:root {
  --bg:        #0c0c0c;
  --bg-card:   #141414;
  --bg-hover:  #1c1c1c;
  --text:      #ddd;
  --muted:     #666;
  --accent:    #458ee8;
  --border:    #242424;
  --radius:    0.75rem;
  --font:      system-ui, -apple-system, 'Segoe UI', Helvetica, Arial, sans-serif;
  --max-w:     52rem;
  --tr:        0.2s ease;
}

[data-theme="light"] {
  --bg:       #f4f8fd;
  --bg-card:  #ffffff;
  --bg-hover: #edf2f9;
  --text:     #1a1a2e;
  --muted:    #64748b;
  --accent:   #2563eb;
  --border:   #dde3ee;
}


*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
img, svg { display: block; max-width: 100%; }
button { cursor: pointer; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }


html {
  font-size: 17px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  min-height: 100vh;
  transition: background var(--tr), color var(--tr);
}


.wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 1.5rem;
}

section { margin-top: 8vh; }


header { padding: 1.5rem 0; }

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

.header-logo {
  font-weight: 700;
  font-size: 0.95em;
  letter-spacing: -0.02em;
}

.header-logo a {
  color: var(--text);
  transition: color var(--tr);
}
.header-logo a:hover { color: var(--accent); }

.header-controls {
  display: flex;
  align-items: center;
  gap: 0.2rem;
}

.ctrl-btn {
  background: none;
  border: 1px solid transparent;
  border-radius: 0.4rem;
  color: var(--muted);
  font: inherit;
  font-size: 0.8em;
  padding: 0.3rem 0.6rem;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  transition: color var(--tr), border-color var(--tr), background var(--tr);
}

.ctrl-btn:hover {
  color: var(--text);
  border-color: var(--border);
  background: var(--bg-card);
}

.ctrl-btn.active {
  color: var(--accent);
  border-color: var(--accent);
}

.ctrl-sep {
  width: 1px;
  height: 1rem;
  background: var(--border);
  margin: 0 0.25rem;
}


.hero {
  margin-top: 6vh;
  display: flex;
  gap: 2.5rem;
  align-items: flex-start;
}

.hero-avatar {
  width: 9rem;
  height: 9rem;
  min-width: 9rem;
  border-radius: 1rem;
  background: linear-gradient(135deg, rgba(69,142,232,.25) 0%, rgba(69,142,232,.08) 100%);
  border: 1px solid rgba(69,142,232,.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3.6rem;
  line-height: 1;
  user-select: none;
  overflow: hidden;
}

.hero-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 1rem;
}

.hero-content { flex: 1; }

.hero-content h1 {
  font-size: 2em;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 0.5rem;
}

.hero-wave {
  display: inline-block;
  animation: wave 1.4s ease 0.6s 1;
  transform-origin: 70% 70%;
}

@keyframes wave {
  0%   { transform: rotate(0deg); }
  10%  { transform: rotate(14deg); }
  20%  { transform: rotate(-8deg); }
  30%  { transform: rotate(14deg); }
  40%  { transform: rotate(-4deg); }
  50%  { transform: rotate(10deg); }
  60%  { transform: rotate(0deg); }
  100% { transform: rotate(0deg); }
}

.hero-subtitle {
  color: var(--muted);
  font-size: 1.05em;
  margin-bottom: 1rem;
}

.hero-bio {
  color: var(--muted);
  font-size: 0.93em;
  line-height: 1.75;
  max-width: 38rem;
  margin-bottom: 1.5rem;
}

.hero-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
}

.hero-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.83em;
  color: var(--muted);
  padding: 0.35rem 0.85rem;
  border: 1px solid var(--border);
  border-radius: 100rem;
  transition: color var(--tr), border-color var(--tr), background var(--tr);
}

.hero-link:hover {
  color: var(--text);
  border-color: var(--muted);
  background: var(--bg-card);
}


.section-label {
  font-size: 0.7em;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.section-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}


.projects-list {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.project-card {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
}
.project-card:last-child { border-bottom: none; }

.project-trigger {
  width: 100%;
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  cursor: pointer;
  background: none;
  border: none;
  text-align: left;
  color: inherit;
  transition: background var(--tr);
}

.project-trigger:hover { background: var(--bg-hover); }

.project-info { flex: 1; min-width: 0; }

.project-name {
  font-size: 0.97em;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.2rem;
}

.project-short {
  font-size: 0.85em;
  color: var(--muted);
  line-height: 1.5;
}

.project-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
  padding-top: 0.1rem;
}

.project-year {
  font-size: 0.78em;
  color: var(--muted);
}

.project-chevron {
  color: var(--muted);
  font-size: 0.75em;
  transition: transform 0.25s ease;
}

.project-card.open .project-chevron { transform: rotate(90deg); }

.project-more {
  display: none;
  padding: 0 1.5rem 1.5rem;
  border-top: 1px solid var(--border);
  margin-top: 0;
}

.project-card.open .project-more { display: block; }

.project-long-desc {
  font-size: 0.875em;
  color: var(--muted);
  line-height: 1.75;
  margin: 1rem 0;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-bottom: 1rem;
}

.tag {
  font-size: 0.7em;
  padding: 0.2rem 0.55rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 0.3rem;
  color: var(--muted);
}

.project-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.btn-action {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.8em;
  color: var(--accent);
  padding: 0.4rem 0.9rem;
  border: 1px solid var(--accent);
  border-radius: 0.4rem;
  transition: background var(--tr), color var(--tr);
}

.btn-action:hover {
  background: var(--accent);
  color: #fff;
}


.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(5.5rem, 1fr));
  gap: 0.75rem;
}

.tech-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  padding: 1.1rem 0.5rem 0.9rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: background var(--tr), border-color var(--tr), transform var(--tr);
}

.tech-item:hover {
  background: var(--bg-hover);
  border-color: rgba(69,142,232,.4);
  transform: translateY(-2px);
}

.tech-item img {
  width: 1.9rem;
  height: 1.9rem;
  object-fit: contain;
}

.tech-name {
  font-size: 0.7em;
  color: var(--muted);
  text-align: center;
  line-height: 1.2;
}


.contact-intro {
  font-size: 0.93em;
  color: var(--muted);
  line-height: 1.75;
  margin-bottom: 1.5rem;
  max-width: 38rem;
}

.contact-socials {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-bottom: 2.5rem;
}

.contact-socials a {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.85em;
  color: var(--muted);
  padding: 0.45rem 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 100rem;
  transition: color var(--tr), border-color var(--tr), background var(--tr);
}

.contact-socials a:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: rgba(69,142,232,.07);
}

.contact-form-wrap {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
}

.contact-form-wrap h3 {
  font-size: 0.95em;
  font-weight: 600;
  margin-bottom: 1.25rem;
}

.form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.form-label {
  font-size: 0.77em;
  color: var(--muted);
  font-weight: 500;
  letter-spacing: 0.02em;
}

.form-input {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  color: var(--text);
  font: inherit;
  font-size: 0.9em;
  padding: 0.6rem 0.9rem;
  outline: none;
  transition: border-color var(--tr);
  width: 100%;
}

.form-input::placeholder { color: var(--muted); opacity: 0.6; }
.form-input:focus { border-color: var(--accent); }

.form-textarea {
  resize: vertical;
  min-height: 8rem;
}

.hp-field { display: none; }

.btn-submit {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 0.5rem;
  font: inherit;
  font-size: 0.875em;
  font-weight: 600;
  padding: 0.7rem 1.5rem;
  transition: opacity var(--tr), transform var(--tr);
  align-self: flex-start;
}

.btn-submit:hover { opacity: 0.88; transform: translateY(-1px); }
.btn-submit:disabled { opacity: 0.55; cursor: not-allowed; transform: none; }

.form-alert {
  display: none;
  padding: 0.7rem 1rem;
  border-radius: 0.5rem;
  font-size: 0.875em;
  align-items: center;
  gap: 0.5rem;
}

.form-alert.success {
  display: flex;
  background: rgba(34,197,94,.1);
  border: 1px solid rgba(34,197,94,.3);
  color: #22c55e;
}

.form-alert.error {
  display: flex;
  background: rgba(239,68,68,.1);
  border: 1px solid rgba(239,68,68,.3);
  color: #ef4444;
}


footer {
  margin-top: 10vh;
  padding: 2rem 0 3rem;
  border-top: 1px solid var(--border);
}

footer .wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.footer-copy {
  font-size: 0.78em;
  color: var(--muted);
}

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

.footer-links a {
  font-size: 0.78em;
  color: var(--muted);
  transition: color var(--tr);
}

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


.page-header {
  margin-top: 4vh;
  margin-bottom: 3rem;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85em;
  color: var(--muted);
  margin-bottom: 1.5rem;
  transition: color var(--tr);
}

.back-link:hover { color: var(--accent); }

.page-title {
  font-size: 1.75em;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.page-content { max-width: 42rem; }

.page-content h2 {
  font-size: 0.97em;
  font-weight: 600;
  color: var(--text);
  margin-top: 2rem;
  margin-bottom: 0.5rem;
}

.page-content p,
.page-content li {
  font-size: 0.9em;
  color: var(--muted);
  line-height: 1.8;
  margin-bottom: 0.6rem;
}

.page-content ul { padding-left: 1.5rem; list-style: disc; }
.page-content a { color: var(--accent); }
.page-content a:hover { text-decoration: underline; }


.fade-in {
  opacity: 0;
  transform: translateY(1rem);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}


[data-theme="light"] .tech-item {
  background: #dce4f0;
  border-color: #c8d4e8;
}

[data-theme="light"] .tech-item:hover {
  background: #ccd7eb;
}

[data-theme="light"] img[alt="GitHub"] {
  filter: invert(1) brightness(0);
}


@media (max-width: 640px) {
  html { font-size: 15px; }

  .hero {
    flex-direction: column;
    align-items: center;
    text-align: center;
    margin-top: 3vh;
  }

  .hero-avatar { width: 7rem; height: 7rem; min-width: 7rem; font-size: 2.8rem; }
  .hero-links  { justify-content: center; }

  .form-row { grid-template-columns: 1fr; }

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

  .tech-grid { grid-template-columns: repeat(auto-fill, minmax(4.5rem, 1fr)); }

  .project-trigger { padding: 1rem; }
  .project-more    { padding: 0 1rem 1rem; }
}

@media (max-width: 400px) {
  .header-logo { display: none; }
}