/* =========================================================
   Durali Asan — Portfolio
   Tek dosya CSS: reset, tema değişkenleri, layout, bileşenler
   ========================================================= */

:root {
  --font-sans: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Consolas', monospace;

  --accent-1: #0f4c81;
  --accent-2: #2f8fd9;
  --accent-3: #63b3f0;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;

  --container-w: 1120px;

  --transition-fast: 160ms ease;
  --transition-med: 320ms cubic-bezier(.4,0,.2,1);

  /* Dark theme (default) */
  --bg: #080b12;
  --bg-elevated: #0d121c;
  --surface: rgba(255, 255, 255, 0.045);
  --surface-strong: rgba(255, 255, 255, 0.08);
  --border: rgba(255, 255, 255, 0.09);
  --text-primary: #eaeef4;
  --text-secondary: #9aa7bd;
  --text-tertiary: #6b7690;
  --shadow-color: rgba(0, 0, 0, 0.45);
  --hero-gradient: radial-gradient(circle at 20% 20%, rgba(47,143,217,0.18), transparent 55%),
                    radial-gradient(circle at 80% 70%, rgba(15,76,129,0.25), transparent 50%);
}

:root[data-theme="light"] {
  --bg: #f4f7fb;
  --bg-elevated: #ffffff;
  --surface: rgba(15, 76, 129, 0.045);
  --surface-strong: rgba(15, 76, 129, 0.08);
  --border: rgba(15, 40, 70, 0.1);
  --text-primary: #101826;
  --text-secondary: #4a5568;
  --text-tertiary: #6b7690;
  --shadow-color: rgba(15, 40, 70, 0.12);
  --hero-gradient: radial-gradient(circle at 20% 20%, rgba(47,143,217,0.12), transparent 55%),
                    radial-gradient(circle at 80% 70%, rgba(15,76,129,0.10), transparent 50%);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]):not([data-theme="light"]) {
    --bg: #f4f7fb;
    --bg-elevated: #ffffff;
    --surface: rgba(15, 76, 129, 0.045);
    --surface-strong: rgba(15, 76, 129, 0.08);
    --border: rgba(15, 40, 70, 0.1);
    --text-primary: #101826;
    --text-secondary: #4a5568;
    --text-tertiary: #6b7690;
    --shadow-color: rgba(15, 40, 70, 0.12);
    --hero-gradient: radial-gradient(circle at 20% 20%, rgba(47,143,217,0.12), transparent 55%),
                      radial-gradient(circle at 80% 70%, rgba(15,76,129,0.10), transparent 50%);
  }
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background-color var(--transition-med), color var(--transition-med);
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; margin: 0; padding: 0; }
h1, h2, h3, p { margin: 0; }

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--accent-2);
  color: #fff;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-sm);
  z-index: 1000;
}
.skip-link:focus {
  left: 1rem;
  top: 1rem;
}

:focus-visible {
  outline: 2px solid var(--accent-3);
  outline-offset: 3px;
}

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

/* ---------- Header / Nav ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(8, 11, 18, 0.6);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--border);
  transition: background-color var(--transition-med), border-color var(--transition-med);
}
:root[data-theme="light"] .site-header { background: rgba(244, 247, 251, 0.7); }

.navbar {
  max-width: var(--container-w);
  margin-inline: auto;
  padding: 0.85rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  color: #fff;
  font-weight: 800;
  font-family: var(--font-mono);
  letter-spacing: 0.5px;
}

.nav-links {
  display: flex;
  gap: 1.75rem;
  margin-inline: auto;
}
.nav-links a {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
  padding: 0.3rem 0;
  transition: color var(--transition-fast);
}
.nav-links a::after {
  content: '';
  position: absolute;
  left: 0; bottom: -2px;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent-2), var(--accent-3));
  transition: width var(--transition-fast);
}
.nav-links a:hover { color: var(--text-primary); }
.nav-links a:hover::after { width: 100%; }

.nav-actions { display: flex; align-items: center; gap: 0.6rem; }

.pill-btn, .icon-btn {
  font-family: var(--font-sans);
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-primary);
  transition: background-color var(--transition-fast), transform var(--transition-fast), border-color var(--transition-fast);
}
.pill-btn {
  border-radius: 999px;
  padding: 0.4rem 0.9rem;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.4px;
}
.icon-btn {
  border-radius: 50%;
  width: 38px;
  height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.pill-btn:hover, .icon-btn:hover {
  background: var(--surface-strong);
  border-color: var(--accent-2);
  transform: translateY(-1px);
}

.icon-moon { display: none; }
:root[data-theme="light"] .icon-sun { display: none; }
:root[data-theme="light"] .icon-moon { display: inline-flex; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--text-primary);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.85rem 1.6rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast);
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  color: #fff;
  box-shadow: 0 8px 24px -8px rgba(47, 143, 217, 0.6);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 28px -8px rgba(47, 143, 217, 0.75); }
.btn-ghost {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-primary);
}
.btn-ghost:hover { background: var(--surface-strong); transform: translateY(-2px); }

.cv-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1.1rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  background: var(--surface);
  transition: all var(--transition-fast);
}
.cv-btn:hover { color: var(--text-primary); border-color: var(--accent-2); }
.cv-btn.active {
  background: linear-gradient(135deg, var(--accent-1), var(--accent-2));
  color: #fff;
  border-color: transparent;
}

/* ---------- Glass ---------- */
.glass {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 8px 30px -12px var(--shadow-color);
  transition: transform var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.glass:hover {
  transform: translateY(-4px);
  border-color: var(--accent-2);
  box-shadow: 0 16px 40px -14px var(--shadow-color);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-top: 5rem;
  background: var(--hero-gradient), var(--bg);
}

#matrix-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0.35;
  pointer-events: none;
}
:root[data-theme="light"] #matrix-canvas { opacity: 0.18; }

.hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.3fr 0.8fr;
  align-items: center;
  gap: 3rem;
  padding-block: 3rem;
}

.hero-greeting {
  font-family: var(--font-mono);
  color: var(--accent-3);
  font-size: 1rem;
  margin-bottom: 0.75rem;
  letter-spacing: 0.5px;
}
.hero-name {
  font-size: clamp(2.4rem, 5vw, 3.6rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, var(--text-primary), var(--accent-3));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-role {
  font-size: clamp(1.05rem, 2vw, 1.3rem);
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
}
.hero-desc {
  max-width: 46ch;
  color: var(--text-secondary);
  margin-bottom: 2rem;
}
.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1.5rem;
}
.hero-cv {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.hero-photo { display: flex; justify-content: center; }
.photo-ring {
  width: 280px;
  height: 280px;
  border-radius: 50%;
  padding: 6px;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
  box-shadow: 0 20px 60px -20px rgba(47, 143, 217, 0.5);
}
.photo-ring img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 50%;
  border: 4px solid var(--bg);
}

.scroll-cue {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  width: 26px;
  height: 42px;
  border: 2px solid var(--border);
  border-radius: 999px;
  z-index: 1;
}
.scroll-cue span {
  position: absolute;
  top: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 8px;
  border-radius: 999px;
  background: var(--accent-3);
  animation: scrollcue 1.6s ease-in-out infinite;
}
@keyframes scrollcue {
  0% { top: 8px; opacity: 1; }
  70% { top: 22px; opacity: 0; }
  100% { top: 22px; opacity: 0; }
}

/* ---------- Sections ---------- */
.section { padding: 6.5rem 0; }
.section-alt { background: var(--bg-elevated); }
.section-tag {
  font-family: var(--font-mono);
  color: var(--accent-3);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 0.75rem;
}
.section-title {
  font-size: clamp(1.7rem, 3.5vw, 2.4rem);
  font-weight: 800;
  margin-bottom: 3rem;
  max-width: 34ch;
}

/* ---------- About ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 2.5rem;
  align-items: start;
}
.about-text { font-size: 1.08rem; color: var(--text-secondary); }
.about-facts { display: flex; flex-direction: column; gap: 1rem; }
.fact-card { padding: 1.1rem 1.3rem; display: flex; flex-direction: column; gap: 0.25rem; }
.fact-label { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.6px; color: var(--text-tertiary); }
.fact-value { font-weight: 600; }

/* ---------- Skills ---------- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}
.skill-group { padding: 1.6rem; }
.skill-group h3 { font-size: 1.05rem; margin-bottom: 1rem; }
.badge-row { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.badge {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  background: var(--surface-strong);
  border: 1px solid var(--border);
  color: var(--text-secondary);
}

/* ---------- Timeline ---------- */
.timeline {
  position: relative;
  padding-left: 2rem;
  border-left: 2px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}
.timeline-item { position: relative; }
.timeline-dot {
  position: absolute;
  left: -2.42rem;
  top: 0.4rem;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-1), var(--accent-3));
  box-shadow: 0 0 0 4px var(--bg);
}
.timeline-content { padding: 1.5rem 1.75rem; }
.timeline-date {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent-3);
}
.timeline-content h3 { margin-block: 0.4rem; font-size: 1.15rem; }
.timeline-org { color: var(--text-tertiary); font-size: 0.9rem; margin-bottom: 0.75rem; }
.timeline-content p:last-child { color: var(--text-secondary); }

/* ---------- Projects ---------- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}
.project-card { padding: 1.75rem; display: flex; flex-direction: column; gap: 0.9rem; }
.project-card h3 { font-size: 1.15rem; }
.project-card p { color: var(--text-secondary); font-size: 0.95rem; }
.project-link {
  font-weight: 600;
  color: var(--accent-3);
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  transition: gap var(--transition-fast);
}
.project-link:hover { gap: 0.55rem; }
.project-links { display: flex; gap: 1.25rem; flex-wrap: wrap; }

/* ---------- Contact ---------- */
.contact-desc { color: var(--text-secondary); max-width: 50ch; margin-bottom: 2.5rem; }
.contact-links { display: flex; flex-wrap: wrap; gap: 1rem; }
.contact-card {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 1rem 1.4rem;
  font-weight: 600;
  font-size: 0.95rem;
}
.contact-card:hover { color: var(--accent-3); }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-tertiary);
}

/* ---------- Scroll reveal ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; text-align: center; }
  .hero-cta, .hero-cv { justify-content: center; }
  .hero-desc { margin-inline: auto; }
  .hero-photo { order: -1; }
  .photo-ring { width: 200px; height: 200px; }
  .about-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: repeat(2, 1fr); }
  .projects-grid { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  .nav-toggle { display: flex; }
  .nav-links {
    position: fixed;
    top: 68px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--bg-elevated);
    border-bottom: 1px solid var(--border);
    padding: 1.5rem;
    gap: 1.25rem;
    transform: translateY(-130%);
    transition: transform var(--transition-med);
  }
  .nav-links.is-open { transform: translateY(0); }
  .skills-grid { grid-template-columns: 1fr; }
  .navbar { padding: 0.85rem 1.25rem; }
}

@media (max-width: 480px) {
  .hero-cta, .hero-cv { flex-direction: column; align-items: stretch; }
  .section { padding: 4.5rem 0; }
}