/**
 * Styles
 * Dark Mode Gaming Theme with Neon Accents
 */

/* ==================== ROOT VARIABLES ==================== */
:root {
    /* Color Palette - Dark Cyber Theme */
    --color-bg-primary: #0a0e1a;
    --color-bg-secondary: #111827;
    --color-bg-tertiary: #1a1f35;
    --color-bg-card: #141b2d;
    
    /* Neon Accents */
    --color-neon-cyan: #00ffff;
    --color-neon-magenta: #ff00ff;
    --color-neon-green: #00ff88;
    --color-neon-blue: #0088ff;
    --color-neon-red: #ff0055;
    --color-neon-yellow: #ffff00;
    
    /* Text Colors */
    --color-text-primary: #e5e7eb;
    --color-text-secondary: #9ca3af;
    --color-text-muted: #6b7280;
    --color-text-accent: var(--color-neon-cyan);
    
    /* Status Colors */
    --color-success: var(--color-neon-green);
    --color-warning: var(--color-neon-yellow);
    --color-error: var(--color-neon-red);
    --color-info: var(--color-neon-blue);
    
    /* Difficulty Colors */
    --color-easy: #00ff88;
    --color-medium: #ffaa00;
    --color-hard: #ff5500;
    --color-expert: #ff0055;
    
    /* Fonts */
    --font-primary: 'Share Tech Mono', monospace;
    --font-heading: 'Orbitron', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    
    /* Borders */
    --border-radius: 4px;
    --border-width: 1px;
    --border-color: rgba(0, 255, 255, 0.3);
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.5);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.6);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.7);
    --shadow-glow: 0 0 20px rgba(0, 255, 255, 0.5);
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 300ms ease;
    --transition-slow: 500ms ease;
}

/* ==================== RESET & BASE ==================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* ==================== BACKGROUND EFFECTS ==================== */
.background-grid {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(rgba(0, 255, 255, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 255, 255, 0.03) 1px, transparent 1px);
    background-size: 50px 50px;
    pointer-events: none;
    z-index: -1;
}

.scanline {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        to bottom,
        transparent 50%,
        rgba(0, 255, 255, 0.02) 51%
    );
    background-size: 100% 4px;
    pointer-events: none;
    z-index: -1;
    animation: scanline 8s linear infinite;
}

@keyframes scanline {
    0% { transform: translateY(0); }
    100% { transform: translateY(100%); }
}

/* ==================== CONTAINER ==================== */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--spacing-md);
}

/* ==================== HEADER ==================== */
.header {
    background: var(--color-bg-secondary);
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-heading);
}

.logo-icon {
    font-size: 2rem;
    color: var(--color-neon-cyan);
    animation: pulse-glow 2s ease-in-out infinite;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--color-text-primary);
    text-shadow: 0 0 10px var(--color-neon-cyan);
}

.version {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    padding: 0.25rem 0.5rem;
    border: 1px solid var(--color-text-muted);
    border-radius: 2px;
}

@keyframes pulse-glow {
    0%, 100% { opacity: 1; text-shadow: 0 0 10px var(--color-neon-cyan); }
    50% { opacity: 0.7; text-shadow: 0 0 20px var(--color-neon-cyan); }
}

/* ==================== NAVIGATION ==================== */
.nav {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.nav-btn {
    font-family: var(--font-heading);
    font-size: 0.875rem;
    font-weight: 700;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: transparent;
    color: var(--color-text-secondary);
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.nav-btn:hover {
    color: var(--color-text-accent);
    border-color: var(--color-text-accent);
    box-shadow: 0 0 10px rgba(0, 255, 255, 0.3);
}

.nav-btn.active {
    background: rgba(0, 255, 255, 0.1);
    color: var(--color-text-accent);
    border-color: var(--color-text-accent);
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.4);
}

.nav-btn.admin-btn {
    text-decoration: none;
    background: linear-gradient(135deg, #DC143C, #8B0000);
    border-color: #DC143C;
    color: #FFFFFF;
    text-shadow: 0 0 5px rgba(220, 20, 60, 0.5);
}

.nav-btn.admin-btn:hover {
    background: linear-gradient(135deg, #FF1744, #DC143C);
    border-color: #FF1744;
    box-shadow: 0 0 15px rgba(220, 20, 60, 0.6);
    color: #FFFFFF;
}

/* ==================== USER CONTROLS ==================== */
.user-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.user-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: rgba(0, 255, 255, 0.05);
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
}

.agent-rank {
    font-family: var(--font-heading);
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--color-neon-green);
    text-shadow: 0 0 5px var(--color-neon-green);
}

.agent-name {
    font-size: 0.875rem;
    color: var(--color-text-primary);
}

.btn-auth, .btn-logout {
    font-family: var(--font-heading);
    font-size: 0.875rem;
    font-weight: 700;
    padding: var(--spacing-sm) var(--spacing-lg);
    background: transparent;
    color: var(--color-text-accent);
    border: var(--border-width) solid var(--color-text-accent);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-auth:hover, .btn-logout:hover {
    background: var(--color-text-accent);
    color: var(--color-bg-primary);
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.5);
}

/* ==================== MAIN CONTENT ==================== */
.main-content {
    min-height: 70vh;
}

.section {
    display: none;
    animation: fadeIn var(--transition-normal);
}

.section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.section-header {
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

.section-header h1 {
    font-family: var(--font-heading);
    font-size: 2rem;
    font-weight: 900;
    color: var(--color-text-accent);
    text-shadow: 0 0 15px var(--color-neon-cyan);
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
}

/* ==================== DASHBOARD ==================== */
.dashboard {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

/* ==================== CARDS ==================== */
.card {
    background: var(--color-bg-card);
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-fast);
}

.card:hover {
    border-color: var(--color-text-accent);
    box-shadow: 0 0 20px rgba(0, 255, 255, 0.2);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: var(--border-width) solid var(--border-color);
}

.card-header h2 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text-accent);
}

.status-indicator {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.75rem;
    color: var(--color-success);
}

.pulse {
    width: 8px;
    height: 8px;
    background: var(--color-success);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; box-shadow: 0 0 5px var(--color-success); }
    50% { opacity: 0.3; box-shadow: 0 0 15px var(--color-success); }
}

/* ==================== STATS ==================== */
.stat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.stat-item {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    min-width: 0; /* Umožní word-wrap */
}

.stat-label {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.stat-value {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text-accent);
    text-shadow: 0 0 10px var(--color-neon-cyan);
    word-break: break-word; /* Zalomí dlouhé texty */
    overflow-wrap: break-word;
}

/* ==================== PROGRESS BAR ==================== */
.progress-bar-container {
    width: 100%;
    height: 20px;
    background: var(--color-bg-tertiary);
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
    overflow: hidden;
    position: relative;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--color-neon-cyan), var(--color-neon-blue));
    box-shadow: 0 0 20px var(--color-neon-cyan);
    transition: width var(--transition-slow);
    position: relative;
    overflow: hidden;
}

.progress-bar::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.3),
        transparent
    );
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

/* ==================== CHALLENGES GRID ==================== */
.challenges-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.challenge-card {
    background: var(--color-bg-card);
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-fast);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.challenge-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--color-neon-cyan), var(--color-neon-magenta));
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.challenge-card:hover::before {
    opacity: 1;
}

.challenge-card:hover {
    border-color: var(--color-text-accent);
    box-shadow: 0 0 25px rgba(0, 255, 255, 0.3);
    transform: translateY(-5px);
}

.challenge-card.locked {
    opacity: 0.5;
    cursor: not-allowed;
    filter: grayscale(0.8);
}

.challenge-card.locked:hover {
    transform: none;
    box-shadow: var(--shadow-md);
}

.challenge-card.completed {
    border-color: var(--color-success);
}

.challenge-card.completed::before {
    background: var(--color-success);
    opacity: 1;
}

.challenge-header {
    display: flex;
    justify-content: space-between;
    align-items: start;
    margin-bottom: var(--spacing-md);
}

.challenge-title {
    font-family: var(--font-heading);
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.challenge-order {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    background: var(--color-bg-tertiary);
    padding: 0.25rem 0.5rem;
    border-radius: var(--border-radius);
}

.challenge-meta {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    flex-wrap: wrap;
}

.challenge-badge {
    font-size: 0.75rem;
    padding: 0.25rem 0.5rem;
    border-radius: var(--border-radius);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.badge-category {
    background: rgba(0, 136, 255, 0.2);
    color: var(--color-neon-blue);
    border: 1px solid var(--color-neon-blue);
}

.badge-difficulty {
    border: 1px solid;
}

.badge-difficulty.easy {
    background: rgba(0, 255, 136, 0.2);
    color: var(--color-easy);
    border-color: var(--color-easy);
}

.badge-difficulty.medium {
    background: rgba(255, 170, 0, 0.2);
    color: var(--color-medium);
    border-color: var(--color-medium);
}

.badge-difficulty.hard {
    background: rgba(255, 85, 0, 0.2);
    color: var(--color-hard);
    border-color: var(--color-hard);
}

.badge-difficulty.expert {
    background: rgba(255, 0, 85, 0.2);
    color: var(--color-expert);
    border-color: var(--color-expert);
}

.badge-points {
    background: rgba(0, 255, 255, 0.2);
    color: var(--color-neon-cyan);
    border: 1px solid var(--color-neon-cyan);
}

.challenge-description {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.challenge-status {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 0.875rem;
    font-weight: 600;
}

.status-icon {
    font-size: 1.25rem;
}

.challenge-status.locked {
    color: var(--color-text-muted);
}

.challenge-status.unlocked {
    color: var(--color-info);
}

.challenge-status.completed {
    color: var(--color-success);
}

/* ==================== LOGS ==================== */
.logs-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.log-entry {
    background: var(--color-bg-card);
    border: var(--border-width) solid var(--border-color);
    border-left: 4px solid var(--color-neon-cyan);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    animation: slideIn var(--transition-normal);
}

@keyframes slideIn {
    from { opacity: 0; transform: translateX(-20px); }
    to { opacity: 1; transform: translateX(0); }
}

.log-entry p {
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-secondary);
    line-height: 1.8;
}

.log-entry strong {
    color: var(--color-text-accent);
}

.log-timestamp {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin-top: var(--spacing-sm);
}

/* ==================== MODALS ==================== */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(10, 14, 26, 0.95);
    backdrop-filter: blur(5px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: var(--spacing-md);
    animation: fadeIn var(--transition-normal);
}

.modal.hidden {
    display: none;
}

.modal-content {
    background: var(--color-bg-secondary);
    border: 2px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-xl);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    box-shadow: 0 0 40px rgba(0, 255, 255, 0.3);
    animation: slideUp var(--transition-normal);
}

.modal-large {
    max-width: 800px;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.modal-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    width: 32px;
    height: 32px;
    background: transparent;
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
    color: var(--color-text-primary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-close:hover {
    background: var(--color-error);
    border-color: var(--color-error);
    box-shadow: 0 0 15px var(--color-error);
}

.modal-header {
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

.modal-header h2 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--color-text-accent);
    text-shadow: 0 0 10px var(--color-neon-cyan);
    margin-bottom: var(--spacing-sm);
}

.modal-header p {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
}

/* ==================== AUTH TABS ==================== */
.auth-tabs {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.auth-tab {
    flex: 1;
    padding: var(--spacing-md);
    background: transparent;
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
    color: var(--color-text-secondary);
    font-family: var(--font-heading);
    font-weight: 700;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.auth-tab:hover {
    color: var(--color-text-accent);
    border-color: var(--color-text-accent);
}

.auth-tab.active {
    background: rgba(0, 255, 255, 0.1);
    color: var(--color-text-accent);
    border-color: var(--color-text-accent);
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.3);
}

/* ==================== FORMS ==================== */
.auth-form {
    display: none;
}

.auth-form.active {
    display: block;
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    font-family: var(--font-heading);
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--color-text-accent);
    margin-bottom: var(--spacing-sm);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.form-group input {
    width: 100%;
    padding: var(--spacing-md);
    background: var(--color-bg-tertiary);
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
    color: var(--color-text-primary);
    font-family: var(--font-primary);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.form-group input:focus {
    outline: none;
    border-color: var(--color-text-accent);
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.3);
}

.form-message {
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
    font-size: 0.875rem;
    display: none;
}

.form-message.error {
    display: block;
    background: rgba(255, 0, 85, 0.1);
    border: var(--border-width) solid var(--color-error);
    color: var(--color-error);
}

.form-message.success {
    display: block;
    background: rgba(0, 255, 136, 0.1);
    border: var(--border-width) solid var(--color-success);
    color: var(--color-success);
}

.btn-submit {
    width: 100%;
    padding: var(--spacing-md);
    background: transparent;
    border: 2px solid var(--color-text-accent);
    border-radius: var(--border-radius);
    color: var(--color-text-accent);
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-submit:hover {
    background: var(--color-text-accent);
    color: var(--color-bg-primary);
    box-shadow: 0 0 20px rgba(0, 255, 255, 0.5);
}

.btn-submit:active {
    transform: scale(0.98);
}

/* ==================== CHALLENGE DETAIL ==================== */
.challenge-detail {
    color: var(--color-text-secondary);
}

.challenge-detail h3 {
    font-family: var(--font-heading);
    color: var(--color-text-accent);
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
}

.challenge-detail code {
    display: inline-block;
    background: var(--color-bg-tertiary);
    padding: 0.25rem 0.5rem;
    border-radius: var(--border-radius);
    color: var(--color-neon-green);
    font-family: var(--font-primary);
}

.challenge-detail pre {
    background: var(--color-bg-tertiary);
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    overflow-x: auto;
    margin: var(--spacing-md) 0;
}

.flag-submit {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-xl);
    border-top: var(--border-width) solid var(--border-color);
}

.flag-input-group {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
}

.flag-input {
    flex: 1;
    padding: var(--spacing-md);
    background: var(--color-bg-tertiary);
    border: var(--border-width) solid var(--border-color);
    border-radius: var(--border-radius);
    color: var(--color-text-primary);
    font-family: var(--font-primary);
}

.btn-submit-flag {
    padding: var(--spacing-md) var(--spacing-xl);
    background: transparent;
    border: 2px solid var(--color-success);
    border-radius: var(--border-radius);
    color: var(--color-success);
    font-family: var(--font-heading);
    font-weight: 700;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-submit-flag:hover {
    background: var(--color-success);
    color: var(--color-bg-primary);
    box-shadow: 0 0 20px var(--color-success);
}

/* ==================== SUCCESS MODAL ==================== */
.modal-success {
    text-align: center;
}

.success-animation {
    margin-bottom: var(--spacing-xl);
}

.success-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto;
    background: var(--color-success);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: var(--color-bg-primary);
    animation: successPop 0.5s ease-out;
    box-shadow: 0 0 40px var(--color-success);
}

@keyframes successPop {
    0% { transform: scale(0); }
    50% { transform: scale(1.2); }
    100% { transform: scale(1); }
}

.success-message {
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
}

.story-chapter {
    background: var(--color-bg-tertiary);
    border: var(--border-width) solid var(--border-color);
    border-left: 4px solid var(--color-neon-cyan);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
    color: var(--color-text-secondary);
    text-align: left;
    line-height: 1.8;
}

/* ==================== FOOTER ==================== */
.footer {
    margin-top: var(--spacing-2xl);
    padding: var(--spacing-xl);
    border-top: var(--border-width) solid var(--border-color);
    text-align: center;
    color: var(--color-text-muted);
    font-size: 0.75rem;
}

/* ==================== UTILITIES ==================== */
.hidden {
    display: none !important;
}

.loading {
    text-align: center;
    padding: var(--spacing-2xl);
    color: var(--color-text-muted);
    font-style: italic;
}

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

.text-success {
    color: var(--color-success);
}

.text-error {
    color: var(--color-error);
}

.text-warning {
    color: var(--color-warning);
}

/* ==================== RESPONSIVE ==================== */
@media (max-width: 768px) {
    .header {
        flex-direction: column;
        text-align: center;
    }
    
    .nav {
        width: 100%;
        justify-content: center;
    }
    
    .user-controls {
        width: 100%;
        justify-content: center;
    }
    
    .stat-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .challenges-grid {
        grid-template-columns: 1fr;
    }
    
    .flag-input-group {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    :root {
        font-size: 14px;
    }
    
    .logo-text {
        font-size: 1.25rem;
    }
    
    .stat-grid {
        grid-template-columns: 1fr;
    }
}

/* ==================== SCROLLBAR ==================== */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-accent);
}

/* ==================== SELECTION ==================== */
::selection {
    background: rgba(0, 255, 255, 0.3);
    color: var(--color-text-primary);
}