:root {
  --primary: #6a11cb;
  --primary-light: #8745de;
  --primary-dark: #5209a1;
  --secondary: #2575fc;
  --secondary-light: #5a9aff;
  --secondary-dark: #1a5dca;
  --dark: #333333;
  --light: #f8f9fa;
  --gray: #6c757d;
  --light-gray: #e9ecef;
  --success: #28a745;
  --danger: #dc3545;
  --warning: #ffc107;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
  background-color: var(--light);
  color: var(--dark);
  line-height: 1.6;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--primary);
  color: white;
  padding: 8px;
  text-decoration: none;
  z-index: 100;
}

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

header {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: white;
  padding: 1rem 0;
  box-shadow: 0 2px 15px rgba(0,0,0,0.1);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  color: white;
  text-decoration: none;
}

.logo span {
  color: var(--warning);
}

.nav-links {
  display: flex;
  list-style: none;
  flex-wrap: wrap;
}

.nav-links li {
  margin-left: 1.5rem;
}

.nav-links a {
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s;
}

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

.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: white;
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.5rem;
}

.btn {
  display: inline-block;
  padding: 0.8rem 1.5rem;
  background-color: var(--warning);
  color: var(--dark);
  text-decoration: none;
  border-radius: 30px;
  font-weight: 600;
  text-align: center;
  transition: all 0.3s;
  border: none;
  cursor: pointer;
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

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

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

.btn-lg {
  padding: 1rem 2rem;
  font-size: 1.1rem;
}

.hero {
  background: linear-gradient(135deg, rgba(106, 17, 203, 0.9) 0%, rgba(37, 117, 252, 0.9) 100%), url('https://images.unsplash.com/photo-1455642305367-68834a9c8827?ixlib=rb-1.2.1&auto=format&fit=crop&w=1350&q=80') center/cover no-repeat;
  color: white;
  padding: 6rem 0;
  text-align: center;
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: 1.5rem;
  font-weight: 800;
}

.hero p {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 0 auto 2rem;
}

.hero-buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-top: 2rem;
  flex-wrap: wrap;
}

.calculator-section {
  padding: 5rem 0;
  background-color: white;
}

.section-title {
  text-align: center;
  margin-bottom: 3rem;
}

.section-title h2 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: var(--primary);
}

.section-title p {
  font-size: 1.1rem;
  color: var(--gray);
  max-width: 800px;
  margin: 0 auto;
}

.calculator {
  background: white;
  border-radius: 15px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
  padding: 2.5rem;
  max-width: 800px;
  margin: 0 auto;
}

.calculator h3 {
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
  color: var(--primary-dark);
  text-align: center;
}

.calculator-tabs {
  display: flex;
  margin-bottom: 2rem;
  border-bottom: 2px solid var(--light-gray);
}

.calculator-tab {
  padding: 1rem 1.5rem;
  border: none;
  background: none;
  font-size: 1rem;
  font-weight: 600;
  color: var(--gray);
  cursor: pointer;
  transition: all 0.3s;
}

.calculator-tab.active {
  color: var(--primary);
  border-bottom: 3px solid var(--primary);
  margin-bottom: -2px;
}

.calculator-content {
  margin-top: 2rem;
}

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

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  color: var(--dark);
}

.form-group select,
.form-group input[type="time"],
.form-group input[type="number"],
.form-group input[type="range"] {
  width: 100%;
  padding: 0.8rem 1rem;
  border: 1px solid var(--light-gray);
  border-radius: 5px;
  font-size: 1rem;
  transition: border-color 0.3s;
}

.form-group select:focus,
.form-group input:focus {
  outline: none;
  border-color: var(--primary-light);
}

.form-group input:invalid:not(:placeholder-shown) {
  border-color: var(--danger);
}

.form-group input:valid:not(:placeholder-shown) {
  border-color: var(--success);
}

.form-feedback {
  font-size: 0.875rem;
  margin-top: 0.25rem;
  display: none;
}

.form-feedback.error {
  color: var(--danger);
  display: block;
}

.form-feedback.success {
  color: var(--success);
  display: block;
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.loading {
  opacity: 0.7;
  pointer-events: none;
}

.result {
  margin-top: 2rem;
  padding: 1.5rem;
  background-color: var(--light);
  border-radius: 10px;
  text-align: center;
}

.result h4 {
  font-size: 1.2rem;
  margin-bottom: 1rem;
  color: var(--dark);
}

.result-times {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
  margin-top: 1rem;
}

.time-option {
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--secondary) 100%);
  color: white;
  padding: 1rem;
  border-radius: 10px;
  min-width: 120px;
  font-weight: 600;
  box-shadow: 0 3px 10px rgba(0,0,0,0.1);
}

.features-section {
  padding: 5rem 0;
  background-color: var(--light);
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.feature {
  background: white;
  border-radius: 15px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  transition: transform 0.3s, box-shadow 0.3s;
}

.feature:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}

.feature-icon {
  height: 150px;
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--secondary) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  color: white;
}

.feature-content {
  padding: 1.5rem;
}

.feature h3 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
  color: var(--primary-dark);
}

.feature p {
  color: var(--gray);
}

.how-it-works {
  padding: 5rem 0;
  background-color: white;
}

.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.step {
  text-align: center;
  padding: 1.5rem;
}

.step-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  border-radius: 50%;
  color: white;
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0 auto 1.5rem;
}

.step h3 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
  color: var(--primary-dark);
}

.step p {
  color: var(--gray);
}

.cycle-info {
  padding: 5rem 0;
  background-color: var(--light);
}

.cycle-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.cycle-image {
  text-align: center;
}

.cycle-image img, .cycle-image svg {
  max-width: 100%;
  border-radius: 15px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.cycle-stages h3 {
  font-size: 1.8rem;
  margin-bottom: 2rem;
  color: var(--primary-dark);
}

.stage {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
  border-left: 3px solid var(--primary);
}

.stage h4 {
  font-size: 1.3rem;
  margin-bottom: 0.5rem;
  color: var(--primary);
}

.stage p {
  color: var(--gray);
}

.testimonials {
  padding: 5rem 0;
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--secondary) 100%);
  color: white;
}

.testimonial-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.testimonial-card {
  background: white;
  border-radius: 15px;
  padding: 2rem;
  color: var(--dark);
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.testimonial-text {
  font-style: italic;
  margin-bottom: 1.5rem;
  position: relative;
}

.testimonial-text::before {
  content: '"';
  font-size: 3rem;
  color: var(--primary-light);
  opacity: 0.3;
  position: absolute;
  top: -20px;
  left: -15px;
}

.testimonial-author {
  display: flex;
  align-items: center;
}

.author-avatar {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background-color: var(--light-gray);
  margin-right: 1rem;
  overflow: hidden;
}

.author-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.author-info h4 {
  font-size: 1.1rem;
  margin-bottom: 0.2rem;
}

.author-info p {
  font-size: 0.9rem;
  color: var(--gray);
}

.faq-section {
  padding: 5rem 0;
  background-color: white;
}

.faqs {
  max-width: 800px;
  margin: 3rem auto 0;
}

.faq-item {
  margin-bottom: 1.5rem;
  border: 1px solid var(--light-gray);
  border-radius: 10px;
  overflow: hidden;
}

.faq-question {
  padding: 1.2rem;
  cursor: pointer;
  background-color: var(--light);
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-question::after {
  content: '+';
  font-size: 1.5rem;
  color: var(--primary);
}

.faq-answer {
  padding: 1.2rem;
  display: none;
  border-top: 1px solid var(--light-gray);
}

.faq-answer.active {
  display: block;
}

.cta-section {
  padding: 5rem 0;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: white;
  text-align: center;
}

.cta-section h2 {
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
}

.cta-section p {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 0 auto 2rem;
}

.blog-section {
  padding: 5rem 0;
  background-color: var(--light);
}

.blog-posts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.blog-post {
  background: white;
  border-radius: 15px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  transition: transform 0.3s, box-shadow 0.3s;
}

.blog-post:hover {
  transform: translateY(-7px);
  box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}

.blog-image {
  height: 200px;
  overflow: hidden;
}

.blog-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s;
}

.blog-post:hover .blog-image img {
  transform: scale(1.05);
}

.blog-content {
  padding: 1.5rem;
}

.blog-date {
  font-size: 0.9rem;
  color: var(--gray);
  margin-bottom: 0.7rem;
}

.blog-post h3 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
  color: var(--primary-dark);
}

.blog-post p {
  color: var(--gray);
  margin-bottom: 1.5rem;
}

.blog-post .read-more {
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
  transition: color 0.3s;
  display: inline-flex;
  align-items: center;
}

.blog-post .read-more:hover {
  color: var(--primary-dark);
}

.blog-post .read-more svg {
  margin-left: 0.5rem;
  transition: transform 0.3s;
}

.blog-post .read-more:hover svg {
  transform: translateX(3px);
}

.sleep-tracker {
  padding: 3rem 0;
  background: white;
}

.tracker-container {
  background: var(--light);
  border-radius: 15px;
  padding: 2rem;
  max-width: 800px;
  margin: 0 auto;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.sleep-quality {
  display: flex;
  justify-content: space-between;
  margin-top: 1.5rem;
}

.sleep-quality span {
  font-size: 0.9rem;
  color: var(--gray);
}

.quality-value {
  font-weight: bold;
  color: var(--primary);
}

.sleep-tips {
  padding: 5rem 0;
  background-color: var(--light);
}

.tips-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

.tip-card {
  background: white;
  border-radius: 15px;
  padding: 2rem;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  transition: transform 0.3s, box-shadow 0.3s;
  border-top: 5px solid var(--primary);
}

.tip-card:hover {
  transform: translateY(-7px);
  box-shadow: 0 15px 30px rgba(0,0,0,0.1);
}

.tip-card h3 {
  font-size: 1.3rem;
  margin-bottom: 1rem;
  color: var(--primary-dark);
}

.tip-card p {
  color: var(--gray);
  margin-bottom: 1.5rem;
}

.tip-card .tip-icon {
  color: var(--primary);
  font-size: 2.5rem;
  margin-bottom: 1.5rem;
  display: block;
}

footer {
  background-color: var(--dark);
  color: white;
  padding: 3rem 0 1.5rem;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-column h3 {
  font-size: 1.3rem;
  margin-bottom: 1.5rem;
  color: var(--warning);
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.7rem;
}

.footer-links a {
  color: white;
  text-decoration: none;
  transition: color 0.3s;
}

.footer-links a:hover {
  color: var(--warning);
}

.footer-column p {
  margin-bottom: 1rem;
}

.social-links {
  display: flex;
  gap: 1rem;
}

.social-links a {
  display: inline-block;
  width: 40px;
  height: 40px;
  background-color: rgba(255,255,255,0.1);
  border-radius: 50%;
  text-align: center;
  line-height: 40px;
  color: white;
  transition: background-color 0.3s;
}

.social-links a:hover {
  background-color: var(--primary-light);
}

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

@media (max-width: 768px) {
  .navbar {
    flex-direction: row;
    justify-content: space-between;
  }

  .menu-toggle {
    display: block;
  }

  .nav-links {
    display: none;
    flex-direction: column;
    width: 100%;
    position: absolute;
    top: 100%;
    left: 0;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    padding: 1rem 0;
    margin: 0;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  }

  .nav-links.active {
    display: flex;
  }

  .nav-links li {
    margin: 0;
    padding: 0.5rem 1.5rem;
  }

  .nav-links li:not(:last-child) {
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }

  header .container {
    position: relative;
  }

  .hero h1 {
    font-size: 2.5rem;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .cycle-container {
    grid-template-columns: 1fr;
  }
}