:root {
  /* Colors */
  --color-bg-start: #ff0066;
  --color-bg-middle: #6600ff;
  --color-bg-end: #00ccff;
  --color-light: #ffffff;
  --color-dark: #121212;
  --color-text: #333333;
  --color-success-bg: #d4edda;
  --color-success-tx: #155724;
  --color-error-bg: #f8d7da;
  --color-error-tx: #721c24;

  /* Spacing */
  --spacer-sm: 0.5rem;
  --spacer: 1rem;
  --spacer-lg: 1.5rem;

  /* Typography */
  --font-family: 'Poppins', sans-serif;
  --font-size-base: 1rem;
  --font-size-lg: 1.25rem;
  --font-size-sm: 0.875rem;

  /* Border radius & shadows */
  --radius: 0.5rem;
  --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.15);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.2);

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-medium: 0.3s ease;
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
}
html, body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  color: var(--color-text);
  background: linear-gradient(135deg, var(--color-bg-start), var(--color-bg-middle), var(--color-bg-end));
  overflow-x: hidden;
}

body.page-vote .floating-buttons {
  display: none;
}

/* Loader Overlay */
.loader {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 1050;
}
.loader .spinner {
  width: 60px;
  height: 60px;
  border: 8px solid rgba(255, 255, 255, 0.3);
  border-top-color: var(--color-bg-middle);
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-bottom: var(--spacer);
}
.loader p {
  color: var(--color-light);
  font-size: var(--font-size-lg);
  margin: 0;
}
@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* Logo Utility */
.logo-btn {
  position: fixed;
  top: var(--spacer);
  left: var(--spacer);
  background: none;
  border: none;
  padding: var(--spacer-sm);
  cursor: pointer;
  z-index: 1002;
}
.logo-btn__img {
  display: block;
  margin: 0 auto;
  height: 1.5rem;
  width: auto;
  max-width: 2.5rem;
}
@media (max-width: 480px) {
  .logo-btn__img {
    max-width: 2rem;
  }
}

/* Floating Admin Buttons */
.floating-buttons {
  position: fixed;
  bottom: var(--spacer-lg);
  left: var(--spacer-lg);
  display: flex;
  gap: var(--spacer-sm);
  z-index: 1002;
}
.floating-btn,
.floating-logout {
  font-size: 1.5rem;
  background: var(--color-light);
  color: var(--color-dark);
  border-radius: 50%;
  width: 3rem;
  height: 3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast);
  text-decoration: none;
}
.floating-btn:hover,
.floating-logout:hover {
  transform: scale(1.1);
}

/* Flash Notifications */
.flash {
  position: fixed;
  top: calc(var(--spacer) + 4rem);
  left: 50%;
  transform: translateX(-50%) translateY(-10px);
  width: 100%;
  max-width: 600px;
  margin: 0 auto;
  padding: var(--spacer-sm) var(--spacer-lg);
  background: var(--color-light);
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  font-size: var(--font-size-sm);
  opacity: 0;
  transition: opacity var(--transition-medium), transform var(--transition-medium);
  z-index: 1003;
}
.flash-show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.flash-success {
  background-color: var(--color-success-bg);
  color: var(--color-success-tx);
}
.flash-error {
  background-color: var(--color-error-bg);
  color: var(--color-error-tx);
}
.flash-close {
  position: absolute;
  top: var(--spacer-sm);
  right: var(--spacer);
  background: none;
  border: none;
  font-size: var(--font-size-lg);
  cursor: pointer;
}

/* Forms & Inputs */
.form-group {
  margin-bottom: var(--spacer);
}
.form-control {
  width: 100%;
  padding: var(--spacer-sm) var(--spacer);
  font-size: var(--font-size-base);
  border: 1px solid #ccc;
  border-radius: var(--radius);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.form-control:focus {
  outline: none;
  border-color: var(--color-bg-middle);
  box-shadow: 0 0 0 3px rgba(102, 0, 255, 0.25);
}
::placeholder {
  color: #999;
}

/* Buttons */
.btn,
a.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacer-sm) var(--spacer-lg);
  font-size: var(--font-size-base);
  background-color: var(--color-bg-start);
  color: var(--color-light);
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  text-decoration: none;
  transition: background-color var(--transition-fast), transform 0.1s ease;
  outline: none;
  -webkit-tap-highlight-color: transparent;
}
.btn:hover,
.btn:focus,
a.btn:hover,
a.btn:focus {
  background-color: #e60053;
  transform: translateY(-2px);
}
.btn:active {
  transform: translateY(0);
}
.btn-block {
  display: block;
  width: 100%;
}

/* Full-screen Centering */
.full-screen-center {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: var(--spacer);
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacer);
}

/* Card */
.card {
  background-color: var(--color-light);
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  padding: var(--spacer-lg) var(--spacer);
  margin: var(--spacer-lg) auto;
  width: 90%;
  min-width: 280px;
  max-width: 600px;
  max-height: calc(100vh - 2 * var(--spacer-lg));
  overflow-y: auto;
}
.card img {
  display: block;
  margin: 0 auto var(--spacer-lg);
  max-width: 180px;
  width: auto;
  height: auto;
}
@media (max-width: 480px) {
  .card img {
    max-width: 140px;
  }
}
@media (min-width: 600px) {
  .card {
    width: 80%;
    min-width: 320px;
  }
}
@media (min-width: 768px) {
  .card {
    width: 70%;
    min-width: 400px;
  }
}
@media (min-width: 992px) {
  .card {
    width: 50%;
    min-width: 500px;
  }
}

/* Lists & Helpers */
.list-unstyled {
  list-style: none;
  margin: 0;
  padding: 0;
}
.text-center {
  text-align: center;
}
.mt-lg {
  margin-top: var(--spacer-lg);
}
.mb-lg {
  margin-bottom: var(--spacer-lg);
}

/* Error Message */
.error-message {
  display: block;
  margin: var(--spacer) 0;
  padding: var(--spacer-sm) var(--spacer);
  background-color: var(--color-error-bg);
  color: var(--color-error-tx);
  border: 1px solid #f5c6cb;
  border-radius: var(--radius);
  text-align: center;
  font-size: var(--font-size-base);
  font-weight: 500;
  animation: slideDownFade 0.4s ease-out;
}
@keyframes slideDownFade {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Concert List */
.concert-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.concert-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--color-light);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  padding: var(--spacer);
  margin-bottom: var(--spacer);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}
.concert-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}
.concert-info {
  flex: 1;
  overflow: hidden;
}
.concert-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-dark);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.concert-date {
  font-size: var(--font-size-sm);
  color: #666;
  margin-top: 0.25rem;
}
.concert-actions {
  display: flex;
  gap: var(--spacer-sm);
  margin-left: var(--spacer);
}
.action-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  background: var(--color-bg-start);
  color: var(--color-light);
  border: none;
  border-radius: 50%;
  font-size: 1.25rem;
  text-decoration: none;
  transition: background var(--transition-fast), transform var(--transition-fast);
}
.action-btn.live {
  background: var(--color-bg-middle);
}
.action-btn.manage {
  background: var(--color-bg-start);
}
.action-btn:hover {
  transform: scale(1.1);
  background: #cc0052;
}
@media (max-width: 600px) {
  .concert-item {
    flex-direction: column;
    align-items: stretch;
  }
  .concert-actions {
    justify-content: flex-end;
    margin-top: var(--spacer);
  }
}

/* Responsive tweaks */
@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacer-sm);
  }
  .btn {
    width: 100%;
    text-align: center;
  }
  .flash {
    top: 3rem;
  }
}