* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
html, body {
  height: 100%;
}
body {
  font-family: 'Rubik', sans-serif;
  background: linear-gradient(to bottom right, #0f0f0f, #1a1a1a);
  color: #ffffff;
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 15px 30px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.4);
  flex-wrap: wrap;
}

.logo {
  flex: 1 1 0;
  display: flex;
  justify-content: center;
  align-items: center;
}

.logo img {
  width: 60px;
  height: 60px;
  object-fit: cover;
}

h2 {
  color: var(--main-accent);
  margin-bottom: 15px;
  text-align: center;
}

input, textarea {
  width: 100%;
  max-width: 600px;
  padding: 10px;
  margin-bottom: 15px;
  border-radius: 10px;
  border: none;
  font-size: 1em;
}

button {
  width: 100%;
  max-width: 600px;
  padding: 12px;
  background: var(--main-accent);
  color: #000;
  border: none;
  border-radius: 10px;
  font-weight: bold;
  cursor: pointer;
  font-size: 1em;
  transition: background 0.3s ease;
}

button:hover {
  background: #baff2f;
}

.error {
  color: red;
  text-align: center;
}

.nav-burger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  position: absolute;
  right: 30px;
  top: 50%;
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  background: var(--main-buttons);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  z-index: 1101;
  font-size: 0;
}

.nav-burger span {
  display: block;
  width: 20px;
  height: 3px;
  background: var(--main-text);
  border-radius: 2px;
  transition: 0.3s;
  position: relative;
  margin: 0;
}

.nav-burger span:not(:last-child) {
  margin-bottom: 6px;
}

.nav-burger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

nav {
  flex: 2 1 0;
  display: flex;
  justify-content: center;
  align-items: center;
}

nav ul {
  display: flex;
  flex-wrap: wrap;
  list-style: none;
  gap: 25px;
  justify-content: center;
  align-items: center;
  margin: 0;
  padding: 0;
  background: none;
  position: static;
}

nav a,
nav button#auth-btn {
  text-decoration: none;
  color: var(--main-accent);
  font-weight: bold;
  font-size: 1.1em;
  transition: color 0.3s ease, text-shadow 0.3s ease;
  background: none;
  border: none;
  cursor: pointer;
  font-family: inherit;
  display: flex;
  align-items: center;
  height: 100%;
  padding: 0 6px;
}
nav a:hover,
nav button#auth-btn:hover {
  color: #ffffff;
  text-shadow: 0 0 10px var(--main-accent);
}

main {
  flex: 1 0 auto;
  padding: 20px;
}

footer {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  padding: 32px 12px 24px 12px;
  background: #111;
  color: var(--main-accent);
  box-shadow: 0 -4px 20px rgba(0,0,0,0.4);
  font-size: 1em;
  min-height: 120px;
  gap: 18px;
  width: 100vw;
  max-width: 100vw;
  text-align: center;
}

.contact {
  width: 50%;
  min-width: 0;
  text-align: left;
  margin-bottom: 10px;
}

.contact h3 {
  color: var(--main-accent);
  margin-bottom: 10px;
}

.social-buttons {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 16px;
  width: auto;
  margin: 0 auto;
  padding: 0;
}

.social-buttons button {
  font-size: 0.98em;
  gap: 8px;
  padding: 0 18px;
  min-width: 120px;
  max-width: 180px;
  width: auto;
  height: 48px;
  border-radius: 24px;
  background: #2e2e2e;
  border: none;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0;
  box-shadow: none;
  transition: background 0.2s;
  cursor: pointer;
  color: var(--main-accent);
  font-weight: 400;
  letter-spacing: 0.01em;
  line-height: 1;
  white-space: nowrap;
}
.social-buttons button span {
  font-size: 0.97em;
  font-weight: 400;
  letter-spacing: 0.01em;
  margin-left: 8px;
  color: #fff;
  white-space: nowrap;
  line-height: 1;
  display: inline;
  vertical-align: middle;
}

@media (max-width: 800px) {
  .social-buttons button span {
    display: none !important;
  }
}

.social-buttons button img,
.social-buttons button svg {
  width: 28px;
  height: 28px;
  display: inline-block;
  vertical-align: middle;
}

@media (max-width: 800px) {
  footer {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-end;
    padding: 24px 0 36px 0;
    background: #181c1f;
    color: var(--main-accent);
    box-shadow: 0 -4px 20px rgba(0,0,0,0.4);
    min-height: 200px;
    width: 100vw;
    max-width: 100vw;
    text-align: center;
    gap: 10px;
    overflow: hidden;
  }
  .contact {
    width: 100%;
    text-align: center;
    margin-bottom: 18px;
  }
  .social-buttons {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    gap: 18px;
    width: 100%;
    margin: 0 auto;
    padding: 0;
    box-sizing: border-box;
  }
  .social-buttons button {
    width: 48px;
    height: 48px;
    min-width: 48px;
    max-width: 48px;
    padding: 0;
    border-radius: 50%;
    font-size: 0 !important;
    gap: 0;
    color: transparent !important;
  }
  .social-buttons button img,
  .social-buttons button svg {
    width: 28px;
    height: 28px;
    display: block;
    font-size: initial !important;
    margin: 0 auto;
  }
  .social-buttons button::after,
  .social-buttons button span,
  .social-buttons button:not(:has(img)) {
    display: none !important;
  }
}

@media (max-width: 800px) {
  nav {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 60px;
    left: 0;
    width: 100vw;
    background: #181c1f;
    z-index: 1002;
    box-shadow: 0 8px 24px rgba(0,0,0,0.5);
    transition: max-height 0.3s, opacity 0.3s;
    max-height: 0;
    opacity: 0;
    pointer-events: none;
    overflow: hidden;
  }
  nav.open {
    display: flex;
    max-height: 400px;
    opacity: 1;
    pointer-events: auto;
    animation: navSlideDown 0.35s cubic-bezier(.4,1.4,.6,1) both;
  }
  nav ul {
    flex-direction: column;
    gap: 18px;
    align-items: center;
    padding: 18px 0;
    margin: 0;
  }
}

@media (max-width: 800px) {
  nav {
    display: none;
  }
  .nav-burger {
    display: inline !important;
  }
}

@media (min-width: 801px) {
  .nav-burger {
    display: none !important;
  }
  nav {
    display: flex !important;
  }
}

@keyframes navSlideDown {
  from {
    transform: translateY(-30px);
    opacity: 0;
  }
  to {
    transform: translateY(0);
    opacity: 1;
  }
}

.social-buttons button:hover {
  background: var(--main-accent);
  color: #23272b;
  transition: background 0.2s, color 0.2s;
  box-shadow: 0 0px 24px var(--main-accent);
}
.social-buttons button:hover span {
  color: var(--main-accent);
}
.social-buttons button:hover img,
.social-buttons button:hover svg {
  filter: brightness(0) saturate(100%) invert(17%) sepia(97%) saturate(749%) hue-rotate(67deg) brightness(102%) contrast(101%);
}

:root {
  --main-bg: #181c1f;
  --main-accent: #9fff00;
  --main-buttons:#2e2e2e;
  --main-text: #fff;
}

body.theme-spring {
  --main-accent: #00c427;
  --main-text: #1a3d1f;
}
body.theme-summer {
  --main-accent: #a32100;
  --main-text: #3d2e00;
}
body.theme-autumn {
  --main-accent: #ff9800;
  --main-text: #3d2200;
}
body.theme-winter {
  --main-accent: #00bfff;
  --main-text: #e3f0ff;
}

body {
  background: var(--main-bg);
  color: var(--main-accent);
}
header, footer {
  background: var(--main-bg);
  color: var(--main-accent);
}
header button{
  background: var(--main-buttons);
  color: var(--main-accent);
}
nav {
  background: var(--main-bg);
}
.social-buttons button,
button {
  background: var(--main-buttons);
  color: #fff;
}
.social-buttons button:hover,
button:hover {
  background: var(--main-buttons);
  color: var(--main-accent);
}
a, nav a, nav button#auth-btn {
  color: var(--main-accent);
}
a:hover, nav a:hover, nav button#auth-btn:hover {
  color: var(--main-accent);
  text-shadow: 0 0 10px var(--main-accent);
}
body.theme-animating::after {
  content: "";
  position: fixed;
  z-index: 9999;
  left: 0; top: 0; right: 0; bottom: 0;
  pointer-events: none;
  background: radial-gradient(circle at 50% 50%, var(--main-accent) 0%, transparent 70%);
  opacity: 0.7;
  animation: themeWave 0.8s cubic-bezier(.4,1.4,.6,1);
}
@keyframes themeWave {
  0% {
    opacity: 0.7;
    transform: scale(0.2);
    filter: blur(40px);
  }
  60% {
    opacity: 1;
    transform: scale(1.1);
    filter: blur(0px);
  }
  100% {
    opacity: 0;
    transform: scale(2.5);
    filter: blur(60px);
  }
}