:root {
  --primary: #078b99;
  --primary-dark: #056d7c;
  --deep: #073f50;
  --text: #12343b;
  --muted: #668087;
  --light: #f4fbfc;
  --border: #dceff2;
  --white: #ffffff;
  --gold: #d6a400;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: Arial, sans-serif;
  background: var(--light);
  color: var(--text);
  line-height: 1.6;
}

a {
  color: inherit;
}

.navbar {
  height: 72px;
  padding: 0 7%;
  background: rgba(255,255,255,.95);
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  border-bottom: 1px solid var(--border);
}

.brand {
  text-decoration: none;
  color: var(--primary);
  font-size: 25px;
  font-weight: 800;
}

.brand span {
  margin-right: 5px;
}

nav {
  display: flex;
  gap: 25px;
}

nav a {
  text-decoration: none;
  color: #31545a;
  font-weight: 600;
}

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

.hero {
  min-height: calc(100vh - 72px);
  padding: 80px 7%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 60px;
  background:
    radial-gradient(circle at 80% 30%, #d9f7fa, transparent 30%),
    linear-gradient(135deg, #e8fbfd, #ffffff);
}

.hero-content {
  max-width: 700px;
}

.eyebrow {
  display: inline-block;
  color: var(--primary);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 2px;
  margin-bottom: 12px;
}

.hero h1 {
  font-size: clamp(45px, 7vw, 78px);
  line-height: 1.02;
  letter-spacing: -2px;
  margin-bottom: 25px;
}

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

.hero p {
  max-width: 620px;
  color: var(--muted);
  font-size: 19px;
  margin-bottom: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: none;
  border-radius: 10px;
  padding: 14px 22px;
  font-size: 15px;
  font-weight: 800;
  cursor: pointer;
  text-decoration: none;
  transition: .2s;
}

.button:hover {
  transform: translateY(-2px);
}

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

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

.secondary {
  color: var(--primary);
  background: white;
  border: 2px solid var(--primary);
}

.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 340px;
}

.water-orbit {
  width: 310px;
  height: 310px;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.water-core {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  background: linear-gradient(145deg, #0ba8ba, #056d91);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 65px;
  box-shadow: 0 25px 60px rgba(5,109,145,.25);
  z-index: 2;
}

.orbit {
  position: absolute;
  border: 1px solid #91dce4;
  border-radius: 50%;
}

.orbit-one {
  width: 270px;
  height: 270px;
}

.orbit-two {
  width: 310px;
  height: 310px;
}

.section {
  padding: 90px 7%;
}

.section-heading {
  max-width: 700px;
  margin: 0 auto 45px;
  text-align: center;
}

.section-heading h2 {
  font-size: clamp(30px, 5vw, 43px);
  line-height: 1.1;
  margin-bottom: 12px;
}

.section-heading p {
  color: var(--muted);
}

.dashboard-grid {
  max-width: 1100px;
  margin: auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.stat-card {
  background: white;
  padding: 25px;
  border: 1px solid var(--border);
  border-radius: 17px;
  box-shadow: 0 8px 30px rgba(0,0,0,.04);
}

.stat-icon {
  display: block;
  font-size: 28px;
  margin-bottom: 14px;
}

.stat-label {
  display: block;
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 5px;
}

.stat-card strong {
  display: block;
  font-size: 25px;
  color: var(--primary);
}

.calculator-section {
  background: white;
}

.calculator-card {
  max-width: 950px;
  margin: auto;
  padding: 35px;
  border-radius: 22px;
  background: var(--light);
  border: 1px solid var(--border);
}

.input-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
}

.input-group label,
.goal-input label {
  display: block;
  font-weight: 800;
  margin-bottom: 8px;
}

.input-with-unit {
  display: flex;
  align-items: center;
  background: white;
  border: 1px solid #c9dfe3;
  border-radius: 10px;
  overflow: hidden;
}

.input-with-unit input {
  min-width: 0;
  flex: 1;
  border: none;
  outline: none;
  padding: 14px;
  font-size: 16px;
}

.input-with-unit span {
  padding-right: 14px;
  color: var(--muted);
  font-size: 13px;
}

.calculate-button {
  width: 100%;
  margin-top: 25px;
}

.estimate-note {
  margin-top: 15px;
  text-align: center;
  font-size: 12px;
  color: var(--muted);
}

.hidden {
  display: none;
}

.results {
  margin-top: 35px;
}

.result-summary {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 15px;
}

.result-summary > div {
  background: white;
  padding: 22px;
  border-radius: 14px;
  border: 1px solid var(--border);
  text-align: center;
}

.result-summary span {
  display: block;
  color: var(--muted);
  font-size: 13px;
}

.result-summary strong {
  display: block;
  color: var(--primary);
  font-size: 30px;
  margin-top: 5px;
}

.analysis {
  margin-top: 35px;
  background: white;
  padding: 30px;
  border-radius: 17px;
  border: 1px solid var(--border);
}

.analysis-header {
  margin-bottom: 25px;
}

.analysis h3 {
  font-size: 24px;
}

.activity {
  margin-bottom: 20px;
}

.activity-label {
  display: flex;
  justify-content: space-between;
  margin-bottom: 7px;
  font-weight: 700;
}

.activity-label strong {
  color: var(--primary);
}

.bar-track {
  height: 13px;
  background: #e3eff1;
  border-radius: 20px;
  overflow: hidden;
}

.bar {
  height: 100%;
  width: 0;
  background: var(--primary);
  border-radius: 20px;
  transition: width .7s ease;
}

.recommendation {
  display: flex;
  gap: 15px;
  margin-top: 30px;
  padding: 20px;
  border-radius: 14px;
  background: #fff8df;
  border-left: 5px solid var(--gold);
}

.recommendation-icon {
  font-size: 27px;
}

.recommendation strong {
  display: block;
  margin-bottom: 4px;
}

.recommendation p {
  color: #635728;
}

.save-button {
  margin-top: 20px;
}

.goal-card {
  max-width: 900px;
  margin: auto;
  background: white;
  padding: 30px;
  border-radius: 20px;
  border: 1px solid var(--border);
  box-shadow: 0 8px 30px rgba(0,0,0,.04);
}

.goal-control {
  display: flex;
  gap: 10px;
}

.goal-control input {
  flex: 1;
  min-width: 0;
  border: 1px solid #c9dfe3;
  border-radius: 10px;
  padding: 13px;
  font-size: 16px;
}

.goal-control span {
  align-self: center;
  margin-left: -45px;
  margin-right: 15px;
  color: var(--muted);
}

.goal-progress {
  margin-top: 35px;
}

.progress-heading {
  display: flex;
  justify-content: space-between;
  margin-bottom: 8px;
}

.progress-heading strong {
  color: var(--primary);
}

.progress-track {
  height: 15px;
  background: #e4eff1;
  border-radius: 20px;
  overflow: hidden;
}

.progress-bar {
  width: 0;
  height: 100%;
  background: var(--primary);
  transition: .6s;
}

.goal-progress p {
  margin-top: 12px;
  color: var(--muted);
  font-size: 14px;
}

.history-list {
  max-width: 900px;
  margin: auto;
}

.history-item {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 20px;
  padding: 20px;
  margin-bottom: 12px;
  background: white;
  border: 1px solid var(--border);
  border-radius: 14px;
}

.history-item strong {
  color: var(--primary);
  font-size: 22px;
}

.history-item small {
  display: block;
  color: var(--muted);
}

.empty-history {
  padding: 50px 20px;
  background: white;
  text-align: center;
  border: 1px dashed #b8d8dd;
  border-radius: 17px;
}

.empty-history span {
  font-size: 45px;
}

.empty-history h3 {
  margin: 10px 0 5px;
}

.empty-history p {
  color: var(--muted);
}

.product-section {
  background: #eaf8fa;
}

.feature-grid {
  max-width: 1000px;
  margin: auto;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.feature-card {
  background: white;
  padding: 30px;
  border-radius: 18px;
  border: 1px solid var(--border);
}

.feature-card > span {
  font-size: 35px;
}

.feature-card h3 {
  margin: 15px 0 7px;
}

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

footer {
  padding: 40px 7%;
  text-align: center;
  color: #a9c9ce;
  background: #032d38;
}

.footer-brand {
  color: white;
  font-size: 24px;
  font-weight: 800;
  margin-bottom: 5px;
}

footer p {
  margin-bottom: 10px;
}

@media (max-width: 900px) {

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

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

  .hero-content {
    max-width: 650px;
  }

  .hero p {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-visual {
    min-width: 0;
  }

}

@media (max-width: 650px) {

  .navbar {
    height: 65px;
  }

  nav {
    display: none;
  }

  .section {
    padding: 65px 5%;
  }

  .hero {
    padding: 60px 5%;
  }

  .hero h1 {
    font-size: 48px;
  }

  .water-orbit {
    transform: scale(.8);
  }

  .dashboard-grid,
  .input-grid,
  .result-summary,
  .feature-grid {
    grid-template-columns: 1fr;
  }

  .calculator-card {
    padding: 20px;
  }

  .goal-control {
    flex-wrap: wrap;
  }

  .goal-control button {
    width: 100%;
  }

  .goal-control span {
    display: none;
  }

  .history-item {
    grid-template-columns: 1fr;
  }

}