/* =========================================================
   Bitumen Calculators - Shared Styles
   Clean, lightweight, mobile-friendly, beginner-friendly
   ========================================================= */

:root {
  --navy: #0f2747;
  --navy-dark: #0a1d35;
  --blue: #1f5ea8;
  --soft-blue: #eaf2fb;
  --white: #ffffff;
  --gray-50: #f4f7fb;
  --gray-100: #edf1f6;
  --gray-200: #d7dee8;
  --gray-500: #5f7188;
  --text: #1c2b3a;
  --success: #13824c;
  --error: #c63b3b;
  --shadow: 0 12px 30px rgba(15, 39, 71, 0.08);
  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 10px;
}

/* Reset / Base */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--text);
  background: var(--gray-50);
  line-height: 1.65;
}

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

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

a:hover {
  text-decoration: underline;
}

/* Layout */
.container {
  width: min(1120px, calc(100% - 2rem));
  margin: 0 auto;
}

.content-narrow {
  width: min(860px, calc(100% - 2rem));
}

.narrow-text {
  max-width: 760px;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid var(--gray-200);
  backdrop-filter: blur(10px);
}

.nav-wrap {
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.logo {
  color: var(--navy);
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: 0.2px;
}

.main-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.main-nav a {
  font-weight: 600;
  color: var(--navy);
}

.main-nav a[aria-current="page"] {
  color: var(--blue);
}

/* Hero / Page heading */
.hero-section {
  padding: 3.2rem 0 2rem;
  background: linear-gradient(180deg, #f7fbff 0%, #eef4fb 100%);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 2rem;
  align-items: start;
}

.page-hero {
  padding: 3rem 0 1.5rem;
  background: linear-gradient(180deg, #f7fbff 0%, #eef4fb 100%);
}

.page-hero-inner h1,
.hero-copy h1 {
  margin: 0 0 1rem;
  line-height: 1.15;
  color: var(--navy);
  font-size: clamp(2rem, 4vw, 3rem);
}

.eyebrow {
  display: inline-block;
  margin: 0 0 0.8rem;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: var(--soft-blue);
  color: var(--navy);
  font-size: 0.92rem;
  font-weight: 700;
}

.lead {
  margin: 0;
  color: var(--gray-500);
  font-size: 1.05rem;
}

/* Cards */
.calculator-card,
.tool-card,
.faq-item {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
}

.featured-card,
.page-card {
  padding: 1.5rem;
}

.calculator-card h2,
.content-section h2,
.faq-section h2,
.tool-links-section h2 {
  margin-top: 0;
  line-height: 1.2;
  color: var(--navy);
}

.card-intro {
  margin-top: -0.2rem;
  color: var(--gray-500);
}

/* Forms */
.form-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.field {
  display: flex;
  flex-direction: column;
}

label {
  margin-bottom: 0.45rem;
  font-weight: 700;
  color: var(--navy);
}

input {
  width: 100%;
  padding: 0.9rem 1rem;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-md);
  background: #fff;
  font-size: 1rem;
  color: var(--text);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

input:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 4px rgba(31, 94, 168, 0.12);
}

.helper-text {
  margin: 1rem 0 0;
  font-size: 0.95rem;
  color: var(--gray-500);
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.2rem;
}

.btn {
  appearance: none;
  border: 0;
  cursor: pointer;
  border-radius: var(--radius-md);
  padding: 0.9rem 1.15rem;
  font-size: 1rem;
  font-weight: 700;
  transition: transform 0.15s ease, background 0.2s ease, color 0.2s ease;
}

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

.btn:active {
  transform: translateY(0);
}

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

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

.btn-outline {
  background: transparent;
  border: 1px solid var(--gray-200);
  color: var(--navy);
}

/* Results */
.result-box {
  margin-top: 1.35rem;
  padding: 1.15rem;
  border-radius: var(--radius-md);
  border: 1px solid #cfe0f5;
  background: linear-gradient(180deg, #f5f9ff 0%, #ecf4ff 100%);
}

.result-box h3 {
  margin-top: 0;
  color: var(--navy);
}

.result-item {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
  padding: 0.85rem 0;
  border-bottom: 1px solid #dbe7f6;
}

.result-item:last-of-type {
  border-bottom: 0;
}

.result-item strong {
  font-size: 1.12rem;
  text-align: right;
}

.message {
  min-height: 1.4rem;
  margin: 0.8rem 0 0;
  font-weight: 600;
}

.error-message {
  color: var(--error);
}

.success-message {
  color: var(--success);
}

/* Tool cards */
.tool-links-section,
.content-section,
.faq-section,
.calculator-section {
  padding: 2rem 0;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.tool-card {
  padding: 1.25rem;
}

.tool-card h3 {
  margin-top: 0;
  margin-bottom: 0.5rem;
}

.tool-card p {
  margin-top: 0;
  color: var(--gray-500);
}

.text-link {
  font-weight: 700;
}

/* Content / FAQ */
.content-section p {
  color: #30445c;
}

.content-section h3 {
  color: var(--navy);
  margin-bottom: 0.45rem;
}

.faq-list {
  display: grid;
  gap: 1rem;
}

.faq-item {
  padding: 1.2rem 1.25rem;
}

.faq-item h3 {
  margin-top: 0;
  margin-bottom: 0.4rem;
  color: var(--navy);
}

.faq-item p {
  margin: 0;
  color: #30445c;
}

/* Footer */
.site-footer {
  padding: 1.5rem 0 2rem;
  border-top: 1px solid var(--gray-200);
  background: #ffffff;
}

.footer-wrap {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
}

.footer-wrap p {
  margin: 0;
  color: var(--gray-500);
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-nav a {
  color: var(--navy);
  font-weight: 600;
}

/* Responsive */
@media (max-width: 920px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }

  .form-grid {
    grid-template-columns: 1fr 1fr;
  }

  .tool-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .nav-wrap,
  .footer-wrap {
    flex-direction: column;
    align-items: flex-start;
    padding: 0.9rem 0;
  }

  .hero-section,
  .page-hero {
    padding-top: 2.2rem;
  }

  .form-grid {
    grid-template-columns: 1fr;
  }

  .button-row {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  .result-item {
    flex-direction: column;
    align-items: flex-start;
  }
}