/* ===== CSS Variables ===== */
:root {
  --bg-primary: #0f1115;
  --bg-secondary: #161b22;
  --bg-tertiary: #1e232b;
  --text-primary: #f0f2f5;
  --text-secondary: #9ca3af;
  --accent: #84a98c;
  --accent-hover: #9dbba4;
  --border: rgba(255, 255, 255, 0.08);
  --radius: 0.75rem;
  --max-width: 960px;
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 3rem;
  --spacing-xl: 5rem;
  --font-body: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --transition: 0.2s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

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

ul,
ol {
  list-style: none;
}

button {
  font-family: inherit;
}

/* ===== Utilities ===== */
.container {
  width: min(100% - 2rem, var(--max-width));
  margin-inline: auto;
}

.section {
  padding-block: var(--spacing-xl);
}

.section-label {
  color: var(--accent);
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-xs);
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: var(--spacing-lg);
}

/* ===== Header & Navigation ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(15, 17, 21, 0.85);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(100% - 2rem, var(--max-width));
  margin-inline: auto;
  padding-block: var(--spacing-sm);
}

.nav-logo {
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text-primary);
}

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

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
}

.nav-menu {
  display: flex;
  gap: var(--spacing-md);
  margin-left: auto;
}

.nav-link {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  font-weight: 500;
}

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

/* ===== Language Switcher ===== */
.lang-switcher {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  margin-left: var(--spacing-md);
  flex-shrink: 0;
}

.lang-btn {
  background: none;
  border: 1px solid transparent;
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-weight: 700;
  width: 2.75rem;
  height: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  border-radius: var(--radius);
  cursor: pointer;
  transition: color var(--transition), border-color var(--transition), background-color var(--transition);
}

.lang-btn svg {
  display: block;
  width: 1.5rem;
  height: 1rem;
  border-radius: 0.125rem;
}

.lang-btn:hover {
  color: var(--text-primary);
}

.lang-btn.is-active {
  color: var(--accent);
  border-color: var(--accent);
  background-color: rgba(132, 169, 140, 0.1);
}

@media (max-width: 640px) {
  .nav-toggle {
    display: block;
    margin-left: auto;
  }

  .nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    margin-left: 0;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    padding: var(--spacing-md);
    gap: var(--spacing-sm);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition);
  }

  .nav-menu.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
}

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--spacing-xl) var(--spacing-sm);
  position: relative;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(to right, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.02) 1px, transparent 1px),
    linear-gradient(to right, rgba(255, 255, 255, 0.045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.045) 1px, transparent 1px);
  background-size:
    48px 48px,
    48px 48px,
    144px 144px,
    144px 144px;
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(ellipse at center, transparent 0%, transparent 55%, var(--bg-primary) 100%),
    linear-gradient(to bottom, transparent 0%, transparent 75%, var(--bg-primary) 100%);
  pointer-events: none;
}

.hero-greeting {
  color: var(--accent);
  font-size: 1rem;
  font-weight: 500;
  margin-bottom: var(--spacing-xs);
}

.hero-title {
  font-size: clamp(2.5rem, 8vw, 4rem);
  font-weight: 800;
  margin-bottom: var(--spacing-sm);
  line-height: 1.1;
}

.hero-tagline {
  color: var(--text-secondary);
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  max-width: 560px;
  margin-bottom: var(--spacing-md);
}

.hero-actions {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
  justify-content: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.9375rem;
  transition: transform var(--transition), background-color var(--transition), color var(--transition);
}

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

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

.btn-secondary {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
}

.btn:hover {
  transform: translateY(-2px);
}

/* ===== Reveal on Scroll ===== */
.reveal {
  opacity: 0;
  transform: translateY(60px) scale(0.96);
  filter: blur(4px);
  transition: opacity 0.8s ease, transform 0.8s ease, filter 0.8s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
  filter: blur(0);
}

.projects-grid .reveal:nth-child(1).is-visible { transition-delay: 0ms; }
.projects-grid .reveal:nth-child(2).is-visible { transition-delay: 120ms; }
.projects-grid .reveal:nth-child(3).is-visible { transition-delay: 240ms; }

.skills-grid .reveal:nth-child(1).is-visible { transition-delay: 0ms; }
.skills-grid .reveal:nth-child(2).is-visible { transition-delay: 120ms; }
.skills-grid .reveal:nth-child(3).is-visible { transition-delay: 240ms; }
.skills-grid .reveal:nth-child(4).is-visible { transition-delay: 360ms; }

@media (prefers-reduced-motion: reduce) {
  .reveal {
    transition: none;
  }
}

/* ===== Projects ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-md);
}

.card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--spacing-md);
  transition: transform var(--transition), border-color var(--transition);
}

.card:hover {
  transform: translateY(-4px);
  border-color: rgba(132, 169, 140, 0.3);
}

.card-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: var(--spacing-xs);
  color: var(--text-primary);
}

.card-text {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  margin-bottom: var(--spacing-sm);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: var(--spacing-md);
}

.card .tag-list {
  margin-top: var(--spacing-sm);
}

.tag {
  background-color: var(--bg-tertiary);
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.625rem;
  border-radius: 9999px;
}

.card-links {
  display: flex;
  gap: var(--spacing-sm);
  font-size: 0.875rem;
  font-weight: 600;
}

.card-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

/* ===== Skills ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--spacing-md);
}

.skill-group {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--spacing-md);
  transition: transform var(--transition), border-color var(--transition);
}

.skill-group:hover {
  transform: translateY(-4px);
  border-color: rgba(132, 169, 140, 0.3);
}

.skill-group-title {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.0625rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

.skill-group-title i {
  color: var(--accent);
  font-size: 1.25rem;
}

.skill-list {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
}

.skill-list li {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  position: relative;
  padding-left: 1rem;
}

.skill-list li::before {
  content: "›";
  position: absolute;
  left: 0;
  color: var(--accent);
}

/* ===== Contact ===== */
.contact-text {
  color: var(--text-secondary);
  max-width: 560px;
  margin-bottom: var(--spacing-md);
}

.contact-links {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-secondary);
  background-color: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--spacing-sm) var(--spacing-md);
  width: fit-content;
  transition: transform var(--transition), border-color var(--transition), color var(--transition);
}

.contact-link:hover {
  color: var(--accent);
  border-color: rgba(132, 169, 140, 0.3);
  transform: translateX(4px);
}

.contact-link i {
  font-size: 1.25rem;
  color: var(--accent);
}

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--border);
  padding-block: var(--spacing-md);
  text-align: center;
}

.footer-text {
  color: var(--text-secondary);
  font-size: 0.875rem;
}

/* ===== Back to Top ===== */
.back-to-top {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 50%;
  background-color: var(--accent);
  color: var(--bg-primary);
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition), visibility var(--transition), transform var(--transition);
  z-index: 50;
}

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

.back-to-top:hover {
  background-color: var(--accent-hover);
  transform: translateY(-2px);
}