/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #ffffff;
  --bg-alt: #f9f9f9;
  --text: #1a1a1a;
  --text-secondary: #555;
  --text-muted: #888;
  --accent: #1a1a1a;
  --link: #0055cc;
  --link-hover: #003399;
  --border: #e5e5e5;
  --card-bg: #ffffff;
  --card-shadow: 0 1px 3px rgba(0,0,0,0.06);
  --card-hover-shadow: 0 4px 12px rgba(0,0,0,0.08);
  --tag-bg: #f0f0f0;
  --tag-text: #444;
  --hero-gradient: linear-gradient(135deg, #f8f8f8 0%, #ffffff 100%);
  --skill-bg: #fafafa;
  --cp-bg: #f8f8f8;
  --cp-border: #e0e0e0;
  --toggle-bg: #f0f0f0;
  --toggle-text: #333;
  --achievement-border-left: #ddd;
  --code-bg: #f5f5f5;
}

[data-theme="dark"] {
  --bg: #0d1117;
  --bg-alt: #161b22;
  --text: #e6edf3;
  --text-secondary: #9da5b0;
  --text-muted: #6e7681;
  --accent: #e6edf3;
  --link: #58a6ff;
  --link-hover: #79c0ff;
  --border: #30363d;
  --card-bg: #161b22;
  --card-shadow: 0 1px 3px rgba(0,0,0,0.3);
  --card-hover-shadow: 0 4px 12px rgba(0,0,0,0.4);
  --tag-bg: #21262d;
  --tag-text: #9da5b0;
  --hero-gradient: linear-gradient(135deg, #0d1117 0%, #161b22 100%);
  --skill-bg: #161b22;
  --cp-bg: #161b22;
  --cp-border: #30363d;
  --toggle-bg: #21262d;
  --toggle-text: #e6edf3;
  --achievement-border-left: #30363d;
  --code-bg: #1c2128;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 72px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  transition: background 0.3s ease, color 0.3s ease;
}

/* ===== GLASS NAVBAR ===== */
.glass-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 999;
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  background: rgba(255, 255, 255, 0.72);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  transition: background 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}
[data-theme="dark"] .glass-nav {
  background: rgba(13, 17, 23, 0.72);
  border-bottom-color: rgba(255, 255, 255, 0.06);
}
.glass-nav.scrolled {
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.06);
}
[data-theme="dark"] .glass-nav.scrolled {
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.nav-inner {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-family: 'Newsreader', Georgia, serif;
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  letter-spacing: -0.02em;
  transition: opacity 0.2s;
}
.nav-logo:hover { opacity: 0.7; text-decoration: none; }

.nav-resume {
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  padding: 5px 11px;
  border-radius: 6px;
  border: 1px solid var(--border);
  transition: color 0.2s, border-color 0.2s, background 0.2s;
  white-space: nowrap;
  margin-left: 14px;
  margin-right: auto;
}
.nav-resume:hover {
  color: var(--text);
  border-color: var(--text-muted);
  background: rgba(0,0,0,0.03);
  text-decoration: none;
}
[data-theme="dark"] .nav-resume:hover { background: rgba(255,255,255,0.05); }

.nav-links {
  display: flex;
  gap: 6px;
}

.nav-link {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  padding: 6px 12px;
  border-radius: 6px;
  transition: color 0.2s, background 0.2s;
  letter-spacing: 0.01em;
}
.nav-link:hover {
  color: var(--text);
  background: rgba(0, 0, 0, 0.04);
  text-decoration: none;
}
[data-theme="dark"] .nav-link:hover {
  background: rgba(255, 255, 255, 0.06);
}
.nav-link.active {
  color: var(--text);
  background: rgba(0, 0, 0, 0.06);
}
[data-theme="dark"] .nav-link.active {
  background: rgba(255, 255, 255, 0.08);
}

.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-hamburger span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text-muted);
  border-radius: 2px;
  transition: all 0.3s ease;
}
.nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

a {
  color: var(--link);
  text-decoration: none;
  transition: color 0.2s;
}
a:hover { color: var(--link-hover); text-decoration: underline; }

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

/* ===== THEME TOGGLE ===== */
.theme-toggle {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 1000;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--toggle-bg);
  color: var(--toggle-text);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}
.theme-toggle:hover {
  transform: scale(1.1);
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}
.icon-sun, .icon-moon { transition: opacity 0.3s; }
.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }

/* ===== CONTAINER ===== */
.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== HERO ===== */
.hero {
  display: flex;
  align-items: flex-start;
  gap: 40px;
  padding: 100px 0 60px;
  border-bottom: 1px solid var(--border);
}

.hero-text { flex: 1; }

.hero-text h1 {
  font-family: 'Newsreader', Georgia, 'Times New Roman', serif;
  font-size: 2.8rem;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--accent);
  margin-bottom: 8px;
}

.hero-title {
  font-size: 1.15rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.hero-tagline {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 24px;
}

.hero-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.hero-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-secondary);
  transition: color 0.2s;
}
.hero-link:hover { color: var(--link); text-decoration: none; }
.hero-link svg { flex-shrink: 0; }

.hero-avatar {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--border);
  flex-shrink: 0;
  margin-top: 12px;
}

/* ===== SECTIONS ===== */
.section {
  padding: 48px 0;
  border-bottom: 1px solid var(--border);
}

.section h2 {
  font-family: 'Newsreader', Georgia, serif;
  font-size: 1.8rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--accent);
  margin-bottom: 32px;
}

/* ===== EXPERIENCE CARDS ===== */
.exp-card {
  margin-bottom: 36px;
  padding-bottom: 32px;
  border-bottom: 1px solid var(--border);
}
.exp-card:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }

.exp-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 4px;
}

.exp-header h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
}

.exp-header a, .exp-header span {
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.exp-meta {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.exp-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
  font-style: italic;
}

.exp-card ul {
  list-style: disc;
  padding-left: 24px;
}
.exp-card li {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 6px;
  line-height: 1.6;
}
.exp-card li a { color: var(--link); }

/* ===== PROJECT CARDS ===== */
.project-card {
  margin-bottom: 36px;
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--card-bg);
  box-shadow: var(--card-shadow);
  transition: box-shadow 0.3s, background 0.3s;
}
.project-card:hover { box-shadow: var(--card-hover-shadow); }

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 8px;
}

.project-header h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  flex: 1;
}

.project-links {
  display: flex;
  gap: 10px;
  flex-shrink: 0;
}
.project-links a {
  color: var(--text-muted);
  transition: color 0.2s;
}
.project-links a:hover { color: var(--link); }

.project-tech {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 4px;
  font-weight: 500;
  letter-spacing: 0.02em;
}

.project-date {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.project-card > p:last-of-type {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.project-preview {
  margin-top: 16px;
  border-radius: 6px;
  overflow: hidden;
  border: 1px solid var(--border);
}
.project-preview img {
  width: 100%;
  display: block;
}

/* ===== SKILLS ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.skills-category {
  padding: 16px 20px;
  background: var(--skill-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: background 0.3s;
}

.skills-category h3 {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.skills-category p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===== ACHIEVEMENTS ===== */
.achievement-card {
  padding: 12px 0 12px 20px;
  margin-bottom: 16px;
  border-left: 3px solid var(--achievement-border-left);
  transition: border-color 0.2s;
}
.achievement-card:hover { border-left-color: var(--link); }

.achievement-card h3 {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 4px;
}

.achievement-card p {
  font-size: 0.88rem;
  color: var(--text-secondary);
}

/* ===== EDUCATION ===== */
.edu-card {
  padding: 20px 24px;
  margin-bottom: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--card-bg);
  transition: background 0.3s;
}

.edu-header {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 8px;
}

.edu-header h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
}

.edu-badge {
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 2px 8px;
  border-radius: 4px;
  background: var(--tag-bg);
  color: var(--tag-text);
}

.edu-degree {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 4px;
}

.edu-meta {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.edu-card p { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 4px; }
.edu-card p:last-child { margin-bottom: 0; }

.edu-courses {
  margin-top: 8px;
  font-size: 0.85rem !important;
  color: var(--text-muted) !important;
}

.edu-small {
  padding: 14px 24px;
}
.edu-small h3 { font-size: 0.95rem; margin-bottom: 2px; }
.edu-small p { font-size: 0.88rem; margin-bottom: 0; }

/* ===== COMPETITIVE PROGRAMMING ===== */
.cp-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
}

.cp-card {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 20px;
  border: 1px solid var(--cp-border);
  border-radius: 8px;
  background: var(--cp-bg);
  color: var(--text);
  transition: all 0.2s;
  text-decoration: none;
}
.cp-card:hover {
  border-color: var(--link);
  text-decoration: none;
  box-shadow: var(--card-hover-shadow);
}
.cp-card strong { font-size: 0.95rem; color: var(--text); }
.cp-card span { font-size: 0.82rem; color: var(--text-muted); }

/* ===== FOOTER ===== */
.footer {
  padding: 40px 0;
  text-align: center;
}
.footer p {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 6px;
}
.footer a { color: var(--text-secondary); }
.footer a:hover { color: var(--link); }
.footer-sub { font-size: 0.82rem; }

/* ===== RESPONSIVE ===== */
@media (max-width: 640px) {
  .nav-hamburger { display: flex; }
  .nav-links {
    display: none;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    flex-direction: column;
    padding: 12px 24px 20px;
    gap: 2px;
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    background: rgba(255, 255, 255, 0.88);
    border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  }
  [data-theme="dark"] .nav-links {
    background: rgba(13, 17, 23, 0.88);
    border-bottom-color: rgba(255, 255, 255, 0.06);
  }
  .nav-links.open { display: flex; }
  .nav-link { padding: 10px 12px; font-size: 0.9rem; }
  .hero {
    flex-direction: column-reverse;
    align-items: center;
    text-align: center;
    gap: 24px;
    padding: 80px 0 40px;
  }
  .hero-text h1 { font-size: 2rem; }
  .hero-avatar { width: 120px; height: 120px; }
  .hero-links { align-items: center; }
  .section h2 { font-size: 1.5rem; }
  .project-card { padding: 16px; }
  .skills-grid { grid-template-columns: 1fr; }
  .cp-grid { grid-template-columns: 1fr; }
  .exp-header { flex-direction: column; gap: 2px; }
  .edu-header { flex-direction: column; gap: 4px; }
  .theme-toggle { bottom: 16px; right: 16px; width: 40px; height: 40px; }
}