/* ==========================================================================
   Mashuke Alam Jim - Portfolio Design System
   Modern Dark Theme | Pure CSS | Zero External Bloat
   ========================================================================== */

:root {
  --bg-primary: #09090b;
  --bg-surface: #121217;
  --bg-surface-hover: #18181f;
  --bg-subtle: #1e1e24;
  --border-color: #27272a;
  --border-color-hover: #3f3f46;
  
  --text-primary: #f4f4f5;
  --text-secondary: #a1a1aa;
  --text-tertiary: #71717a;
  
  --accent-primary: #10b981;
  --accent-secondary: #06b6d4;
  --accent-glow: rgba(16, 185, 129, 0.15);
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", "Cascadia Code", "Fira Code", monospace;
  
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-glow: 0 0 25px var(--accent-glow);
  
  --transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  color-scheme: dark;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  padding-bottom: 4rem;
}

/* Base Container */
.container {
  max-width: 860px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Typography */
h1, h2, h3, h4 {
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.025em;
}

p {
  color: var(--text-secondary);
}

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

/* ==========================================================================
   Header & Navigation
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(9, 9, 11, 0.75);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 0;
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text-primary);
}

.brand-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  color: #000;
  font-weight: 800;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
}

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

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  padding: 4.5rem 0 3rem;
}

.hero-status {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
}

.status-dot {
  width: 8px;
  height: 8px;
  background-color: var(--accent-primary);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent-primary);
}

.hero-title {
  font-size: 2.75rem;
  letter-spacing: -0.04em;
  margin-bottom: 0.75rem;
}

.hero-title .gradient-text {
  background: linear-gradient(120deg, #ffffff 40%, var(--accent-primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-role {
  font-size: 1.2rem;
  font-weight: 500;
  color: var(--accent-primary);
  margin-bottom: 1rem;
  font-family: var(--font-mono);
}

.hero-bio {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 680px;
  margin-bottom: 2rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  flex-wrap: wrap;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.2rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
}

.btn-primary {
  background-color: var(--text-primary);
  color: var(--bg-primary);
}

.btn-primary:hover {
  background-color: #ffffff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: var(--bg-surface);
  border-color: var(--border-color);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background-color: var(--bg-surface-hover);
  border-color: var(--border-color-hover);
  transform: translateY(-1px);
}

/* ==========================================================================
   Section Headers
   ========================================================================== */
.section {
  padding: 3.5rem 0 1rem;
}

.section-header {
  margin-bottom: 2rem;
}

.section-tag {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent-primary);
  margin-bottom: 0.35rem;
  display: block;
}

.section-title {
  font-size: 1.75rem;
}

/* ==========================================================================
   Featured Projects Bento Grid
   ========================================================================== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

.project-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.project-card:hover {
  border-color: var(--border-color-hover);
  background-color: var(--bg-surface-hover);
  transform: translateY(-3px);
  box-shadow: var(--shadow-glow);
}

.project-card.featured {
  grid-column: span 2;
  background: linear-gradient(145deg, rgba(18, 18, 23, 0.9), rgba(24, 24, 31, 0.9));
}

.project-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.75rem;
}

.project-title {
  font-size: 1.2rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.project-links {
  display: flex;
  gap: 0.5rem;
}

.project-link-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  background: var(--bg-subtle);
  color: var(--text-secondary);
  transition: var(--transition);
}

.project-link-icon:hover {
  color: var(--text-primary);
  background: var(--border-color-hover);
}

.project-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  line-height: 1.6;
}

.project-tech-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: auto;
}

.tech-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
  background: var(--bg-subtle);
  color: var(--text-secondary);
  border: 1px solid rgba(255, 255, 255, 0.04);
}

.tech-tag.highlight {
  color: var(--accent-primary);
  background: rgba(16, 185, 129, 0.1);
  border-color: rgba(16, 185, 129, 0.2);
}

/* ==========================================================================
   The CS Lab / Sandbox Section
   ========================================================================== */
.lab-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.lab-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.2rem;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
  text-decoration: none;
}

.lab-card:hover {
  border-color: var(--accent-primary);
  background: var(--bg-surface-hover);
  transform: translateY(-2px);
}

.lab-icon {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
}

.lab-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.35rem;
}

.lab-desc {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ==========================================================================
   Skills / Toolkit
   ========================================================================== */
.skills-wrapper {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.skill-category {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
}

.skill-cat-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.skill-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.skill-pill {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 0.3rem 0.7rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
}

/* ==========================================================================
   Contact & Footer
   ========================================================================== */
.contact-card {
  background: linear-gradient(145deg, var(--bg-surface), var(--bg-subtle));
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  text-align: center;
  margin-top: 1rem;
}

.contact-card h3 {
  font-size: 1.75rem;
  margin-bottom: 0.75rem;
}

.contact-card p {
  max-width: 500px;
  margin: 0 auto 1.5rem;
  font-size: 0.95rem;
}

.footer {
  margin-top: 5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-tertiary);
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-links {
  display: flex;
  gap: 1.25rem;
}

.footer-links a:hover {
  color: var(--text-primary);
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */
@media (max-width: 768px) {
  .hero-title {
    font-size: 2.15rem;
  }
  
  .projects-grid {
    grid-template-columns: 1fr;
  }
  
  .project-card.featured {
    grid-column: span 1;
  }
  
  .lab-grid {
    grid-template-columns: 1fr;
  }
  
  .contact-card {
    padding: 1.75rem;
  }
  
  .footer {
    flex-direction: column;
    text-align: center;
  }
}