/* ========================================
   Remind - 极简风格静态官网样式表
   ======================================== */

/* CSS Variables */
:root {
  --color-primary: #10b981;
  --color-primary-light: #34d399;
  --color-primary-dark: #059669;
  --color-secondary: #6366f1;
  --color-text: #1f2937;
  --color-text-light: #6b7280;
  --color-text-lighter: #9ca3af;
  --color-bg: #ffffff;
  --color-bg-alt: #f9fafb;
  --color-bg-dark: #111827;
  --color-border: #e5e7eb;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 1rem;
  --transition: all 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

ul {
  list-style: none;
}

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

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ========================================
   Header & Navigation
   ======================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: -0.02em;
}

.logo img {
  width: 2rem;
  height: 2rem;
  object-fit: contain;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2.5rem;
}

.nav-links a {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text-light);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: var(--transition);
}

.nav-links a:hover {
  color: var(--color-text);
}

.nav-links a:hover::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 0.5rem;
  background: none;
  border: none;
  cursor: pointer;
}

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

/* ========================================
   Hero Section
   ======================================== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 6rem 0 4rem;
  overflow: hidden;
  background: linear-gradient(135deg, #f0fdf4 0%, #ecfdf5 50%, #d1fae5 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 600px;
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  line-height: 1.15;
  color: var(--color-text);
  margin-bottom: 1.5rem;
  letter-spacing: -0.03em;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-light);
  margin-bottom: 2.5rem;
  line-height: 1.7;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.875rem 1.75rem;
  font-size: 0.9375rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  transition: var(--transition);
  cursor: pointer;
}

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

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

.btn-secondary {
  background: white;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

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

/* Hero Decoration */
.hero-decoration {
  position: absolute;
  top: 50%;
  right: -10%;
  transform: translateY(-50%);
  z-index: 1;
}

.circle {
  position: absolute;
  border-radius: 50%;
  opacity: 0.5;
}

.circle-1 {
  width: 400px;
  height: 400px;
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.2), rgba(16, 185, 129, 0.05));
  top: -200px;
  right: 0;
}

.circle-2 {
  width: 300px;
  height: 300px;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.15), rgba(99, 102, 241, 0.05));
  top: 0;
  right: 150px;
}

.circle-3 {
  width: 200px;
  height: 200px;
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.3), rgba(16, 185, 129, 0.1));
  top: 100px;
  right: 300px;
}

/* ========================================
   Section Styles
   ======================================== */
.section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.section-header h2 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.section-header p {
  font-size: 1.0625rem;
  color: var(--color-text-light);
}

.section-header-left {
  text-align: left;
}

/* ========================================
   Features Section
   ======================================== */
.features {
  padding: 6rem 0;
  background: var(--color-bg);
}

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

.feature-card {
  padding: 2rem;
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.feature-icon {
  width: 3rem;
  height: 3rem;
  margin-bottom: 1.25rem;
}

.feature-icon svg {
  width: 100%;
  height: 100%;
  color: var(--color-primary);
}

.feature-card h3 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.75rem;
}

.feature-card p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
  line-height: 1.7;
}

/* ========================================
   About Section
   ======================================== */
.about {
  padding: 6rem 0;
  background: var(--color-bg-alt);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.about-text p {
  font-size: 1rem;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 1.5rem;
}

.about-list {
  margin-top: 2rem;
}

.about-list li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 0;
  font-size: 1rem;
  color: var(--color-text);
}

.check-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 1.5rem;
  height: 1.5rem;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  font-size: 0.75rem;
  font-weight: 700;
}

.about-image {
  display: flex;
  justify-content: center;
}

.image-placeholder {
  width: 100%;
  max-width: 400px;
  aspect-ratio: 1;
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-primary));
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
}

.image-placeholder span {
  font-size: 3rem;
  font-weight: 700;
  color: white;
  opacity: 0.9;
}

/* ========================================
   Contact Section
   ======================================== */
.contact {
  padding: 6rem 0;
  background: var(--color-bg);
}

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

.contact-card {
  text-align: center;
  padding: 2.5rem 1.5rem;
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
  transition: var(--transition);
}

.contact-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.contact-icon {
  width: 3.5rem;
  height: 3.5rem;
  margin: 0 auto 1.25rem;
}

.contact-icon svg {
  width: 100%;
  height: 100%;
  color: var(--color-primary);
}

.contact-card h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.5rem;
}

.contact-card p {
  font-size: 0.9375rem;
  color: var(--color-text-light);
}

.contact-card a {
  color: var(--color-primary);
}

.contact-card a:hover {
  text-decoration: underline;
}

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

.footer-content {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 4rem;
  margin-bottom: 3rem;
}

.footer-brand .logo {
  display: inline-block;
  margin-bottom: 1rem;
}

.footer-brand p {
  font-size: 0.9375rem;
  color: rgba(255, 255, 255, 0.6);
  max-width: 280px;
}

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

.footer-column h4 {
  font-size: 0.9375rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  color: white;
}

.footer-column ul li {
  margin-bottom: 0.75rem;
}

.footer-column a {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.6);
  transition: var(--transition);
}

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

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
}

.footer-bottom p {
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.5);
  margin-bottom: 0.5rem;
}

.footer-bottom .icp {
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.4);
  margin-bottom: 0;
}

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

  .about-content {
    gap: 3rem;
  }

  .hero-decoration {
    opacity: 0.5;
  }
}

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 4rem;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 1.5rem;
    gap: 1.25rem;
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
  }

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

  .nav-toggle {
    display: flex;
  }

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

  .nav-toggle.active span:nth-child(2) {
    opacity: 0;
  }

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

  .hero {
    min-height: auto;
    padding: 8rem 0 4rem;
    text-align: center;
  }

  .hero-content {
    max-width: 100%;
  }

  .hero-buttons {
    justify-content: center;
  }

  .hero-decoration {
    display: none;
  }

  .features-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .about-content {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }

  .about-image {
    order: -1;
  }

  .image-placeholder {
    max-width: 280px;
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .footer-content {
    grid-template-columns: 1fr;
    gap: 2rem;
    text-align: center;
  }

  .footer-brand p {
    max-width: 100%;
  }

  .footer-links {
    grid-template-columns: repeat(2, 1fr);
    justify-items: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 1rem;
  }

  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1rem;
  }

  .btn {
    width: 100%;
    padding: 1rem;
  }

  .hero-buttons {
    flex-direction: column;
    width: 100%;
    max-width: 280px;
    margin: 0 auto;
  }

  .section-header h2 {
    font-size: 1.75rem;
  }

  .feature-card,
  .contact-card {
    padding: 1.5rem;
  }

  .footer-links {
    grid-template-columns: 1fr;
  }
}

/* ========================================
   Accessibility
   ======================================== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }
}

/* Focus styles */
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Screen reader only */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}