/* CyberThinkCTF — minimal public interface */

:root,
[data-bs-theme="dark"] {
  color-scheme: dark;
  --ct-bg: #080b0f;
  --ct-surface: #0e1319;
  --ct-surface-hover: #121a22;
  --ct-border: #27313b;
  --ct-border-strong: #455363;
  --ct-text: #f2f5f7;
  --ct-text-secondary: #b7c0c8;
  --ct-text-muted: #84909b;
  --ct-accent: #55dbe8;
  --ct-accent-hover: #82e7f0;
  --ct-accent-ink: #061014;
  --ct-success: #55d98a;
  --ct-warning: #f2c66d;
  --ct-danger: #ff7f8d;
  --bs-body-bg: var(--ct-bg);
  --bs-body-color: var(--ct-text);
  --bs-secondary-color: var(--ct-text-muted);
  --bs-tertiary-bg: var(--ct-surface);
  --bs-border-color: var(--ct-border);
  --bs-primary-rgb: 85, 219, 232;
  --bs-link-color-rgb: 85, 219, 232;
  --bs-link-hover-color-rgb: 130, 231, 240;
}

[data-bs-theme="light"] {
  color-scheme: light;
  --ct-bg: #f7f9fa;
  --ct-surface: #ffffff;
  --ct-surface-hover: #f0f4f5;
  --ct-border: #d5dde1;
  --ct-border-strong: #82919a;
  --ct-text: #10171c;
  --ct-text-secondary: #3e4d55;
  --ct-text-muted: #687780;
  --ct-accent: #087d88;
  --ct-accent-hover: #066b74;
  --ct-accent-ink: #ffffff;
  --ct-success: #167a42;
  --ct-warning: #8a5b0b;
  --ct-danger: #b42c40;
  --bs-body-bg: var(--ct-bg);
  --bs-body-color: var(--ct-text);
  --bs-secondary-color: var(--ct-text-muted);
  --bs-tertiary-bg: var(--ct-surface);
  --bs-border-color: var(--ct-border);
  --bs-primary-rgb: 8, 125, 136;
  --bs-link-color-rgb: 8, 125, 136;
  --bs-link-hover-color-rgb: 6, 107, 116;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  min-height: 100%;
  scroll-behavior: smooth;
}

body.ct-body {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  padding-top: 65px;
  overflow-x: hidden;
  background: var(--ct-bg);
  color: var(--ct-text);
  font-family:
    Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  font-size: 1rem;
  line-height: 1.6;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

main {
  min-width: 0;
  flex: 1 0 auto;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  margin-top: 0;
  color: var(--ct-text);
  font-family:
    Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  font-weight: 680;
  letter-spacing: -0.035em;
}

p {
  color: var(--ct-text-secondary);
}

a {
  color: var(--ct-accent);
  text-underline-offset: 0.2em;
}

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

code,
kbd,
pre,
.ct-countdown,
.ct-event-meta,
.ct-page-stats,
.ct-score-table,
.ct-rank {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-variant-numeric: tabular-nums;
}

::selection {
  background: var(--ct-accent);
  color: var(--ct-accent-ink);
}

[x-cloak] {
  display: none !important;
}

:focus-visible {
  outline: 2px solid var(--ct-accent) !important;
  outline-offset: 3px !important;
  box-shadow: none !important;
}

.ct-skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 2000;
  padding: 0.55rem 0.8rem;
  border: 1px solid var(--ct-accent);
  border-radius: 0.3rem;
  background: var(--ct-bg);
  color: var(--ct-text);
  font-weight: 700;
  transform: translateY(-180%);
  transition: transform 120ms ease-out;
}

.ct-skip-link:focus {
  color: var(--ct-text);
  transform: translateY(0);
}

.btn {
  min-height: 44px;
  border-radius: 0.35rem;
  font-weight: 700;
  letter-spacing: 0;
  box-shadow: none !important;
  transition:
    color 120ms ease-out,
    background-color 120ms ease-out,
    border-color 120ms ease-out;
}

.btn-primary {
  --bs-btn-color: var(--ct-accent-ink);
  --bs-btn-bg: var(--ct-accent);
  --bs-btn-border-color: var(--ct-accent);
  --bs-btn-hover-color: var(--ct-accent-ink);
  --bs-btn-hover-bg: var(--ct-accent-hover);
  --bs-btn-hover-border-color: var(--ct-accent-hover);
  --bs-btn-active-color: var(--ct-accent-ink);
  --bs-btn-active-bg: var(--ct-accent-hover);
  --bs-btn-active-border-color: var(--ct-accent-hover);
}

.btn-outline-light,
.btn-outline-secondary {
  --bs-btn-color: var(--ct-text);
  --bs-btn-border-color: var(--ct-border-strong);
  --bs-btn-hover-color: var(--ct-text);
  --bs-btn-hover-bg: var(--ct-surface-hover);
  --bs-btn-hover-border-color: var(--ct-accent);
  --bs-btn-active-color: var(--ct-text);
  --bs-btn-active-bg: var(--ct-surface-hover);
  --bs-btn-active-border-color: var(--ct-accent);
}

.form-control,
.form-select {
  min-height: 46px;
  border: 1px solid var(--ct-border-strong);
  border-radius: 0.35rem;
  background-color: var(--ct-surface);
  color: var(--ct-text);
  box-shadow: none;
}

.form-control::placeholder {
  color: var(--ct-text-muted);
  opacity: 0.8;
}

.form-control:hover,
.form-select:hover {
  border-color: var(--ct-text-muted);
}

.form-control:focus,
.form-select:focus {
  border-color: var(--ct-accent);
  background-color: var(--ct-surface);
  color: var(--ct-text);
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--ct-accent) 22%, transparent);
}

.form-label {
  margin-bottom: 0.4rem;
  color: var(--ct-text);
  font-size: 0.88rem;
  font-weight: 700;
}

.form-text,
.text-muted {
  color: var(--ct-text-muted) !important;
}

.alert {
  border: 1px solid currentColor;
  border-radius: 0.35rem;
  background: var(--ct-surface);
}

.alert-danger {
  color: var(--ct-danger);
}

.alert-success {
  color: var(--ct-success);
}

.alert-warning {
  color: var(--ct-warning);
}

.alert-info {
  color: var(--ct-accent);
}

/* Navigation */

.ct-navbar {
  min-height: 65px;
  border-bottom: 1px solid var(--ct-border);
  background: var(--ct-bg);
}

.ct-navbar .container {
  min-height: 48px;
}

.ct-brand {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--ct-text);
  font-size: 0.92rem;
  font-weight: 750;
  letter-spacing: -0.02em;
}

.ct-brand:hover {
  color: var(--ct-text);
}

.ct-brand img {
  width: 30px;
  height: 30px;
  flex: 0 0 auto;
}

.ct-navbar .navbar-collapse {
  gap: 0.75rem;
}

.ct-navbar__primary {
  margin-inline: auto;
  gap: 0;
}

.ct-navbar .nav-link {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  padding: 0.5rem 0.7rem !important;
  border-radius: 0.25rem;
  color: var(--ct-text-secondary);
  font-size: 0.84rem;
  font-weight: 650;
  cursor: pointer;
}

.ct-navbar .nav-link:hover,
.ct-navbar .nav-link.active {
  background: var(--ct-surface);
  color: var(--ct-text);
}

.ct-navbar .nav-link.active {
  color: var(--ct-accent);
}

.ct-navbar__actions {
  align-items: center;
  gap: 0.1rem;
}

.ct-navbar__login {
  min-height: 38px;
  display: inline-flex;
  align-items: center;
  padding-inline: 0.9rem;
  white-space: nowrap;
}

.ct-navbar__register {
  white-space: nowrap;
}

.ct-nav-icon {
  min-width: 44px;
}

.ct-account-button {
  max-width: 12rem;
}

.ct-account-button > span:last-child {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.ct-avatar {
  width: 26px;
  height: 26px;
  display: inline-grid;
  flex: 0 0 auto;
  place-items: center;
  border: 1px solid var(--ct-border-strong);
  border-radius: 50%;
  color: var(--ct-accent);
  font-size: 0.72rem;
  font-weight: 800;
}

.ct-dropdown {
  min-width: 14rem;
  padding: 0.35rem;
  border: 1px solid var(--ct-border);
  border-radius: 0.35rem;
  background: var(--ct-surface);
  box-shadow: none;
}

.ct-dropdown .dropdown-item {
  min-height: 40px;
  display: flex;
  align-items: center;
  gap: 0.65rem;
  border-radius: 0.25rem;
  color: var(--ct-text-secondary);
  font-size: 0.88rem;
}

.ct-dropdown .dropdown-item:hover,
.ct-dropdown .dropdown-item:focus,
.ct-dropdown .dropdown-item.active {
  background: var(--ct-surface-hover);
  color: var(--ct-text);
}

.ct-dropdown .dropdown-item i {
  width: 1rem;
  color: var(--ct-text-muted);
  text-align: center;
}

.ct-dropdown .ct-dropdown__danger {
  color: var(--ct-danger);
}

.ct-dropdown .dropdown-divider {
  border-color: var(--ct-border);
}

.navbar-toggler {
  width: 44px;
  height: 44px;
  display: inline-grid;
  padding: 0;
  place-items: center;
  border: 1px solid var(--ct-border);
  border-radius: 0.3rem;
  color: var(--ct-text);
}

.ct-menu-icon,
.ct-menu-icon::before,
.ct-menu-icon::after {
  width: 19px;
  height: 1px;
  display: block;
  background: currentColor;
  content: "";
}

.ct-menu-icon {
  position: relative;
}

.ct-menu-icon::before {
  position: absolute;
  top: -6px;
}

.ct-menu-icon::after {
  position: absolute;
  top: 6px;
}

/* Footer */

.ct-footer {
  flex: 0 0 auto;
  padding: 1.25rem 0;
  border-top: 1px solid var(--ct-border);
  background: var(--ct-bg);
}

.ct-footer__inner {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 1.25rem;
}

.ct-footer__brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--ct-text);
  font-size: 0.84rem;
  font-weight: 700;
}

.ct-footer__brand img {
  width: 24px;
  height: 24px;
}

.ct-footer nav {
  display: flex;
  gap: 1rem;
}

.ct-footer nav a,
.ct-footer small {
  color: var(--ct-text-muted);
  font-size: 0.78rem;
}

.ct-footer small {
  justify-self: end;
}

/* Landing */

.ct-eyebrow {
  margin: 0 0 1rem;
  color: var(--ct-accent);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.7rem;
  font-weight: 750;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

.ct-hero {
  padding: clamp(4rem, 9vw, 7rem) 0 clamp(3rem, 7vw, 5rem);
  border-bottom: 1px solid var(--ct-border);
}

.ct-hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(19rem, 0.75fr);
  align-items: end;
  gap: clamp(3rem, 8vw, 7rem);
}

.ct-hero h1 {
  max-width: 11ch;
  margin-bottom: 1.25rem;
  font-size: clamp(3.15rem, 7vw, 5.8rem);
  font-weight: 620;
  line-height: 0.94;
  letter-spacing: -0.065em;
}

.ct-hero h1 span {
  color: var(--ct-accent);
}

.ct-hero__lead {
  max-width: 38rem;
  margin-bottom: 1.75rem;
  font-size: clamp(1rem, 1.8vw, 1.12rem);
}

.ct-event-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.8rem 1.8rem;
  margin: 0 0 1.8rem;
}

.ct-event-meta > div {
  min-width: 8rem;
}

.ct-event-meta dt {
  margin-bottom: 0.15rem;
  color: var(--ct-text-muted);
  font-size: 0.64rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.ct-event-meta dd {
  max-width: 29rem;
  margin: 0;
  color: var(--ct-text);
  font-size: 0.78rem;
}

.ct-hero__actions,
.ct-flag-preview__actions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.ct-hero__actions .btn,
.ct-flag-preview__actions .btn {
  padding-inline: 1.1rem;
}

.ct-text-link {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  color: var(--ct-text-secondary);
  font-size: 0.88rem;
  font-weight: 650;
}

.ct-text-link:hover {
  color: var(--ct-accent);
}

.ct-countdown {
  padding: 1.1rem;
  border: 1px solid var(--ct-border);
  border-radius: 0.35rem;
  background: var(--ct-surface);
}

.ct-countdown__heading {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  margin-bottom: 1rem;
}

.ct-event-clock__label {
  color: var(--ct-accent);
  font-size: 0.64rem;
  font-weight: 750;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.ct-event-clock__date {
  color: var(--ct-text);
  font-size: 0.78rem;
  font-weight: 650;
}

.ct-countdown__grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-top: 1px solid var(--ct-border);
}

.ct-countdown__grid > span {
  min-width: 0;
  display: flex;
  flex-direction: column;
  padding: 0.9rem 0.45rem 0;
  border-right: 1px solid var(--ct-border);
  text-align: center;
}

.ct-countdown__grid > span:first-child {
  padding-left: 0;
}

.ct-countdown__grid > span:last-child {
  padding-right: 0;
  border-right: 0;
}

.ct-countdown__grid strong {
  color: var(--ct-text);
  font-size: clamp(1.35rem, 3vw, 1.8rem);
  font-weight: 600;
  line-height: 1;
}

.ct-countdown__grid small {
  margin-top: 0.35rem;
  color: var(--ct-text-muted);
  font-family: Inter, sans-serif;
  font-size: 0.62rem;
}

.ct-countdown__live {
  min-height: 4.5rem;
  display: none;
  margin: 0;
  place-items: center;
  border-top: 1px solid var(--ct-border);
  color: var(--ct-success);
  font-weight: 700;
  text-align: center;
}

.ct-countdown[data-phase="live"] .ct-countdown__grid,
.ct-countdown[data-phase="finished"] .ct-countdown__grid {
  display: none;
}

.ct-countdown[data-phase="live"] .ct-countdown__live,
.ct-countdown[data-phase="finished"] .ct-countdown__live {
  display: grid;
}

.ct-countdown[data-phase="finished"] .ct-countdown__live {
  color: var(--ct-text-secondary);
}

.ct-section {
  padding: clamp(3rem, 7vw, 5rem) 0;
}

.ct-section--flag {
  padding-block: clamp(3rem, 7vw, 5rem);
}

.ct-flag-preview {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(19rem, 0.9fr) auto;
  align-items: center;
  gap: clamp(1.5rem, 4vw, 3rem);
}

.ct-flag-preview__copy .ct-eyebrow {
  margin-bottom: 0.45rem;
}

.ct-flag-preview h2 {
  margin-bottom: 0.35rem;
  font-size: clamp(1.5rem, 3vw, 2rem);
}

.ct-flag-preview__copy > p:last-child {
  max-width: 34rem;
  margin: 0;
  font-size: 0.9rem;
}

.ct-flag-preview__answer {
  min-width: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: 0.45rem;
  padding: 0.75rem;
  border: 1px solid var(--ct-border);
  border-radius: 0.35rem;
  background: var(--ct-surface);
}

.ct-flag-preview__answer > span {
  grid-column: 1 / -1;
  color: var(--ct-text-muted);
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.ct-flag-preview__answer code {
  min-width: 0;
  overflow-x: auto;
  color: var(--ct-accent);
  font-size: 0.8rem;
  font-weight: 650;
  white-space: nowrap;
  scrollbar-width: thin;
}

.ct-flag-copy {
  min-width: 44px;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.5rem 0.65rem;
  border: 1px solid var(--ct-border-strong);
  border-radius: 0.3rem;
  background: transparent;
  color: var(--ct-text);
  font-size: 0.72rem;
  font-weight: 700;
  cursor: pointer;
}

.ct-flag-copy:hover {
  border-color: var(--ct-accent);
  background: var(--ct-surface-hover);
}

/* Interior pages */

.ct-page-hero {
  padding: clamp(3rem, 7vw, 5rem) 0 clamp(2.5rem, 5vw, 4rem);
  border-bottom: 1px solid var(--ct-border);
}

.ct-page-hero h1 {
  margin-bottom: 0.6rem;
  font-size: clamp(2.7rem, 6vw, 4.8rem);
  font-weight: 620;
  line-height: 1;
  letter-spacing: -0.055em;
}

.ct-page-hero p:last-child {
  max-width: 40rem;
  margin: 0;
  font-size: 0.98rem;
}

.ct-page-hero__row {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 2rem;
}

.ct-page-stats {
  display: flex;
  flex: 0 0 auto;
  gap: 1.5rem;
  margin: 0;
}

.ct-page-stats > div {
  min-width: 5rem;
}

.ct-page-stats dt {
  color: var(--ct-text-muted);
  font-size: 0.62rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.ct-page-stats dd {
  margin: 0.1rem 0 0;
  color: var(--ct-accent);
  font-size: 1.25rem;
  font-weight: 700;
}

.ct-generic-page {
  padding-block: clamp(3rem, 7vw, 5rem);
}

.ct-generic-page > :first-child {
  margin-top: 0;
}

.ct-generic-page img {
  max-width: 100%;
  height: auto;
}

/* Rules */

.ct-rules {
  padding-top: clamp(3rem, 6vw, 5rem);
}

.ct-rules__intro {
  display: grid;
  grid-template-columns: 8rem minmax(0, 1fr);
  gap: 1.25rem;
  margin-bottom: 1.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--ct-border);
}

.ct-rules__intro strong {
  color: var(--ct-accent);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.ct-rules__intro p {
  margin: 0;
  color: var(--ct-text);
}

.ct-rules__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border-top: 1px solid var(--ct-border);
}

.ct-rules__grid article {
  position: relative;
  min-height: 11rem;
  padding: 1.5rem;
  border-right: 1px solid var(--ct-border);
  border-bottom: 1px solid var(--ct-border);
}

.ct-rules__grid article:nth-child(even) {
  border-right: 0;
}

.ct-rules__grid article > span {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  color: var(--ct-text-muted);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.68rem;
}

.ct-rules__grid h2 {
  margin-bottom: 0.65rem;
  padding-right: 2.5rem;
  font-size: 1.1rem;
}

.ct-rules__grid p {
  margin: 0;
  font-size: 0.9rem;
}

.ct-rules__notice {
  display: flex;
  align-items: flex-start;
  gap: 0.9rem;
  margin-top: 1.5rem;
  padding: 1rem 0;
  border-top: 1px solid var(--ct-warning);
  border-bottom: 1px solid var(--ct-warning);
}

.ct-rules__notice > i {
  margin-top: 0.2rem;
  color: var(--ct-warning);
}

.ct-rules__notice h2 {
  margin-bottom: 0.35rem;
  font-size: 1rem;
}

.ct-rules__notice p {
  margin: 0;
}

/* Challenges */

.ct-challenges-shell {
  padding-top: clamp(2.5rem, 5vw, 4rem);
  padding-bottom: clamp(4rem, 8vw, 7rem);
}

.ct-category-section {
  margin-bottom: clamp(3rem, 6vw, 5rem);
  scroll-margin-top: 6rem;
}

.ct-category-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
  padding-bottom: 0.7rem;
  border-bottom: 1px solid var(--ct-border);
}

.ct-category-header h2 {
  margin: 0;
  font-size: clamp(1.2rem, 3vw, 1.55rem);
}

.ct-category-header small {
  color: var(--ct-text-muted);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.68rem;
}

.ct-challenge-card {
  min-height: 8.5rem;
  display: flex;
  flex-direction: column;
  padding: 1rem;
  border: 1px solid var(--ct-border) !important;
  border-radius: 0.35rem;
  background: var(--ct-surface) !important;
  color: var(--ct-text) !important;
  text-align: left;
  box-shadow: none !important;
  cursor: pointer;
  transition:
    border-color 120ms ease-out,
    background-color 120ms ease-out !important;
}

.ct-challenge-card:hover {
  border-color: var(--ct-accent) !important;
  background: var(--ct-surface-hover) !important;
}

.ct-challenge-card.challenge-solved {
  border-color: var(--ct-success) !important;
}

.ct-challenge-card__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  color: var(--ct-text-muted);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.68rem;
}

.ct-challenge-card__top > strong {
  color: var(--ct-accent);
  font-weight: 700;
}

.challenge-solved .ct-challenge-card__top > strong {
  color: var(--ct-success);
}

.ct-challenge-card__status {
  color: var(--ct-text-muted);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.ct-challenge-card__status--solved {
  color: var(--ct-success);
}

.ct-challenge-card__name {
  display: block;
  margin: 1rem 0 auto;
  overflow-wrap: anywhere;
  color: var(--ct-text);
  font-size: 1.02rem;
  font-weight: 680;
  line-height: 1.35;
}

.ct-challenge-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.85rem;
}

.ct-challenge-card__tags > span {
  max-width: 10rem;
  overflow: hidden;
  color: var(--ct-text-muted);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 0.62rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.ct-challenge-card__tags > span:not(:last-child)::after {
  margin-left: 0.35rem;
  color: var(--ct-border-strong);
  content: "·";
}

.ct-loading {
  min-height: 16rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.7rem;
  color: var(--ct-text-muted);
}

.ct-loading__spinner {
  width: 1.3rem;
  height: 1.3rem;
  display: inline-block;
  border: 2px solid var(--ct-border);
  border-top-color: var(--ct-accent);
  border-radius: 50%;
  animation: ct-spin 700ms linear infinite;
}

@keyframes ct-spin {
  to {
    transform: rotate(360deg);
  }
}

#challenge-window .modal-dialog {
  max-width: 820px;
}

#challenge-window .modal-content {
  max-height: 90dvh;
  overflow: hidden;
  border: 1px solid var(--ct-border);
  border-radius: 0.35rem;
  background: var(--ct-surface);
  box-shadow: none;
}

#challenge-window .modal-body {
  overflow-y: auto;
  overscroll-behavior: contain;
}

#challenge-window .btn-close {
  min-width: 44px;
  min-height: 44px;
  border-radius: 0.25rem;
  background-color: var(--ct-surface-hover);
}

#challenge-window .nav-tabs {
  padding-right: 3.5rem;
  border-color: var(--ct-border);
}

#challenge-window .nav-tabs .nav-link {
  min-height: 44px;
  border: 0;
  border-bottom: 2px solid transparent;
  color: var(--ct-text-muted);
  font-size: 0.8rem;
  font-weight: 700;
}

#challenge-window .nav-tabs .nav-link.active {
  border-bottom-color: var(--ct-accent);
  background: transparent;
  color: var(--ct-text);
}

#challenge-window .challenge-name {
  margin-top: 0.8rem;
  font-size: clamp(1.8rem, 5vw, 2.5rem);
}

#challenge-window .challenge-value {
  color: var(--ct-accent);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 1.05rem;
}

#challenge-window .challenge-desc {
  display: block;
  margin-block: 1.5rem;
  color: var(--ct-text-secondary);
}

#challenge-window .challenge-desc img {
  max-width: 100%;
  border: 1px solid var(--ct-border);
}

#challenge-window code {
  color: var(--ct-accent);
}

#challenge-window pre {
  padding: 1rem;
  overflow: auto;
  border: 1px solid var(--ct-border);
  border-radius: 0.3rem;
  background: var(--ct-bg);
}

#challenge-window details {
  margin-bottom: 0.7rem;
  border-top: 1px solid var(--ct-border);
  border-bottom: 1px solid var(--ct-border);
}

#challenge-window summary {
  min-height: 44px;
  padding: 0.65rem 0;
  color: var(--ct-text);
  font-weight: 700;
  cursor: pointer;
}

#challenge-window .challenge-tag {
  border: 1px solid var(--ct-border);
  background: transparent !important;
  color: var(--ct-accent);
}

#challenge-window .btn-file {
  min-height: 44px;
  display: inline-flex !important;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  border-color: var(--ct-border);
  background: transparent;
  color: var(--ct-text);
}

#challenge-window .submit-row {
  align-items: end;
}

.ct-flag-label {
  display: block;
}

#challenge-window .challenge-input,
#challenge-window .challenge-submit {
  min-height: 48px;
}

.modal-backdrop.show {
  opacity: 0.78;
}

/* Scoreboard */

.ct-score-shell {
  max-width: 920px;
  padding-top: clamp(2.5rem, 5vw, 4rem);
  padding-bottom: clamp(4rem, 8vw, 7rem);
}

.ct-score-card {
  overflow: hidden;
  border-top: 1px solid var(--ct-border);
  border-bottom: 1px solid var(--ct-border);
}

.ct-score-card__heading {
  min-height: 64px;
  display: flex;
  align-items: center;
  padding: 0.9rem 0;
  border-bottom: 1px solid var(--ct-border);
}

.ct-score-card__heading h2 {
  margin: 0;
  font-size: 1rem;
}

.ct-brackets {
  gap: 0.3rem;
  padding: 0.75rem 0;
  overflow-x: auto;
  border-bottom: 1px solid var(--ct-border);
  scrollbar-width: thin;
}

.ct-brackets .nav-link {
  min-height: 40px;
  flex: 0 0 auto;
  border: 1px solid var(--ct-border);
  border-radius: 0.3rem;
  color: var(--ct-text-secondary);
  font-size: 0.76rem;
  font-weight: 700;
}

.ct-brackets .nav-link.active {
  border-color: var(--ct-accent);
  background: var(--ct-accent);
  color: var(--ct-accent-ink);
}

.ct-score-table {
  margin: 0;
  color: var(--ct-text);
}

.ct-score-table > :not(caption) > * > * {
  padding: 0.95rem 0.4rem;
  border-bottom-color: var(--ct-border);
  background: transparent;
  color: inherit;
}

.ct-score-table thead th {
  color: var(--ct-text-muted);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.ct-score-table th:first-child {
  width: 5rem;
  text-align: center;
}

.ct-score-table th:last-child,
.ct-score-table td:last-child {
  width: 8rem;
  text-align: right;
}

.ct-score-table tbody tr:hover {
  background: var(--ct-surface);
}

.ct-score-table tbody tr:last-child > * {
  border-bottom: 0;
}

.ct-score-table a {
  color: var(--ct-text);
  font-weight: 650;
  text-decoration: none;
}

.ct-score-table a:hover {
  color: var(--ct-accent);
}

.ct-score-account {
  min-width: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
}

.ct-score-table strong {
  color: var(--ct-accent);
  font-weight: 700;
}

.ct-rank {
  color: var(--ct-text-muted);
  font-size: 0.74rem;
  font-weight: 500;
}

.ct-bracket-badge {
  margin-left: 0 !important;
  border: 1px solid var(--ct-border);
  background: transparent;
  color: var(--ct-text-muted);
  font-weight: 500;
}

.ct-empty-state {
  min-height: 15rem;
  display: grid;
  place-content: center;
  padding: 2rem;
  text-align: center;
}

.ct-empty-state h3 {
  margin-bottom: 0.3rem;
  font-size: 1rem;
}

.ct-empty-state p {
  margin: 0;
}

/* Authentication */

.ct-auth {
  min-height: calc(100dvh - 65px);
  display: grid;
  align-items: center;
  padding: clamp(2.5rem, 7vw, 5rem) 0;
}

.ct-auth-shell {
  max-width: 30rem;
  margin: 0 auto;
  border-top: 1px solid var(--ct-border);
  border-bottom: 1px solid var(--ct-border);
}

.ct-auth-aside {
  display: none;
}

.ct-auth-card {
  padding: clamp(2rem, 5vw, 3rem) 0;
}

.ct-auth-card__brand {
  margin-bottom: 1.25rem;
}

.ct-auth-card__brand img {
  width: 36px;
  height: 36px;
}

.ct-auth-card h1 {
  margin-bottom: 0.45rem;
  font-size: clamp(2.2rem, 6vw, 3.2rem);
}

.ct-auth-card__lead {
  margin-bottom: 1.7rem;
}

.ct-form .mb-3 {
  margin-bottom: 1rem !important;
}

.ct-label-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.4rem;
}

.ct-label-row .form-label {
  margin: 0;
}

.ct-label-row a {
  font-size: 0.76rem;
}

.ct-password-field {
  position: relative;
}

.ct-password-field .form-control {
  padding-right: 3.3rem !important;
}

.ct-password-field button {
  position: absolute;
  top: 1px;
  right: 1px;
  width: 44px;
  height: 44px;
  display: grid;
  padding: 0;
  place-items: center;
  border: 0;
  border-radius: 0.25rem;
  background: transparent;
  color: var(--ct-text-muted);
}

.ct-password-field button:hover {
  background: var(--ct-surface-hover);
  color: var(--ct-text);
}

.ct-auth-divider {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  margin-block: 1.2rem;
  color: var(--ct-text-muted);
  font-size: 0.72rem;
}

.ct-auth-divider::before,
.ct-auth-divider::after {
  height: 1px;
  flex: 1;
  background: var(--ct-border);
  content: "";
}

.ct-auth-card__switch {
  margin: 1.5rem 0 0;
  color: var(--ct-text-muted);
  font-size: 0.86rem;
  text-align: center;
}

.ct-auth-card__legal {
  margin: 1rem 0 0;
  color: var(--ct-text-muted);
  font-size: 0.7rem;
  text-align: center;
}

/* Core pages */

.jumbotron {
  margin: 0;
  padding: clamp(3rem, 7vw, 5rem) 0;
  border-bottom: 1px solid var(--ct-border);
  background: var(--ct-bg) !important;
}

.jumbotron h1 {
  margin: 0;
  font-size: clamp(2.4rem, 6vw, 4rem);
  letter-spacing: -0.05em;
}

.table {
  --bs-table-color: var(--ct-text);
  --bs-table-bg: transparent;
  --bs-table-striped-bg: var(--ct-surface);
  --bs-table-striped-color: var(--ct-text);
  --bs-table-border-color: var(--ct-border);
}

.card,
.list-group-item {
  border-color: var(--ct-border);
  border-radius: 0.35rem;
  background: var(--ct-surface);
  color: var(--ct-text);
  box-shadow: none;
}

.nav-pills .nav-link {
  color: var(--ct-text-secondary);
}

.nav-pills .nav-link.active {
  background: var(--ct-accent);
  color: var(--ct-accent-ink);
}

.pagination {
  --bs-pagination-bg: var(--ct-surface);
  --bs-pagination-border-color: var(--ct-border);
  --bs-pagination-color: var(--ct-text-secondary);
  --bs-pagination-hover-bg: var(--ct-surface-hover);
  --bs-pagination-hover-color: var(--ct-text);
  --bs-pagination-active-bg: var(--ct-accent);
  --bs-pagination-active-border-color: var(--ct-accent);
  --bs-pagination-active-color: var(--ct-accent-ink);
}

/* Responsive */

@media (min-width: 1200px) {
  .container {
    max-width: 1120px;
  }
}

@media (max-width: 991.98px) {
  .ct-navbar .navbar-collapse {
    max-height: calc(100dvh - 76px);
    margin-top: 0.55rem;
    padding: 0.5rem;
    overflow-y: auto;
    border: 1px solid var(--ct-border);
    background: var(--ct-surface);
  }

  .ct-navbar__primary,
  .ct-navbar__actions {
    align-items: stretch;
    gap: 0;
  }

  .ct-navbar .nav-link {
    justify-content: flex-start;
  }

  .ct-navbar__login {
    justify-content: center;
    margin-block: 0.25rem;
  }

  .ct-account-button {
    max-width: none;
  }

  .ct-hero__inner {
    grid-template-columns: 1fr;
    align-items: start;
    gap: 2.5rem;
  }

  .ct-countdown {
    width: min(100%, 34rem);
  }

  .ct-flag-preview {
    grid-template-columns: minmax(0, 1fr) minmax(18rem, 0.9fr);
  }

  .ct-flag-preview__actions {
    grid-column: 1 / -1;
  }
}

@media (max-width: 767.98px) {
  .ct-footer__inner {
    grid-template-columns: 1fr;
    justify-items: center;
    text-align: center;
  }

  .ct-footer small {
    justify-self: center;
  }

  .ct-page-hero__row {
    align-items: flex-start;
    flex-direction: column;
  }

  .ct-page-stats {
    width: 100%;
  }

  .ct-rules__grid {
    grid-template-columns: 1fr;
  }

  .ct-rules__grid article,
  .ct-rules__grid article:nth-child(even) {
    border-right: 0;
  }

  .ct-flag-preview {
    grid-template-columns: 1fr;
  }

  .ct-flag-preview__actions {
    grid-column: auto;
  }
}

@media (max-width: 575.98px) {
  body.ct-body {
    font-size: 0.96rem;
  }

  .container {
    --bs-gutter-x: 2.25rem;
  }

  .ct-brand span {
    max-width: 10rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }

  .ct-hero {
    padding-block: 3.25rem;
  }

  .ct-hero h1 {
    font-size: clamp(2.8rem, 14vw, 4rem);
  }

  .ct-event-meta {
    display: grid;
    gap: 0.8rem;
  }

  .ct-hero__actions,
  .ct-flag-preview__actions {
    width: 100%;
  }

  .ct-hero__actions .btn,
  .ct-flag-preview__actions .btn {
    flex: 1 1 auto;
  }

  .ct-countdown {
    width: 100%;
    padding: 0.9rem;
  }

  .ct-countdown__grid strong {
    font-size: 1.25rem;
  }

  .ct-countdown__grid small {
    font-size: 0.56rem;
  }

  .ct-flag-preview__answer {
    grid-template-columns: minmax(0, 1fr) 44px;
  }

  .ct-flag-copy {
    padding-inline: 0;
  }

  .ct-flag-copy span {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
  }

  .ct-page-hero {
    padding-block: 3rem 2.5rem;
  }

  .ct-page-stats > div {
    min-width: 0;
    flex: 1;
  }

  .ct-rules__intro {
    grid-template-columns: 1fr;
    gap: 0.4rem;
  }

  .ct-auth {
    display: block;
    padding: 0;
  }

  .ct-auth .container {
    --bs-gutter-x: 2.25rem;
  }

  .ct-auth-shell {
    min-height: calc(100dvh - 65px);
  }

  .ct-auth-card {
    padding-block: 2.25rem 3rem;
  }

  #challenge-window .modal-dialog {
    max-width: none;
    height: 100dvh;
    margin: 0;
  }

  #challenge-window .modal-content {
    height: 100dvh;
    max-height: 100dvh;
    border: 0;
    border-radius: 0;
  }

  #challenge-window .modal-body {
    padding: 1rem !important;
  }

  #challenge-window .nav-tabs {
    overflow-x: auto;
    flex-wrap: nowrap;
    scrollbar-width: none;
  }

  #challenge-window .nav-tabs .nav-link {
    white-space: nowrap;
  }

  .ct-score-table > :not(caption) > * > * {
    padding-inline: 0.25rem;
  }

  .ct-score-table th:first-child {
    width: 3rem;
  }

  .ct-score-table th:last-child,
  .ct-score-table td:last-child {
    width: 5.5rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}