:root {
  --navy: #0B1F33;
  --blue: #087EFC;
  --cyan: #00B8D9;
  --background: #F4F8FC;
  --card: #FFFFFF;
  --text: #152033;
  --grey: #6B7280;
  --light-blue: #EAF4FF;
  --border: #DCE7F2;
  --shadow: 0 14px 40px rgba(11, 31, 51, .10);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font-family: Arial, Helvetica, sans-serif; color: var(--text); background: var(--background); line-height: 1.55; }
a { color: inherit; text-decoration: none; }
button, input, select { font: inherit; }
.container { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }

.site-header { position: sticky; top: 0; z-index: 50; background: rgba(255,255,255,.94); backdrop-filter: blur(14px); border-bottom: 1px solid var(--border); }
.nav-wrap { min-height: 76px; display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; font-size: 1.15rem; color: var(--navy); }
.brand img { width: 46px; height: 46px; object-fit: contain; }
.main-nav { display: flex; align-items: center; gap: 28px; font-weight: 700; color: #334155; }
.main-nav a:hover { color: var(--blue); }
.menu-toggle { display: none; border: 0; background: transparent; font-size: 1.8rem; color: var(--navy); }

.hero { padding: 90px 0 80px; background: radial-gradient(circle at 85% 20%, rgba(0,184,217,.16), transparent 28%), linear-gradient(135deg, #071a2c 0%, #0B1F33 55%, #0d4c91 100%); color: white; overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.15fr .85fr; align-items: center; gap: 60px; }
.eyebrow, .section-kicker { font-size: .78rem; letter-spacing: .12em; font-weight: 800; }
.eyebrow { color: #9edfff; margin-bottom: 12px; }
.hero h1 { font-size: clamp(3rem, 8vw, 5.6rem); line-height: .95; margin: 0 0 18px; letter-spacing: -.06em; }
.hero-lead { font-size: clamp(1.25rem, 2.5vw, 1.7rem); font-weight: 700; max-width: 650px; margin: 0 0 12px; }
.hero-text { color: #d9e8f6; max-width: 650px; font-size: 1.05rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.btn { display: inline-flex; align-items: center; justify-content: center; min-height: 50px; padding: 0 22px; border-radius: 14px; font-weight: 800; }
.btn-primary { background: white; color: var(--navy); }
.btn-primary:hover { transform: translateY(-1px); }
.btn-secondary { border: 1px solid rgba(255,255,255,.35); color: white; background: rgba(255,255,255,.08); }
.hero-card { min-height: 390px; border-radius: 30px; padding: 36px; display: flex; flex-direction: column; align-items: center; justify-content: center; background: linear-gradient(150deg, rgba(255,255,255,.16), rgba(255,255,255,.05)); border: 1px solid rgba(255,255,255,.18); box-shadow: 0 30px 70px rgba(0,0,0,.20); text-align: center; }
.hero-card img { width: min(290px, 80%); max-height: 250px; object-fit: contain; filter: drop-shadow(0 15px 25px rgba(0,0,0,.25)); }
.hero-card-title { font-size: 1.35rem; font-weight: 800; margin-top: 12px; }
.hero-card-subtitle { color: #c8dced; margin-top: 4px; }

.section { padding: 90px 0; }
.section-soft { background: #eaf2f9; }
.section-heading { display: flex; justify-content: space-between; align-items: end; gap: 30px; margin-bottom: 30px; }
.section-heading h2, .about-grid h2, .app-panel h2 { margin: 6px 0 8px; font-size: clamp(2rem, 4vw, 3rem); line-height: 1.05; letter-spacing: -.04em; color: var(--navy); }
.section-heading p { max-width: 410px; color: var(--grey); margin: 0; }
.section-kicker { color: var(--blue); }

.calculator-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.calc-card { width: 100%; border: 0; cursor: pointer; color: white; text-align: left; display: grid; grid-template-columns: 52px 1fr 24px; align-items: center; gap: 14px; padding: 20px; border-radius: 18px; background: linear-gradient(135deg, var(--navy), #0d5fc4); box-shadow: var(--shadow); transition: transform .18s ease, box-shadow .18s ease; }
.calc-card:hover { transform: translateY(-3px); box-shadow: 0 18px 45px rgba(11,31,51,.18); }
.calc-card:last-child { grid-column: 1 / -1; }
.calc-card strong { display: block; font-size: 1.06rem; }
.calc-card small { display: block; color: #c8e4ff; margin-top: 2px; }
.calc-card b { font-size: 1.5rem; text-align: right; }
.calc-icon { width: 52px; height: 52px; display: grid; place-items: center; border-radius: 15px; background: rgba(255,255,255,.12); font-size: 1.8rem; line-height: 1; }
.material-icons, .material-icons-round { font-weight: normal; font-style: normal; letter-spacing: normal; text-transform: none; display: inline-block; white-space: nowrap; word-wrap: normal; direction: ltr; -webkit-font-feature-settings: "liga"; -webkit-font-smoothing: antialiased; }
.calc-icon.material-icons, .calc-icon.material-icons-round { display: grid; place-items: center; width: 52px; height: 52px; }

.learning-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.learning-card { width: 100%; text-align: left; border: 0; color: white; border-radius: 20px; padding: 24px; min-height: 220px; background: linear-gradient(145deg, var(--navy), var(--blue)); box-shadow: var(--shadow); cursor: pointer; font: inherit; transition: transform .18s ease, box-shadow .18s ease; }
.learning-card:hover { transform: translateY(-3px); box-shadow: 0 18px 40px rgba(11,31,51,.18); }
.learning-card:focus-visible { outline: 3px solid #00b8d9; outline-offset: 3px; }
.learning-card span { color: #8bdfff; font-weight: 900; }
.learning-card h3 { margin: 18px 0 8px; font-size: 1.15rem; }
.learning-card p { color: #dbeeff; margin: 0 0 16px; font-size: .95rem; }
.learning-card b { color: #8bdfff; font-size: .9rem; }
.learning-content h3 { color: var(--navy); margin: 22px 0 8px; font-size: 1.15rem; }
.learning-content p { color: var(--grey); line-height: 1.65; }
.learning-content ul { margin: 8px 0 18px; padding-left: 22px; color: #27364a; line-height: 1.7; }
.learning-content li { margin-bottom: 5px; }
.learning-answer { margin: 10px 0 18px; padding: 12px 14px; border-radius: 12px; background: var(--light-blue); color: var(--navy); font-weight: 700; }

.app-section { background: white; }
.app-panel { border-radius: 28px; padding: 50px; display: grid; grid-template-columns: 1fr 300px; gap: 40px; align-items: center; background: linear-gradient(135deg, #eaf4ff, #e8fafd); border: 1px solid var(--border); }
.app-panel p { color: var(--grey); max-width: 650px; }
.store-buttons { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 22px; }
.store-button { background: var(--navy); color: white; padding: 13px 20px; border-radius: 12px; font-weight: 800; }
.app-badge { min-height: 250px; display: grid; place-items: center; border-radius: 24px; background: white; box-shadow: var(--shadow); }
.app-badge img { width: 210px; max-height: 210px; object-fit: contain; }

.about-grid { display: grid; grid-template-columns: 1.4fr .6fr; gap: 50px; align-items: center; }
.about-grid p { color: var(--grey); max-width: 700px; }
.info-card { display: flex; flex-direction: column; gap: 5px; padding: 28px; border-radius: 20px; background: linear-gradient(145deg, var(--navy), var(--blue)); color: white; box-shadow: var(--shadow); }
.info-card span { color: #d2eaff; }
.info-card a { color: white; font-weight: 700; margin-top: 10px; }

.site-footer { background: var(--navy); color: #c9d9e8; padding: 28px 0; }
.footer-wrap { display: flex; justify-content: space-between; gap: 20px; align-items: center; }
.footer-links { display: flex; gap: 20px; flex-wrap: wrap; }
.footer-links a:hover { color: white; }

.modal { position: fixed; inset: 0; z-index: 100; display: none; }
.modal.open { display: block; }
.modal-backdrop { position: absolute; inset: 0; background: rgba(3,15,27,.68); backdrop-filter: blur(5px); }
.modal-dialog { position: relative; width: min(680px, calc(100% - 30px)); max-height: calc(100vh - 40px); overflow: auto; margin: 20px auto; background: white; border-radius: 24px; padding: 34px; box-shadow: 0 30px 80px rgba(0,0,0,.3); }
.modal-close { position: absolute; right: 18px; top: 14px; width: 40px; height: 40px; border: 0; border-radius: 50%; background: var(--light-blue); color: var(--navy); font-size: 1.8rem; cursor: pointer; }
.calc-title { margin: 0 50px 4px 0; color: var(--navy); font-size: 2rem; }
.calc-description { color: var(--grey); margin: 0 0 22px; }
.calc-form { display: grid; gap: 14px; }
.field { display: grid; gap: 6px; }
.field label { font-weight: 700; color: var(--navy); }
.field input, .field select { width: 100%; border: 1px solid #cbd9e6; border-radius: 12px; padding: 13px 14px; outline: none; background: white; }
.field input:focus, .field select:focus { border-color: var(--blue); box-shadow: 0 0 0 3px rgba(8,126,252,.12); }
.result-box { margin-top: 20px; padding: 20px; border-radius: 16px; background: var(--light-blue); border: 1px solid #cde6ff; }
.result-label { color: var(--grey); font-size: .9rem; }
.result-value { color: var(--navy); font-size: 2rem; font-weight: 900; margin-top: 3px; }
.formula { margin-top: 15px; color: var(--grey); font-size: .92rem; }
.note { margin-top: 15px; color: var(--grey); font-size: .88rem; }

@media (max-width: 900px) {
  .hero-grid, .app-panel, .about-grid { grid-template-columns: 1fr; }
  .hero-card { min-height: 320px; }
  .learning-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 700px) {
  .container { width: min(100% - 28px, 1120px); }
  .main-nav { display: none; position: absolute; top: 76px; left: 0; right: 0; padding: 18px 20px; background: white; border-bottom: 1px solid var(--border); flex-direction: column; align-items: stretch; gap: 0; }
  .main-nav.open { display: flex; }
  .main-nav a { padding: 13px 0; }
  .menu-toggle { display: block; }
  .hero { padding: 65px 0; }
  .hero-card { min-height: 270px; padding: 24px; }
  .section { padding: 65px 0; }
  .section-heading { display: block; }
  .section-heading p { margin-top: 14px; }
  .calculator-grid { grid-template-columns: 1fr; }
  .calc-card:last-child { grid-column: auto; }
  .learning-grid { grid-template-columns: 1fr; }
  .app-panel { padding: 30px 22px; }
  .footer-wrap { flex-direction: column; align-items: flex-start; }
  .modal-dialog { padding: 26px 20px; }
}

.field input:disabled,
.field select:disabled {
  background: #eef2f7;
  color: #9aa4b2;
  border-color: #d7dee8;
  cursor: not-allowed;
  opacity: 1;
}

.field input:disabled::placeholder {
  color: #aeb7c3;
}


.nav-support {
  color: var(--blue) !important;
}

.support-section {
  padding-top: 20px;
}

.support-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  padding: 34px 38px;
  border-radius: 26px;
  background: linear-gradient(135deg, var(--navy) 0%, #1458a8 62%, var(--blue) 100%);
  color: white;
  box-shadow: var(--shadow);
}

.support-copy {
  max-width: 760px;
}

.support-copy .section-kicker {
  color: #9edfff;
}

.support-copy h2 {
  margin: 8px 0 10px;
  font-size: clamp(1.7rem, 3vw, 2.4rem);
  line-height: 1.1;
}

.support-copy p {
  margin: 0;
  color: #d9e8f6;
  max-width: 720px;
}

.btn-support {
  flex-shrink: 0;
  background: white;
  color: var(--navy);
  gap: 8px;
}

.btn-support:hover {
  transform: translateY(-1px);
}

.btn-support .material-icons {
  font-size: 20px;
}

@media (max-width: 760px) {
  .support-card {
    flex-direction: column;
    align-items: flex-start;
    padding: 28px;
  }

  .btn-support {
    width: 100%;
  }
}