@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&display=swap');

/* ===================== CSS CUSTOM PROPERTIES ===================== */
:root {
  /* Colors */
  --color-navy: #1e3a5f;
  --color-navy-dark: #132848;
  --color-navy-light: #2d5282;
  --color-orange: #e8600a;
  --color-orange-hover: #c4510a;
  --color-bg: #ffffff;
  --color-bg-alt: #f4f7fb;
  --color-bg-dark: #0f2035;
  --color-text: #1a202c;
  --color-text-muted: #4a5568;
  --color-border: #dde3ea;
  --color-success: #1a7f5a;
  --color-warning: #b45309;
  --color-highlight: #fff3cd;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 2rem;
  --text-4xl: 2.75rem;
  --text-5xl: 3.5rem;
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  --font-extrabold: 800;

  /* Layout */
  --max-width: 1100px;
  --article-max-width: 760px;
  --section-padding-v: 80px;
  --section-padding-v-mobile: 48px;
  --radius-sm: 4px;
  --radius: 8px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.12);
}

/* ===================== BASE RESET ===================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  line-height: 1.6;
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

img, svg {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
}

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

.section {
  padding: var(--section-padding-v) 0;
}

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

.section--dark {
  background: var(--color-bg-dark);
  color: white;
}

/* ===================== NAVIGATION ===================== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: #fff;
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 16px;
}

.nav__logo {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--color-navy);
  text-decoration: none;
  flex-shrink: 0;
  display: flex;
  align-items: center;
}

.nav__links {
  display: flex;
  gap: 32px;
  list-style: none;
  flex: 1;
  justify-content: center;
}

.nav__links a {
  color: var(--color-text-muted);
  font-weight: var(--font-medium);
  text-decoration: none;
  font-size: var(--text-sm);
  transition: color 0.15s;
}

.nav__links a:hover {
  color: var(--color-navy);
}

.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav__hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-navy);
  border-radius: 2px;
  transition: transform 0.2s;
}

/* ===================== BUTTONS ===================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 48px;
  padding: 0 24px;
  border-radius: var(--radius);
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  font-family: var(--font-sans);
  cursor: pointer;
  border: 2px solid transparent;
  text-decoration: none;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
  white-space: nowrap;
}

.btn--primary {
  background: var(--color-orange);
  color: #fff;
  border-color: var(--color-orange);
}

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

.btn--secondary {
  background: transparent;
  border-color: var(--color-navy);
  color: var(--color-navy);
}

.btn--secondary:hover {
  background: var(--color-navy);
  color: #fff;
}

.btn--lg {
  height: 56px;
  padding: 0 32px;
  font-size: var(--text-lg);
}

.btn--sm {
  height: 36px;
  padding: 0 16px;
  font-size: var(--text-sm);
}

/* ===================== CARDS ===================== */
.card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

/* ===================== HERO ===================== */
.hero {
  background: var(--color-bg-dark);
  color: #fff;
  padding: 96px 0 80px;
  text-align: center;
}

.hero__eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: var(--text-sm);
  color: var(--color-orange);
  font-weight: var(--font-semibold);
  margin-bottom: 16px;
}

.hero__title {
  font-size: var(--text-5xl);
  font-weight: var(--font-extrabold);
  line-height: 1.1;
  max-width: 760px;
  margin: 0 auto 20px;
}

.hero__subtitle {
  font-size: var(--text-xl);
  color: rgba(255,255,255,0.75);
  max-width: 560px;
  margin: 0 auto 40px;
}

/* ===================== STATS STRIP ===================== */
.stats-strip {
  background: var(--color-navy);
  color: #fff;
  padding: 24px 0;
}

.stats-strip__inner {
  display: flex;
  justify-content: space-around;
  gap: 24px;
  flex-wrap: wrap;
}

.stat-item {
  text-align: center;
}

.stat-item__number {
  font-size: var(--text-3xl);
  font-weight: var(--font-extrabold);
  color: var(--color-orange);
  font-family: var(--font-mono);
}

.stat-item__label {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.7);
  margin-top: 4px;
}

/* ===================== FEATURE GRID ===================== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card__icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.feature-card__title {
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  color: var(--color-navy);
  margin-bottom: 8px;
}

.feature-card__badge {
  display: inline-block;
  font-size: var(--text-xs);
  background: var(--color-highlight);
  color: var(--color-warning);
  padding: 2px 8px;
  border-radius: 20px;
  font-weight: var(--font-semibold);
}

/* ===================== ARTICLE GRID ===================== */
.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.article-card__meta {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: 8px;
}

.article-card__title {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--color-navy);
  margin-bottom: 8px;
  line-height: 1.3;
}

.article-card__excerpt {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* ===================== CALCULATOR WIDGET ===================== */
.calc-widget {
  max-width: 680px;
  margin: 0 auto;
}

.calc-header {
  background: var(--color-navy);
  color: #fff;
  padding: 20px 24px;
  border-radius: var(--radius) var(--radius) 0 0;
}

.calc-body {
  background: #fff;
  border: 1px solid var(--color-border);
  border-top: none;
  padding: 32px 24px;
  border-radius: 0 0 var(--radius) var(--radius);
}

.calc-input-group {
  margin-bottom: 24px;
}

.calc-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: var(--font-semibold);
  margin-bottom: 8px;
}

.calc-value-display {
  font-family: var(--font-mono);
  font-weight: var(--font-bold);
  color: var(--color-orange);
}

.calc-slider {
  width: 100%;
  accent-color: var(--color-orange);
  cursor: pointer;
  height: 6px;
}

.calc-preview {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin: 24px 0;
}

.calc-preview__label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: 8px;
}

.calc-preview__value {
  font-size: var(--text-3xl);
  font-weight: var(--font-extrabold);
  font-family: var(--font-mono);
  color: var(--color-orange);
}

.calc-result-blur {
  filter: blur(6px);
  user-select: none;
  pointer-events: none;
}

/* ===================== EMAIL MODAL ===================== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.modal-overlay.hidden {
  display: none;
}

.modal-box {
  background: #fff;
  border-radius: var(--radius-lg);
  padding: 40px;
  max-width: 480px;
  width: 100%;
}

.modal-title {
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  color: var(--color-navy);
  margin-bottom: 8px;
}

.modal-subtitle {
  color: var(--color-text-muted);
  margin-bottom: 24px;
}

/* ===================== COMPARISON TABLES ===================== */
.comparison-table {
  width: 100%;
  border-collapse: collapse;
  border: 1px solid var(--color-border);
  font-size: var(--text-sm);
}

.comparison-table th {
  background: var(--color-navy);
  color: #fff;
  padding: 12px 16px;
  text-align: left;
  font-weight: var(--font-semibold);
}

.comparison-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--color-border);
}

.comparison-table tr:nth-child(even) td {
  background: var(--color-bg-alt);
}

.comparison-table tr.winner td {
  border-left: 3px solid var(--color-orange);
}

/* ===================== CALLOUT BOXES ===================== */
.callout {
  padding: 16px 20px;
  border-radius: var(--radius);
  border-left: 4px solid;
  margin: 24px 0;
}

.callout--info {
  background: #eff6ff;
  border-color: #3b82f6;
}

.callout--warning {
  background: #fffbeb;
  border-color: var(--color-warning);
}

.callout--tip {
  background: #f0fdf4;
  border-color: var(--color-success);
}

.callout--danger {
  background: #fef2f2;
  border-color: #dc2626;
}

/* ===================== FOOTER ===================== */
.footer {
  background: var(--color-navy-dark);
  color: rgba(255,255,255,0.85);
  padding: 64px 0 32px;
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}

.footer__logo {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: #fff;
  margin-bottom: 12px;
}

.footer__tagline {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.6);
}

.footer__heading {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: #fff;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 16px;
}

.footer__links {
  list-style: none;
}

.footer__links li {
  margin-bottom: 8px;
}

.footer__links a {
  color: rgba(255,255,255,0.65);
  text-decoration: none;
  font-size: var(--text-sm);
  transition: color 0.15s;
}

.footer__links a:hover {
  color: #fff;
}

.footer__bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 24px;
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.4);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

/* ===================== FORM ELEMENTS ===================== */
.form-group {
  margin-bottom: 16px;
}

.form-label {
  display: block;
  font-weight: var(--font-medium);
  margin-bottom: 6px;
  font-size: var(--text-sm);
}

.form-input {
  width: 100%;
  height: 48px;
  padding: 0 16px;
  border: 2px solid var(--color-border);
  border-radius: var(--radius);
  font-size: var(--text-base);
  font-family: var(--font-sans);
  outline: none;
  transition: border-color 0.15s;
}

.form-input:focus {
  border-color: var(--color-navy);
}

/* ===================== TABLE WRAP ===================== */
.table-wrap {
  overflow-x: auto;
  margin: 32px 0;
}

/* ===================== RESPONSIVE ===================== */
@media (max-width: 1024px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer__grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --section-padding-v: 48px;
  }
  .hero__title {
    font-size: var(--text-4xl);
  }
  .feature-grid,
  .article-grid {
    grid-template-columns: 1fr;
  }
  .footer__grid {
    grid-template-columns: 1fr;
  }
  .nav__links {
    display: none;
  }
  .nav__hamburger {
    display: flex;
  }
  .nav--open .nav__links {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    background: #fff;
    padding: 16px 24px;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    z-index: 99;
  }
  .modal-box {
    padding: 24px;
  }
}