/* ======================================================
   Arman Mahmud — Statistical & Research Consultant
   Clean, minimal, academic design
   ====================================================== */

/* ---------- Custom Properties ---------- */
:root {
  --color-primary: #1a365d;
  --color-primary-light: #2c4a7c;
  --color-primary-dark: #0f2440;
  --color-accent: #c9963a;
  --color-accent-light: #dbb06a;
  --color-accent-hover: #b8852e;

  --color-bg: #ffffff;
  --color-bg-alt: #f6f8fb;
  --color-bg-card: #ffffff;
  --color-surface: #edf1f7;

  --color-text: #2d3748;
  --color-text-light: #64748b;
  --color-text-inv: #ffffff;

  --color-border: #e2e8f0;

  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-serif: 'Source Serif 4', Georgia, 'Times New Roman', serif;

  --shadow-sm: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04);
  --shadow-md: 0 4px 12px rgba(0,0,0,.07), 0 2px 4px rgba(0,0,0,.04);
  --shadow-lg: 0 12px 32px rgba(0,0,0,.08), 0 4px 8px rgba(0,0,0,.04);
  --shadow-card: 0 2px 8px rgba(26,54,93,.06);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --transition: 0.25s cubic-bezier(.4,0,.2,1);
  --container: 1120px;
  --navbar-h: 64px;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: var(--navbar-h); }
body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { cursor: pointer; border: none; background: none; font: inherit; }
input, select, textarea {
  font: inherit;
  color: inherit;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.7rem 1rem;
  width: 100%;
  background: var(--color-bg);
  transition: border-color var(--transition);
}
input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(201,150,58,.15);
}
textarea { resize: vertical; }
::selection { background: var(--color-accent-light); color: var(--color-primary-dark); }

/* ---------- Container ---------- */
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.925rem;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  white-space: nowrap;
}
.btn--primary {
  background: var(--color-accent);
  color: var(--color-primary-dark);
  box-shadow: 0 2px 8px rgba(201,150,58,.25);
}
.btn--primary:hover {
  background: var(--color-accent-hover);
  box-shadow: 0 4px 16px rgba(201,150,58,.35);
  transform: translateY(-1px);
}
.btn--outline {
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
  background: transparent;
}
.btn--outline:hover {
  background: var(--color-primary);
  color: var(--color-text-inv);
}
.btn--sm { padding: 0.55rem 1.25rem; font-size: 0.85rem; }
.btn--full { width: 100%; justify-content: center; }

/* ---------- Navbar ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--navbar-h);
  z-index: 1000;
  background: rgba(255,255,255,.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition);
}
.navbar--scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}
.navbar__inner {
  display: flex;
  align-items: center;
  height: 100%;
  gap: 2rem;
}
.navbar__logo {
  display: flex;
  align-items: center;
}
.navbar__logo-img {
  height: 40px;
  width: auto;
  border-radius: 4px;
}
.accent-dot { color: var(--color-accent); }
.navbar__links {
  display: flex;
  gap: 0.25rem;
  margin-left: auto;
}
.navbar__links a {
  padding: 0.5rem 0.9rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-light);
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}
.navbar__links a:hover,
.navbar__links a.active {
  color: var(--color-primary);
  background: var(--color-bg-alt);
}
.navbar__cta { margin-left: 0.5rem; }
.navbar__toggle { display: none; }

/* Mobile nav toggle */
.navbar__toggle {
  width: 28px;
  height: 20px;
  position: relative;
  flex-direction: column;
  justify-content: space-between;
  display: none;
}
.navbar__toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--color-primary);
  border-radius: 2px;
  transition: all var(--transition);
}
.navbar__toggle.open span:nth-child(1) { transform: translateY(9px) rotate(45deg); }
.navbar__toggle.open span:nth-child(2) { opacity: 0; }
.navbar__toggle.open span:nth-child(3) { transform: translateY(-9px) rotate(-45deg); }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(160deg, var(--color-primary-dark) 0%, var(--color-primary) 50%, var(--color-primary-light) 100%);
  color: var(--color-text-inv);
  overflow: hidden;
}
.hero__canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.35;
  pointer-events: none;
}
.hero__content {
  position: relative;
  text-align: center;
  padding: 6rem 1.5rem 4rem;
  max-width: 720px;
}
.hero__greeting {
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent-light);
  margin-bottom: 0.75rem;
  opacity: 0;
  animation: fadeUp 0.8s ease forwards 0.2s;
}
.hero__name {
  font-family: var(--font-serif);
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
  opacity: 0;
  animation: fadeUp 0.8s ease forwards 0.4s;
}
.hero__title {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  font-weight: 500;
  color: var(--color-accent-light);
  margin-bottom: 1.25rem;
  opacity: 0;
  animation: fadeUp 0.8s ease forwards 0.6s;
}
.hero__tagline {
  font-family: var(--font-serif);
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  font-style: italic;
  opacity: 0;
  color: rgba(255,255,255,.85);
  margin-bottom: 2rem;
  animation: fadeUp 0.8s ease forwards 0.8s;
}
.hero__actions {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2rem;
  opacity: 0;
  animation: fadeUp 0.8s ease forwards 1s;
}
.hero .btn--primary {
  background: var(--color-accent);
  color: var(--color-primary-dark);
}
.hero .btn--outline {
  border-color: rgba(255,255,255,.5);
  color: var(--color-text-inv);
}
.hero .btn--outline:hover {
  background: rgba(255,255,255,.1);
  border-color: #fff;
}
.hero__location {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  color: rgba(255,255,255,.6);
  opacity: 0;
  animation: fadeUp 0.8s ease forwards 1.15s;
}
.hero__scroll {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2.5s infinite;
}
.hero__scroll a {
  color: rgba(255,255,255,.4);
  transition: color var(--transition);
}
.hero__scroll a:hover { color: rgba(255,255,255,.8); }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes bounce {
  0%, 60%, 100% { transform: translateX(-50%) translateY(0); }
  30% { transform: translateX(-50%) translateY(8px); }
}

/* ---------- Sections (shared) ---------- */
.section {
  padding: 5rem 0;
}
.section--alt {
  background: var(--color-bg-alt);
}
.section__title {
  font-family: var(--font-serif);
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 700;
  color: var(--color-primary);
  text-align: center;
  margin-bottom: 0.5rem;
}
.section__subtitle {
  text-align: center;
  color: var(--color-text-light);
  margin-bottom: 2.5rem;
  max-width: 540px;
  margin-left: auto;
  margin-right: auto;
}

/* ---------- About ---------- */
.about__grid {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 3rem;
  align-items: start;
  margin-top: 2.5rem;
}
.about__photo {
  position: relative;
}
.about__photo img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: var(--radius-lg);
  border: 4px solid var(--color-surface);
  box-shadow: var(--shadow-md);
}
.about__photo::after {
  content: '';
  position: absolute;
  inset: 8px -8px -8px 8px;
  border: 2px solid var(--color-accent);
  border-radius: var(--radius-lg);
  z-index: -1;
  opacity: 0.4;
}
.about__text p {
  margin-bottom: 1rem;
  font-size: 1rem;
  line-height: 1.8;
}
.about__text p:first-child::first-line {
  font-weight: 600;
}

/* Counters */
.about__counters {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-top: 3rem;
  padding-top: 3rem;
  border-top: 1px solid var(--color-border);
}
.counter {
  text-align: center;
}
.counter__number {
  display: block;
  font-family: var(--font-serif);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-accent);
  line-height: 1.2;
}
.counter__label {
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-top: 0.25rem;
  display: block;
}

/* ---------- Services ---------- */
.currency-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 2.5rem;
}
.currency-toggle__label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-light);
  transition: color var(--transition);
}
.currency-toggle__label.active { color: var(--color-primary); }
.currency-toggle__switch {
  width: 48px;
  height: 26px;
  background: var(--color-surface);
  border-radius: 13px;
  position: relative;
  transition: background var(--transition);
  border: 1.5px solid var(--color-border);
}
.currency-toggle__thumb {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--color-accent);
  transition: transform var(--transition);
  box-shadow: 0 1px 4px rgba(0,0,0,.15);
}
.currency-toggle__switch.bdt .currency-toggle__thumb {
  transform: translateX(22px);
}

.services__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

.service-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}
.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--color-accent);
  transform: scaleX(0);
  transition: transform var(--transition);
}
.service-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
  border-color: var(--color-accent-light);
}
.service-card:hover::before { transform: scaleX(1); }

.service-card__icon {
  width: 44px;
  height: 44px;
  background: var(--color-bg-alt);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  color: var(--color-primary);
}
.service-card__icon svg { width: 22px; height: 22px; }

.service-card__title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 0.5rem;
  line-height: 1.4;
}
.service-card__desc {
  font-size: 0.875rem;
  color: var(--color-text-light);
  margin-bottom: 1rem;
  line-height: 1.6;
}
.service-card__list {
  margin-bottom: 1.25rem;
  flex: 1;
}
.service-card__list li {
  font-size: 0.825rem;
  padding: 0.3rem 0;
  padding-left: 1.25rem;
  position: relative;
  color: var(--color-text);
}
.service-card__list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.7rem;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
}
.service-card__price {
  margin-bottom: 1rem;
}
.price {
  font-family: var(--font-serif);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-primary);
}
.price--quote {
  font-size: 1.1rem;
  color: var(--color-text-light);
  font-style: italic;
}
.price-label {
  font-size: 0.75rem;
  color: var(--color-text-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-left: 0.35rem;
}
.service-card__cta { align-self: flex-start; }

/* ---------- Process / Timeline ---------- */
.timeline {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 0;
  margin-top: 3rem;
  position: relative;
}
.timeline__step {
  flex: 1;
  max-width: 240px;
  text-align: center;
  position: relative;
  padding: 0 1rem;
}
.timeline__icon {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--color-bg-alt);
  border: 2px solid var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  color: var(--color-accent);
  position: relative;
  z-index: 2;
}
.timeline__icon svg { width: 24px; height: 24px; }
.timeline__number {
  font-family: var(--font-serif);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: 0.5rem;
  letter-spacing: 0.1em;
}
.timeline__number::before { content: 'Step '; }
.timeline__title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 0.35rem;
}
.timeline__desc {
  font-size: 0.825rem;
  color: var(--color-text-light);
  line-height: 1.6;
}
.timeline__connector {
  flex: 0 0 60px;
  height: 2px;
  background: var(--color-border);
  margin-top: 28px;
  position: relative;
}
.timeline__connector::after {
  content: '';
  position: absolute;
  right: -4px;
  top: -3px;
  width: 8px;
  height: 8px;
  border-top: 2px solid var(--color-accent);
  border-right: 2px solid var(--color-accent);
  transform: rotate(45deg);
}

/* ---------- Skills ---------- */
.skills__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 2rem;
  margin-top: 2.5rem;
}
.skill-group {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}
.skill-group__title {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.skill-group__title svg { flex-shrink: 0; color: var(--color-accent); }
.skill-group__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.35rem 0.85rem;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-primary-light);
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: 50px;
  transition: all var(--transition);
}
.tag:hover {
  border-color: var(--color-accent);
  background: rgba(201,150,58,.08);
}
.tag--strong {
  background: var(--color-primary);
  color: var(--color-text-inv);
  border-color: var(--color-primary);
}
.tag--strong:hover {
  background: var(--color-primary-light);
  border-color: var(--color-primary-light);
}
.tag small {
  font-weight: 400;
  opacity: 0.75;
}

/* ---------- Contact ---------- */
.contact__grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 3rem;
  margin-top: 2.5rem;
  align-items: start;
}
.contact__form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}
.form-group label {
  display: block;
  font-size: 0.825rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 0.35rem;
}
.contact__card {
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 2rem;
}
.contact__card h3 {
  font-family: var(--font-serif);
  font-size: 1.25rem;
  color: var(--color-primary);
  margin-bottom: 0.75rem;
}
.contact__card > p {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-bottom: 1.5rem;
  line-height: 1.7;
}
.contact__links {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.contact__link {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text);
  padding: 0.5rem 0;
  transition: color var(--transition);
}
.contact__link:hover { color: var(--color-accent); }
.contact__link svg { width: 18px; height: 18px; flex-shrink: 0; }

/* ---------- Footer ---------- */
.footer {
  background: var(--color-primary-dark);
  color: rgba(255,255,255,.6);
  padding: 2.5rem 0;
}
.footer__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.footer__logo {
  display: inline-block;
}
.footer__logo-img {
  height: 36px;
  width: auto;
  border-radius: 4px;
}
.footer__brand p {
  font-size: 0.8rem;
  margin-top: 0.25rem;
}
.footer__links {
  display: flex;
  gap: 1.5rem;
}
.footer__links a {
  font-size: 0.825rem;
  transition: color var(--transition);
}
.footer__links a:hover { color: var(--color-accent-light); }
.footer__note {
  width: 100%;
  text-align: center;
  font-size: 0.8rem;
  margin-top: 0.5rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255,255,255,.1);
}

/* ---------- Scroll animations ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal--visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .about__grid {
    grid-template-columns: 1fr;
    gap: 2rem;
    text-align: center;
  }
  .about__photo {
    max-width: 200px;
    margin: 0 auto;
  }
  .about__counters {
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
  }
  .contact__grid {
    grid-template-columns: 1fr;
  }
  .timeline {
    flex-direction: column;
    align-items: center;
  }
  .timeline__step {
    max-width: 360px;
    margin-bottom: 1rem;
  }
  .timeline__connector {
    width: 2px;
    height: 40px;
    flex: 0 0 40px;
    margin-top: 0;
  }
  .timeline__connector::after {
    right: -3px;
    top: auto;
    bottom: -4px;
    transform: rotate(135deg);
  }
}

@media (max-width: 768px) {
  :root { --navbar-h: 56px; }
  .navbar__links,
  .navbar__cta {
    display: none;
  }
  .navbar__toggle { display: flex; }

  /* Mobile menu */
  .navbar__links.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: var(--navbar-h);
    left: 0;
    right: 0;
    background: rgba(255,255,255,.98);
    backdrop-filter: blur(16px);
    padding: 1.5rem;
    gap: 0.5rem;
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-lg);
    animation: slideDown 0.3s ease;
  }
  .navbar__links.open a {
    font-size: 1rem;
    padding: 0.75rem;
    border-radius: var(--radius-sm);
  }
  .navbar__cta.open {
    display: inline-flex;
    position: fixed;
    top: calc(var(--navbar-h) + 260px);
    left: 1.5rem;
    right: 1.5rem;
    justify-content: center;
    z-index: 1001;
  }

  @keyframes slideDown {
    from { opacity: 0; transform: translateY(-8px); }
    to   { opacity: 1; transform: translateY(0); }
  }

  .hero__actions { flex-direction: column; align-items: center; }
  .hero__actions .btn { width: 100%; max-width: 260px; justify-content: center; }

  .about__counters { grid-template-columns: 1fr; }
  .services__grid { grid-template-columns: 1fr; }
  .skills__grid { grid-template-columns: 1fr; }
  .footer__inner { flex-direction: column; text-align: center; }
  .footer__links { justify-content: center; }
}

@media (max-width: 480px) {
  .section { padding: 3.5rem 0; }
  .hero__content { padding: 5rem 1rem 3rem; }
}