/* ===== CSS Variables & Design Tokens ===== */
:root {
  --bg-primary: #0a0a0a;
  --bg-secondary: #111111;
  --bg-card: rgba(255, 255, 255, 0.03);
  --bg-card-hover: rgba(255, 255, 255, 0.06);
  --bg-glass: rgba(255, 255, 255, 0.05);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-color-hover: rgba(255, 255, 255, 0.15);
  --text-primary: #f5f5f5;
  --text-secondary: #a0a0a0;
  --text-muted: #6b6b6b;
  --accent: #ffffff;
  --accent-dim: rgba(255, 255, 255, 0.1);
  --gradient-subtle: linear-gradient(135deg, rgba(255,255,255,0.05) 0%, rgba(255,255,255,0.02) 100%);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.4);
  --shadow-glow: 0 0 40px rgba(255, 255, 255, 0.03);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-xl: 24px;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  --max-width: 800px;
}

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

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

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

/* ===== Utility ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 80px 0;
}

.section-label {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}

.section-text {
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.8;
  max-width: 680px;
}

.divider {
  border: none;
  border-top: 1px solid var(--border-color);
  margin: 0;
}

/* ===== Navigation ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(10, 10, 10, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  transition: background var(--transition-smooth);
}

.navbar-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.navbar-brand {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.navbar-brand span {
  color: var(--text-muted);
  font-weight: 400;
}

.navbar-links {
  display: flex;
  gap: 28px;
  list-style: none;
}

.navbar-links a {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

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

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.4rem;
  cursor: pointer;
}

/* ===== Hero ===== */
.hero {
  padding: 140px 0 80px;
  text-align: center;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(255,255,255,0.02) 0%, transparent 70%);
  pointer-events: none;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  border-radius: 100px;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.hero-badge .dot {
  width: 6px;
  height: 6px;
  background: #4ade80;
  border-radius: 50%;
  animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.hero h1 {
  font-size: clamp(2.2rem, 6vw, 3.6rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
}

.hero h1 .highlight {
  background: linear-gradient(135deg, #e0e0e0, #808080);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 520px;
  margin: 0 auto 40px;
  line-height: 1.7;
}

/* ===== Calculator ===== */
.calculator {
  padding: 40px 0 80px;
}

.calc-card {
  background: var(--gradient-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 48px 40px;
  box-shadow: var(--shadow-card);
  position: relative;
  overflow: hidden;
}

.calc-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.1), transparent);
}

.calc-header {
  text-align: center;
  margin-bottom: 40px;
}

.calc-header h2 {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.calc-header p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.calc-form {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.input-group {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
}

.input-group label {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  white-space: nowrap;
}

.time-input {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 14px 20px;
  font-size: 1.3rem;
  font-family: var(--font-body);
  font-weight: 600;
  color: var(--text-primary);
  text-align: center;
  width: 160px;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  -webkit-appearance: none;
  appearance: none;
}

.time-input:focus {
  outline: none;
  border-color: rgba(255, 255, 255, 0.25);
  box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.05);
}

/* Webkit time input icon */
.time-input::-webkit-calendar-picker-indicator {
  filter: invert(1);
  opacity: 0.5;
  cursor: pointer;
}

.btn-calculate {
  background: var(--text-primary);
  color: var(--bg-primary);
  border: none;
  border-radius: var(--radius-md);
  padding: 14px 40px;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: var(--font-body);
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), opacity var(--transition-fast);
}

.btn-calculate:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(255, 255, 255, 0.1);
}

.btn-calculate:active {
  transform: translateY(0);
}

/* Results */
.results {
  margin-top: 40px;
  display: none;
}

.results.show {
  display: block;
  animation: fadeUp 0.5s ease;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

.results-label {
  text-align: center;
  font-size: 0.8rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
}

.result-item {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px 16px;
  text-align: center;
  transition: border-color var(--transition-fast), transform var(--transition-fast);
}

.result-item:hover {
  border-color: var(--border-color-hover);
  transform: translateY(-2px);
}

.result-item.recommended {
  border-color: rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.04);
}

.result-time {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 4px;
}

.result-cycles {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 500;
}

.result-tag {
  display: inline-block;
  margin-top: 8px;
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #4ade80;
  background: rgba(74, 222, 128, 0.08);
  padding: 3px 10px;
  border-radius: 100px;
}

.results-hint {
  text-align: center;
  margin-top: 20px;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ===== Content Sections ===== */
.content-section {
  padding: 60px 0;
}

.content-card {
  background: var(--gradient-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px;
  transition: border-color var(--transition-smooth);
}

.content-card:hover {
  border-color: var(--border-color-hover);
}

.content-card h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.content-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.8;
  margin-bottom: 12px;
}

.content-card p:last-child {
  margin-bottom: 0;
}

.content-card ul {
  list-style: none;
  margin: 16px 0;
}

.content-card ul li {
  color: var(--text-secondary);
  font-size: 0.95rem;
  padding: 6px 0;
  padding-left: 20px;
  position: relative;
}

.content-card ul li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  width: 6px;
  height: 6px;
  background: var(--text-muted);
  border-radius: 50%;
  transform: translateY(-50%);
}

/* ===== Age Table ===== */
.age-table-wrapper {
  overflow-x: auto;
  margin-top: 20px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

.age-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.age-table thead {
  background: rgba(255, 255, 255, 0.04);
}

.age-table th {
  padding: 14px 20px;
  text-align: left;
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-color);
}

.age-table td {
  padding: 14px 20px;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border-color);
}

.age-table tr:last-child td {
  border-bottom: none;
}

.age-table tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

/* ===== FAQ ===== */
.faq-section {
  padding: 60px 0 80px;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 32px;
}

.faq-item {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--border-color-hover);
}

.faq-question {
  width: 100%;
  background: var(--bg-card);
  border: none;
  padding: 20px 24px;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: var(--font-body);
  color: var(--text-primary);
  text-align: left;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  transition: background var(--transition-fast);
}

.faq-question:hover {
  background: var(--bg-card-hover);
}

.faq-icon {
  font-size: 1.2rem;
  color: var(--text-muted);
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

.faq-item.open .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
}

.faq-item.open .faq-answer {
  max-height: 400px;
}

.faq-answer-inner {
  padding: 0 24px 20px;
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.8;
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--border-color);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  gap: 24px;
  list-style: none;
}

.footer-links a {
  font-size: 0.8rem;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

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

/* ===== Cookie Banner ===== */
.cookie-banner {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  z-index: 2000;
  background: rgba(17, 17, 17, 0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid var(--border-color);
  padding: 20px 24px;
  transform: translateY(100%);
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.cookie-banner.show {
  transform: translateY(0);
}

.cookie-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}

.cookie-text {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.6;
  flex: 1;
  min-width: 250px;
}

.cookie-text a {
  color: var(--text-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.cookie-buttons {
  display: flex;
  gap: 8px;
  flex-shrink: 0;
}

.cookie-btn {
  border: none;
  border-radius: var(--radius-sm);
  padding: 10px 20px;
  font-size: 0.8rem;
  font-weight: 600;
  font-family: var(--font-body);
  cursor: pointer;
  transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.cookie-btn:active {
  transform: scale(0.97);
}

.cookie-btn-accept {
  background: var(--text-primary);
  color: var(--bg-primary);
}

.cookie-btn-accept:hover {
  opacity: 0.9;
}

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

.cookie-btn-decline:hover {
  border-color: var(--border-color-hover);
  color: var(--text-primary);
}

/* ===== Animations ===== */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 640px) {
  .navbar-links {
    display: none;
    position: absolute;
    top: 60px;
    left: 0;
    right: 0;
    background: rgba(10, 10, 10, 0.95);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-color);
    gap: 12px;
  }

  .navbar-links.open {
    display: flex;
  }

  .mobile-toggle {
    display: block;
  }

  .hero {
    padding: 120px 0 60px;
  }

  .calc-card {
    padding: 32px 20px;
  }

  .input-group {
    flex-direction: column;
  }

  .content-card {
    padding: 28px 20px;
  }

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

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  .cookie-inner {
    flex-direction: column;
    text-align: center;
  }

  .cookie-buttons {
    width: 100%;
    justify-content: center;
  }
}

/* ===== Modals ===== */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 3000;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-smooth), visibility var(--transition-smooth);
}

.modal-overlay.show {
  opacity: 1;
  visibility: visible;
}

.modal {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -40%);
  width: 90%;
  max-width: 600px;
  max-height: 85vh;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  z-index: 3001;
  display: flex;
  flex-direction: column;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-smooth), transform var(--transition-smooth), visibility var(--transition-smooth);
}

.modal.show {
  opacity: 1;
  visibility: visible;
  transform: translate(-50%, -50%);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
}

.modal-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
}

.modal-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
  transition: color var(--transition-fast);
}

.modal-close:hover {
  color: var(--text-primary);
}

.modal-content {
  padding: 24px;
  overflow-y: auto;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

.modal-content h3 {
  color: var(--text-primary);
  font-size: 1.05rem;
  margin: 24px 0 12px;
}

.modal-content h3:first-child {
  margin-top: 0;
}

.modal-content p {
  margin-bottom: 16px;
}

.modal-content p:last-child {
  margin-bottom: 0;
}

@media (max-width: 640px) {
  .modal {
    width: 95%;
    max-height: 90vh;
  }
}