem;
  line-height: 1.5;
  border-radius: var(--border-radius-md);
  transition: all var(--transition-normal);
  cursor: pointer;
}

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

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

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

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

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

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

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.25rem;
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

/* 头部导航 */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  background-color: var(--white);
  box-shadow: var(--shadow-sm);
  z-index: 1000;
  transition: all var(--transition-normal);
}

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

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
}

.logo img {
  height: 40px;
  margin-right: 10px;
}

.logo-text {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--dark);
}

.nav-menu {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-item {
  margin-left: 2rem;
}

.nav-link {
  color: var(--medium-dark);
  font-weight: 500;
  transition: color var(--transition-fast);
}

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

.nav-cta {
  margin-left: 2rem;
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--dark);
  cursor: pointer;
}

/* 英雄区域 */
.hero {
  padding: calc(var(--header-height) + 4rem) 0 4rem;
  background-color: var(--light);
  position: relative;
  overflow: hidden;
}

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

.hero-content {
  flex: 0 0 50%;
  max-width: 50%;
}

.hero-title {
  font-size: 3.5rem;
  margin-bottom: 1.5rem;
  line-height: 1.2;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--medium-dark);
  margin-bottom: 2rem;
}

.hero-cta {
  display: flex;
  gap: 1rem;
}

.hero-image {
  flex: 0 0 45%;
  max-width: 45%;
}

/* 特性部分 */
.features {
  padding: 6rem 0;
}

.section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.section-title {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.section-subtitle {
  font-size: 1.25rem;
  color: var(--medium-dark);
  max-width: 700px;
  margin: 0 auto;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.feature-card {
  background-color: var(--white);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-md);
  padding: 2rem;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

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

.feature-icon {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 1.5rem;
}

.feature-title {
  font-size: 1.5rem;
  margin-bottom: 1rem;
}

.feature-description {
  color: var(--medium-dark);
}

/* 如何工作部分 */
.how-it-works {
  padding: 6rem 0;
  background-color: var(--light);
}

.steps {
  display: flex;
  justify-content: space-between;
  margin-top: 4rem;
}

.step {
  flex: 0 0 30%;
  max-width: 30%;
  text-align: center;
  position: relative;
}

.step:not(:last-child)::after {
  content: '';
  position: absolute;
  top: 2.5rem;
  right: -15%;
  width: 30%;
  height: 2px;
  background-color: var(--medium-light);
}

.step-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 5rem;
  height: 5rem;
  background-color: var(--primary-color);
  color: var(--white);
  font-size: 2rem;
  font-weight: 700;
  border-radius: 50%;
  margin: 0 auto 1.5rem;
}

.step-title {
  font-size: 1.5rem;
  margin-bottom: 1rem;
}

.step-description {
  color: var(--medium-dark);
}

/* 定价部分 */
.pricing {
  padding: 6rem 0;
}

.pricing-cards {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-top: 4rem;
}

.pricing-card {
  flex: 0 0 calc(33.333% - 2rem);
  max-width: calc(33.333% - 2rem);
  background-color: var(--white);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-md);
  padding: 3rem 2rem;
  text-align: center;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

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

.pricing-card.featured {
  border: 2px solid var(--primary-color);
  transform: scale(1.05);
}

.pricing-card.featured:hover {
  transform: scale(1.05) translateY(-5px);
}

.pricing-header {
  margin-bottom: 2rem;
}

.pricing-title {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
}

.pricing-subtitle {
  color: var(--medium);
  font-size: 0.875rem;
}

.pricing-price {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 2rem;
}

.pricing-price span {
  font-size: 1rem;
  font-weight: 400;
  color: var(--medium);
}

.pricing-features {
  list-style: none;
  padding: 0;
  margin: 0 0 2rem;
}

.pricing-feature {
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--medium-light);
}

.pricing-feature:last-child {
  border-bottom: none;
}

/* 联系表单 */
.contact {
  padding: 6rem 0;
  background-color: var(--light);
}

.contact-container {
  display: flex;
  gap: 4rem;
}

.contact-info {
  flex: 0 0 40%;
  max-width: 40%;
}

.contact-title {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
}

.contact-description {
  margin-bottom: 2rem;
}

.contact-details {
  list-style: none;
  padding: 0;
  margin: 0;
}

.contact-detail {
  display: flex;
  align-items: flex-start;
  margin-bottom: 1.5rem;
}

.contact-icon {
  flex: 0 0 1.5rem;
  font-size: 1.25rem;
  color: var(--primary-color);
  margin-right: 1rem;
}

.contact-text {
  flex: 1;
}

.contact-form {
  flex: 0 0 55%;
  max-width: 55%;
  background-color: var(--white);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-md);
  padding: 2.5rem;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.form-control {
  display: block;
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  line-height: 1.5;
  color: var(--dark);
  background-color: var(--white);
  background-clip: padding-box;
  border: 1px solid var(--medium-light);
  border-radius: var(--border-radius-sm);
  transition: border-color var(--transition-fast);
}

.form-control:focus {
  border-color: var(--primary-color);
  outline: 0;
}

textarea.form-control {
  height: auto;
  min-height: 150px;
  resize: vertical;
}

.form-check {
  display: flex;
  align-items: flex-start;
  margin-bottom: 1rem;
}

.form-check-input {
  margin-right: 0.5rem;
  margin-top: 0.25rem;
}

.form-check-label {
  font-size: 0.875rem;
}

/* 页脚 */
.footer {
  background-color: var(--dark);
  color: var(--white);
  padding: 4rem 0 2rem;
}

.footer-container {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2rem;
}

.footer-brand {
  margin-bottom: 1.5rem;
}

.footer-logo {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 1rem;
  display: inline-block;
}

.footer-description {
  color: var(--medium-light);
  margin-bottom: 1.5rem;
}

.footer-heading {
  font-size: 1.25rem;
  margin-bottom: 1.5rem;
  color: var(--white);
}

.footer-links {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-link {
  margin-bottom: 0.75rem;
}

.footer-link a {
  color: var(--medium-light);
  transition: color var(--transition-fast);
}

.footer-link a:hover {
  color: var(--primary-light);
}

.footer-contact {
  color: var(--medium-light);
  margin-bottom: 0.75rem;
}

.footer-contact strong {
  color: var(--white);
}

.footer-bottom {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-copyright {
  color: var(--medium-light);
  font-size: 0.875rem;
}

/* 响应式设计 */
@media (max-width: 1200px) {
  :root {
    --container-max-width: 960px;
  }
  
  .hero-title {
    font-size: 3rem;
  }
}

@media (max-width: 992px) {
  :root {
    --container-max-width: 720px;
  }
  
  .hero-title {
    font-size: 2.5rem;
  }
  
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .pricing-cards {
    flex-wrap: wrap;
  }
  
  .pricing-card {
    flex: 0 0 calc(50% - 1rem);
    max-width: calc(50% - 1rem);
    margin-bottom: 2rem;
  }
  
  .footer-container {
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
  }
}

@media (max-width: 768px) {
  :root {
    --container-max-width: 540px;
    --header-height: 60px;
  }
  
  .mobile-menu-toggle {
    display: block;
  }
  
  .nav-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    height: calc(100vh - var(--header-height));
    background-color: var(--white);
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding: 2rem 0;
    transform: translateX(100%);
    transition: transform var(--transition-normal);
    z-index: 999;
  }
  
  .nav-menu.active {
    transform: translateX(0);
  }
  
  .nav-item {
    margin: 0 0 1.5rem;
  }
  
  .nav-cta {
    margin: 1rem 0 0;
  }
  
  .hero-container {
    flex-direction: column;
  }
  
  .hero-content,
  .hero-image {
    flex: 0 0 100%;
    max-width: 100%;
  }
  
  .hero-content {
    margin-bottom: 3rem;
    text-align: center;
  }
  
  .hero-cta {
    justify-content: center;
  }
  
  .steps {
    flex-direction: column;
  }
  
  .step {
    flex: 0 0 100%;
    max-width: 100%;
    margin-bottom: 3rem;
  }
  
  .step:not(:last-child)::after {
    top: auto;
    bottom: -1.5rem;
    right: auto;
    left: 50%;
    transform: translateX(-50%);
    width: 2px;
    height: 3rem;
  }
  
  .contact-container {
    flex-direction: column;
  }
  
  .contact-info,
  .contact-form {
    flex: 0 0 100%;
    max-width: 100%;
  }
  
  .contact-info {
    margin-bottom: 2rem;
  }
}

@media (max-width: 576px) {
  .hero-title {
    font-size: 2rem;
  }
  
  .section-title {
    font-size: 2rem;
  }
  
  .features-grid {
    grid-template-columns: 1fr;
  }
  
  .pricing-card {
    flex: 0 0 100%;
    max-width: 100%;
  }
  
  .footer-container {
    grid-template-columns: 1fr;
  }
  
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
  
  .footer-copyright {
    margin-bottom: 1rem;
  }
}