/* ============================================================
   PORTFOLIO — MD FAHIMUL ISLAM
   style.css
   ============================================================ */

/* ---- CSS Variables ---- */
:root {
  --clr-primary:       #2563eb;
  --clr-primary-dark:  #1d4ed8;
  --clr-primary-light: #dbeafe;
  --clr-accent:        #06b6d4;
  --clr-bg:            #0f172a;
  --clr-bg-alt:        #1e293b;
  --clr-card:          #1e293b;
  --clr-card-hover:    #263451;
  --clr-text:          #e2e8f0;
  --clr-text-muted:    #94a3b8;
  --clr-heading:       #f8fafc;
  --clr-border:        #334155;
  --clr-success:       #22c55e;

  --font-family: 'Inter', system-ui, -apple-system, sans-serif;

  --radius-sm:  0.375rem;
  --radius-md:  0.75rem;
  --radius-lg:  1.25rem;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.5);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.6);

  --transition: 0.3s ease;

  --navbar-height: 70px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family);
  background-color: var(--clr-bg);
  color: var(--clr-text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--clr-primary);
  text-decoration: none;
  transition: color var(--transition);
}

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

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

ul {
  list-style: none;
}

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
}

/* ---- Utility ---- */
.container {
  width: min(90%, 1100px);
  margin-inline: auto;
}

.section {
  padding: 6rem 0;
}

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

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  color: var(--clr-heading);
  text-align: center;
  margin-bottom: 0.5rem;
}

.section-title span {
  color: var(--clr-primary);
}

.section-subtitle {
  text-align: center;
  color: var(--clr-text-muted);
  margin-bottom: 3.5rem;
  font-size: 1.05rem;
}

/* ---- Buttons ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius-full);
  font-size: 0.95rem;
  font-weight: 600;
  transition: all var(--transition);
  cursor: pointer;
  white-space: nowrap;
}

.btn-primary {
  background: var(--clr-primary);
  color: #fff;
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.4);
}

.btn-primary:hover {
  background: var(--clr-primary-dark);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.6);
}

.btn-outline {
  border: 2px solid var(--clr-primary);
  color: var(--clr-primary);
}

.btn-outline:hover {
  background: var(--clr-primary);
  color: #fff;
  transform: translateY(-2px);
}

.btn-full {
  width: 100%;
  justify-content: center;
}

/* ============================================================
   NAVBAR
   ============================================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--navbar-height);
  z-index: 1000;
  transition: background var(--transition), box-shadow var(--transition);
}

.navbar.scrolled {
  background: rgba(15, 23, 42, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.5);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--clr-heading);
  letter-spacing: -0.5px;
}

.nav-logo span {
  color: var(--clr-primary);
}

.nav-menu {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-link {
  color: var(--clr-text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  position: relative;
  padding-bottom: 2px;
  transition: color var(--transition);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--clr-primary);
  transition: width var(--transition);
}

.nav-link:hover,
.nav-link.active {
  color: var(--clr-heading);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
  z-index: 1100;
}

.bar {
  display: block;
  width: 25px;
  height: 3px;
  background: var(--clr-text);
  border-radius: var(--radius-full);
  transition: all var(--transition);
}

.hamburger.open .bar:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}
.hamburger.open .bar:nth-child(2) {
  opacity: 0;
}
.hamburger.open .bar:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--navbar-height);
  position: relative;
  overflow: hidden;
}

/* Subtle gradient background */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 60% at 70% 40%, rgba(37, 99, 235, 0.12), transparent 70%);
  pointer-events: none;
}

.hero-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
  padding-block: 4rem;
}

.hero-greeting {
  color: var(--clr-accent);
  font-size: 1rem;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.hero-name {
  font-size: clamp(2rem, 5vw, 3.5rem);
  font-weight: 800;
  color: var(--clr-heading);
  line-height: 1.15;
  margin-bottom: 0.5rem;
}

.hero-title {
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  font-weight: 600;
  color: var(--clr-primary);
  margin-bottom: 1.25rem;
}

.hero-bio {
  color: var(--clr-text-muted);
  max-width: 480px;
  margin-bottom: 2rem;
  font-size: 1.05rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
}

.hero-social {
  display: flex;
  gap: 1rem;
}

.hero-social a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: var(--radius-full);
  border: 2px solid var(--clr-border);
  color: var(--clr-text-muted);
  font-size: 1.1rem;
  transition: all var(--transition);
}

.hero-social a:hover {
  border-color: var(--clr-primary);
  color: var(--clr-primary);
  transform: translateY(-3px);
}

/* Profile photo */
.hero-image {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-image-wrapper {
  position: relative;
  width: min(340px, 100%);
  aspect-ratio: 1;
  border-radius: var(--radius-full);
}

/* Animated ring */
.hero-image-wrapper::before {
  content: '';
  position: absolute;
  inset: -6px;
  border-radius: var(--radius-full);
  background: conic-gradient(var(--clr-primary), var(--clr-accent), var(--clr-primary));
  animation: spin 6s linear infinite;
  z-index: 0;
}

.hero-image-wrapper::after {
  content: '';
  position: absolute;
  inset: -3px;
  border-radius: var(--radius-full);
  background: var(--clr-bg);
  z-index: 1;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.profile-photo {
  position: relative;
  z-index: 2;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: var(--radius-full);
}

/* Scroll hint */
.hero-scroll-hint {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
}

.hero-scroll-hint a {
  color: var(--clr-text-muted);
  font-size: 1.2rem;
  transition: color var(--transition);
}

.hero-scroll-hint a:hover {
  color: var(--clr-primary);
}

@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50%       { transform: translateX(-50%) translateY(8px); }
}

/* ============================================================
   ABOUT
   ============================================================ */
.about-grid {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: 3rem;
  align-items: start;
}

.about-text p {
  color: var(--clr-text-muted);
  margin-bottom: 1.25rem;
  font-size: 1rem;
}

.about-details {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.detail-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--clr-text);
  font-size: 0.95rem;
}

.detail-item i {
  color: var(--clr-primary);
  font-size: 1rem;
  width: 20px;
  flex-shrink: 0;
}

/* Stats */
.about-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.stat-card {
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: 1.5rem 1rem;
  text-align: center;
  transition: transform var(--transition), box-shadow var(--transition);
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.stat-number {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  color: var(--clr-primary);
  line-height: 1;
  margin-bottom: 0.4rem;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--clr-text-muted);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ============================================================
   SKILLS
   ============================================================ */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.skill-category {
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.skill-category:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--clr-primary);
}

.skill-category-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.skill-category-header i {
  font-size: 1.4rem;
  color: var(--clr-primary);
}

.skill-category-header h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--clr-heading);
}

.skill-list {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.skill-list li {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.9rem;
  color: var(--clr-text-muted);
}

.skill-list li i {
  color: var(--clr-success);
  font-size: 0.85rem;
  flex-shrink: 0;
}

/* ============================================================
   EXPERIENCE (TIMELINE)
   ============================================================ */
.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--clr-border);
}

.timeline-item {
  position: relative;
  margin-bottom: 3rem;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: -2.4rem;
  top: 0.4rem;
  width: 14px;
  height: 14px;
  border-radius: var(--radius-full);
  background: var(--clr-primary);
  border: 3px solid var(--clr-bg);
  box-shadow: 0 0 0 2px var(--clr-primary);
}

.timeline-content {
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  transition: box-shadow var(--transition);
}

.timeline-content:hover {
  box-shadow: var(--shadow-md);
}

.timeline-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.5rem;
  flex-wrap: wrap;
}

.timeline-role {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--clr-heading);
}

.timeline-badge {
  background: var(--clr-primary-light);
  color: var(--clr-primary);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2em 0.75em;
  border-radius: var(--radius-full);
}

.timeline-company,
.timeline-date {
  font-size: 0.9rem;
  color: var(--clr-text-muted);
  margin-bottom: 0.35rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.timeline-duties {
  margin-top: 1rem;
  padding-left: 1.25rem;
  list-style: disc;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.timeline-duties li {
  font-size: 0.92rem;
  color: var(--clr-text-muted);
}

/* ============================================================
   CONTACT
   ============================================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 3rem;
  align-items: start;
}

/* Contact info cards */
.contact-info {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.contact-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-md);
  padding: 1rem 1.25rem;
  transition: transform var(--transition), border-color var(--transition);
}

.contact-card:hover {
  transform: translateX(4px);
  border-color: var(--clr-primary);
}

.contact-card > i {
  font-size: 1.3rem;
  color: var(--clr-primary);
  flex-shrink: 0;
  width: 24px;
  text-align: center;
}

.contact-card h4 {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--clr-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.2rem;
}

.contact-card p,
.contact-card a {
  font-size: 0.95rem;
  color: var(--clr-text);
}

.contact-card a:hover {
  color: var(--clr-accent);
}

/* Contact form */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-group label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--clr-text);
}

.form-group input,
.form-group textarea {
  background: var(--clr-card);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  color: var(--clr-text);
  font-family: inherit;
  font-size: 0.95rem;
  transition: border-color var(--transition), box-shadow var(--transition);
  resize: vertical;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--clr-text-muted);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--clr-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.2);
}

.form-note {
  font-size: 0.875rem;
  text-align: center;
  min-height: 1.2em;
}

.form-note.success {
  color: var(--clr-success);
}

.form-note.error {
  color: #f87171;
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--clr-bg);
  border-top: 1px solid var(--clr-border);
  padding: 1.75rem 0;
}

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

.footer p {
  color: var(--clr-text-muted);
  font-size: 0.875rem;
}

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

.footer-social a {
  color: var(--clr-text-muted);
  font-size: 1.1rem;
  transition: color var(--transition);
}

.footer-social a:hover {
  color: var(--clr-primary);
}

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

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   RESPONSIVE — Tablet (≤900px)
   ============================================================ */
@media (max-width: 900px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-text {
    order: 2;
  }

  .hero-image {
    order: 1;
  }

  .hero-bio {
    margin-inline: auto;
  }

  .hero-actions,
  .hero-social {
    justify-content: center;
  }

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

  .about-stats {
    grid-template-columns: repeat(4, 1fr);
  }

  .skills-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

/* ============================================================
   RESPONSIVE — Mobile (≤600px)
   ============================================================ */
@media (max-width: 600px) {
  .hamburger {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    inset: 0;
    background: var(--clr-bg);
    flex-direction: column;
    justify-content: center;
    gap: 2.5rem;
    transform: translateX(100%);
    transition: transform var(--transition);
    z-index: 999;
  }

  .nav-menu.open {
    transform: translateX(0);
  }

  .nav-link {
    font-size: 1.4rem;
  }

  .hero-image-wrapper {
    width: min(240px, 80vw);
  }

  .about-stats {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .footer-container {
    flex-direction: column;
    text-align: center;
  }
}