:root {
  --color-text: #333333;
  --color-text-muted: #6c6c6c;
  --color-heading: #222222;
  --color-bg: #ffffff;
  --color-surface: #f5f5f5;
  --color-accent: #4f46e5;
  --color-accent-hover: #3730a3;

  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;

  --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.15);

  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 3rem;
  --space-xl: 5rem;

  --transition: 0.2s ease;
}

* {
  box-sizing: border-box;
}

html {
  background-color: #ffffff;
  scroll-behavior: smooth;
}

body {
  color: var(--color-text);
  background-color: var(--color-bg);
  font-family: 'Montserrat', sans-serif;
  margin: 0;
}

.hero {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: var(--space-sm);
  background-image:
    linear-gradient(to bottom, rgba(255, 255, 255, 0) 90%, #ffffff 100%),
    repeating-linear-gradient(
      90deg,
      #61ff61 0%,
      #61ff61 16.66%,
      #ff61ff 16.66%,
      #ff61ff 33.33%,
      #8b00ff 33.33%,
      #8b00ff 50%,
      #ff2525 50%,
      #ff2525 66.66%,
      #ff7f00 66.66%,
      #ff7f00 83.33%,
      #0000ff 83.33%,
      #0000ff 100%
    );
}

.hero-content {
  background-color: var(--color-bg);
  padding: var(--space-lg) clamp(var(--space-md), 6vw, var(--space-xl));
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  text-align: center;
  max-width: min(640px, 100%);
}

.hero-logo {
  display: block;
  width: min(400px, 100%);
  height: auto;
  margin: 0 auto;
}

.hero-content h1 {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-heading);
  margin: 0 0 var(--space-sm) 0;
}

.hero-content p {
  font-size: 1.2rem;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-md) 0;
}

section {
  padding: var(--space-xl) var(--space-sm);
}

.title {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--color-heading);
  text-align: center;
  max-width: 40rem;
  margin: 0 auto var(--space-xs) auto;
  margin-top: 5rem;
}

.subtitle {
  color: var(--color-text-muted);
  font-size: 1rem;
  text-align: center;
  margin: 0 auto var(--space-md) auto;
}

.cta-button {
  display: inline-block;
  background-color: var(--color-accent);
  color: var(--color-bg);
  border: none;
  padding: 0.75rem 2rem;
  font-size: 1rem;
  font-weight: bold;
  border-radius: var(--radius-sm);
  font-family: inherit;
  cursor: pointer;
  text-decoration: none;
  transition: background-color var(--transition);
}

.cta-button:hover {
  background-color: var(--color-accent-hover);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-sm);
  max-width: 60rem;
  margin: 0 auto;
  scroll-margin-top: 5rem;
}

.card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  padding: var(--space-md);
  text-align: center;
  text-decoration: none;
  color: inherit;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition);
}

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

.card h3 {
  margin: 0;
  color: var(--color-heading);
}

.card p {
  margin: 0;
  color: var(--color-text-muted);
}

.sub-subtitle {
  text-align: center;
}

.navbar {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: var(--space-sm) var(--space-md);
  width: 100%;
  background-color: #222222;
  padding: var(--space-sm) var(--space-md);
  box-shadow: var(--shadow-sm);
}

.navbar a {
  color: #ffffff;
  text-decoration: none;
  font-weight: 700;
  font-size: 0.95rem;
  white-space: nowrap;
  opacity: 0.85;
  transition: opacity var(--transition);
}

.navbar a:hover {
  opacity: 1;
}

.navbar-logo {
  display: flex;
  align-items: center;
  opacity: 1;
}

.navbar-logo img {
  height: 28px;
  width: auto;
  display: block;
}

.navbar.navbar-scroll {
  position: fixed;
  top: 0;
  left: 0;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-100%);
  transition: all 0.3s ease-in-out;
}

.navbar.navbar-scroll.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.about {
  background-color: var(--color-surface);
}

.about .title {
  margin-top: 0;
}

.about .subtitle {
  max-width: 40rem;
  margin-left: auto;
  margin-right: auto;
}

.site-footer {
  text-align: center;
  padding: var(--space-md) var(--space-sm);
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.site-footer p {
  margin: 0.25rem 0;
}

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

.hidden {
  display: none !important;
}

.navbar-auth {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-left: auto;
}

.nav-btn {
  background-color: var(--color-accent);
  color: #ffffff;
  border: none;
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
  font-weight: 700;
  font-family: inherit;
  white-space: nowrap;
  border-radius: var(--radius-sm);
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
  opacity: 1;
  transition: background-color var(--transition);
}

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

.profile-container {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  color: #ffffff;
  font-weight: 700;
  font-size: 0.9rem;
}

.avatar {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--color-accent);
  color: #ffffff;
  font-size: 0.85rem;
  font-weight: 700;
  flex-shrink: 0;
}

.auth-section {
  display: flex;
  justify-content: center;
  padding: var(--space-xl) var(--space-sm);
}

.auth-card {
  display: flex;
  flex-direction: column;
  width: 100%;
  max-width: 24rem;
  background-color: var(--color-bg);
  padding: var(--space-lg) var(--space-md);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.auth-title {
  margin-top: 0;
}

.form-label {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--color-heading);
  margin: var(--space-sm) 0 var(--space-xs) 0;
}

.form-input {
  font-family: inherit;
  font-size: 1rem;
  padding: 0.6rem 0.75rem;
  border: 1px solid #d5d5d5;
  border-radius: var(--radius-sm);
}

.form-input:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 1px;
}

.form-error {
  background-color: #fdecea;
  color: #b3261e;
  border-radius: var(--radius-sm);
  padding: 0.6rem 0.75rem;
  font-size: 0.9rem;
}

.auth-submit {
  margin-top: var(--space-md);
  width: 100%;
}

.auth-switch {
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  margin: var(--space-md) 0 0 0;
}

.auth-switch a {
  color: var(--color-accent);
}

.page-back {
  text-align: center;
  margin: var(--space-md) 0 var(--space-xl);
}

.choice-field {
  border: 0;
  margin: var(--space-sm) 0 0;
  padding: 0;
  min-width: 0;
}

.choice-field .form-label {
  display: block;
  float: left;
  width: 100%;
  margin-top: 0;
  padding: 0;
}

.choice-group {
  clear: both;
}

.choice-group {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xs);
}

.choice input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.choice span {
  display: block;
  padding: 0.6rem 0.5rem;
  border: 1px solid #d5d5d5;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-size: 0.9rem;
  font-weight: 700;
  text-align: center;
  cursor: pointer;
  transition: background-color var(--transition), border-color var(--transition), color var(--transition);
}

.choice span:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.choice input:checked + span {
  border-color: var(--color-accent);
  background-color: var(--color-accent);
  color: #ffffff;
}

.choice input:focus-visible + span {
  outline: 2px solid var(--color-accent);
  outline-offset: 1px;
}