:root {
  --bg-page: #F8FAFC;
  --bg-hero-start: #F0FDFA;
  --bg-hero-end: #F1F5F9;
  --bg-card: #FFFFFF;
  --primary-accent: #0D9488;
  --primary-accent-light: #CCFBF1;
  --text-dark: #1E293B;
  --text-medium: #475569;
  --text-light: #94A3B8;
  --border-color: #E2E8F0;
  --error-bg: #FEF2F2;
  --error-text: #DC2626;
  --warning-bg: #FFFBEB;
  --warning-text: #B45309;
  --success-bg: #ECFDF5;
  --success-text: #065F46;
  --bg-light: #F1F5F9;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-page);
  color: var(--text-medium);
  line-height: 1.6;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  color: var(--text-dark);
  line-height: 1.2;
  font-weight: 600;
}

h1 {
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 1rem;
}

h2.section-title {
  font-size: clamp(1.25rem, 4vw, 1.5rem);
  margin-bottom: 1.25rem;
}

h3.subsection-title {
  font-size: clamp(1rem, 3vw, 1.1rem);
  margin-bottom: 0.75rem;
}

/* Navigation */
.navbar {
  background-color: var(--bg-card);
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
  position: sticky;
  top: 0;
  z-index: 1000;
  width: 100%;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem clamp(0.75rem, 3vw, 1rem);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-logo {
  height: 32px;
  width: auto;
}

.brand-name {
  font-weight: 700;
  color: var(--text-dark);
  font-size: 1.1rem;
}

/* Navigation Toggle */
.nav-toggle {
  display: flex;
  flex-direction: column;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  gap: 0.25rem;
  z-index: 1002;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background-color: var(--text-dark);
  transition: all 0.3s ease;
  transform-origin: center;
}

/* Navigation Slider */
.nav-slider {
  position: fixed;
  top: 0;
  right: -100%;
  width: 300px;
  height: 100vh;
  background-color: var(--bg-card);
  box-shadow: -4px 0 20px rgba(0, 0, 0, 0.1);
  transition: right 0.3s ease-in-out;
  z-index: 1001;
  overflow-y: auto;
}

.nav-slider.active {
  right: 0;
}

.slider-content {
  padding: 1.5rem;
  height: 100%;
}

.slider-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.slider-close {
  background: none;
  border: none;
  font-size: 1.25rem;
  color: var(--text-dark);
  cursor: pointer;
  padding: 0.5rem;
  z-index: 1002;
}

.slider-links {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.slider-link {
  display: block;
  padding: 1rem;
  color: var(--text-dark);
  text-decoration: none;
  font-weight: 500;
  border-radius: 0.5rem;
  transition: all 0.2s;
}

.slider-link:hover, .slider-link.active {
  background-color: var(--primary-accent-light);
  color: var(--primary-accent);
}

/* Overlay when slider is open */
.nav-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

.nav-overlay.active {
  opacity: 1;
  visibility: visible;
}

/* Hero Section */
.hero-section {
  background: linear-gradient(135deg, var(--bg-hero-start) 0%, var(--bg-hero-end) 100%);
  padding: clamp(2rem, 6vw, 4rem) clamp(1rem, 4vw, 2rem);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-content {
  max-width: 800px;
  margin: 0 auto;
}

.hero-text p {
  font-size: clamp(1rem, 3vw, 1.25rem);
  margin-bottom: 2rem;
  color: var(--text-medium);
}

/* Cards */
.card {
  background-color: var(--bg-card);
  border-radius: 1rem;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
  padding: clamp(1.5rem, 4vw, 2rem);
  margin-bottom: 1.5rem;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

.main-card {
  margin-top: 2rem !important;
  position: relative;
  z-index: 10;
}

/* Centered Form Container */
.centered-form-container {
  max-width: 800px;
  margin: 0 auto;
  width: 100%;
}

/* Form Elements */
.form-section {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.input-group label {
  font-weight: 500;
  color: var(--text-dark);
}

.input-group input, .input-group select {
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: 0.5rem;
  font-size: 1rem;
  transition: all 0.2s;
  background-color: white;
}

.input-group input:focus, .input-group select:focus {
  outline: none;
  border-color: var(--primary-accent);
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.1);
}

.input-help {
  font-size: 0.875rem;
  color: var(--text-light);
}

/* Calculator Type Selection */
.type-toggle {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.type-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  padding: 1rem;
  border: 1px solid var(--border-color);
  border-radius: 0.5rem;
  background-color: white;
  color: var(--text-dark);
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 500;
}

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

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

.type-btn i {
  font-size: 1.25rem;
}

/* Unit Selection */
.unit-toggle {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.unit-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 1rem;
  border: 1px solid var(--border-color);
  border-radius: 0.5rem;
  background-color: white;
  color: var(--text-dark);
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 500;
}

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

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

/* Time Inputs */
.time-inputs {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 0.75rem;
}

.time-input-group {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.time-input-group input {
  text-align: center;
}

.time-input-group label {
  font-size: 0.75rem;
  text-align: center;
  color: var(--text-light);
}

/* Pace Inputs */
.pace-inputs {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 0.75rem;
  align-items: end;
}

.pace-input-group {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.pace-input-group input {
  text-align: center;
}

.pace-input-group label {
  font-size: 0.75rem;
  text-align: center;
  color: var(--text-light);
}

.pace-unit {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 46px;
  padding: 0 1rem;
  background-color: var(--bg-page);
  border-radius: 0.5rem;
  font-weight: 500;
  color: var(--text-dark);
}

/* Buttons */
.calculate-button {
  background-color: var(--primary-accent);
  color: white;
  border: none;
  padding: 1rem 1.5rem;
  border-radius: 0.5rem;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.2s;
  text-align: center;
  width: 100%;
  margin: 2rem 0 !important;
}

.calculate-button:hover {
  background-color: #0f766e;
  transform: translateY(-2px);
}

.cta-button {
  display: inline-block;
  background-color: var(--primary-accent);
  color: white;
  padding: 1rem 2rem;
  border-radius: 0.5rem;
  text-decoration: none;
  font-weight: 600;
  transition: all 0.2s;
  border: none;
  cursor: pointer;
}

.cta-button:hover {
  background-color: #0f766e;
  transform: translateY(-2px);
}

/* Results Section */
.results-section {
  background-color: var(--bg-page);
  border-radius: 0.5rem;
  padding: 1.5rem;
  border: 1px solid var(--border-color);
  margin-top: 1.5rem !important;
}

.result-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.5rem;
  background-color: white;
  border-radius: 0.75rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.result-icon {
  width: 60px;
  height: 60px;
  background-color: var(--primary-accent-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.result-icon i {
  font-size: 1.5rem;
  color: var(--primary-accent);
}

.result-content {
  flex: 1;
}

.result-content h4 {
  color: var(--text-light);
  font-size: 0.9rem;
  margin-bottom: 0.25rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.result-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-accent);
  line-height: 1;
}

.result-unit {
  font-size: 1rem;
  color: var(--text-light);
}

/* Training Zones */
.training-zones {
  margin-top: 2rem;
}

.zones-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

@media (min-width: 768px) {
  .zones-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.zone-card {
  background: white;
  border-radius: 0.75rem;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
}

.zone-header {
  padding: 1rem;
  color: white;
  text-align: center;
}

.zone-header.easy-run {
  background-color: var(--success-text);
}

.zone-header.tempo-run {
  background-color: var(--warning-text);
}

.zone-header.interval-run {
  background-color: var(--error-text);
}

.zone-header h5 {
  margin: 0;
  font-size: 1rem;
}

.zone-content {
  padding: 1rem;
  text-align: center;
}

.zone-content p {
  font-size: 0.875rem;
  color: var(--text-medium);
  margin-bottom: 0.75rem;
}

.zone-pace {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-dark);
}

/* Common Distances */
.common-distances {
  margin-top: 2rem;
}

.distance-buttons {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
}

@media (min-width: 480px) {
  .distance-buttons {
    grid-template-columns: repeat(4, 1fr);
  }
}

.distance-button {
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: 0.5rem;
  background-color: white;
  color: var(--text-dark);
  cursor: pointer;
  transition: all 0.2s;
  font-weight: 500;
}

.distance-button:hover {
  border-color: var(--primary-accent);
  color: var(--primary-accent);
}

/* Message Boxes */
.message-box {
  padding: 1rem;
  border-radius: 0.5rem;
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.message-box i {
  font-size: 1.25rem;
  margin-top: 0.125rem;
}

.message-content {
  flex: 1;
}

.message-content h4 {
  margin-bottom: 0.25rem;
  font-size: 1rem;
}

.error-box {
  background-color: var(--error-bg);
  color: var(--error-text);
  border-left: 4px solid var(--error-text);
}

.success-box {
  background-color: var(--success-bg);
  color: var(--success-text);
  border-left: 4px solid var(--success-text);
}

/* Animations */
.animate-on-load {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeInUp 0.6s ease forwards;
}

@keyframes fadeInUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Privacy Notice */
.privacy-notice {
  padding: 1rem;
  border-radius: 0.5rem;
  margin-top: 1rem;
  background-color: var(--success-bg);
  border-left: 4px solid var(--success-text);
}

.privacy-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
  color: var(--text-dark);
}

.privacy-text {
  font-size: 0.875rem;
  color: var(--text-medium);
}

/* Content Sections */
.content-section {
  padding: 3rem 1rem;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

.section-subtitle {
  text-align: center;
  color: var(--text-medium);
  margin-bottom: 2rem;
  font-size: 1.1rem;
}

/* Enhanced Overview Section */
.overview-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 2rem;
}

@media (min-width: 768px) {
  .overview-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.overview-card {
  background: var(--bg-card);
  border-radius: 0.75rem;
  padding: 1.5rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.overview-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

.overview-icon {
  width: 60px;
  height: 60px;
  background-color: var(--primary-accent-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

.overview-icon i {
  font-size: 1.5rem;
  color: var(--primary-accent);
}

.overview-card h3 {
  color: var(--primary-accent);
  font-size: 1.1rem;
  margin-bottom: 0.75rem;
  font-weight: 600;
  line-height: 1.4;
}

.overview-card p {
  color: var(--text-medium);
  line-height: 1.6;
  font-size: 0.95rem;
}

/* Use Cases Section */
.usecases-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 2rem;
}

@media (min-width: 768px) {
  .usecases-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .usecases-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.usecase-card {
  background: var(--bg-card);
  border-radius: 0.75rem;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.usecase-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

.usecase-header {
  padding: 1.5rem;
  background-color: var(--primary-accent-light);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.usecase-header i {
  font-size: 1.5rem;
  color: var(--primary-accent);
}

.usecase-header h3 {
  color: var(--text-dark);
  font-size: 1.1rem;
  margin: 0;
}

.usecase-content {
  padding: 1.5rem;
}

.problem-solution h4 {
  color: var(--primary-accent);
  font-size: 1rem;
  margin: 1rem 0 0.5rem;
}

.problem-solution h4:first-child {
  margin-top: 0;
}

.problem-solution p {
  font-size: 0.9rem;
  line-height: 1.5;
  margin-bottom: 0.75rem;
}

.pro-tip {
  background-color: var(--warning-bg);
  border-left: 4px solid var(--warning-text);
  padding: 1rem;
  border-radius: 0.25rem;
  margin: 1rem 0;
}

.pro-tip h5 {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--warning-text);
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.pro-tip p {
  font-size: 0.85rem;
  line-height: 1.5;
  margin: 0;
}

.metrics {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-top: 1rem;
}

.metric {
  text-align: center;
  padding: 0.75rem;
  background-color: var(--bg-page);
  border-radius: 0.5rem;
}

.metric-value {
  display: block;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-accent);
}

.metric-label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-light);
  margin-top: 0.25rem;
}

/* How-To Guide */
.howto-steps {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-top: 2rem;
}

.howto-step {
  display: flex;
  gap: 1.5rem;
}

.step-number {
  width: 40px;
  height: 40px;
  background-color: var(--primary-accent);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  flex-shrink: 0;
}

.step-content {
  flex: 1;
  background: var(--bg-card);
  border-radius: 0.75rem;
  padding: 1.5rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
}

.step-content h3 {
  color: var(--primary-accent);
  font-size: 1.1rem;
  margin-bottom: 0.75rem;
}

.step-content p {
  margin-bottom: 1rem;
  line-height: 1.6;
}

.quick-tip {
  background-color: var(--success-bg);
  border-left: 4px solid var(--success-text);
  padding: 1rem;
  border-radius: 0.25rem;
  margin: 1rem 0;
}

.quick-tip h5 {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--success-text);
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.quick-tip p {
  font-size: 0.85rem;
  line-height: 1.5;
  margin: 0;
}

.troubleshooting {
  background-color: var(--error-bg);
  border-left: 4px solid var(--error-text);
  padding: 1rem;
  border-radius: 0.25rem;
  margin: 1rem 0 0;
}

.troubleshooting h5 {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--error-text);
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.troubleshooting p {
  font-size: 0.85rem;
  line-height: 1.5;
  margin: 0;
}

/* Tips & Best Practices */
.tips-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 2rem;
}

@media (min-width: 768px) {
  .tips-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.tip-card {
  display: flex;
  gap: 1rem;
  background: var(--bg-card);
  border-radius: 0.75rem;
  padding: 1.5rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.tip-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

.tip-number {
  width: 40px;
  height: 40px;
  background-color: var(--primary-accent);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  flex-shrink: 0;
}

.tip-content {
  flex: 1;
}

.tip-content h3 {
  color: var(--primary-accent);
  font-size: 1.1rem;
  margin-bottom: 0.75rem;
}

.tip-content p {
  margin-bottom: 1rem;
  line-height: 1.6;
}

.optimal-settings, .pitfall {
  background-color: var(--bg-page);
  padding: 0.75rem;
  border-radius: 0.5rem;
  margin: 0.75rem 0;
}

.optimal-settings h5, .pitfall h5 {
  color: var(--text-dark);
  font-size: 0.9rem;
  margin-bottom: 0.25rem;
}

.optimal-settings p, .pitfall p {
  font-size: 0.85rem;
  margin: 0;
  line-height: 1.5;
}

.optimal-settings {
  border-left: 3px solid var(--success-text);
}

.pitfall {
  border-left: 3px solid var(--error-text);
}

/* Enhanced FAQ Section */
.faq-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 2rem;
}

@media (min-width: 768px) {
  .faq-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.faq-item {
  background: var(--bg-card);
  border-radius: 0.75rem;
  padding: 1.5rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
}

.faq-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

.faq-item h3 {
  color: var(--primary-accent);
  font-size: 1.1rem;
  margin-bottom: 0.75rem;
  font-weight: 600;
  line-height: 1.4;
}

.faq-item p {
  color: var(--text-medium);
  line-height: 1.6;
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

.faq-item p:last-child {
  margin-bottom: 0;
}

/* Why Choose Us Section */
.advantages-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-top: 2rem;
}

@media (min-width: 768px) {
  .advantages-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .advantages-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.advantage-card {
  background: var(--bg-card);
  border-radius: 0.75rem;
  padding: 1.5rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
  text-align: center;
}

.advantage-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

.advantage-icon {
  width: 70px;
  height: 70px;
  background-color: var(--primary-accent-light);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
}

.advantage-icon i {
  font-size: 1.75rem;
  color: var(--primary-accent);
}

.advantage-card h3 {
  color: var(--primary-accent);
  font-size: 1.1rem;
  margin-bottom: 0.75rem;
}

.advantage-card p {
  color: var(--text-medium);
  line-height: 1.6;
  font-size: 0.95rem;
  margin-bottom: 1rem;
}

.advantage-metrics {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.metric-item {
  text-align: center;
  padding: 0.75rem;
  background-color: var(--bg-page);
  border-radius: 0.5rem;
}

.metric-value {
  display: block;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--primary-accent);
}

.metric-label {
  display: block;
  font-size: 0.7rem;
  color: var(--text-light);
  margin-top: 0.25rem;
}

/* Success Stories Section */
.success-stories {
  display: flex;
  flex-direction: column;
  gap: 2rem;
  margin-top: 2rem;
}

.success-story {
  background: var(--bg-card);
  border-radius: 0.75rem;
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
}

.story-header {
  padding: 1.5rem;
  background-color: var(--primary-accent-light);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.runner-info h3 {
  color: var(--text-dark);
  font-size: 1.1rem;
  margin-bottom: 0.25rem;
}

.runner-details {
  color: var(--text-medium);
  font-size: 0.9rem;
}

.improvement {
  text-align: center;
}

.improvement-value {
  display: block;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-accent);
}

.improvement-label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-medium);
  margin-top: 0.25rem;
}

.story-content {
  padding: 1.5rem;
}

.before-after {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}

@media (min-width: 768px) {
  .before-after {
    grid-template-columns: 1fr 1fr;
  }
}

.before h4, .after h4 {
  color: var(--primary-accent);
  font-size: 1rem;
  margin-bottom: 0.5rem;
}

.before p, .after p {
  font-size: 0.9rem;
  line-height: 1.5;
}

.implementation {
  margin-bottom: 1.5rem;
}

.implementation h5 {
  color: var(--text-dark);
  font-size: 1rem;
  margin-bottom: 0.5rem;
}

.implementation ul {
  padding-left: 1.5rem;
}

.implementation li {
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
  line-height: 1.5;
}

.testimonial blockquote {
  background-color: var(--bg-page);
  padding: 1.5rem;
  border-radius: 0.5rem;
  border-left: 4px solid var(--primary-accent);
  font-style: italic;
  margin: 0;
}

/* Technical Deep Dive Section */
.technical-content {
  margin-top: 2rem;
}

.technical-section {
  margin-bottom: 2.5rem;
}

.technical-section h3 {
  color: var(--primary-accent);
  font-size: 1.2rem;
  margin-bottom: 1rem;
  border-bottom: 2px solid var(--primary-accent-light);
  padding-bottom: 0.5rem;
}

.technical-section p {
  margin-bottom: 1.5rem;
  line-height: 1.6;
}

.algorithm-explanations, .validation-methods, .privacy-details, .performance-optimizations {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .algorithm-explanations, .validation-methods, .privacy-details, .performance-optimizations {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .algorithm-explanations, .validation-methods, .privacy-details, .performance-optimizations {
    grid-template-columns: repeat(3, 1fr);
  }
}

.algorithm, .validation, .privacy-feature, .optimization {
  background: var(--bg-card);
  border-radius: 0.75rem;
  padding: 1.5rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
}

.algorithm h4, .validation h4, .privacy-feature h4, .optimization h4 {
  color: var(--primary-accent);
  font-size: 1rem;
  margin-bottom: 0.75rem;
}

.algorithm p, .validation p, .privacy-feature p, .optimization p {
  font-size: 0.9rem;
  line-height: 1.5;
  margin-bottom: 0.75rem;
}

.algorithm code {
  background-color: var(--bg-page);
  padding: 0.75rem;
  border-radius: 0.5rem;
  display: block;
  font-family: monospace;
  margin-bottom: 0.75rem;
  border-left: 3px solid var(--primary-accent);
}

.algorithm ul {
  padding-left: 1.5rem;
}

.algorithm li {
  margin-bottom: 0.5rem;
  font-size: 0.9rem;
  line-height: 1.5;
}

/* Footer */
.footer {
  background-color: var(--bg-card);
  padding: 2rem 1rem;
  margin-top: 4rem;
  text-align: center;
  border-top: 1px solid var(--border-color);
}

.footer-content {
  max-width: 800px;
  margin: 0 auto;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin: 1rem 0;
}

.footer-links a {
  color: var(--text-medium);
  text-decoration: none;
  transition: color 0.2s;
}

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

.disclaimer {
  font-size: 0.875rem;
  color: var(--text-light);
  margin-top: 1rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* Responsive Adjustments */
@media (max-width: 767px) {
  .type-toggle {
    grid-template-columns: 1fr;
  }
  
  .time-inputs {
    grid-template-columns: 1fr;
  }
  
  .pace-inputs {
    grid-template-columns: 1fr 1fr;
  }
  
  .pace-unit {
    grid-column: 1 / span 2;
    margin-top: 0.5rem;
  }
  
  .zones-grid {
    grid-template-columns: 1fr;
  }
  
  .howto-step {
    flex-direction: column;
    gap: 1rem;
  }
  
  .step-number {
    align-self: flex-start;
  }
  
  .tip-card {
    flex-direction: column;
    gap: 1rem;
  }
  
  .story-header {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .result-card {
    flex-direction: column;
    text-align: center;
  }
  
  .footer-links {
    flex-direction: column;
    gap: 0.5rem;
  }
  
  .metrics, .advantage-metrics {
    grid-template-columns: 1fr;
  }
}