/* ============================================================
   সার্থক (Sharthok) — Premium Service Agency
   Complete Stylesheet
   ============================================================ */

/* --- CSS Custom Properties / Color Palette --- */
:root {
  --bg-primary: #0A0A0A;
  --bg-secondary: #111111;
  --bg-tertiary: #0F0F0F;
  --bg-card: #1A1A1A;
  --accent-gold: #C69749;
  --accent-hover: #D4A853;
  --accent-muted: #8B7355;
  --text-primary: #F5F0E8;
  --text-secondary: #A09888;
  --border-color: #2A2A2A;
  --border-light: #333333;
  --error: #C0392B;
  --success: #27AE60;
  --font-size-base: 16px;
  --transition-speed: 0.3s;
  --glass-bg: rgba(26, 26, 26, 0.85);
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.5);
  --gold-glow: 0 0 20px rgba(198, 151, 73, 0.15);
  --radius: 8px;
  --max-width: 1200px;
}

/* --- Reset & Base --- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: var(--font-size-base);
}

body {
  font-family: 'Hind Siliguri', 'Inter', sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* --- Noise Texture Overlay --- */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 9999;
  opacity: 0.03;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 256px 256px;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-family: 'Playfair Display', Georgia, serif;
  font-weight: 600;
  line-height: 1.3;
  color: var(--text-primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.8rem; }
h3 { font-size: 1.3rem; }

a {
  color: var(--accent-gold);
  text-decoration: none;
  transition: color var(--transition-speed) ease;
}

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

img { max-width: 100%; height: auto; }

::selection {
  background: var(--accent-gold);
  color: var(--bg-primary);
}

/* --- Section Decorative Heading Lines --- */
.section-title-wrapper {
  position: relative;
  margin-bottom: 3rem;
  text-align: center;
}

.section-title-wrapper h2 {
  display: inline-block;
  position: relative;
  margin-bottom: 1rem;
}

.section-title-wrapper h2::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 2px;
  background: var(--accent-gold);
  border-radius: 1px;
}

.section-title-wrapper .section-subtitle {
  display: block;
  font-family: 'Inter', sans-serif;
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-top: 0.75rem;
  font-weight: 400;
}

/* --- Container --- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* --- Layout Sections --- */
section {
  padding: 5rem 0;
  position: relative;
}

section:nth-child(even) {
  background: var(--bg-secondary);
}

/* ============================================================
   HEADER / NAVIGATION
   ============================================================ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(10, 10, 10, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: background var(--transition-speed) ease;
}

.header.scrolled {
  background: rgba(10, 10, 10, 0.98);
  box-shadow: 0 2px 20px rgba(0,0,0,0.5);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

.logo {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--accent-gold);
  letter-spacing: 1px;
  text-decoration: none;
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 2rem;
  align-items: center;
}

.nav-links a {
  color: var(--text-secondary);
  font-family: 'Inter', sans-serif;
  font-size: 0.875rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  position: relative;
  padding: 4px 0;
  transition: color var(--transition-speed) ease;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--accent-gold);
  transition: width var(--transition-speed) ease;
}

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

.nav-links a:hover::after {
  width: 100%;
}

.nav-cta {
  display: inline-block;
  background: transparent;
  border: 1px solid var(--accent-gold);
  color: var(--accent-gold) !important;
  padding: 8px 20px !important;
  border-radius: var(--radius);
  font-weight: 600 !important;
  transition: all var(--transition-speed) ease;
  text-transform: none !important;
  letter-spacing: 0 !important;
}

.nav-cta:hover {
  background: var(--accent-gold);
  color: var(--bg-primary) !important;
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
  background: none;
  border: none;
  padding: 8px;
  z-index: 1001;
}

.hamburger span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  margin: 3px 0;
  transition: all var(--transition-speed) ease;
  border-radius: 2px;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(6px, -6px);
}

/* ============================================================
   HERO SECTION
   ============================================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 6rem 0 4rem;
  position: relative;
  overflow: hidden;
  background: var(--bg-primary);
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -30%;
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(198,151,73,0.04) 0%, transparent 70%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(198,151,73,0.03) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  max-width: 800px;
}

.hero-badge {
  display: inline-block;
  font-family: 'Inter', sans-serif;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--accent-gold);
  border: 1px solid rgba(198,151,73,0.3);
  padding: 6px 18px;
  border-radius: 100px;
  margin-bottom: 2rem;
  letter-spacing: 1px;
  text-transform: uppercase;
}

.hero h1 {
  font-size: 3.5rem;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
}

.hero h1 .gold-text {
  color: var(--accent-gold);
}

.hero-sub {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 2.5rem;
  max-width: 650px;
  margin-left: auto;
  margin-right: auto;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  border-radius: var(--radius);
  font-family: 'Hind Siliguri', 'Inter', sans-serif;
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-speed) ease;
  border: 1px solid transparent;
  text-decoration: none;
  line-height: 1.4;
}

.btn-primary {
  background: var(--accent-gold);
  color: #1A1A1A;
  border-color: var(--accent-gold);
}

.btn-primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  color: #1A1A1A;
  transform: translateY(-1px);
  box-shadow: var(--gold-glow);
}

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

.btn-secondary:hover {
  background: rgba(198,151,73,0.08);
  color: var(--accent-hover);
  border-color: var(--accent-hover);
  transform: translateY(-1px);
}

/* --- Background "S" Logo --- */
.hero-symbol {
  position: absolute;
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 30rem;
  font-weight: 700;
  color: rgba(198,151,73,0.02);
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
  user-select: none;
  z-index: 1;
}

/* ============================================================
   SERVICES SECTION
   ============================================================ */
.services {
  background: var(--bg-secondary);
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.service-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 2rem;
  transition: all var(--transition-speed) ease;
  position: relative;
  overflow: hidden;
}

.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 0;
  background: var(--accent-gold);
  transition: height var(--transition-speed) ease;
}

.service-card:hover {
  transform: translateY(-4px);
  border-color: rgba(198,151,73,0.3);
  box-shadow: var(--gold-glow);
}

.service-card:hover::before {
  height: 100%;
}

.service-icon {
  font-size: 1.8rem;
  margin-bottom: 1rem;
  display: block;
}

.service-card h3 {
  font-size: 1.15rem;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.service-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.7;
}

/* ============================================================
   PROCESS SECTION
   ============================================================ */
.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  position: relative;
}

.process-steps::before {
  content: '';
  position: absolute;
  top: 2rem;
  left: 2rem;
  right: 2rem;
  height: 1px;
  background: linear-gradient(90deg, var(--accent-gold), var(--border-color), transparent);
  z-index: 0;
}

.process-step {
  text-align: center;
  position: relative;
  z-index: 1;
}

.process-step-number {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border: 2px solid var(--accent-gold);
  border-radius: 50%;
  margin: 0 auto 1.25rem;
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--accent-gold);
  background: var(--bg-secondary);
  transition: all var(--transition-speed) ease;
}

.process-step:hover .process-step-number {
  background: var(--accent-gold);
  color: var(--bg-primary);
  box-shadow: var(--gold-glow);
}

.process-step h3 {
  font-size: 1.1rem;
  margin-bottom: 0.75rem;
  color: var(--text-primary);
}

.process-step p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.6;
  max-width: 250px;
  margin: 0 auto;
}

/* ============================================================
   WHY US SECTION
   ============================================================ */
.why-us {
  background: var(--bg-tertiary);
}

.why-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.why-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 2rem;
  transition: all var(--transition-speed) ease;
}

.why-card:hover {
  border-color: rgba(198,151,73,0.25);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.why-card-icon {
  width: 48px;
  height: 48px;
  background: rgba(198,151,73,0.1);
  border: 1px solid rgba(198,151,73,0.2);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  margin-bottom: 1rem;
  color: var(--accent-gold);
}

.why-card h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.why-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.7;
}

/* ============================================================
   CONTACT SECTION
   ============================================================ */
.contact-form-wrapper {
  max-width: 640px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.4rem;
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.form-group label .required {
  color: var(--accent-gold);
  margin-left: 2px;
}

.form-control {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-family: 'Hind Siliguri', 'Inter', sans-serif;
  font-size: 0.95rem;
  transition: border-color var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
}

.form-control:focus {
  outline: none;
  border-color: var(--accent-gold);
  box-shadow: 0 0 0 2px rgba(198,151,73,0.15);
}

.form-control::placeholder {
  color: #555;
  opacity: 0.6;
}

textarea.form-control {
  min-height: 140px;
  resize: vertical;
}

select.form-control {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath fill='%23A09888' d='M6 8L0 0h12z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 40px;
  cursor: pointer;
}

select.form-control option {
  background: var(--bg-card);
  color: var(--text-primary);
}

.form-submit {
  margin-top: 0.5rem;
}

.btn-submit {
  width: 100%;
  padding: 14px 32px;
  background: var(--accent-gold);
  color: #1A1A1A;
  border: none;
  border-radius: var(--radius);
  font-family: 'Hind Siliguri', 'Inter', sans-serif;
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-speed) ease;
}

.btn-submit:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: var(--gold-glow);
}

.btn-submit:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

/* Form Messages */
.form-message {
  padding: 1rem 1.25rem;
  border-radius: var(--radius);
  margin-bottom: 1.25rem;
  font-size: 0.9rem;
  display: none;
}

.form-message.success {
  display: block;
  background: rgba(39, 174, 96, 0.1);
  border: 1px solid rgba(39, 174, 96, 0.3);
  color: var(--success);
}

.form-message.error {
  display: block;
  background: rgba(192, 57, 43, 0.1);
  border: 1px solid rgba(192, 57, 43, 0.3);
  color: var(--error);
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  padding: 3rem 0 1.5rem;
  text-align: center;
}

.footer-brand {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-gold);
  margin-bottom: 0.5rem;
}

.footer-tagline {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 2rem;
  font-style: italic;
}

.footer-divider {
  width: 60px;
  height: 1px;
  background: var(--border-color);
  margin: 0 auto 1.5rem;
}

.footer-bottom {
  color: var(--text-secondary);
  font-size: 0.8rem;
  opacity: 0.6;
}

/* ============================================================
   SCROLL ANIMATIONS (Intersection Observer)
   ============================================================ */
.fade-in-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in-up.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in-up-delay-1 { transition-delay: 0.1s; }
.fade-in-up-delay-2 { transition-delay: 0.2s; }
.fade-in-up-delay-3 { transition-delay: 0.3s; }
.fade-in-up-delay-4 { transition-delay: 0.4s; }

/* ============================================================
   RESPONSIVE BREAKPOINTS
   ============================================================ */

/* Tablet */
@media (max-width: 768px) {
  html { font-size: 15px; }

  h1 { font-size: 2rem; }
  h2 { font-size: 1.5rem; }

  section { padding: 3.5rem 0; }

  /* Nav */
  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background: rgba(17, 17, 17, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    justify-content: center;
    gap: 2rem;
    padding: 4rem 2rem;
    transition: right 0.4s ease;
    border-left: 1px solid var(--border-color);
    box-shadow: -10px 0 40px rgba(0,0,0,0.5);
  }

  .nav-links.active {
    right: 0;
  }

  .nav-links a {
    font-size: 1rem;
  }

  .hamburger {
    display: flex;
  }

  .nav-cta {
    text-align: center;
    width: 100%;
  }

  /* Hero */
  .hero h1 { font-size: 2.2rem; }
  .hero-sub { font-size: 1rem; }
  .hero-symbol { font-size: 18rem; }

  .hero-cta { flex-direction: column; align-items: center; }
  .hero-cta .btn { width: 100%; max-width: 320px; }

  /* Services */
  .services-grid { grid-template-columns: 1fr; }
  .service-card { padding: 1.5rem; }

  /* Process */
  .process-steps {
    grid-template-columns: repeat(2, 1fr);
  }

  .process-steps::before { display: none; }

  .process-step p { max-width: 100%; }

  /* Why Us */
  .why-grid { grid-template-columns: 1fr; }
}

/* Mobile Small */
@media (max-width: 480px) {
  html { font-size: 14px; }

  .container { padding: 0 1rem; }

  h1 { font-size: 1.8rem; }

  .hero h1 { font-size: 1.8rem; }
  .hero-symbol { font-size: 12rem; }

  .process-steps { grid-template-columns: 1fr; gap: 2rem; }

  .btn { padding: 10px 24px; font-size: 0.9rem; }
}

/* Desktop Large */
@media (min-width: 1200px) {
  .hero h1 { font-size: 3.8rem; }
  .services-grid { gap: 2rem; }
  .service-card { padding: 2.5rem; }
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }

  html { scroll-behavior: auto; }

  .fade-in-up {
    opacity: 1;
    transform: none;
  }
}