/* D REVENUE SERVICES LTD — Unique Minimalist One-Column with Sticky Chapters | Warm-Neutral + Ice-Blue | 2026 */
:root {
  --bg: #F5F0E6;
  --text: #1A2A3A;
  --accent: #4A90A4;
  --accent2: #6BA3B5;
  --light: #E8E4DC;
  --card: #FFFFFF;
  --muted: #5A6A7A;
}

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

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.8;
  font-size: 1.08rem;
}

h1, h2, h3 { font-weight: 700; letter-spacing: -0.025em; }

h1 { font-size: clamp(3rem, 7vw, 5.2rem); }
h2 { font-size: clamp(2.2rem, 5vw, 3.2rem); }

a { color: inherit; text-decoration: none; }

.container { max-width: 1280px; margin: 0 auto; padding: 0 2rem; }

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(245, 240, 230, 0.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--light);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.8rem 0;
}

.logo {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.04em;
}

.nav-links {
  display: flex;
  gap: 2.8rem;
  list-style: none;
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 2px;
  transition: color 0.2s ease;
}

.nav-links a:hover { color: var(--accent); }

.menu-btn {
  display: none;
  background: none;
  border: 2px solid var(--text);
  padding: 0.6rem 1.2rem;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2px;
  cursor: pointer;
}

/* Hero */
.hero {
  min-height: 95vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: linear-gradient(180deg, #F5F0E6 0%, #E8E4DC 100%);
  position: relative;
}

.hero-content {
  max-width: 820px;
}

.hero h1 {
  margin-bottom: 2rem;
  line-height: 1.1;
}

.hero p {
  font-size: 1.3rem;
  color: var(--muted);
  max-width: 620px;
  margin: 0 auto 3rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.8rem;
  padding: 1.2rem 3rem;
  border: 2px solid var(--accent);
  color: var(--accent);
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 2.5px;
  border-radius: 0;
  transition: all 0.3s ease;
}

.btn:hover {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}

/* Main Layout with Sticky Chapters */
.main-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 4rem;
  max-width: 1280px;
  margin: 0 auto;
  padding: 4rem 2rem;
}

@media (max-width: 900px) {
  .main-layout {
    grid-template-columns: 1fr;
  }
  
  .sticky-nav {
    position: static !important;
    margin-bottom: 3rem;
  }
}

/* Sticky Chapter Navigation */
.sticky-nav {
  position: sticky;
  top: 100px;
  height: fit-content;
  background: var(--card);
  border: 1px solid var(--light);
  padding: 2.5rem 2rem;
  border-radius: 0;
}

.sticky-nav h4 {
  font-size: 0.9rem;
  margin-bottom: 1.8rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 2px;
}

.sticky-nav ul {
  list-style: none;
}

.sticky-nav li {
  margin-bottom: 1rem;
}

.sticky-nav a {
  color: var(--text);
  font-size: 0.95rem;
  transition: color 0.2s ease;
  display: block;
  padding: 0.4rem 0;
}

.sticky-nav a:hover,
.sticky-nav a.active {
  color: var(--accent);
  font-weight: 600;
}

/* Article Sections */
.article-section {
  margin-bottom: 6rem;
  scroll-margin-top: 120px;
}

.article-section h2 {
  font-size: 2.4rem;
  margin-bottom: 2rem;
  color: var(--accent);
  line-height: 1.2;
}

.article-section p {
  color: var(--muted);
  font-size: 1.1rem;
  margin-bottom: 1.8rem;
}

/* Long Text Section */
.long-text {
  background: var(--light);
  padding: 5rem 4rem;
  margin: 5rem 0;
  max-width: 820px;
  margin-left: auto;
  margin-right: auto;
}

.long-text h2 {
  text-align: center;
  margin-bottom: 3rem;
}

/* Contact Form */
.contact-form {
  max-width: 620px;
  margin: 5rem auto;
}

.form-group {
  margin-bottom: 2rem;
}

.form-group label {
  display: block;
  font-weight: 700;
  margin-bottom: 0.7rem;
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 1.5px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 1.3rem 1.5rem;
  border: 2px solid var(--light);
  background: white;
  font-size: 1.05rem;
  border-radius: 0;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--accent);
  outline: none;
}

.form-group textarea {
  min-height: 180px;
  resize: vertical;
}

.form-submit {
  width: 100%;
  justify-content: center;
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.form-submit:hover {
  background: #3A7A8A;
  border-color: #3A7A8A;
}

/* Thank You */
.thankyou {
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 2rem;
}

.thankyou-content {
  max-width: 580px;
}

.thankyou-content h1 {
  font-size: 3.8rem;
  margin-bottom: 1.5rem;
}

/* Footer */
.footer {
  background: #1A2A3A;
  color: #B8C4D0;
  padding: 5rem 0 3rem;
  font-size: 0.92rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 4rem;
  margin-bottom: 4rem;
}

.footer h4 {
  color: white;
  font-size: 0.95rem;
  margin-bottom: 1.5rem;
  text-transform: uppercase;
  letter-spacing: 2px;
}

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

.footer-links li {
  margin-bottom: 0.7rem;
}

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

.footer-bottom {
  border-top: 1px solid #2A3A4A;
  padding-top: 2.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

/* Responsive */
@media (max-width: 900px) {
  .nav-links { display: none; }
  .menu-btn { display: block; }
  
  .footer-grid { grid-template-columns: 1fr; }
}