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

:root {
  --primary: #3A7CA5;
  --primary-dark: #2D6282;
  --primary-light: #4A9AC7;
  --bg: #F7FAFB;
  --bg-alt: #EDF3F6;
  --card: #FFFFFF;
  --text: #1E3A4F;
  --text-secondary: #5A7D95;
  --text-light: #8FAABB;
  --border: #DCE6ED;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 2px 16px rgba(58, 124, 165, 0.08);
  --shadow-lg: 0 8px 32px rgba(58, 124, 165, 0.12);
  --max-width: 960px;
  --transition: 0.2s ease;
}

html {
  scroll-behavior: smooth;
}

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

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

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

/* ── Navigation ── */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 24px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  color: var(--text);
}

.nav-logo img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.nav-logo .droplet {
  width: 36px;
  height: 36px;
  background: var(--primary);
  border-radius: 50% 50% 50% 0;
  transform: rotate(-45deg);
  display: flex;
  align-items: center;
  justify-content: center;
}

.nav-logo .droplet span {
  transform: rotate(45deg);
  color: white;
  font-size: 16px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 15px;
  font-weight: 500;
  transition: color var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary);
}

.nav-cta {
  background: var(--primary);
  color: white !important;
  padding: 8px 20px;
  border-radius: 24px;
  font-weight: 600;
  font-size: 14px;
  transition: background var(--transition), transform var(--transition);
}

.nav-cta:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  margin: 5px 0;
  border-radius: 2px;
  transition: var(--transition);
}

@media (max-width: 680px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 16px 24px;
    gap: 16px;
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
  }
  .nav-links.open { display: flex; }
}

/* ── Hero ── */
.hero {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 80px 24px 60px;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  background: var(--bg-alt);
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
  padding: 6px 16px;
  border-radius: 20px;
  margin-bottom: 24px;
  letter-spacing: 0.5px;
}

.hero h1 {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 800;
  line-height: 1.15;
  color: var(--text);
  margin-bottom: 20px;
  letter-spacing: -0.5px;
}

.hero h1 .accent {
  color: var(--primary);
}

.hero p {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

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

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--primary);
  color: white;
  padding: 14px 32px;
  border-radius: 28px;
  font-weight: 600;
  font-size: 16px;
  border: none;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  box-shadow: 0 4px 16px rgba(58, 124, 165, 0.25);
}

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(58, 124, 165, 0.3);
  color: white;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  color: var(--text-secondary);
  padding: 14px 28px;
  border-radius: 28px;
  font-weight: 600;
  font-size: 16px;
  border: 2px solid var(--border);
  cursor: pointer;
  transition: all var(--transition);
}

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

/* ── Features Grid ── */
.features {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 24px 80px;
}

.features h2 {
  text-align: center;
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 12px;
}

.features .subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 16px;
  margin-bottom: 48px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.feature-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: transform var(--transition), box-shadow var(--transition);
}

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

.feature-icon {
  width: 48px;
  height: 48px;
  background: var(--bg-alt);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 8px;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 14px;
  line-height: 1.65;
}

/* ── Section ── */
.section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 60px 24px;
}

.section-narrow {
  max-width: 720px;
}

.section h1 {
  font-size: 36px;
  font-weight: 800;
  margin-bottom: 8px;
  letter-spacing: -0.3px;
}

.section .page-subtitle {
  color: var(--text-secondary);
  font-size: 16px;
  margin-bottom: 40px;
}

/* ── Legal Pages ── */
.legal-content {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 36px;
}

.legal-content h2 {
  font-size: 20px;
  font-weight: 700;
  margin: 32px 0 12px;
  color: var(--text);
}

.legal-content h2:first-child {
  margin-top: 0;
}

.legal-content p,
.legal-content li {
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.8;
  margin-bottom: 12px;
}

.legal-content ul {
  padding-left: 24px;
  margin-bottom: 16px;
}

.legal-content li {
  margin-bottom: 6px;
}

.legal-meta {
  font-size: 13px;
  color: var(--text-light);
  margin-bottom: 28px;
}

/* ── Contact Page ── */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

@media (max-width: 680px) {
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

.contact-info-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
}

.contact-info-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 16px;
}

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 20px;
}

.contact-item-icon {
  width: 40px;
  height: 40px;
  min-width: 40px;
  background: var(--bg-alt);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
}

.contact-item-text strong {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 2px;
}

.contact-item-text span {
  color: var(--text-secondary);
  font-size: 14px;
}

.contact-form-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
}

.contact-form-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 20px;
}

.form-group {
  margin-bottom: 16px;
}

.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-family: inherit;
  color: var(--text);
  background: var(--bg);
  transition: border-color var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  border-color: var(--primary);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

.form-submit {
  width: 100%;
  padding: 14px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 15px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: background var(--transition);
}

.form-submit:hover {
  background: var(--primary-dark);
}

/* ── Footer ── */
.footer {
  background: var(--text);
  color: rgba(255, 255, 255, 0.7);
  margin-top: 80px;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 48px 24px 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

@media (max-width: 680px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }
}

.footer-brand p {
  font-size: 14px;
  line-height: 1.7;
  max-width: 300px;
}

.footer h4 {
  color: white;
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

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

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.6);
  font-size: 14px;
  transition: color var(--transition);
}

.footer-links a:hover {
  color: white;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 13px;
}

.footer-bottom a {
  color: rgba(255, 255, 255, 0.5);
}

.footer-bottom a:hover {
  color: white;
}

/* ── CTA Banner ── */
.cta-banner {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  border-radius: var(--radius);
  padding: 56px 40px;
  text-align: center;
  color: white;
  margin: 0 24px;
  max-width: calc(var(--max-width) - 48px);
  margin-left: auto;
  margin-right: auto;
}

.cta-banner h2 {
  font-size: 28px;
  font-weight: 800;
  margin-bottom: 12px;
}

.cta-banner p {
  font-size: 16px;
  opacity: 0.85;
  margin-bottom: 28px;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

.btn-white {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: white;
  color: var(--primary);
  padding: 14px 32px;
  border-radius: 28px;
  font-weight: 700;
  font-size: 16px;
  border: none;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition);
}

.btn-white:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.15);
  color: var(--primary);
}

/* ── Utilities ── */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }

/* App Store Buttons */
.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin-bottom: 48px;
}

.app-btn img {
  height: 44px;
  width: auto;
  transition: transform var(--transition);
}

.app-btn:hover img {
  transform: translateY(-2px);
}

/* Phone Mockup */
.hero-mockup {
  perspective: 1000px;
  margin-top: 40px;
}

.phone-frame {
  width: 280px;
  height: 560px;
  background: #1e1e1e;
  margin: 0 auto;
  border-radius: 40px;
  padding: 12px;
  border: 4px solid #333;
  box-shadow: 0 20px 50px rgba(0,0,0,0.1), 0 5px 15px rgba(0,0,0,0.05);
  transform: rotateX(10deg);
}

.phone-screen {
  width: 100%;
  height: 100%;
  background: var(--bg);
  border-radius: 30px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  padding: 20px;
}

/* Internal App UI Styles */
.fluid-tank {
  flex: 1;
  background: #eef4f8;
  border-radius: 20px;
  margin: 20px 0;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.water-level {
  position: absolute;
  bottom: 0;
  width: 100%;
  height: 60%;
  background: linear-gradient(180deg, var(--primary-light) 0%, var(--primary) 100%);
}

.tank-label {
  position: relative;
  font-weight: 700;
  color: var(--text);
  z-index: 1;
}

.log-item {
  display: flex;
  justify-content: space-between;
  padding: 10px;
  background: white;
  margin-bottom: 8px;
  border-radius: 10px;
  font-size: 12px;
  box-shadow: var(--shadow);
}