/* ===== Variables – Colour palette & theme ===== */
:root {
  --dark: #061E29;
  --medium: #1D546D;
  --accent: #5F9598;
  --light: #F3F4F4;
  --white: #ffffff;
  --font: 'Plus Jakarta Sans', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 4px 24px rgba(6, 30, 41, 0.12);
  --shadow-hover: 0 8px 32px rgba(6, 30, 41, 0.18);
  --transition: 0.25s ease;

  /* Light theme (default) – semantic tokens */
  --bg-page: #F3F4F4;
  --text-primary: #061E29;
  --text-secondary: #1D546D;
  --bg-card: #ffffff;
  --bg-section-alt: #ffffff;
  --border-card: rgba(29, 84, 109, 0.12);
  --tag-bg: rgba(95, 149, 152, 0.15);
  --tag-bg-muted: rgba(95, 149, 152, 0.12);
  --about-code-bg: #e8eaeb;
  --timeline-marker-border: #F3F4F4;
  --modal-bg: #ffffff;
  --modal-footer-bg: #F3F4F4;
  --card-shine-highlight: rgba(255, 255, 255, 0.6);
  --header-bg: rgba(255, 255, 255, 0.95);
  --header-text: #061E29;
  --header-border: rgba(29, 84, 109, 0.15);
  --footer-bg: #e8eaea;
  --footer-text: #061E29;
  /* About: code block in light theme uses light bg + dark syntax */
  --about-code-text: #061E29;
  --code-key: #7c3aed;
  --code-class: #b45309;
  --code-fn: #0369a1;
  --code-var: #b91c1c;
  --code-str: #15803d;
  /* Contact & CV – light theme */
  --contact-bg: #e8eaea;
  --contact-text: #061E29;
  --contact-card-bg: rgba(255, 255, 255, 0.9);
  --contact-card-inner: rgba(255, 255, 255, 0.95);
  --contact-card-border: rgba(29, 84, 109, 0.2);
  --contact-btn-outline: rgba(6, 30, 41, 0.4);
  --contact-btn-outline-hover: #1D546D;
  --contact-note-code-bg: rgba(6, 30, 41, 0.08);
  /* Hero – light theme */
  --hero-bg: #e8eaea;
  --hero-text: #061E29;
  --hero-label: #1D546D;
  --hero-grid: rgba(29, 84, 109, 0.08);
  --hero-gradient: linear-gradient(to top, #e8eaea, transparent);
  --hero-scroll: rgba(6, 30, 41, 0.5);
  --hero-scroll-border: rgba(29, 84, 109, 0.3);
  --hero-btn-outline: rgba(6, 30, 41, 0.5);
  --hero-title-highlight: #1D546D;
  --hero-title-glow: rgba(95, 149, 152, 0.15);
  --click-ripple: rgba(95, 149, 152, 0.35);
}

[data-theme="light"] {
  /* Açık tema – hero ve contact kesin uygulansın */
  --contact-bg: #e8eaea;
  --contact-text: #061E29;
  --contact-card-bg: rgba(255, 255, 255, 0.9);
  --contact-card-inner: rgba(255, 255, 255, 0.95);
  --contact-card-border: rgba(29, 84, 109, 0.2);
  --contact-btn-outline: rgba(6, 30, 41, 0.4);
  --contact-btn-outline-hover: #1D546D;
  --hero-bg: #e8eaea;
  --hero-text: #061E29;
  --hero-label: #1D546D;
  --hero-grid: rgba(29, 84, 109, 0.08);
  --hero-gradient: linear-gradient(to top, #e8eaea, transparent);
  --hero-scroll: rgba(6, 30, 41, 0.5);
  --hero-scroll-border: rgba(29, 84, 109, 0.3);
  --hero-btn-outline: rgba(6, 30, 41, 0.5);
}

[data-theme="dark"] {
  --click-ripple: rgba(0, 255, 70, 0.22);
  --hero-title-highlight: #5F9598;
  --hero-title-glow: rgba(95, 149, 152, 0.2);
  --bg-page: #061E29;
  --text-primary: #F3F4F4;
  --text-secondary: #5F9598;
  --bg-card: #0e2832;
  --bg-section-alt: #0a1f28;
  --border-card: rgba(95, 149, 152, 0.25);
  --tag-bg: rgba(95, 149, 152, 0.2);
  --tag-bg-muted: rgba(95, 149, 152, 0.15);
  --about-code-bg: #0a1f28;
  --about-code-text: #F3F4F4;
  --code-key: #c678dd;
  --code-class: #e5c07b;
  --code-fn: #61afef;
  --code-var: #e06c75;
  --code-str: #98c379;
  --timeline-marker-border: #0e2832;
  --modal-bg: #0e2832;
  --modal-footer-bg: #0a1f28;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-hover: 0 8px 32px rgba(0, 0, 0, 0.4);
  --card-shine-highlight: rgba(255, 255, 255, 0.15);
  --header-bg: rgba(6, 30, 41, 0.95);
  --header-text: #F3F4F4;
  --header-border: rgba(95, 149, 152, 0.2);
  --footer-bg: #0a1f28;
  --footer-text: #F3F4F4;
  /* Contact & CV – dark theme */
  --contact-bg: #061E29;
  --contact-text: #F3F4F4;
  --contact-card-bg: rgba(29, 84, 109, 0.25);
  --contact-card-inner: rgba(29, 84, 109, 0.35);
  --contact-card-border: rgba(95, 149, 152, 0.2);
  --contact-btn-outline: rgba(243, 244, 244, 0.35);
  --contact-btn-outline-hover: #5F9598;
  --contact-note-code-bg: rgba(255, 255, 255, 0.1);
  /* Hero – dark theme */
  --hero-bg: #061E29;
  --hero-text: #F3F4F4;
  --hero-label: #5F9598;
  --hero-grid: rgba(95, 149, 152, 0.06);
  --hero-gradient: linear-gradient(to top, #061E29, transparent);
  --hero-scroll: rgba(243, 244, 244, 0.7);
  --hero-scroll-border: rgba(243, 244, 244, 0.4);
  --hero-btn-outline: rgba(243, 244, 244, 0.5);
}

/* Animasyon: hover'da dönen gradient çerçeve */
@keyframes card-border-spin {
  to { transform: rotate(360deg); }
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-page);
  overflow-x: hidden;
  transition: background var(--transition), color var(--transition);
}

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

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

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

ul {
  list-style: none;
}

.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Erişilebilirlik: klavye ile ilk odakta görünür */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  z-index: 200;
  padding: 0.75rem 1.25rem;
  background: var(--accent);
  color: var(--dark);
  font-weight: 600;
  border-radius: var(--radius);
  transition: top 0.2s ease;
}
.skip-link:focus {
  top: 1rem;
  outline: 2px solid var(--light);
  outline-offset: 2px;
}

/* ===== Click bubbles effect ===== */
.click-bubbles {
  position: fixed;
  pointer-events: none;
  z-index: 9999;
  left: 0;
  top: 0;
}

.click-bubble {
  position: absolute;
  width: 10px;
  height: 10px;
  margin-left: -5px;
  margin-top: -5px;
  border-radius: 50%;
  background: var(--click-ripple);
  opacity: 0.9;
  animation: click-bubble-out 0.7s ease-out forwards;
  --tx: 0px;
  --ty: 0px;
}

@keyframes click-bubble-out {
  to {
    transform: translate(var(--tx), var(--ty)) scale(0.2);
    opacity: 0;
  }
}

/* ===== Header & Nav ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--header-bg);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--header-border);
  transition: background var(--transition), border-color var(--transition), color var(--transition);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.nav-logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--header-text);
  letter-spacing: 0.05em;
  transition: color var(--transition);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  color: var(--header-text);
  font-weight: 500;
  font-size: 0.9rem;
  transition: color var(--transition);
}

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

.nav-cta {
  background: var(--accent);
  color: #061E29 !important;
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
}

.nav-cta:hover {
  background: #6fa8ab;
  color: #061E29 !important;
}

.nav-link.is-active {
  color: var(--accent);
}

/* Language switcher (TR / EN) */
.lang-switcher {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}
.lang-btn {
  font-family: var(--font);
  font-size: 0.875rem;
  font-weight: 600;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--header-text);
  padding: 0.25rem 0.5rem;
  border-radius: 6px;
  transition: color 0.2s ease, background 0.2s ease;
}
.lang-btn:hover {
  color: var(--accent);
}
.lang-btn.is-active {
  color: var(--accent);
  background: rgba(95, 149, 152, 0.15);
}
.lang-sep {
  color: var(--header-text);
  opacity: 0.5;
  font-weight: 500;
  user-select: none;
}

/* Theme toggle (light/dark) */
.theme-toggle {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  padding: 0;
  background: rgba(0, 0, 0, 0.06);
  border: 1px solid var(--header-border);
  border-radius: var(--radius);
  color: var(--header-text);
  font-size: 1.2rem;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

[data-theme="dark"] .theme-toggle {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
}

.theme-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.theme-icon {
  position: absolute;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.theme-icon-moon {
  opacity: 0;
}

.theme-icon-sun {
  opacity: 1;
}

[data-theme="dark"] .theme-icon-moon {
  opacity: 1;
}

[data-theme="dark"] .theme-icon-sun {
  opacity: 0;
}

.theme-toggle .theme-icon-sun,
.theme-toggle .theme-icon-moon {
  position: absolute;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--header-text);
  border-radius: 2px;
  transition: background var(--transition);
}

/* ===== Hero (theme-aware) ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 6rem 0 4rem;
  background: var(--hero-bg);
  color: var(--hero-text);
  transition: background var(--transition), color var(--transition);
}

.hero-bg {
  position: absolute;
  inset: 0;
  overflow: hidden;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--hero-grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--hero-grid) 1px, transparent 1px);
  background-size: 48px 48px;
  transition: background-image var(--transition);
}

.hero-gradient {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 40%;
  background: var(--hero-gradient);
  pointer-events: none;
  transition: background var(--transition);
}

/* Matrix: hero content ile sağ kenar arasındaki boşlukta ortalanmış çerçeve */
.hero-matrix {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 52%;
  right: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
  z-index: 0;
}

.hero-matrix-frame {
  width: min(520px, 92%);
  max-width: 100%;
  height: 260px;
  border: 2px solid rgba(95, 149, 152, 0.5);
  border-radius: 16px;
  overflow: hidden;
  position: relative;
  background: rgba(6, 30, 41, 0.38);
  box-shadow:
    0 0 0 1px rgba(0, 0, 0, 0.05),
    0 12px 40px rgba(0, 0, 0, 0.08),
    inset 0 0 80px rgba(0, 0, 0, 0.1);
}

[data-theme="dark"] .hero-matrix-frame {
  border-color: rgba(0, 255, 70, 0.3);
  background: rgba(0, 0, 0, 0.55);
  box-shadow:
    0 0 0 1px rgba(0, 255, 70, 0.1),
    0 12px 48px rgba(0, 0, 0, 0.4),
    inset 0 0 100px rgba(0, 0, 0, 0.2);
}

/* Küçük/orta ekran: matrix gizle */
@media (max-width: 1024px) {
  .hero-matrix {
    display: none;
  }
}

@media (min-width: 1025px) and (max-width: 1200px) {
  .hero-matrix {
    left: 54%;
    right: 1rem;
  }
  .hero-matrix-frame {
    width: min(400px, 90%);
    height: 220px;
  }
}

.hero-matrix canvas {
  display: block;
  width: 100%;
  height: 100%;
  opacity: 0.82;
}

[data-theme="dark"] .hero-matrix canvas {
  opacity: 0.88;
}

.hero-matrix-fade {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 64px;
  background: linear-gradient(to right, rgba(6, 30, 41, 0.55), transparent);
  pointer-events: none;
  transition: opacity var(--transition);
}

[data-theme="dark"] .hero-matrix-fade {
  background: linear-gradient(to right, rgba(0, 0, 0, 0.55), transparent);
}

.hero-content {
  position: relative;
  z-index: 1;
}

.hero-label {
  display: inline-block;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--hero-label);
  margin-bottom: 0.9rem;
  padding: 0.45rem 1rem;
  border: 1px solid var(--hero-label-border, rgba(29, 84, 109, 0.4));
  border-radius: 8px;
  background: var(--hero-label-bg, rgba(29, 84, 109, 0.06));
  transition: color var(--transition), border-color var(--transition), background var(--transition);
}

[data-theme="dark"] .hero-label {
  --hero-label-border: rgba(95, 149, 152, 0.35);
  --hero-label-bg: rgba(95, 149, 152, 0.08);
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 0.25rem;
  letter-spacing: -0.02em;
  position: relative;
}

.hero-title-inner {
  display: inline-block;
  background: linear-gradient(
    110deg,
    var(--hero-text) 0%,
    var(--hero-text) 35%,
    var(--hero-title-highlight) 50%,
    var(--hero-text) 65%,
    var(--hero-text) 100%
  );
  background-size: 200% 100%;
  background-clip: text;
  -webkit-background-clip: text;
  color: transparent;
  animation: hero-title-shimmer 4s ease-in-out infinite;
  text-shadow: 0 0 32px var(--hero-title-glow);
  transition: background var(--transition);
}

@keyframes hero-title-shimmer {
  0%, 100% { background-position: 100% 50%; }
  50% { background-position: 0% 50%; }
}

.hero-subtitle {
  font-size: 1.35rem;
  color: var(--hero-label);
  font-weight: 500;
  margin-bottom: 1.25rem;
  transition: color var(--transition);
}

.hero-desc {
  max-width: 520px;
  font-size: 1.05rem;
  opacity: 0.9;
  margin-bottom: 2rem;
  color: var(--hero-text);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-family: var(--font);
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius);
  transition: all var(--transition);
  cursor: pointer;
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--accent);
  color: var(--dark);
}

.btn-primary:hover {
  background: #6fa8ab;
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
}

.btn-outline {
  background: transparent;
  color: var(--light);
  border-color: rgba(243, 244, 244, 0.4);
}

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

.hero .btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.hero-scroll {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8rem;
  color: var(--hero-scroll);
  transition: color var(--transition);
}

.scroll-indicator {
  width: 24px;
  height: 40px;
  border: 2px solid var(--hero-scroll-border);
  border-radius: 12px;
  position: relative;
  transition: border-color var(--transition);
}

.scroll-indicator::after {
  content: '';
  position: absolute;
  top: 6px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 8px;
  background: var(--accent);
  border-radius: 2px;
  animation: scroll-bounce 2s ease-in-out infinite;
}

@keyframes scroll-bounce {
  0%, 100% { opacity: 1; transform: translateX(-50%) translateY(0); }
  50% { opacity: 0.5; transform: translateX(-50%) translateY(8px); }
}

/* ===== Sections ===== */
.section {
  padding: 5rem 0;
}

.section-alt {
  background: var(--bg-section-alt);
  box-shadow: inset 0 1px 0 rgba(6, 30, 41, 0.06);
  transition: background var(--transition);
}

[data-theme="dark"] .section-alt {
  box-shadow: inset 0 1px 0 rgba(95, 149, 152, 0.08);
}

.section-title {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 2.5rem;
  letter-spacing: -0.02em;
}

/* ===== About ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: start;
}

.about-text p {
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.about-lead {
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.about-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 1.5rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.about-code {
  background: var(--about-code-bg);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  overflow-x: auto;
  box-shadow: var(--shadow);
}

.about-code pre {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--about-code-text);
  transition: color var(--transition);
}

.code-key { color: var(--code-key); }
.code-class { color: var(--code-class); }
.code-fn { color: var(--code-fn); }
.code-var { color: var(--code-var); }
.code-str { color: var(--code-str); }

/* ===== Skills (kart + çerçeve animasyonu) ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.skill-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition), background var(--transition), border-color var(--transition);
}

.skill-card::before {
  content: '';
  position: absolute;
  inset: -2px;
  background: conic-gradient(from 0deg, var(--accent), var(--medium), var(--accent), var(--medium));
  border-radius: inherit;
  z-index: 0;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.skill-card::after {
  content: '';
  position: absolute;
  inset: 2px;
  background: var(--bg-card);
  border-radius: calc(var(--radius-lg) - 2px);
  z-index: 1;
  transition: background var(--transition);
}

.skill-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-4px);
}

.skill-card:hover::before {
  opacity: 1;
  animation: card-border-spin 2.5s linear infinite;
}

.skill-card > * {
  position: relative;
  z-index: 2;
}

.skill-category {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent);
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.skill-tags li {
  background: var(--tag-bg);
  color: var(--text-primary);
  padding: 0.35rem 0.75rem;
  border-radius: 6px;
  font-size: 0.85rem;
  font-weight: 500;
}

/* ===== Experience (Timeline) ===== */
.timeline {
  position: relative;
  max-width: 640px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 12px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--accent), var(--medium));
  border-radius: 2px;
}

.timeline-heading {
  font-size: 0.95rem;
  font-weight: 600;
  margin: 1.5rem 0 0.75rem 3rem;
  padding-bottom: 0.25rem;
}
.timeline-heading:first-child {
  margin-top: 0;
}

.timeline-item {
  position: relative;
  padding-left: 3rem;
  padding-bottom: 2.5rem;
}

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

.timeline-marker {
  position: absolute;
  left: 0;
  top: 0.25rem;
  width: 26px;
  height: 26px;
  background: var(--medium);
  border: 4px solid var(--timeline-marker-border);
  border-radius: 50%;
  box-shadow: var(--shadow);
}

.timeline-content h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.2rem;
}

.timeline-content h4 {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.timeline-date {
  display: inline-block;
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.timeline-content p {
  font-size: 0.95rem;
  color: var(--text-primary);
  opacity: 0.9;
}

.timeline-heading {
  color: var(--text-secondary);
}

/* ===== Projects (kart + çerçeve animasyonu) ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.project-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition), background var(--transition), border-color var(--transition);
}

.project-card::before {
  content: '';
  position: absolute;
  inset: -2px;
  background: conic-gradient(from 0deg, var(--accent), var(--medium), var(--accent), var(--medium));
  border-radius: inherit;
  z-index: 0;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.project-card::after {
  content: '';
  position: absolute;
  inset: 2px;
  background: var(--bg-card);
  border-radius: calc(var(--radius-lg) - 2px);
  z-index: 1;
  transition: background var(--transition);
}

.project-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-4px);
}

.project-card:hover::before {
  opacity: 1;
  animation: card-border-spin 2.5s linear infinite;
}

/* Işık geçişi (shine) animasyonu – hover’da kart üzerinden geçer */
.card-shine {
  position: absolute;
  inset: 0;
  z-index: 3;
  pointer-events: none;
  border-radius: inherit;
  background: linear-gradient(
    105deg,
    transparent 0%,
    transparent 40%,
    rgba(255, 255, 255, 0.4) 45%,
    var(--card-shine-highlight) 50%,
    rgba(255, 255, 255, 0.3) 55%,
    transparent 60%,
    transparent 100%
  );
  background-size: 200% 100%;
  background-position: 150% 0;
  transition: background-position 0.6s ease;
}

.project-card:hover .card-shine {
  background-position: -50% 0;
}

.project-card > * {
  position: relative;
  z-index: 2;
}

.project-card-wide {
  grid-column: 1 / -1;
}

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 0.75rem;
}

.project-header h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
}

.project-year {
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 600;
  white-space: nowrap;
}

.project-card p {
  font-size: 0.95rem;
  color: var(--text-primary);
  margin-bottom: 1rem;
  flex-grow: 1;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1rem;
}

.project-tags li {
  font-size: 0.75rem;
  padding: 0.25rem 0.6rem;
  background: var(--tag-bg-muted);
  color: var(--text-secondary);
  border-radius: 4px;
}

.project-link {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--accent);
  margin-top: auto;
}

.project-link:hover {
  color: var(--text-secondary);
}

/* ===== Achievements (card + frame animation) ===== */
.achievements-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}

.achievement-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition), background var(--transition), border-color var(--transition);
}

.achievement-card::before {
  content: '';
  position: absolute;
  inset: -2px;
  background: conic-gradient(from 0deg, var(--accent), var(--medium), var(--accent), var(--medium));
  border-radius: inherit;
  z-index: 0;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.achievement-card::after {
  content: '';
  position: absolute;
  inset: 2px;
  background: var(--bg-card);
  border-radius: calc(var(--radius-lg) - 2px);
  z-index: 1;
  transition: background var(--transition);
}

.achievement-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-4px);
}

.achievement-card:hover::before {
  opacity: 1;
  animation: card-border-spin 2.5s linear infinite;
}

.achievement-card > * {
  position: relative;
  z-index: 2;
}

.achievement-icon {
  font-size: 2rem;
  display: block;
  margin-bottom: 0.75rem;
}

.achievement-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}

.achievement-card p {
  font-size: 0.95rem;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.achievement-card p:last-child {
  margin-bottom: 0;
}

/* ===== Contact / CTA (theme-aware) ===== */
.section-cta {
  background: var(--contact-bg);
  color: var(--contact-text);
  transition: background var(--transition), color var(--transition);
}

.section-cta .section-title {
  color: var(--contact-text);
}

.section-cta .container {
  max-width: 640px;
}

.contact-card {
  position: relative;
  background: var(--contact-card-bg);
  border: 1px solid var(--contact-card-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition), background var(--transition), border-color var(--transition);
}

.contact-card::before {
  content: '';
  position: absolute;
  inset: -2px;
  background: conic-gradient(from 0deg, var(--accent), var(--medium), var(--accent), var(--medium));
  border-radius: inherit;
  z-index: 0;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.contact-card::after {
  content: '';
  position: absolute;
  inset: 2px;
  background: var(--contact-card-inner);
  border-radius: calc(var(--radius-lg) - 2px);
  z-index: 1;
  transition: background var(--transition);
}

.contact-card:hover {
  box-shadow: 0 0 32px rgba(95, 149, 152, 0.2);
  transform: translateY(-2px);
}

.contact-card:hover::before {
  opacity: 1;
  animation: card-border-spin 2.5s linear infinite;
}

.contact-card .contact-lead,
.contact-card .contact-actions {
  position: relative;
  z-index: 2;
}

.contact-lead {
  max-width: 100%;
  margin-bottom: 2rem;
  opacity: 0.95;
  color: var(--contact-text);
}

.contact-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.section-cta .btn-primary {
  background: var(--accent);
  color: #061E29;
}

.section-cta .btn-outline {
  color: var(--contact-text);
  border-color: var(--contact-btn-outline);
  transition: border-color var(--transition), color var(--transition);
}

.section-cta .btn-outline:hover {
  border-color: var(--contact-btn-outline-hover);
  color: var(--contact-btn-outline-hover);
}

.contact-note {
  font-size: 0.85rem;
  opacity: 0.8;
  color: var(--contact-text);
}

.contact-note code {
  background: var(--contact-note-code-bg);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  font-family: var(--font-mono);
  color: var(--contact-text);
}

/* ===== Proje detay modal (açılır pencere) ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  background: rgba(6, 30, 41, 0.75);
  backdrop-filter: blur(6px);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.modal-overlay.is-open {
  opacity: 1;
  visibility: visible;
}

.modal-window {
  position: relative;
  width: 100%;
  max-width: 520px;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  background: var(--modal-bg);
  border-radius: var(--radius-lg);
  box-shadow: 0 24px 48px rgba(6, 30, 41, 0.25), 0 0 0 1px rgba(95, 149, 152, 0.2);
  transform: scale(0.95) translateY(10px);
  transition: transform 0.3s ease, background var(--transition);
  overflow: hidden;
}

.modal-overlay.is-open .modal-window {
  transform: scale(1) translateY(0);
}

.modal-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem 1.5rem;
  background: linear-gradient(135deg, var(--medium) 0%, var(--dark) 100%);
  color: var(--light);
}

.modal-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0;
  color: var(--light);
}

.modal-year {
  font-size: 0.85rem;
  color: var(--accent);
  font-weight: 600;
  flex-shrink: 0;
}

.modal-close {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  background: rgba(255, 255, 255, 0.15);
  border: none;
  border-radius: var(--radius);
  color: var(--light);
  font-size: 1.5rem;
  line-height: 1;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease;
}

.modal-close:hover {
  background: rgba(255, 255, 255, 0.25);
  color: var(--white);
}

.modal-body {
  padding: 1.5rem;
  overflow-y: auto;
  flex: 1;
  min-height: 0;
}

.modal-desc {
  margin: 0 0 1rem;
  font-size: 0.95rem;
  line-height: 1.65;
  color: var(--text-primary);
}

.modal-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin: 0;
  list-style: none;
}

.modal-tags li {
  font-size: 0.75rem;
  padding: 0.25rem 0.6rem;
  background: var(--tag-bg-muted);
  color: var(--text-secondary);
  border-radius: 4px;
}

.modal-footer {
  padding: 1rem 1.5rem;
  border-top: 1px solid var(--border-card);
  background: var(--modal-footer-bg);
  transition: background var(--transition), border-color var(--transition);
}

.modal-link {
  display: inline-flex;
}

/* Kart tıklanabilir görünsün */
.project-card[data-project] {
  cursor: pointer;
}

.project-card[data-project] .project-link {
  pointer-events: auto;
}

/* ===== Footer ===== */
.footer {
  background: var(--footer-bg);
  color: var(--footer-text);
  padding: 2rem 0;
  font-size: 0.9rem;
  transition: background var(--transition), color var(--transition);
}

.footer .container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

.footer-links a {
  color: var(--footer-text);
  transition: color var(--transition);
}

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

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 4rem;
    right: -100%;
    width: 80%;
    max-width: 320px;
    height: calc(100vh - 4rem);
    background: var(--header-bg);
    flex-direction: column;
    align-items: flex-start;
    padding: 2rem;
    gap: 1rem;
    transition: right var(--transition);
    border-left: 1px solid rgba(95, 149, 152, 0.2);
  }

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

  .nav-menu {
    border-left: 1px solid var(--header-border);
  }

  .nav-toggle {
    display: flex;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }

  .about-code {
    order: -1;
  }

  .timeline::before {
    left: 8px;
  }

  .timeline-marker {
    width: 18px;
    height: 18px;
    left: -1px;
  }

  .timeline-item {
    padding-left: 2.5rem;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  .contact-actions {
    flex-direction: column;
  }

  .contact-actions .btn {
    width: 100%;
  }
}