/* ============================================
   Tahrim Ahmed Miad — Portfolio
   ============================================ */

:root {
  --bg: #0a0b10;
  --bg-alt: #0d0f16;
  --surface: #12141d;
  --surface-2: #181b26;
  --border: #232735;
  --border-soft: #1b1e29;

  --text: #eef0f6;
  --text-dim: #9aa1b4;
  --text-faint: #656d82;

  --accent: #6c8cff;
  --accent-2: #22d3ee;
  --accent-soft: rgba(108, 140, 255, 0.12);
  --gold: #f2b84b;

  --radius: 16px;
  --radius-sm: 10px;
  --container: 1180px;

  --shadow-card: 0 20px 40px -20px rgba(0, 0, 0, 0.55);
  --transition: 220ms cubic-bezier(.4,0,.2,1);

  --header-bg: rgba(10, 11, 16, 0.72);
  --mobile-nav-bg: rgba(10, 11, 16, 0.98);
  --grid-line: rgba(255, 255, 255, 0.025);
  --glow-opacity-1: 0.35;
  --glow-opacity-2: 0.18;
}

:root[data-theme="light"] {
  --bg: #f7f8fb;
  --bg-alt: #eef0f6;
  --surface: #ffffff;
  --surface-2: #f1f3f8;
  --border: #e3e6ee;
  --border-soft: #ebedf3;

  --text: #12131a;
  --text-dim: #565c70;
  --text-faint: #868b9f;

  --accent: #4a5fe0;
  --accent-2: #0891b2;
  --accent-soft: rgba(74, 95, 224, 0.09);
  --gold: #b45309;

  --shadow-card: 0 20px 40px -20px rgba(15, 23, 42, 0.14);

  --header-bg: rgba(247, 248, 251, 0.78);
  --mobile-nav-bg: rgba(247, 248, 251, 0.98);
  --grid-line: rgba(10, 15, 30, 0.035);
  --glow-opacity-1: 0.14;
  --glow-opacity-2: 0.10;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  transition: background-color 300ms ease, color 300ms ease;
}

h1, h2, h3, h4 {
  font-family: 'Sora', 'Inter', sans-serif;
  color: var(--text);
  margin: 0;
  letter-spacing: -0.02em;
}

p { margin: 0; }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { margin: 0; padding: 0; list-style: none; }

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Background decor ---------- */
.bg-glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  z-index: 0;
  pointer-events: none;
  opacity: var(--glow-opacity-1);
  transition: opacity var(--transition);
}
.bg-glow--one {
  width: 560px; height: 560px;
  top: -180px; left: -140px;
  background: radial-gradient(circle, var(--accent) 0%, transparent 70%);
}
.bg-glow--two {
  width: 620px; height: 620px;
  top: 40vh; right: -220px;
  background: radial-gradient(circle, var(--accent-2) 0%, transparent 70%);
  opacity: var(--glow-opacity-2);
}
.bg-grid {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, var(--grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-line) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 40%, transparent 100%);
}

header, main, footer { position: relative; z-index: 1; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform var(--transition), background var(--transition), border-color var(--transition), box-shadow var(--transition);
  white-space: nowrap;
}
.btn--primary {
  background: linear-gradient(135deg, var(--accent), #8f6ff0);
  color: #fff;
  box-shadow: 0 8px 24px -8px rgba(108, 140, 255, 0.55);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 12px 28px -8px rgba(108, 140, 255, 0.7); }

.btn--outline {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}
.btn--outline:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }

.btn--ghost {
  background: var(--surface);
  border-color: var(--border);
  color: var(--text-dim);
}
.btn--ghost:hover { color: var(--text); border-color: var(--accent); }

.btn--sm { padding: 9px 18px; font-size: 0.85rem; }
.btn--lg { padding: 16px 32px; font-size: 1rem; }
.btn--block { width: 100%; margin-top: 6px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(14px);
  background: var(--header-bg);
  border-bottom: 1px solid var(--border-soft);
  transition: background-color 300ms ease, border-color 300ms ease;
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}
.brand {
  font-family: 'Sora', sans-serif;
  font-weight: 700;
  font-size: 1.3rem;
  letter-spacing: 0.02em;
}
.brand-dot { color: var(--accent); }

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}
.nav-link {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-dim);
  transition: color var(--transition);
  position: relative;
}
.nav-link:hover { color: var(--text); }

.nav-actions { display: flex; align-items: center; gap: 14px; }

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-dim);
  cursor: pointer;
  padding: 0;
  transition: border-color var(--transition), color var(--transition), transform var(--transition);
}
.theme-toggle:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }
.theme-toggle svg { width: 18px; height: 18px; }
.theme-toggle .icon-moon { display: none; }
:root[data-theme="light"] .theme-toggle .icon-sun { display: none; }
:root[data-theme="light"] .theme-toggle .icon-moon { display: block; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}
.nav-toggle span {
  width: 22px; height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

/* ---------- Sections ---------- */
.section { padding: 120px 0; }
.section--alt { background: var(--bg-alt); }

.section-tag {
  color: var(--accent);
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: 12px;
}
.section-title {
  font-size: clamp(1.8rem, 3.2vw, 2.6rem);
  font-weight: 700;
  margin-bottom: 20px;
}
.section-lead {
  color: var(--text-dim);
  font-size: 1.05rem;
  max-width: 640px;
  margin-bottom: 48px;
}

/* ---------- Hero ---------- */
.hero {
  padding: 190px 0 120px;
  position: relative;
}
.hero-inner { max-width: 880px; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text-dim);
  font-size: 0.9rem;
  font-weight: 500;
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 8px 18px;
  border-radius: 999px;
  margin-bottom: 28px;
}
.dot-live {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: #34d399;
  box-shadow: 0 0 0 4px rgba(52, 211, 153, 0.18);
}

.hero-title {
  font-size: clamp(2.4rem, 5.5vw, 4.2rem);
  font-weight: 800;
  line-height: 1.12;
  margin-bottom: 26px;
}
.text-gradient {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-sub {
  font-size: 1.15rem;
  color: var(--text-dim);
  max-width: 620px;
  margin-bottom: 40px;
}
.hero-cta { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 64px; }

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 20px;
  padding-top: 40px;
  border-top: 1px solid var(--border-soft);
}
.stat { display: flex; flex-direction: column; gap: 4px; }
.stat-num {
  font-family: 'Sora', sans-serif;
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--text);
}
.stat-label { font-size: 0.85rem; color: var(--text-faint); }

/* ---------- About ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 56px;
  align-items: start;
}
.about-text p { color: var(--text-dim); margin-bottom: 18px; font-size: 1.02rem; }
.about-badges { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 24px; }
.badge {
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid rgba(108, 140, 255, 0.25);
  padding: 7px 16px;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
}

.about-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow-card);
}
.about-card-row {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--border-soft);
  font-size: 0.92rem;
}
.about-card-row:first-child { padding-top: 0; }
.about-card-label { color: var(--text-faint); }
.about-card-value { color: var(--text); font-weight: 600; text-align: right; }
.about-card-value a { color: var(--accent); }

/* ---------- Skills ---------- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}
.skill-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: transform var(--transition), border-color var(--transition);
}
.skill-card:hover { transform: translateY(-4px); border-color: rgba(108,140,255,0.4); }
.skill-card h3 { font-size: 1.05rem; margin-bottom: 16px; }
.chip-row { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-dim);
  font-size: 0.8rem;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: 8px;
}

/* ---------- Experience Timeline ---------- */
.timeline {
  position: relative;
  padding-left: 32px;
  border-left: 2px solid var(--border);
}
.timeline-item { position: relative; margin-bottom: 40px; }
.timeline-item:last-child { margin-bottom: 0; }
.timeline-dot {
  position: absolute;
  left: -39px;
  top: 8px;
  width: 16px; height: 16px;
  border-radius: 50%;
  background: var(--bg);
  border: 3px solid var(--accent);
}
.timeline-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 32px;
}
.timeline-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 4px;
}
.timeline-head h3 { font-size: 1.2rem; }
.timeline-date {
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 600;
  white-space: nowrap;
}
.timeline-company { color: var(--text-dim); font-weight: 500; margin-bottom: 16px; }
.timeline-card ul { display: flex; flex-direction: column; gap: 10px; }
.timeline-card li {
  color: var(--text-dim);
  font-size: 0.95rem;
  padding-left: 20px;
  position: relative;
}
.timeline-card li::before {
  content: '';
  position: absolute;
  left: 0; top: 9px;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent-2);
}

/* ---------- Projects ---------- */
.project-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 28px;
}
.project-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}
.project-card:hover {
  transform: translateY(-6px);
  border-color: rgba(108, 140, 255, 0.35);
  box-shadow: var(--shadow-card);
}
.project-thumb {
  display: block;
  position: relative;
  height: 210px;
  overflow: hidden;
  background: var(--surface-2);
  border-bottom: 1px solid var(--border);
}
.project-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
  transition: transform 420ms ease;
}
.project-card:hover .project-thumb img { transform: scale(1.06); }

.project-body {
  padding: 24px 24px 26px;
  display: flex;
  flex-direction: column;
  flex: 1;
}
.project-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 12px;
}
.project-top h3 { font-size: 1.1rem; }
.project-tag {
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 5px 10px;
  border-radius: 999px;
  white-space: nowrap;
}
.project-body p {
  color: var(--text-dim);
  font-size: 0.92rem;
  margin-bottom: 20px;
  flex: 1;
}
.project-link {
  color: var(--accent);
  font-weight: 600;
  font-size: 0.9rem;
  transition: gap var(--transition), color var(--transition);
}
.project-link:hover { color: var(--accent-2); }

/* ---------- Education ---------- */
.edu-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}
.edu-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px;
  display: flex;
  align-items: center;
  gap: 22px;
}
.edu-logo {
  width: 68px;
  height: 68px;
  object-fit: contain;
  background: #fff;
  border-radius: 12px;
  padding: 8px;
  flex-shrink: 0;
}
.edu-info h3 { font-size: 1.05rem; margin-bottom: 6px; }
.edu-school { color: var(--text-dim); font-size: 0.9rem; margin-bottom: 4px; }
.edu-date { color: var(--text-faint); font-size: 0.82rem; font-weight: 600; }

/* ---------- Contact ---------- */
.contact-panel {
  background: linear-gradient(160deg, var(--surface), var(--surface-2));
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 64px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.contact-text .section-title { margin-bottom: 16px; }
.contact-text .section-lead { margin: 0 auto 36px; }
.contact-actions { display: flex; gap: 16px; flex-wrap: wrap; justify-content: center; margin-bottom: 32px; }
.social-row { display: flex; gap: 28px; }
.social-row a {
  color: var(--text-dim);
  font-weight: 600;
  font-size: 0.9rem;
  transition: color var(--transition);
}
.social-row a:hover { color: var(--accent); }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border-soft);
  padding: 32px 0;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  color: var(--text-faint);
  font-size: 0.85rem;
}

/* ---------- Back to top ---------- */
.back-to-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 46px; height: 46px;
  border-radius: 50%;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity var(--transition), transform var(--transition), border-color var(--transition);
  z-index: 40;
}
.back-to-top.visible { opacity: 1; pointer-events: auto; transform: translateY(0); }
.back-to-top:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- Reveal animation ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 700ms cubic-bezier(.4,0,.2,1), transform 700ms cubic-bezier(.4,0,.2,1);
}
.reveal.is-visible { opacity: 1; transform: translateY(0); }

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 980px) {
  .about-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .project-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .hero-stats { grid-template-columns: repeat(2, minmax(0,1fr)); row-gap: 28px; }
  .edu-grid { grid-template-columns: 1fr; }
  .contact-panel { padding: 48px 28px; }
}

@media (max-width: 760px) {
  .nav-links {
    position: absolute;
    top: 76px;
    left: 0; right: 0;
    background: var(--mobile-nav-bg);
    border-bottom: 1px solid var(--border-soft);
    flex-direction: column;
    align-items: flex-start;
    padding: 20px 24px 28px;
    gap: 18px;
    transform: translateY(-12px);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition), transform var(--transition);
  }
  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .nav-toggle { display: flex; }
  .nav-actions .btn--ghost { display: none; }

  .hero { padding: 150px 0 80px; }
  .section { padding: 80px 0; }
  .skills-grid { grid-template-columns: 1fr; }
  .project-grid { grid-template-columns: 1fr; }
  .timeline { padding-left: 24px; }
  .timeline-dot { left: -31px; }
  .timeline-card { padding: 22px 20px; }
  .contact-panel { padding: 36px 20px; }
  .contact-actions { flex-direction: column; width: 100%; }
  .contact-actions .btn { width: 100%; }
}

@media (max-width: 480px) {
  .hero-stats { grid-template-columns: 1fr 1fr; }
  .hero-title { font-size: 2.1rem; }
}