/* ============================================================
   LMQ Studio — Personal Website Styles
   ============================================================ */

/* ---------- CSS Variables ---------- */
:root {
  --color-bg: #0a0a0f;
  --color-bg-alt: #111118;
  --color-card: #16161e;
  --color-border: #22222e;
  --color-text: #e4e4e7;
  --color-text-muted: #88889a;
  --color-primary: #6366f1;
  --color-primary-glow: rgba(99, 102, 241, 0.25);
  --color-accent: #22d3ee;
  --color-gradient-1: #6366f1;
  --color-gradient-2: #22d3ee;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "SF Mono", Consolas, monospace;
  --nav-height: 64px;
  --max-width: 1100px;
  --radius: 12px;
  --radius-lg: 16px;
  --transition: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

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

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

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

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

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

.section {
  padding: 100px 0;
  position: relative;
}

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

.section-header {
  margin-bottom: 60px;
  text-align: center;
}

.section-number {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-primary);
  letter-spacing: 2px;
  font-weight: 500;
}

.section-header h2 {
  font-size: 2.2rem;
  font-weight: 700;
  margin: 8px 0 16px;
  background: linear-gradient(135deg, var(--color-gradient-1), var(--color-gradient-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-line {
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), transparent);
  border-radius: 2px;
  margin: 0 auto;
}

.highlight {
  background: linear-gradient(135deg, var(--color-gradient-1), var(--color-gradient-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 50px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all var(--transition);
  font-family: inherit;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
  border-color: var(--color-primary);
  box-shadow: 0 4px 20px var(--color-primary-glow);
}

.btn-primary:hover {
  background: #5558e6;
  border-color: #5558e6;
  box-shadow: 0 6px 28px var(--color-primary-glow);
  transform: translateY(-2px);
  color: #fff;
}

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-2px);
}

/* ---------- Navbar ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition);
}

.navbar.scrolled {
  border-bottom-color: var(--color-border);
  background: rgba(10, 10, 15, 0.96);
}

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

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.5px;
  background: linear-gradient(135deg, var(--color-gradient-1), var(--color-gradient-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 32px;
}

.nav-link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-muted);
  position: relative;
  padding: 4px 0;
  transition: color var(--transition);
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--transition);
  border-radius: 1px;
}

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

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

/* Toggle button (hamburger) */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  z-index: 1001;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 1px;
  transition: all 0.3s ease;
}

.nav-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

.nav-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------- Hero ---------- */
#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% 40%, rgba(99, 102, 241, 0.08), transparent),
              radial-gradient(ellipse 60% 50% at 80% 60%, rgba(34, 211, 238, 0.06), transparent);
  pointer-events: none;
}

.hero-container {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding-top: var(--nav-height);
}

.hero-content {
  text-align: center;
  max-width: 720px;
  animation: fadeUp 1s ease forwards;
}

.hero-badge {
  display: inline-block;
  padding: 6px 18px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 1px;
  border-radius: 50px;
  background: rgba(99, 102, 241, 0.12);
  color: var(--color-primary);
  border: 1px solid rgba(99, 102, 241, 0.25);
  margin-bottom: 24px;
  font-family: var(--font-mono);
}

.hero-title {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
  letter-spacing: -1px;
}

.hero-desc {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  margin-bottom: 36px;
  line-height: 1.8;
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 40px;
}

.hero-social {
  display: flex;
  justify-content: center;
  gap: 20px;
}

.hero-social a {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 1.1rem;
  transition: all var(--transition);
}

.hero-social a:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: rgba(99, 102, 241, 0.08);
  transform: translateY(-3px);
}

.scroll-indicator {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--color-text-muted);
  font-size: 0.75rem;
  font-family: var(--font-mono);
  letter-spacing: 1px;
  opacity: 0.5;
  animation: fadeUp 1.5s ease 1s forwards;
  opacity: 0;
}

.scroll-line {
  width: 1px;
  height: 32px;
  background: linear-gradient(to bottom, var(--color-text-muted), transparent);
  animation: scrollPulse 2s ease infinite;
}

@keyframes scrollPulse {
  0%, 100% { opacity: 0.3; }
  50% { opacity: 1; }
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ---------- About ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-text p {
  color: var(--color-text-muted);
  margin-bottom: 16px;
  font-size: 1.05rem;
}

.about-intro {
  font-size: 1.15rem !important;
  color: var(--color-text) !important;
  line-height: 1.8;
}

.about-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

.about-tags span {
  padding: 6px 16px;
  border-radius: 50px;
  font-size: 0.82rem;
  font-weight: 500;
  background: rgba(99, 102, 241, 0.08);
  border: 1px solid rgba(99, 102, 241, 0.2);
  color: var(--color-primary);
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.stat-item {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 28px 16px;
  text-align: center;
  transition: all var(--transition);
}

.stat-item:hover {
  border-color: var(--color-primary);
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(99, 102, 241, 0.1);
}

.stat-number {
  display: block;
  font-size: 2rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--color-gradient-1), var(--color-gradient-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-label {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* ---------- Projects ---------- */
.project-filters {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 40px;
}

.filter-btn {
  padding: 8px 20px;
  border-radius: 50px;
  border: 1px solid var(--color-border);
  background: transparent;
  color: var(--color-text-muted);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
}

.filter-btn:hover,
.filter-btn.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}

.project-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.project-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  opacity: 0;
  transition: opacity var(--transition);
}

.project-card:hover {
  border-color: rgba(99, 102, 241, 0.3);
  transform: translateY(-6px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
}

.project-card:hover::before {
  opacity: 1;
}

.project-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  background: rgba(99, 102, 241, 0.1);
  color: var(--color-primary);
  font-size: 1.3rem;
  margin-bottom: 20px;
}

.project-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.project-card p {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  line-height: 1.7;
  margin-bottom: 16px;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.project-tags span {
  padding: 4px 12px;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 500;
  background: rgba(34, 211, 238, 0.08);
  border: 1px solid rgba(34, 211, 238, 0.15);
  color: var(--color-accent);
}

/* ---------- Research ---------- */
.research-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.research-card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 36px 32px;
  transition: all var(--transition);
  position: relative;
}

.research-card:hover {
  border-color: rgba(99, 102, 241, 0.3);
  transform: translateY(-4px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.25);
}

.research-num {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 1px;
  margin-bottom: 12px;
}

.research-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.research-card p {
  color: var(--color-text-muted);
  font-size: 0.92rem;
  line-height: 1.7;
}

/* ---------- Timeline (Experience) ---------- */
.timeline {
  max-width: 700px;
  margin: 0 auto;
  position: relative;
  padding-left: 40px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 16px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--color-primary), var(--color-accent), transparent);
  opacity: 0.3;
}

.timeline-item {
  position: relative;
  margin-bottom: 48px;
}

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

.timeline-dot {
  position: absolute;
  left: -32px;
  top: 4px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-primary);
  border: 3px solid var(--color-bg);
  box-shadow: 0 0 0 2px var(--color-primary);
}

.timeline-content {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px 28px;
  transition: all var(--transition);
}

.timeline-content:hover {
  border-color: rgba(99, 102, 241, 0.25);
  transform: translateX(4px);
}

.timeline-date {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-primary);
  letter-spacing: 1px;
  font-weight: 500;
}

.timeline-content h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 6px 0 4px;
}

.timeline-content h4 {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-muted);
  margin-bottom: 10px;
}

.timeline-content p {
  font-size: 0.88rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ---------- Contact ---------- */
.contact-wrapper {
  display: grid;
  grid-template-columns: 1fr 1.1fr;
  gap: 60px;
  align-items: flex-start;
}

.contact-desc {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  margin-bottom: 32px;
  line-height: 1.8;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 18px;
  font-size: 0.95rem;
}

.contact-item i {
  width: 20px;
  color: var(--color-primary);
  font-size: 1.1rem;
}

.contact-item a {
  color: var(--color-text-muted);
  transition: color var(--transition);
}

.contact-item a:hover {
  color: var(--color-primary);
}

.resume-link {
  font-weight: 600;
  color: var(--color-primary) !important;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 14px 18px;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  background: var(--color-card);
  color: var(--color-text);
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color var(--transition);
  outline: none;
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

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

.contact-form button {
  align-self: flex-start;
}

/* ---------- Footer ---------- */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.footer-content p {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.footer-brand {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 4px;
  background: linear-gradient(135deg, var(--color-gradient-1), var(--color-gradient-2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---------- Back to Top ---------- */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  border: none;
  cursor: pointer;
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition);
  z-index: 999;
  box-shadow: 0 4px 16px var(--color-primary-glow);
}

.back-to-top.show {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 24px var(--color-primary-glow);
}

/* ---------- Animations (scroll reveal) ---------- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

/* ============================================================
   Responsive
   ============================================================ */

/* Tablet */
@media (max-width: 900px) {
  .section { padding: 72px 0; }
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
  .contact-wrapper { grid-template-columns: 1fr; gap: 40px; }
  .hero-title { font-size: 2.5rem; }
  .section-header h2 { font-size: 1.8rem; }
}

/* Mobile */
@media (max-width: 640px) {
  .section { padding: 56px 0; }
  .container { padding: 0 20px; }

  /* Nav */
  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 70%;
    max-width: 300px;
    height: 100vh;
    background: var(--color-bg);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 28px;
    transition: right 0.4s ease;
    border-left: 1px solid var(--color-border);
  }

  .nav-menu.open { right: 0; }

  .nav-link { font-size: 1.05rem; }

  .nav-toggle { display: flex; }

  /* Hero */
  .hero-title { font-size: 2rem; }
  .hero-desc { font-size: 1rem; }
  .hero-actions { flex-direction: column; align-items: center; }
  .btn { width: 100%; max-width: 280px; justify-content: center; }

  /* Grid */
  .project-grid { grid-template-columns: 1fr; }
  .research-grid { grid-template-columns: 1fr; }
  .about-stats { grid-template-columns: repeat(3, 1fr); gap: 10px; }
  .stat-item { padding: 20px 12px; }

  /* Timeline */
  .timeline { padding-left: 28px; }
  .timeline-dot { left: -20px; width: 10px; height: 10px; }

  /* Contact form */
  .contact-form button { align-self: stretch; }

  /* Back to top */
  .back-to-top { bottom: 20px; right: 20px; width: 40px; height: 40px; }
}

/* Small mobile */
@media (max-width: 400px) {
  .hero-title { font-size: 1.65rem; }
  .about-stats { grid-template-columns: 1fr; }
}