* {
  box-sizing: border-box;
}


:root {
  --font-main: Inter, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;

  /* Dark mode (default) */
  --bg-gradient: linear-gradient(135deg, #12351d 0%, #142c1b 45%, #101713 100%);
  --header-bg: #4caf50;
  --text-primary: #f3faf5;
  --text-secondary: #d7e6dc;
  --primary-green: #4caf50;
  --primary-green-bright: #5fce63;
  --dark-green: #0c5f30;
  --button-text: #ffffff;
  --toggle-bg: rgba(255, 255, 255, 0.08);
  --toggle-bg-hover: rgba(255, 255, 255, 0.16);
  --toggle-icon: #eafbee;
  --focus-ring: #7fe58a;
  --glow-strong: rgba(76, 175, 80, 0.35);
  --glow-soft: rgba(76, 175, 80, 0.15);
  --card-shadow: rgba(0, 0, 0, 0.35);
}

[data-theme="light"] {
  --bg-gradient: linear-gradient(135deg, #f4faf4 0%, #eef7ee 50%, #eaf4ea 100%);
  --header-bg: #4caf50;
  --text-primary: #132218;
  --text-secondary: #2c4a34;
  --primary-green: #4caf50;
  --primary-green-bright: #3f9c43;
  --dark-green: #087f3f;
  --button-text: #ffffff;
  --toggle-bg: rgba(255, 255, 255, 0.35);
  --toggle-bg-hover: rgba(255, 255, 255, 0.55);
  --toggle-icon: #ffffff;
  --focus-ring: #087f3f;
  --glow-strong: rgba(76, 175, 80, 0.18);
  --glow-soft: rgba(76, 175, 80, 0.08);
  --card-shadow: rgba(20, 60, 30, 0.12);
}

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  overflow: hidden;
}

body {
  font-family: var(--font-main);
  background: var(--bg-gradient);
  color: var(--text-primary);
  height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background 300ms ease, color 300ms ease;
}

a {
  text-decoration: none;
  color: inherit;
}

button {
  font-family: inherit;
}

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

/* ---------- Header ---------- */

.site-header {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
  padding: 0 48px;
  background: var(--header-bg);
  transition: background 300ms ease;
}

.brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-logo {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: block;
}

.brand-name {
  font-size: 22px;
  font-weight: 700;
  color: #ffffff;
  letter-spacing: -0.01em;
}

[data-theme="light"] .brand-name {
  color: #ffffff;
}

.theme-toggle {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: none;
  background: var(--toggle-bg);
  color: var(--toggle-icon);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 200ms ease, transform 200ms ease;
}

.theme-toggle:hover {
  background: var(--toggle-bg-hover);
  transform: translateY(-1px);
}

.theme-toggle:active {
  transform: translateY(0);
}

.theme-toggle .icon {
  width: 26px;
  height: 26px;
}

.icon-moon { display: none; }
.icon-sun { display: block; }

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

/* ---------- Hero / Main content ---------- */

.hero {
  flex: 1;
  min-height: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px 24px;
  position: relative;
}

.hero::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 640px;
  height: 640px;
  transform: translate(-50%, -50%);
  background: radial-gradient(circle, var(--glow-soft) 0%, rgba(0, 0, 0, 0) 70%);
  pointer-events: none;
  z-index: 0;
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  max-width: 720px;
}

.hero-logo {
  width: 130px;
  height: 130px;
  border: 6px solid var(--primary-green);
  border-radius: 50%;
  box-shadow: 0 0 20px var(--glow-strong), 0 0 45px var(--glow-soft);
  transition: box-shadow 300ms ease;
}

.hero-title {
  margin: 20px 0 0 0;
  font-size: 46px;
  font-weight: 800;
  color: var(--primary-green-bright);
  letter-spacing: -0.02em;
}

.hero-subtitle {
  margin: 14px 0 0 0;
  font-size: 22px;
  font-weight: 400;
  color: var(--text-secondary);
  max-width: 34ch;
  line-height: 1.4;
}

/* ---------- Portfolio buttons ---------- */

.portfolio-buttons {
  margin-top: 32px;
  display: flex;
  flex-direction: row;
  gap: 20px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  font-weight: 700;
  font-size: 16px;
  color: var(--button-text);
  cursor: pointer;
  transition: background 200ms ease, box-shadow 200ms ease, transform 200ms ease;
}

.btn-portfolio {
  width: 250px;
  height: 60px;
  background: var(--primary-green);
  box-shadow: 0 8px 24px var(--glow-strong);
}

.btn-portfolio:hover {
  background: var(--primary-green-bright);
  box-shadow: 0 10px 30px var(--glow-strong), 0 0 30px var(--glow-soft);
  transform: translateY(-2px);
}

.btn-portfolio:active {
  transform: translateY(0);
  box-shadow: 0 4px 14px var(--glow-strong);
}

/* ---------- Footer ---------- */

.site-footer {
  flex-shrink: 0;
  background: var(--header-bg);
  padding: 14px 24px;
  text-align: center;
  transition: background 300ms ease;
}

.site-footer p {
  margin: 0;
  font-size: 13px;
  font-weight: 600;
  color: #ffffff;
  opacity: 0.9;
}

/* ---------- Responsive ---------- */

@media (max-width: 768px) {
  .site-header {
    height: 72px;
    padding: 0 20px;
  }

  .brand-logo {
    width: 36px;
    height: 36px;
  }

  .brand-name {
    font-size: 18px;
  }

  .theme-toggle {
    width: 46px;
    height: 46px;
  }

  .theme-toggle .icon {
    width: 22px;
    height: 22px;
  }

  .hero {
    padding: 20px 20px;
  }

  .hero-logo {
    width: 90px;
    height: 90px;
  }

  .hero-title {
    font-size: 32px;
    margin-top: 14px;
  }

  .hero-subtitle {
    font-size: 16px;
    margin-top: 10px;
  }

  .portfolio-buttons {
    flex-direction: column;
    width: 100%;
    margin-top: 20px;
    gap: 12px;
  }

  .btn-portfolio {
    width: 100%;
    height: 52px;
    font-size: 15px;
  }
}

@media (max-width: 375px) {
  .hero-title {
    font-size: 26px;
  }

  .hero-subtitle {
    font-size: 15px;
  }

  .hero-logo {
    width: 76px;
    height: 76px;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
  }
}