/* ============================================
   DevNull CTF — Pixo + DevNull Branding
   Operation Blackout
   ============================================ */

/* Fonts */
@import url('https://fonts.googleapis.com/css2?family=Share+Tech+Mono&family=Rajdhani:wght@400;500;600;700&family=VT323&display=swap');

/* Root Variables */
:root {
  --dn-bg: #1a1d29;
  --dn-bg-dark: #0f1117;
  --dn-text: #e0e0e0;
  --dn-text-muted: #7a7a8a;
  --dn-accent: #5a9fd4;
  --dn-accent-glow: rgba(90, 159, 212, 0.4);
  --dn-error: #d45a5a;
  --dn-success: #5ad4a5;
  --dn-warning: #d4a55a;
  --dn-border: rgba(90, 159, 212, 0.15);
  --dn-card-bg: rgba(26, 29, 41, 0.9);
  --dn-nav-bg: #0f1117;
  --dn-input-bg: rgba(15, 17, 23, 0.8);
  --dn-input-text: #e0e0e0;
  --dn-input-border: rgba(90, 159, 212, 0.15);
  --dn-font-body: 'Rajdhani', sans-serif;
  --dn-font-mono: 'Share Tech Mono', monospace;
  --dn-font-retro: 'VT323', monospace;
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--dn-font-body);
  background: var(--dn-bg-dark);
  color: var(--dn-text);
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
}

/* CRT Scanline Overlay */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: repeating-linear-gradient(
    0deg,
    rgba(0, 0, 0, 0.15) 0px,
    rgba(0, 0, 0, 0.15) 1px,
    transparent 1px,
    transparent 3px
  );
  pointer-events: none;
  z-index: 9999;
  opacity: 0.3;
}

/* CRT Flicker */
@keyframes crt-flicker {
  0% { opacity: 0.97; }
  5% { opacity: 0.95; }
  10% { opacity: 0.98; }
  15% { opacity: 0.96; }
  20% { opacity: 0.99; }
  50% { opacity: 0.96; }
  80% { opacity: 0.98; }
  90% { opacity: 0.95; }
  100% { opacity: 0.98; }
}

body {
  /* crt-flicker removed to prevent rapid 6.6Hz strobe/flicker on light/dark mode */
  animation: none;
}

/* Halftone Texture */
body::after {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: radial-gradient(circle, rgba(90, 159, 212, 0.03) 1px, transparent 1px);
  background-size: 4px 4px;
  pointer-events: none;
  z-index: 1;
  opacity: 0.4;
}

/* Corner Frames */
.corner-frame {
  position: fixed;
  width: 80px;
  height: 80px;
  border: 1px solid var(--dn-border);
  pointer-events: none;
  z-index: 2;
}
.corner-tl { top: 15px; left: 15px; border-right: none; border-bottom: none; }
.corner-tr { top: 15px; right: 15px; border-left: none; border-bottom: none; }
.corner-bl { bottom: 15px; left: 15px; border-right: none; border-top: none; }
.corner-br { bottom: 15px; right: 15px; border-left: none; border-top: none; }

/* ============================================
   NAVBAR
   ============================================ */
.navbar {
  background: var(--dn-nav-bg) !important;
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--dn-border) !important;
  padding: 0.6rem 0;
  font-family: var(--dn-font-mono);
  position: relative;
  z-index: 10000;
}

.navbar-brand {
  font-family: var(--dn-font-mono) !important;
  font-size: 1.1rem;
  letter-spacing: 0.15em;
  color: #fff !important;
  text-transform: uppercase;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.navbar-brand img {
  height: 28px;
  filter: brightness(1.2);
}

.nav-link {
  font-family: var(--dn-font-body) !important;
  color: var(--dn-text-muted) !important;
  font-size: 0.9rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  transition: color 0.3s ease;
  position: relative;
}

.nav-link:hover, .nav-link.active {
  color: #fff !important;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--dn-accent);
  transition: width 0.3s ease;
}

.nav-link:hover::after {
  width: 100%;
}

html, body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1 0 auto;
  position: relative;
  z-index: auto;
  padding-top: 70px;
  padding-bottom: 3.5rem;
  min-height: auto;
}

.container {
  max-width: 1200px;
}

/* ============================================
   CARDS & CHALLENGES
   ============================================ */
.card, .bg-dark {
  background: var(--dn-card-bg) !important;
  border: 1px solid var(--dn-border) !important;
  border-radius: 4px !important;
}

.card-header {
  background: rgba(15, 17, 23, 0.8) !important;
  border-bottom: 1px solid var(--dn-border) !important;
  font-family: var(--dn-font-mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.challenge-button {
  font-family: var(--dn-font-mono);
  background: transparent;
  border: 1px solid var(--dn-accent);
  color: var(--dn-accent);
  padding: 0.6rem 1.5rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  transition: all 0.3s ease;
  cursor: pointer;
}

.challenge-button:hover {
  background: var(--dn-accent);
  color: var(--dn-bg-dark);
  box-shadow: 0 0 15px var(--dn-accent-glow);
}

/* ============================================
   CATEGORY PILLS
   ============================================ */
.category-badge {
  font-family: var(--dn-font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 0.3rem 0.8rem;
  border: 1px solid var(--dn-border);
  color: var(--dn-accent);
  background: transparent;
  display: inline-block;
}

/* ============================================
   FORMS & INPUTS
   ============================================ */
.form-control, .form-input, input[type="text"], input[type="password"], input[type="email"], textarea {
  background: var(--dn-input-bg) !important;
  border: 1px solid var(--dn-input-border) !important;
  color: var(--dn-input-text) !important;
  font-family: var(--dn-font-body);
  border-radius: 2px !important;
  transition: border-color 0.3s ease;
}

.form-control:focus, .form-input:focus, input:focus, textarea:focus {
  border-color: var(--dn-accent) !important;
  box-shadow: 0 0 8px var(--dn-accent-glow) !important;
  outline: none;
}

.form-label {
  font-family: var(--dn-font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--dn-text-muted);
}

/* ============================================
   BUTTONS
   ============================================ */
.btn-primary {
  background: var(--dn-accent) !important;
  border-color: var(--dn-accent) !important;
  color: #fff !important;
  font-family: var(--dn-font-mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  border-radius: 2px !important;
  transition: all 0.3s ease;
}

.btn-primary:hover {
  background: #4a8fc4 !important;
  box-shadow: 0 0 15px var(--dn-accent-glow);
  transform: translateY(-1px);
}

.btn-outline-secondary {
  border-color: var(--dn-border) !important;
  color: var(--dn-text-muted) !important;
  font-family: var(--dn-font-mono);
  letter-spacing: 0.08em;
  border-radius: 2px !important;
}

.btn-outline-secondary:hover {
  border-color: var(--dn-accent) !important;
  color: var(--dn-accent) !important;
  background: transparent !important;
}

/* ============================================
   SCOREBOARD
   ============================================ */
.scoreboard-table th {
  font-family: var(--dn-font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--dn-accent);
  border-bottom: 1px solid var(--dn-border) !important;
}

.scoreboard-table td {
  border-bottom: 1px solid rgba(90, 159, 212, 0.08) !important;
}

.scoreboard-table tr:hover {
  background: rgba(90, 159, 212, 0.05) !important;
}

/* Score pulse animation */
@keyframes score-glow {
  0% { text-shadow: 0 0 5px var(--dn-accent-glow); }
  50% { text-shadow: 0 0 15px var(--dn-accent-glow); }
  100% { text-shadow: 0 0 5px var(--dn-accent-glow); }
}

.score-pulse {
  animation: score-glow 2s ease-in-out infinite;
}

/* ============================================
   LOADING ANIMATION
   ============================================ */
.ctf-loading {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--dn-bg-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 99999;
  transition: opacity 0.5s ease;
}

.ctf-loading.hidden {
  opacity: 0;
  pointer-events: none;
}

.ctf-loading img {
  max-width: 300px;
  image-rendering: pixelated;
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
  position: relative !important;
  margin-top: auto;
  bottom: auto !important;
  width: 100%;
  background: var(--dn-bg-dark);
  border-top: 1px solid var(--dn-border);
  padding: 1.5rem 0;
  font-family: var(--dn-font-mono);
  font-size: 0.75rem;
  color: var(--dn-text-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.footer a {
  color: var(--dn-accent) !important;
  text-decoration: none;
}

.footer a:hover {
  text-shadow: 0 0 8px var(--dn-accent-glow);
}

.dn-theme-credit {
  line-height: 1.25;
  margin-bottom: 0.2rem;
}

.dn-theme-credit a {
  text-decoration: none;
  letter-spacing: 0.055em;
  text-transform: uppercase;
}

.dn-theme-credit span {
  color: var(--dn-accent);
  letter-spacing: 0.14em;
}

body.dn-dialog-open {
  overflow: hidden;
  animation: none;
  opacity: 1;
}

.dn-dialog-shell {
  position: fixed;
  inset: 0;
  z-index: 10000;
  display: grid;
  place-items: center;
  padding: 1rem;
}

.dn-dialog-shell[hidden] {
  display: none;
}

.dn-dialog-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(1, 5, 9, 0.86);
  backdrop-filter: blur(5px);
}

.dn-dialog {
  position: relative;
  width: min(100%, 31rem);
  padding: 2rem;
  overflow: hidden;
  color: var(--dn-text);
  border: 1px solid var(--dn-accent);
  background: linear-gradient(145deg, rgba(13, 24, 30, 0.98), rgba(3, 8, 12, 0.99));
  box-shadow: 0 0 0 1px rgba(0, 255, 170, 0.12), 0 0 42px var(--dn-accent-glow);
}

.dn-dialog::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(0deg, transparent 0 4px, rgba(255, 255, 255, 0.018) 5px);
}

.dn-dialog-sigil {
  display: grid;
  width: 2.7rem;
  height: 2.7rem;
  margin-bottom: 1.15rem;
  place-items: center;
  color: #020906;
  background: var(--dn-accent);
  font: 900 1.35rem/1 var(--dn-font-mono);
  box-shadow: 0 0 18px var(--dn-accent-glow);
}

.dn-dialog-kicker,
.dn-dialog-cost {
  color: var(--dn-accent);
  font: 700 0.7rem/1.4 var(--dn-font-mono);
  letter-spacing: 0.15em;
}

.dn-dialog h2 {
  margin: 0.35rem 0 0.8rem;
  font-family: var(--dn-font-mono);
  font-size: clamp(1.3rem, 4vw, 1.8rem);
}

.dn-dialog #dn-dialog-copy {
  color: var(--dn-text-muted);
}

.dn-dialog-cost {
  margin: 1.25rem 0;
  padding: 0.8rem;
  border-left: 2px solid var(--dn-accent);
  background: rgba(0, 255, 170, 0.055);
}

.dn-dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.65rem;
}

.dn-dialog-actions button {
  padding: 0.65rem 1rem;
  font: 700 0.72rem/1 var(--dn-font-mono);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-radius: 0;
}

.dn-dialog-cancel {
  color: var(--dn-text-muted);
  border: 1px solid var(--dn-border);
  background: transparent;
}

.dn-dialog-confirm {
  color: #020906;
  border: 1px solid var(--dn-accent);
  background: var(--dn-accent);
  box-shadow: 0 0 14px var(--dn-accent-glow);
}

.dn-instance-panel {
  margin: 1rem 0 1.35rem;
  padding: 1rem;
  border: 1px solid var(--dn-border);
  border-left: 3px solid var(--dn-accent);
  background: linear-gradient(110deg, rgba(0, 255, 170, 0.055), rgba(4, 10, 14, 0.92));
}

[data-bs-theme="light"] {
  --dn-bg: #f8fafc;
  --dn-bg-dark: #ffffff;
  --dn-text: #0f172a;
  --dn-text-muted: #64748b;
  --dn-accent: #0284c7;
  --dn-accent-glow: rgba(2, 132, 199, 0.25);
  --dn-border: #cbd5e1;
  --dn-card-bg: #ffffff;
  --dn-nav-bg: #e2e8f0;
  --dn-input-bg: #ffffff;
  --dn-input-text: #0f172a;
  --dn-input-border: #94a3b8;
}

[data-bs-theme="light"] body::before {
  opacity: 0.04 !important;
}

[data-bs-theme="light"] .dn-dialog-backdrop {
  background: rgba(12, 24, 31, 0.62);
  backdrop-filter: blur(3px);
}

[data-bs-theme="light"] .dn-dialog {
  color: #12222b;
  border-color: #176b87;
  background: #f7fbfd;
  box-shadow: 0 18px 60px rgba(5, 24, 34, 0.32), 0 0 0 1px rgba(23, 107, 135, 0.18);
}

[data-bs-theme="light"] .dn-dialog::before {
  opacity: 0.18;
}

[data-bs-theme="light"] .dn-dialog-sigil,
[data-bs-theme="light"] .dn-dialog-confirm {
  color: #ffffff;
  border-color: #176b87;
  background: #176b87;
  box-shadow: none;
}

[data-bs-theme="light"] .dn-dialog-kicker,
[data-bs-theme="light"] .dn-dialog-cost {
  color: #0b617e;
}

[data-bs-theme="light"] .dn-dialog #dn-dialog-copy {
  color: #344b57;
}

[data-bs-theme="light"] .dn-dialog-cost {
  border-left-color: #176b87;
  background: #e4f2f7;
}

[data-bs-theme="light"] .dn-dialog-cancel {
  color: #213943;
  border-color: #78909c;
  background: #ffffff;
}

[data-bs-theme="light"] .dn-instance-panel {
  color: #263b45;
  border-color: #aec6d0;
  border-left-color: #176b87;
  background: #f4f9fb;
}

[data-bs-theme="light"] .dn-instance-head strong {
  color: #12222b;
}

[data-bs-theme="light"] .dn-instance-kicker,
[data-bs-theme="light"] .dn-instance-status {
  color: #0b617e;
}

/* ============================================
   CHALLENGE MODAL & FLAG FEEDBACK (DARK & LIGHT)
   ============================================ */

/* Flag Input & Button Feedback States */
.dn-input-error {
  border-color: var(--dn-error) !important;
  box-shadow: 0 0 12px rgba(212, 90, 90, 0.45) !important;
  animation: dn-input-shake 0.35s ease-in-out;
}

.dn-input-success {
  border-color: var(--dn-success) !important;
  box-shadow: 0 0 16px rgba(90, 212, 165, 0.5) !important;
}

@keyframes dn-input-shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-6px); }
  40%, 80% { transform: translateX(6px); }
}

.dn-btn-error {
  background: var(--dn-error) !important;
  border-color: var(--dn-error) !important;
  color: #fff !important;
  box-shadow: 0 0 10px rgba(212, 90, 90, 0.4) !important;
}

.dn-btn-success {
  background: var(--dn-success) !important;
  border-color: var(--dn-success) !important;
  color: #0b0d13 !important;
  box-shadow: 0 0 15px rgba(90, 212, 165, 0.5) !important;
}

/* Alert Notification Banner Styling (Dark Mode default) */
.notification-row .alert {
  padding: 0.85rem 1.25rem;
  font-family: var(--dn-font-mono);
  font-size: 0.88rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  border-radius: 4px;
  margin-top: 1rem;
  transition: all 0.25s ease;
  display: block;
}

.notification-row .alert-danger {
  background: rgba(212, 90, 90, 0.14) !important;
  color: #ff7878 !important;
  border: 1px solid #d45a5a !important;
  box-shadow: 0 0 16px rgba(212, 90, 90, 0.25) !important;
}

.notification-row .alert-success {
  background: rgba(90, 212, 165, 0.14) !important;
  color: #5affba !important;
  border: 1px solid #5ad4a5 !important;
  box-shadow: 0 0 20px rgba(90, 212, 165, 0.3) !important;
}

.notification-row .alert-info {
  background: rgba(90, 159, 212, 0.14) !important;
  color: #8acaff !important;
  border: 1px solid #5a9fd4 !important;
}

.notification-row .alert-warning {
  background: rgba(212, 165, 90, 0.14) !important;
  color: #ffd07a !important;
  border: 1px solid #d4a55a !important;
}

/* Light Mode Overrides for Challenge Modal & Inputs */
[data-bs-theme="light"] .modal-content {
  background: #ffffff !important;
  border: 1px solid #cbd5e1 !important;
  box-shadow: 0 20px 50px rgba(15, 23, 42, 0.2) !important;
  color: #0f172a !important;
}

[data-bs-theme="light"] .modal-content .modal-body {
  background: #ffffff !important;
  color: #0f172a !important;
}

[data-bs-theme="light"] .modal-content h2,
[data-bs-theme="light"] .modal-content h3,
[data-bs-theme="light"] .modal-content .challenge-name,
[data-bs-theme="light"] .modal-content .challenge-value,
[data-bs-theme="light"] .modal-content .challenge-desc,
[data-bs-theme="light"] .modal-content p,
[data-bs-theme="light"] .modal-content li,
[data-bs-theme="light"] .modal-content span:not(.badge):not(.status-led),
[data-bs-theme="light"] .modal-content strong,
[data-bs-theme="light"] .modal-content em,
[data-bs-theme="light"] .modal-content label {
  color: #0f172a !important;
}

[data-bs-theme="light"] .challenge-desc p,
[data-bs-theme="light"] .challenge-desc span,
[data-bs-theme="light"] .challenge-desc strong {
  color: #1e293b !important;
}

[data-bs-theme="light"] .challenge-desc a {
  color: #0284c7 !important;
  text-decoration: underline !important;
}

[data-bs-theme="light"] .challenge-connection-info {
  color: #0f172a !important;
  background: #f1f5f9 !important;
  border: 1px solid #cbd5e1 !important;
  padding: 0.4rem 0.8rem;
  border-radius: 4px;
}

[data-bs-theme="light"] .modal-content code {
  background: #f1f5f9 !important;
  color: #0f172a !important;
  border: 1px solid #e2e8f0 !important;
}

[data-bs-theme="light"] .modal-content .text-muted,
[data-bs-theme="light"] .modal-content small.text-muted,
[data-bs-theme="light"] .modal-content small {
  color: #475569 !important;
}

[data-bs-theme="light"] .modal-content .nav-tabs {
  border-bottom-color: #cbd5e1 !important;
}

[data-bs-theme="light"] .modal-content .nav-tabs .nav-link {
  color: #475569 !important;
}

[data-bs-theme="light"] .modal-content .nav-tabs .nav-link.active {
  color: #0369a1 !important;
  border-color: #cbd5e1 #cbd5e1 #ffffff !important;
  background: #ffffff !important;
}

/* Hints / details in light mode */
[data-bs-theme="light"] .challenge-hints details,
[data-bs-theme="light"] .modal-content details {
  background: #f8fafc !important;
  border: 1px solid #cbd5e1 !important;
  border-radius: 4px;
  padding: 0.5rem 0.75rem;
  margin-bottom: 0.5rem;
  color: #0f172a !important;
}

[data-bs-theme="light"] .challenge-hints details summary,
[data-bs-theme="light"] .modal-content details summary {
  color: #0369a1 !important;
  font-weight: 600 !important;
  cursor: pointer;
}

[data-bs-theme="light"] .challenge-hints details[open],
[data-bs-theme="light"] .modal-content details[open] {
  background: #ffffff !important;
  border-color: #94a3b8 !important;
}

/* Light mode Flag Input & Submit */
[data-bs-theme="light"] #challenge-input,
[data-bs-theme="light"] .challenge-input,
[data-bs-theme="light"] .form-control,
[data-bs-theme="light"] input[type="text"],
[data-bs-theme="light"] input[type="password"],
[data-bs-theme="light"] input[type="email"],
[data-bs-theme="light"] textarea {
  background: #ffffff !important;
  border: 1px solid #94a3b8 !important;
  color: #0f172a !important;
}

[data-bs-theme="light"] #challenge-input::placeholder,
[data-bs-theme="light"] .challenge-input::placeholder,
[data-bs-theme="light"] .form-control::placeholder,
[data-bs-theme="light"] input::placeholder {
  color: #64748b !important;
}

[data-bs-theme="light"] #challenge-input:focus,
[data-bs-theme="light"] .form-control:focus {
  border-color: #0284c7 !important;
  box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.2) !important;
  background: #ffffff !important;
  color: #0f172a !important;
}

[data-bs-theme="light"] #challenge-submit {
  background: #0284c7 !important;
  border-color: #0284c7 !important;
  color: #ffffff !important;
  font-weight: 600 !important;
}

[data-bs-theme="light"] #challenge-submit:hover {
  background: #0369a1 !important;
  border-color: #0369a1 !important;
  color: #ffffff !important;
}

/* Modal Close button in light mode */
[data-bs-theme="light"] .btn-close {
  filter: none !important;
  opacity: 0.7;
}

[data-bs-theme="light"] .btn-close:hover {
  opacity: 1;
}

/* Light mode alert banners */
[data-bs-theme="light"] .notification-row .alert-danger {
  background: #fef2f2 !important;
  color: #991b1b !important;
  border: 1px solid #f87171 !important;
}

[data-bs-theme="light"] .notification-row .alert-success {
  background: #f0fdf4 !important;
  color: #166534 !important;
  border: 1px solid #4ade80 !important;
}

[data-bs-theme="light"] .dn-input-error,
[data-bs-theme="light"] #challenge-input.is-invalid {
  border-color: #dc2626 !important;
  background: #fef2f2 !important;
  color: #991b1b !important;
}

[data-bs-theme="light"] .dn-input-success,
[data-bs-theme="light"] #challenge-input.is-valid {
  border-color: #16a34a !important;
  background: #f0fdf4 !important;
  color: #166534 !important;
}

[data-bs-theme="light"] .dn-btn-error,
[data-bs-theme="light"] #challenge-submit.btn-danger {
  background: #dc2626 !important;
  border-color: #dc2626 !important;
  color: #ffffff !important;
}

[data-bs-theme="light"] .dn-btn-success,
[data-bs-theme="light"] #challenge-submit.btn-success {
  background: #16a34a !important;
  border-color: #16a34a !important;
  color: #ffffff !important;
}

.dn-instance-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
}

.dn-instance-head strong {
  display: block;
  margin-top: 0.2rem;
  color: var(--dn-text);
  font-family: var(--dn-font-mono);
  font-size: 1rem;
}

.dn-instance-kicker,
.dn-instance-status,
.dn-instance-panel small {
  font-family: var(--dn-font-mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.dn-instance-kicker,
.dn-instance-status {
  color: var(--dn-accent);
  font-size: 0.65rem;
}

.dn-instance-status {
  padding: 0.35rem 0.5rem;
  border: 1px solid currentColor;
}

.dn-instance-panel[data-state="stopped"] .dn-instance-status { color: #82909a; }
.dn-instance-panel[data-state="starting"] .dn-instance-status { color: #ffd166; }
.dn-instance-panel[data-state="error"] .dn-instance-status { color: #ff5d73; }
.dn-instance-panel > p { margin: 0.9rem 0; color: var(--dn-text-muted); }
.dn-instance-panel small { display: block; margin-top: 0.8rem; color: var(--dn-text-muted); font-size: 0.57rem; }

.dn-instance-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.dn-instance-controls button,
.dn-instance-controls a {
  padding: 0.55rem 0.75rem;
  color: var(--dn-text);
  border: 1px solid var(--dn-border);
  border-radius: 0;
  background: rgba(255, 255, 255, 0.025);
  font: 700 0.65rem/1 var(--dn-font-mono);
  letter-spacing: 0.06em;
  text-decoration: none;
  text-transform: uppercase;
}

.dn-instance-controls [data-instance-action="start"],
.dn-instance-controls [data-instance-open] {
  color: #020906;
  border-color: var(--dn-accent);
  background: var(--dn-accent);
}

.dn-instance-controls button:disabled { opacity: 0.45; cursor: wait; }

/* ============================================
   SCROLLBAR
   ============================================ */
::-webkit-scrollbar {
  width: 6px;
}

::-webkit-scrollbar-track {
  background: var(--dn-bg-dark);
}

::-webkit-scrollbar-thumb {
  background: var(--dn-accent);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: #4a8fc4;
}

/* ============================================
   CHALLENGE MODAL / VIEW
   ============================================ */
.modal-backdrop {
  z-index: 10010 !important;
}

/* The fixed navigation lives at z-index:10000. Keep CTFd's challenge view
   above it and constrain its content to the browser viewport. */
.modal {
  z-index: 10020 !important;
  padding: 1rem 0;
  overflow-y: auto;
}

.modal-dialog {
  min-height: calc(100% - 2rem);
  margin: 0 auto;
}

.modal-content {
  max-height: calc(100vh - 2rem);
  overflow-y: auto;
}

.challenge-desc {
  font-family: var(--dn-font-body);
  line-height: 1.7;
  color: var(--dn-text);
}

.challenge-desc code {
  font-family: var(--dn-font-mono);
  background: rgba(90, 159, 212, 0.1);
  padding: 0.15rem 0.4rem;
  border-radius: 2px;
  color: var(--dn-accent);
  font-size: 0.9em;
}

.flag-input {
  font-family: var(--dn-font-mono);
  background: rgba(15, 17, 23, 0.9);
  border: 1px solid var(--dn-accent);
  color: var(--dn-accent);
  padding: 0.8rem 1rem;
  font-size: 0.95rem;
  letter-spacing: 0.05em;
  width: 100%;
  border-radius: 2px;
}

.flag-input::placeholder {
  color: var(--dn-text-muted);
  opacity: 0.5;
}

.flag-input:focus {
  box-shadow: 0 0 15px var(--dn-accent-glow);
  outline: none;
}

/* ============================================
   NOTIFICATIONS / TOASTS
   ============================================ */
.toast {
  background: var(--dn-card-bg) !important;
  border: 1px solid var(--dn-border) !important;
  color: var(--dn-text) !important;
  font-family: var(--dn-font-mono);
  border-radius: 2px !important;
}

.toast-success {
  border-color: var(--dn-success) !important;
}

.toast-error {
  border-color: var(--dn-error) !important;
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 768px) {
  .corner-frame { display: none; }
  body::before { opacity: 0.15; }
  .navbar-brand { font-size: 0.9rem; }
}

/* ============================================
   MISC UTILITIES
   ============================================ */
.text-accent { color: var(--dn-accent) !important; }
.text-muted-dn { color: var(--dn-text-muted) !important; }
.bg-dn { background: var(--dn-bg) !important; }
.border-dn { border-color: var(--dn-border) !important; }
.font-mono { font-family: var(--dn-font-mono) !important; }
.font-retro { font-family: var(--dn-font-retro) !important; }
.letter-space { letter-spacing: 0.15em; }
.text-uppercase { text-transform: uppercase; }

/* Glow effect */
.glow {
  text-shadow: 0 0 10px var(--dn-accent-glow);
}

/* Typing cursor */
@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.cursor-blink::after {
  content: '|';
  animation: blink 1s step-end infinite;
  color: var(--dn-accent);
}

/* Operation Blackout loader */
.op-blackout-loader {
  width: 84px;
  height: 84px;
  display: block;
  object-fit: contain;
  filter: drop-shadow(0 0 10px rgba(0, 229, 255, 0.8))
          drop-shadow(0 0 22px rgba(255, 45, 152, 0.35));
  animation: blackout-loader-pulse 1.35s ease-in-out infinite,
             blackout-loader-orbit 6s linear infinite;
}

/* Operation Blackout landing page */
.dn-header-brand { display: inline-flex; align-items: center; gap: .55rem; }
.dn-header-logo { width: 34px; height: 34px; object-fit: contain; border-radius: 6px; }

.ob-home {
  position: relative;
  max-width: 1040px;
  margin: .75rem auto;
  padding: clamp(1rem, 2vw, 1.5rem);
  overflow: hidden;
  text-align: center;
  border: 1px solid var(--dn-border);
  background: radial-gradient(circle at 50% 0%, rgba(0, 229, 255, 0.12), transparent 42%), var(--dn-card-bg);
}
body:has(.ob-home) main { flex: 1 1 auto; display: flex; flex-direction: column; justify-content: center; align-items: center; padding: clamp(0.75rem, 2vh, 1.75rem) 1.25rem !important; margin: 0 !important; }
body:has(.ob-home) footer.footer { flex-shrink: 0; height: auto !important; min-height: auto !important; padding: clamp(0.45rem, 1.1vh, 0.75rem) 0 !important; margin-top: 0 !important; line-height: 1.4 !important; }
body:has(.ob-home) footer.footer .container { height: auto !important; min-height: auto !important; margin: 0 auto !important; padding: 0 !important; }
.ob-scanline { position: absolute; inset: 0 0 auto; height: 2px; background: linear-gradient(90deg, transparent, var(--dn-accent), transparent); box-shadow: 0 0 18px var(--dn-accent); }
.ob-kicker { margin: 0 0 1rem; color: var(--dn-accent); font: 0.75rem var(--dn-font-mono); letter-spacing: 0.2em; }
.ob-home h1 { margin: 0; color: #ffffff; font: clamp(2.4rem, 6vw, 4.25rem) var(--dn-font-retro); letter-spacing: 0.04em; text-transform: uppercase; }
.ob-home h1 .ob-operation-text,
.ob-home h1 .dn-white-text { color: #ffffff; text-shadow: none; }
.ob-home h1 .dn-accent-text,
.ob-home h1 span.dn-accent-text { color: var(--dn-accent); text-shadow: 0 0 18px var(--dn-accent-glow); }
.ob-lede { max-width: 620px; margin: .75rem auto 1.25rem; color: var(--dn-text-muted); font-size: 1rem; }
/* ============================================
   DevNull Mechanical Split-Flap Clock Architecture
   ============================================ */
:root {
  --card-width: clamp(34px, 5.2vw, 64px);
  --card-height: clamp(52px, 8vw, 92px);
  --card-radius: 5px;
  --card-bg-top: #181c26;
  --card-bg-bottom: #12151e;
  --card-text: #f4f6fa;
  --seam-gap: 2px;
}

.ob-countdown {
  margin: 0 auto 1.5rem;
  max-width: 780px;
  padding: 0;
  border: none;
  background: transparent;
}

/* Clock Housing Enclosure */
.flip-clock-chassis {
  position: relative;
  background: linear-gradient(180deg, #161924 0%, #0d1017 100%);
  border: 1px solid #283042;
  box-shadow:
    0 0 0 1px rgba(0, 0, 0, 0.85),
    0 20px 40px rgba(0, 0, 0, 0.65),
    inset 0 1px 0 rgba(255, 255, 255, 0.1),
    inset 0 -1px 0 rgba(0, 0, 0, 0.6);
  border-radius: 10px;
  padding: 1.25rem 1.6rem 1.1rem;
  width: 100%;
  box-sizing: border-box;
  user-select: none;
}

/* Chassis Top Corner Screws / Rivets */
.flip-clock-chassis::before,
.flip-clock-chassis::after {
  content: '';
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, #5a627a 0%, #1c202a 80%);
  box-shadow: inset 0 1px 1px rgba(255,255,255,0.4), 0 1px 2px rgba(0,0,0,0.8);
  top: 10px;
}
.flip-clock-chassis::before { left: 12px; }
.flip-clock-chassis::after { right: 12px; }

/* Subdued Glass Sheen Reflection */
.chassis-glass-glare {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 40%;
  background: linear-gradient(135deg, rgba(255,255,255,0.035) 0%, rgba(255,255,255,0.008) 50%, transparent 100%);
  pointer-events: none;
  border-radius: 10px 10px 0 0;
}

/* Telemetry Header Bar */
.clock-telemetry-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  padding-bottom: 0.65rem;
  margin-bottom: 1.1rem;
  font-size: 0.68rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  font-family: var(--dn-font-mono);
}
.telemetry-status {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--dn-accent);
}
.status-led {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--dn-accent);
  box-shadow: 0 0 8px var(--dn-accent);
  animation: led-pulse 2s infinite ease-in-out;
}
@keyframes led-pulse {
  0%, 100% { opacity: 0.9; transform: scale(1); }
  50% { opacity: 0.3; transform: scale(0.8); }
}
.telemetry-node {
  color: var(--dn-text-muted);
}

/* Main Clock Modules Board */
.split-flap-board {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: clamp(0.35rem, 1.2vw, 0.9rem);
  perspective: 1000px;
}

/* Unit Group */
.flap-unit-group {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.flap-digits-pair {
  display: flex;
  gap: 4px;
  background: #080a0f;
  padding: 5px;
  border-radius: 7px;
  box-shadow: inset 0 2px 5px rgba(0,0,0,0.9), 0 1px 0 rgba(255,255,255,0.05);
  border: 1px solid #1a1e2b;
}

/* Separator Colon Pillar */
.flap-separator {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 10px;
  height: var(--card-height);
  padding: 0 1px;
}
.flap-separator-dot {
  width: clamp(4px, 0.7vw, 7px);
  height: clamp(4px, 0.7vw, 7px);
  border-radius: 50%;
  background: #252d3d;
  box-shadow: inset 0 1px 2px rgba(0,0,0,0.8), 0 1px 0 rgba(255,255,255,0.08);
}
.flap-separator-dot.active {
  background: var(--dn-accent);
  box-shadow: 0 0 8px var(--dn-accent-glow);
}

/* Single Split-Flap Digit Module */
.split-flap-digit {
  position: relative;
  width: var(--card-width);
  height: var(--card-height);
  perspective: 600px;
  font-size: clamp(1.9rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: var(--card-height);
  text-align: center;
  user-select: none;
}

/* Side Hinge Pivot Notches */
.split-flap-digit::before,
.split-flap-digit::after {
  content: '';
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 6px;
  background: #080a0e;
  border: 1px solid #252b3a;
  z-index: 20;
  pointer-events: none;
}
.split-flap-digit::before {
  left: -2px;
  border-radius: 0 2px 2px 0;
}
.split-flap-digit::after {
  right: -2px;
  border-radius: 2px 0 0 2px;
}

/* Top Retaining Escapement Pawl (Mechanical Clip) */
.split-flap-digit .escapement-pawl {
  position: absolute;
  top: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 7px;
  height: 4px;
  background: #353e54;
  border-radius: 1px 1px 2px 2px;
  box-shadow: 0 1px 2px rgba(0,0,0,0.8), inset 0 1px 0 rgba(255,255,255,0.25);
  z-index: 25;
  pointer-events: none;
}

/* Flap Halves */
.flap-half {
  position: absolute;
  left: 0;
  right: 0;
  overflow: hidden;
  box-sizing: border-box;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.flap-glyph {
  display: block;
  width: 100%;
  height: var(--card-height);
  line-height: var(--card-height);
  text-align: center;
  color: var(--card-text);
  font-family: 'Rajdhani', var(--dn-font-mono), sans-serif;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-shadow: 0 1px 2px rgba(0,0,0,0.8);
}

/* Upper Flap Half */
.flap-top {
  top: 0;
  height: calc(var(--card-height) / 2);
  transform-origin: bottom center;
  border-radius: var(--card-radius) var(--card-radius) 0 0;
  background: linear-gradient(180deg, #1b202c 0%, #131620 90%, #0d0f15 100%);
  border: 1px solid #272f40;
  border-bottom: 0;
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.1);
}
.flap-top .flap-glyph {
  margin-top: 0;
}

/* Lower Flap Half */
.flap-bottom {
  bottom: 0;
  height: calc(var(--card-height) / 2);
  transform-origin: top center;
  border-radius: 0 0 var(--card-radius) var(--card-radius);
  background: linear-gradient(180deg, #0c0e14 0%, #11141c 15%, #171b25 100%);
  border: 1px solid #272f40;
  border-top: 0;
  box-shadow: inset 0 -1px 0 rgba(0,0,0,0.5), 0 3px 5px rgba(0,0,0,0.4);
}
.flap-bottom .flap-glyph {
  margin-top: calc(var(--card-height) * -0.5);
}

/* Central Seam Gap Bar */
.split-flap-digit .seam-bar {
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: var(--seam-gap);
  transform: translateY(-50%);
  background: #06080b;
  box-shadow: 0 0 2px rgba(0, 0, 0, 0.95);
  z-index: 15;
  pointer-events: none;
}

/* Stationary Background Cards */
.flap-static-top { z-index: 1; }
.flap-static-bottom { z-index: 1; }

/* Animated Falling Flaps */
.flap-falling-top {
  z-index: 5;
  transform: rotateX(0deg);
}
.flap-falling-bottom {
  z-index: 6;
  transform: rotateX(90deg);
}

/* 3D Flip Mechanics & Physical Bounce */
.split-flap-digit.is-flipping .flap-falling-top {
  animation: flap-fall-top 0.16s cubic-bezier(0.4, 0, 0.7, 1) forwards;
}

.split-flap-digit.is-flipping .flap-falling-bottom {
  animation: flap-fall-bottom 0.22s cubic-bezier(0.2, 0.8, 0.4, 1.25) 0.13s forwards;
}

@keyframes flap-fall-top {
  0% {
    transform: rotateX(0deg);
    filter: brightness(1);
  }
  100% {
    transform: rotateX(-90deg);
    filter: brightness(0.45);
  }
}

@keyframes flap-fall-bottom {
  0% {
    transform: rotateX(90deg);
    filter: brightness(0.5);
  }
  65% {
    transform: rotateX(0deg);
    filter: brightness(1.05);
  }
  80% {
    transform: rotateX(5.5deg);
  }
  90% {
    transform: rotateX(-2deg);
  }
  100% {
    transform: rotateX(0deg);
    filter: brightness(1);
  }
}

/* Label under digits */
.flap-unit-label {
  margin-top: 0.55rem;
  font-size: 0.62rem;
  letter-spacing: 0.18em;
  color: var(--dn-accent);
  text-transform: uppercase;
  font-weight: 600;
  font-family: var(--dn-font-mono);
}

/* Control Panel & Audio Button */
.clock-controls-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 1.2rem;
  padding-top: 0.75rem;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  flex-wrap: wrap;
  gap: 0.75rem;
}

.clock-status-caption {
  font-size: 0.76rem;
  color: #94a3b8;
  letter-spacing: 0.05em;
  font-family: var(--dn-font-mono);
}
.clock-status-caption strong {
  color: #f1f5f9;
}

.clock-buttons {
  display: flex;
  gap: 0.5rem;
}

.btn-tactical {
  background: #131722;
  color: var(--dn-text);
  border: 1px solid #283042;
  padding: 0.35rem 0.7rem;
  font-family: var(--dn-font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-radius: 4px;
  cursor: pointer;
  transition: all 0.15s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}
.btn-tactical:hover {
  background: #1c2333;
  border-color: var(--dn-accent);
  color: #fff;
  box-shadow: 0 0 10px var(--dn-accent-glow);
}
.btn-tactical.active {
  border-color: var(--dn-success);
  color: var(--dn-success);
  background: rgba(0, 255, 136, 0.08);
}
.ob-actions { display: flex; justify-content: center; flex-wrap: wrap; gap: .6rem; margin-bottom: 1.25rem; }
.ob-actions a { padding: .65rem .95rem; font: .75rem var(--dn-font-mono); letter-spacing: 0.1em; text-decoration: none; text-transform: uppercase; }
.ob-primary { color: #000; background: var(--dn-accent); box-shadow: 0 0 18px var(--dn-accent-glow); }
.ob-secondary { color: var(--dn-text); border: 1px solid var(--dn-border); }
.ob-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: .65rem; text-align: left; }
.ob-grid article { padding: .8rem; border-top: 2px solid var(--dn-accent); background: rgba(255,255,255,0.025); }
.ob-grid span { color: var(--dn-accent); font: 0.75rem var(--dn-font-mono); }
.ob-grid h2 { margin: .35rem 0; color: var(--dn-text); font: 1rem var(--dn-font-retro); text-transform: uppercase; }
.ob-grid p, .ob-footnote { margin: 0; color: var(--dn-text-muted); font-size: .78rem; }
.ob-footnote { margin-top: .8rem; font-family: var(--dn-font-mono); }
.ob-rules { max-width: 900px; margin: 2.5rem auto; padding: clamp(1.5rem, 5vw, 3.5rem); border: 1px solid var(--dn-border); background: var(--dn-card-bg); }
.ob-rules h1 { margin: 0; color: var(--dn-text); font-family: var(--dn-font-retro); text-transform: uppercase; }
.ob-rules ol { margin: 2rem 0; padding: 0; list-style: none; counter-reset: rules; }
.ob-rules li { position: relative; margin: .75rem 0; padding: 1rem 1rem 1rem 3.6rem; color: var(--dn-text-muted); border-left: 2px solid var(--dn-border); background: rgba(255,255,255,.025); counter-increment: rules; }
.ob-rules li::before { content: counter(rules, decimal-leading-zero); position: absolute; left: 1rem; color: var(--dn-accent); font-family: var(--dn-font-mono); }
.ob-rules li strong { color: var(--dn-text); }
@media (max-width: 650px) {
  :root {
    --card-width: clamp(20px, 6vw, 30px);
    --card-height: clamp(32px, 9.6vw, 48px);
    --card-radius: 4px;
  }
  .ob-home {
    margin: 0.5rem auto;
    padding: 0.75rem 0.4rem;
  }
  .ob-grid { grid-template-columns: 1fr; }
  .flip-clock-chassis {
    padding: 0.85rem 0.4rem 0.75rem;
    border-radius: 8px;
  }
  .split-flap-board {
    gap: clamp(2px, 0.8vw, 4px);
  }
  .flap-digits-pair {
    padding: 2px;
    gap: 2px;
    border-radius: 4px;
  }
  .split-flap-digit {
    font-size: clamp(1.15rem, 5.2vw, 1.75rem);
  }
  .flap-unit-label {
    font-size: 0.5rem;
    letter-spacing: 0.06em;
    margin-top: 0.2rem;
  }
  .flap-separator {
    gap: 5px;
    padding: 0;
  }
  .flap-separator-dot {
    width: 4px;
    height: 4px;
  }
  .clock-telemetry-bar {
    font-size: 0.54rem;
    letter-spacing: 0.08em;
    margin-bottom: 0.6rem;
    flex-direction: column;
    gap: 0.2rem;
  }
  .clock-controls-bar {
    margin-top: 0.75rem;
    flex-direction: column;
    gap: 0.5rem;
    align-items: center;
    text-align: center;
  }
  .clock-status-caption {
    font-size: 0.65rem;
    text-align: center;
    line-height: 1.4;
  }
}

@media (max-width: 380px) {
  :root {
    --card-width: 18px;
    --card-height: 28px;
  }
  .split-flap-digit {
    font-size: 1rem;
  }
  .flip-clock-chassis {
    padding: 0.6rem 0.25rem;
  }
  .flap-digits-pair {
    padding: 1px;
    gap: 1px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .split-flap-digit.is-flipping .flap-falling-top,
  .split-flap-digit.is-flipping .flap-falling-bottom {
    animation: none;
  }
}

@keyframes blackout-loader-pulse {
  0%, 100% { opacity: 0.72; transform: scale(0.92); }
  50% { opacity: 1; transform: scale(1.06); }
}

@keyframes blackout-loader-orbit {
  from { rotate: 0deg; }
  to { rotate: 360deg; }
}

@media (prefers-reduced-motion: reduce) {
  .op-blackout-loader { animation: none; }
}

/* Matrix rain background (optional) */
.matrix-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  opacity: 0.03;
  pointer-events: none;
}