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

:root {
  --primary: #2563eb;
  --primary-light: #dbeafe;
  --primary-dark: #1d4ed8;
  --accent: #0ea5e9;
  --text: #1e293b;
  --text-light: #64748b;
  --bg: #ffffff;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --warning-bg: #fef3c7;
  --warning-border: #f59e0b;
  --warning-text: #92400e;
  --info-bg: #e0f2fe;
  --info-border: #0ea5e9;
  --info-text: #0c4a6e;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.1);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 70px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== Language Toggle ===== */
.lang-toggle {
  position: fixed;
  top: 16px;
  right: 16px;
  z-index: 100;
  display: flex;
  background: var(--bg);
  border-radius: 20px;
  box-shadow: var(--shadow-md);
  overflow: hidden;
  border: 1px solid var(--border);
}

.lang-btn {
  padding: 6px 16px;
  border: none;
  background: transparent;
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-light);
  cursor: pointer;
  transition: all var(--transition);
}

.lang-btn.active {
  background: var(--primary);
  color: #fff;
}

.lang-btn:hover:not(.active) {
  background: var(--bg-alt);
}

/* ===== Hero ===== */
.hero {
  background: linear-gradient(135deg, #1e3a5f 0%, #2563eb 50%, #0ea5e9 100%);
  color: #fff;
  padding: 80px 20px 60px;
  text-align: center;
}

.hero-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto 20px;
  background: rgba(255,255,255,0.15);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(10px);
}

.hero-icon svg {
  width: 48px;
  height: 48px;
  color: #fff;
}

.hero h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.hero p {
  font-size: 1rem;
  opacity: 0.9;
  max-width: 480px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ===== Navigation ===== */
.nav-bar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: center;
  gap: 8px;
  padding: 12px 16px;
  box-shadow: var(--shadow);
}

.nav-link {
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-light);
  padding: 6px 16px;
  border-radius: 20px;
  transition: all var(--transition);
}

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

/* ===== Sections ===== */
.section {
  padding: 56px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-title {
  text-align: center;
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 36px;
  color: var(--text);
  letter-spacing: -0.02em;
}

/* ===== Overview Cards ===== */
.overview-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

@media (min-width: 600px) {
  .overview-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.overview-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 20px;
  text-align: center;
  transition: all var(--transition);
}

.overview-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.card-icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 16px;
  color: var(--primary);
}

.card-icon svg {
  width: 100%;
  height: 100%;
}

.overview-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.overview-card p {
  font-size: 0.875rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* ===== Image Placeholder ===== */
.image-placeholder {
  margin-top: 32px;
}

.placeholder-box {
  background: var(--bg-alt);
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 48px 20px;
  text-align: center;
  color: var(--text-light);
}

.placeholder-box svg {
  width: 48px;
  height: 48px;
  color: var(--border);
  margin-bottom: 12px;
}

.placeholder-box p {
  font-size: 0.875rem;
}

/* ===== Steps ===== */
.steps {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.step {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.step-number {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  background: var(--primary);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
  box-shadow: 0 2px 8px rgba(37,99,235,0.3);
}

.step-content {
  flex: 1;
  background: var(--bg);
  border-radius: var(--radius);
  padding: 24px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.step-content h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.step-content p {
  font-size: 0.9rem;
  color: var(--text-light);
  line-height: 1.7;
}

.step-image-placeholder {
  margin-top: 16px;
  background: var(--bg-alt);
  border: 2px dashed var(--border);
  border-radius: var(--radius-sm);
  padding: 32px;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-light);
}

/* ===== Adjustment Cards ===== */
.adjust-content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

@media (min-width: 600px) {
  .adjust-content {
    grid-template-columns: repeat(3, 1fr);
  }
}

.adjust-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
  text-align: center;
  transition: all var(--transition);
}

.adjust-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.adjust-icon {
  width: 40px;
  height: 40px;
  margin: 0 auto 14px;
  color: var(--primary);
}

.adjust-icon svg {
  width: 100%;
  height: 100%;
}

.adjust-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.adjust-card p {
  font-size: 0.875rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* ===== Tips ===== */
.tips-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

@media (min-width: 600px) {
  .tips-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.tip-card {
  border-radius: var(--radius);
  padding: 20px;
  border-left: 4px solid;
}

.tip-warning {
  background: var(--warning-bg);
  border-left-color: var(--warning-border);
}

.tip-info {
  background: var(--info-bg);
  border-left-color: var(--info-border);
}

.tip-badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 2px 10px;
  border-radius: 4px;
  margin-bottom: 8px;
}

.tip-warning .tip-badge {
  background: var(--warning-border);
  color: var(--warning-text);
}

.tip-info .tip-badge {
  background: var(--info-border);
  color: var(--info-text);
}

.tip-card p {
  font-size: 0.9rem;
  line-height: 1.6;
}

.tip-warning p {
  color: var(--warning-text);
}

.tip-info p {
  color: var(--info-text);
}

/* ===== Support ===== */
.support-box {
  text-align: center;
  background: linear-gradient(135deg, #eff6ff, #e0f2fe);
  border-radius: var(--radius);
  padding: 48px 24px;
  border: 1px solid var(--primary-light);
}

.support-box h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.support-box p {
  font-size: 0.9rem;
  color: var(--text-light);
  max-width: 420px;
  margin: 0 auto 24px;
  line-height: 1.6;
}

.btn {
  display: inline-block;
  text-decoration: none;
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 12px 32px;
  border-radius: 8px;
  cursor: pointer;
  transition: all var(--transition);
  border: none;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 2px 8px rgba(37,99,235,0.3);
}

.btn-primary:hover {
  background: var(--primary-dark);
  box-shadow: 0 4px 16px rgba(37,99,235,0.4);
  transform: translateY(-1px);
}

/* ===== Footer ===== */
.footer {
  background: #1e293b;
  color: rgba(255,255,255,0.7);
  text-align: center;
  padding: 32px 20px;
  font-size: 0.85rem;
  line-height: 1.6;
}

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

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

/* ===== Mobile Tweaks ===== */
@media (max-width: 480px) {
  .hero {
    padding: 70px 16px 48px;
  }

  .hero h1 {
    font-size: 1.4rem;
  }

  .section {
    padding: 40px 0;
  }

  .section-title {
    font-size: 1.25rem;
    margin-bottom: 28px;
  }

  .step-content {
    padding: 18px;
  }

  .nav-bar {
    gap: 4px;
    padding: 10px 8px;
  }

  .nav-link {
    font-size: 13px;
    padding: 5px 12px;
  }

  .lang-toggle {
    top: 12px;
    right: 12px;
  }

  .lang-btn {
    padding: 5px 12px;
    font-size: 13px;
  }
}