:root {
    --bg-primary: #0a0a0a;
    --bg-secondary: #111111;
    --text-primary: #ffffff;
    --text-secondary: #aaaaaa;
    --accent-red: #ff003c;
    --accent-dark-red: #cc002f;
    --border-color: #222222;
    --card-bg: #151515;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: var(--bg-secondary);
    border-bottom: 2px solid var(--accent-red);
    padding: 1rem 0;
    margin-bottom: 2rem;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent-red);
    text-decoration: none;
}

.logo span {
    color: var(--text-primary);
}

.nav {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link:hover {
    color: var(--accent-red);
}

/* Cards */
.challenges-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.challenge-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    transition: all 0.3s ease;
    position: relative;
}

.challenge-card:hover {
    border-color: var(--accent-red);
    transform: translateY(-2px);
}

.challenge-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1rem;
}

.challenge-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-primary);
}

.challenge-points {
    background: var(--accent-red);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-weight: bold;
    font-size: 0.9rem;
}

.challenge-category {
    display: inline-block;
    background: var(--bg-secondary);
    color: var(--accent-red);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.8rem;
    margin-bottom: 1rem;
}

.challenge-description {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

/* Form Elements */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    font-weight: 500;
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: 0.75rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-primary);
    font-family: inherit;
    transition: border-color 0.3s;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--accent-red);
}

.form-textarea {
    min-height: 150px;
    resize: vertical;
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background: var(--accent-red);
    color: white;
    border: none;
    border-radius: 4px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.3s;
    text-decoration: none;
    text-align: center;
}

.btn:hover {
    background: var(--accent-dark-red);
}

.btn-block {
    width: 100%;
}

.btn-secondary {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--border-color);
}

.flag-input-group {
    display: flex;
    gap: 0.5rem;
}

.flag-input {
    flex: 1;
}

/* Admin Panel */
.admin-header {
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.admin-title {
    font-size: 2rem;
    color: var(--accent-red);
    margin-bottom: 1rem;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 8px;
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    color: var(--accent-red);
    font-weight: bold;
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Messages */
.message {
    padding: 1rem;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.message.success {
    background: rgba(0, 255, 0, 0.1);
    border: 1px solid rgba(0, 255, 0, 0.3);
    color: #00ff00;
}

.message.error {
    background: rgba(255, 0, 0, 0.1);
    border: 1px solid rgba(255, 0, 0, 0.3);
    color: var(--accent-red);
}

/* Login Page */
.login-container {
    max-width: 400px;
    margin: 5rem auto;
    padding: 2rem;
    background: var(--card-bg);
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.login-title {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--accent-red);
}

/* File Upload */
.file-upload {
    border: 2px dashed var(--border-color);
    border-radius: 4px;
    padding: 2rem;
    text-align: center;
    cursor: pointer;
    transition: border-color 0.3s;
}

.file-upload:hover {
    border-color: var(--accent-red);
}

.file-upload input[type="file"] {
    display: none;
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem 0;
    color: var(--text-secondary);
    border-top: 1px solid var(--border-color);
    margin-top: 3rem;
}

/* Category Select */
.category-select-group {
    position: relative;
}

#category-select option[value="__custom__"] {
    color: var(--accent-red);
    font-weight: bold;
}

#custom-category-group {
    animation: slideDown 0.3s ease-out;
}

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

/* Category tags */
.category-tag {
    display: inline-block;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    padding: 0.5rem 1rem;
    border-radius: 4px;
    font-size: 0.9rem;
    margin-right: 0.5rem;
    margin-bottom: 0.5rem;
    border: 1px solid var(--border-color);
    transition: all 0.3s;
    cursor: pointer;
}

.category-tag:hover {
    border-color: var(--accent-red);
    color: var(--accent-red);
}

.category-tag.active {
    background: var(--accent-red);
    color: white;
    border-color: var(--accent-red);
}

/* Auth links */
.auth-links {
    text-align: center;
    margin-top: 1.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.auth-link {
    color: var(--accent-red);
    text-decoration: none;
}

.auth-link:hover {
    text-decoration: underline;
}

/* Leaderboard */
.leaderboard-row {
    transition: background 0.3s;
}

.leaderboard-row:hover {
    background: var(--bg-secondary);
}

/* Responsive */
@media (max-width: 768px) {
    .challenges-grid {
        grid-template-columns: 1fr;
    }
    
    .header-content {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav {
        justify-content: center;
    }
    
    table {
        display: block;
        overflow-x: auto;
    }
}