/* THEME VARIABLES */
:root {
  --color-bg: #0f1115;
  --color-bg-alt: #181c23;
  --color-surface: #232a33;
  --color-surface-alt: #2d3641;
  --color-border: #394555;
  --color-accent: #ffbb33;
  --color-accent-hover: #ffc955;
  --color-accent-fg: #2a2000;
  --color-danger: #ff4d4f;
  --color-success: #33d685;
  --color-warn: #f0b429;
  --color-text: #e6edf3;
  --color-text-muted: #a0afc1;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 14px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.35);
  --trans-fast: 120ms ease;
  --trans-slow: 260ms cubic-bezier(.4, .14, .3, 1);
  --font-stack: "Inter", "Segoe UI", "Arial", sans-serif;
  --grid-gap: 18px;
}

/* General body styling */
body {
  font-family: var(--font-stack);
  margin: 0;
  padding: 0 0 60px;
  box-sizing: border-box;
  background: radial-gradient(circle at 30% 20%, #16202b 0%, #0f1115 70%);
  color: var(--color-text);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

/* Headings */
h1 {
  font-size: clamp(1.9rem, 2.6vw, 2.4rem);
  text-align: center;
  color: var(--color-text);
  margin: 24px 0 10px;
  letter-spacing: 0.5px;
  font-weight: 600;
}

h1+a,
h1+div a {
  margin-top: 4px;
}

/* Available boards section */
a {
  color: var(--color-accent);
  text-decoration: none;
  display: inline-block;
  text-align: center;
  font-weight: 500;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  transition: var(--trans-fast);
}

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

/* Form section */
form {
  max-width: 860px;
  margin: 28px auto 0;
  padding: 34px 40px 42px;
  background: linear-gradient(145deg, var(--color-surface) 0%, var(--color-surface-alt) 100%);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

form:before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 85% -10%, rgba(255, 187, 51, 0.15), transparent 60%),
    radial-gradient(circle at -5% 110%, rgba(51, 214, 133, 0.12), transparent 65%);
  pointer-events: none;
}

/* Input labels */
label {
  display: block;
  font-weight: 500;
  margin-bottom: 6px;
  font-size: 0.9rem;
  letter-spacing: 0.5px;
  color: var(--color-text-muted);
}

/* Text input field */
input[type="text"] {
  width: 100%;
  padding: 14px 16px;
  margin: 0 0 24px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-alt);
  color: var(--color-text);
  border-radius: var(--radius-md);
  box-sizing: border-box;
  font-size: 0.95rem;
  transition: var(--trans-fast);
}

input[type="text"]:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 2px rgba(255, 187, 51, 0.25);
}

/* Options section */
div h2 {
  font-size: 1.05rem;
  margin: 0 0 12px;
  color: var(--color-text-muted);
  font-weight: 500;
  letter-spacing: 0.5px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
}

div {
  margin-bottom: 18px;
}

input[type="checkbox"] {
  margin-right: 10px;
}

div div {
  display: flex;
  align-items: center;
  margin-bottom: 10px;
}

/* Button styling */
button {
  width: 100%;
  padding: 16px 20px;
  background: linear-gradient(90deg, var(--color-accent) 0%, var(--color-accent-hover) 100%);
  color: var(--color-accent-fg);
  border: none;
  border-radius: var(--radius-md);
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  letter-spacing: 0.5px;
  box-shadow: 0 4px 10px -2px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(255, 187, 51, 0.2);
  transition: var(--trans-slow);
  position: relative;
  overflow: hidden;
}

button:before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 30% 50%, rgba(255, 255, 255, 0.35), transparent 70%);
  opacity: 0;
  transition: var(--trans-slow);
}

button:hover:before {
  opacity: 0.6;
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px -2px rgba(0, 0, 0, 0.55), 0 0 0 1px rgba(255, 187, 51, 0.3);
}

button:active {
  transform: translateY(0);
}

button.disabled,
button:disabled {
  opacity: .45;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: 0 0 0 1px rgba(255, 255, 255, 0.05);
  filter: saturate(.4);
}

/* Mobile responsiveness */
@media (max-width: 768px) {
  form {
    padding: 28px 26px 34px;
  }

  button {
    font-size: 0.95rem;
  }

  div h2 {
    font-size: 0.95rem;
  }
}

div.options-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: var(--grid-gap);
  margin-bottom: 26px;
  align-items: start;
}

div.options-container>div {
  display: flex;
  align-items: center;
  margin-bottom: 10px;
}

.option-label {
  --pad-x: 14px;
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 14px var(--pad-x) 14px 14px;
  border-radius: var(--radius-md);
  cursor: pointer;
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  position: relative;
  transition: var(--trans-fast), background 220ms ease;
  font-size: 0.85rem;
  line-height: 1.3;
  color: var(--color-text);
  box-shadow: var(--shadow-sm);
}

.option-label:hover {
  background: var(--color-surface);
}

.option-label:active {
  transform: translateY(1px);
}

.option-label input[type="checkbox"] {
  margin-top: 2px;
  accent-color: var(--color-accent);
}

.option-label input[type="checkbox"]:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.option-label input[type="checkbox"]:checked+span {
  color: var(--color-accent);
  font-weight: 500;
}

.option-label span {
  flex: 1 1 auto;
}

.option-label:before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, rgba(255, 187, 51, 0.08), rgba(51, 214, 133, 0.07));
  opacity: 0;
  pointer-events: none;
  transition: var(--trans-slow);
  border-radius: inherit;
}

.option-label:hover:before {
  opacity: 1;
}

.option-label input[type="checkbox"]:checked~span:after {
  content: "✔";
  font-size: 0.75rem;
  margin-left: 6px;
  color: var(--color-success);
  vertical-align: top;
}

/* Selection status indicators */
.choose-status {
  font-size: 0.7rem;
  margin-left: 4px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.choose-status.need {
  color: var(--color-warn);
}

.choose-status.ok {
  color: var(--color-success);
}

.choose-status.over {
  color: var(--color-danger);
}

/* Group container refinement */
.difficulty-group {
  padding: 22px 24px 28px;
  background: linear-gradient(165deg, var(--color-surface) 0%, var(--color-surface-alt) 100%);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  position: relative;
  box-shadow: 0 2px 6px -2px rgba(0, 0, 0, 0.45), 0 0 0 1px rgba(255, 255, 255, 0.04);
  backdrop-filter: blur(3px);
  transition: border-color var(--trans-fast), background 300ms ease;
  overflow: hidden;
}

.difficulty-group:hover {
  border-color: var(--color-accent);
}

.difficulty-group:hover h2 {
  color: var(--color-text);
}

.difficulty-group:before {
  display: none;
}

.difficulty-group h2 {
  transition: color var(--trans-fast);
}

/* Layout helpers for list of existing boards */
.boards-list {
  display: grid;
  grid-auto-rows: min-content;
  grid-template-columns: repeat(auto-fit, minmax(140px, max-content));
  justify-content: center;
  justify-items: center;
  align-items: center;
  gap: 14px 18px;
  margin: 12px auto 40px;
  padding: 0 8px;
  list-style: none;
  max-width: 1000px;
  width: 100%;
  position: relative;
}

.boards-list a {
  background: var(--color-surface);
  padding: 12px 20px;
  border-radius: 999px;
  font-size: 0.78rem;
  letter-spacing: 0.7px;
  text-transform: uppercase;
  font-weight: 650;
  border: 1px solid var(--color-border);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.4), 0 0 0 1px rgba(255, 255, 255, 0.03);
  color: var(--color-text-muted);
  position: relative;
  overflow: hidden;
  text-decoration: none;
  transition: 160ms ease, background 220ms ease;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.boards-list a:before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, rgba(255, 187, 51, 0.08), rgba(51, 214, 133, 0.07));
  opacity: 0;
  transition: 220ms ease;
}

.boards-list a:hover:before {
  opacity: 1;
}

.boards-list a:hover {
  background: var(--color-surface-alt);
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: 0 4px 10px -2px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(255, 187, 51, 0.25);
}

.boards-list a:active {
  transform: translateY(0);
}

.boards-list a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

/* Scrollbars (webkit) */
::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: #111418;
}

::-webkit-scrollbar-thumb {
  background: #2c333d;
  border-radius: 8px;
}

::-webkit-scrollbar-thumb:hover {
  background: #3a4653;
}

/* Fancy field / input styling */
.field {
  margin: 0 0 34px;
  position: relative;
}

.field-label {
  display: block;
  font-size: 0.7rem;
  letter-spacing: 1px;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin: 0 0 8px;
}

.input-shell {
  position: relative;
}

.text-input {
  width: 100%;
  padding: 16px 18px 14px;
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-size: 0.95rem;
  line-height: 1.2;
  letter-spacing: 0.3px;
  font-family: var(--font-stack);
  transition: border-color var(--trans-fast), background 160ms ease, box-shadow 200ms ease;
}

.text-input::placeholder {
  color: #5c6774;
  opacity: .75;
}

.text-input:hover {
  background: #1d2229;
}

.text-input:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 2px rgba(255, 187, 51, 0.18), 0 0 0 6px rgba(255, 187, 51, 0.08);
}

.text-input:focus+.input-glow {
  opacity: 1;
  transform: scale(1);
}

.text-input.error {
  border-color: var(--color-danger);
  box-shadow: 0 0 0 2px rgba(255, 77, 79, 0.28);
}

.input-shell .input-glow {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: var(--radius-md);
  background: radial-gradient(circle at 25% 20%, rgba(255, 187, 51, 0.15), transparent 60%),
    radial-gradient(circle at 80% 70%, rgba(51, 214, 133, 0.12), transparent 65%);
  pointer-events: none;
  opacity: 0;
  transform: scale(.98);
  transition: 320ms cubic-bezier(.4, .18, .3, 1);
  filter: blur(2px);
}

.text-input:disabled {
  opacity: .55;
  cursor: not-allowed;
}

.input-error {
  margin-top: 6px;
  font-size: 0.7rem;
  color: var(--color-danger);
  min-height: 14px;
  font-weight: 600;
  letter-spacing: .5px;
}

.input-hint {
  margin-top: 6px;
  font-size: 0.65rem;
  color: var(--color-text-muted);
  letter-spacing: .5px;
}