:root {
    --bg-color: #0a0a0a;
    --card-bg: #161616;
    --text-primary: #ffffff;
    --text-secondary: #cccccc;
    --accent-color: #4dabff;
    --accent-hover: #70bcff;
    --border-color: #333333;
    --error-bg: #441111;
    --error-text: #ff9999;
    --success-bg: #113311;
    --success-text: #99ff99;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    margin: 0;
    padding: 20px;
}

.auth-container {
    max-width: 400px;
    margin: 50px auto;
    background: var(--card-bg);
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.8);
    border: 1px solid var(--border-color);
}

.auth-container h2 {
    text-align: center;
    color: var(--text-primary);
    margin-bottom: 25px;
    font-weight: bold;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    color: var(--text-primary);
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 12px;
    box-sizing: border-box;
    background-color: #222;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: #fff;
    font-size: 16px;
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent-color);
    background-color: #2a2a2a;
}

.btn {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 4px;
    background-color: var(--accent-color);
    color: #000;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    margin-top: 10px;
    transition: all 0.2s;
}

.btn:hover {
    background-color: var(--accent-hover);
    transform: translateY(-1px);
}

.auth-link {
    text-align: center;
    margin-top: 15px;
    font-size: 14px;
    color: var(--text-secondary);
}

.auth-link a {
    color: var(--accent-color);
    text-decoration: underline;
}

.error {
    color: var(--error-text);
    background: var(--error-bg);
    padding: 12px;
    border-radius: 4px;
    margin-bottom: 15px;
    text-align: center;
    border: 1px solid var(--error-text);
}

.success {
    color: var(--success-text);
    background: var(--success-bg);
    padding: 12px;
    border-radius: 4px;
    margin-bottom: 15px;
    text-align: center;
    border: 1px solid var(--success-text);
}

.nav-back {
    margin-bottom: 20px;
}

.nav-back a {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: bold;
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-back a:hover {
    color: var(--accent-color);
}

/* Common utility classes for High Contrast Dark Mode */
.card, .hero, .tile {
    background-color: var(--card-bg) !important;
    color: var(--text-primary) !important;
    border: 1px solid var(--border-color) !important;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--text-primary) !important;
    font-weight: bold !important;
}

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