:root {
    --bg-dark: #0f172a;
    --glass-bg: rgba(255, 255, 255, 0.07);
    --glass-border: rgba(255, 255, 255, 0.12);
    --primary-neon: #00d2ff;
    --secondary-neon: #3a7bd5;
    --text-bright: #f1f5f9;
    --text-dim: #94a3b8;
    --accent-red: #ff4757;
}

body, html {
    margin: 0; padding: 0;
    height: 100%;
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background: radial-gradient(circle at center, #1e293b, #0f172a);
    color: var(--text-bright);
    display: flex;
    align-items: center;
    justify-content: center;
}

.login-container {
    width: 100%;
    max-width: 400px;
    padding: 20px;
}

.glass-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    backdrop-filter: blur(15px);
    padding: 40px 30px;
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.5);
    text-align: center;
}

.brand h1 {
    margin: 0;
    font-size: 2rem;
    letter-spacing: 2px;
    background: linear-gradient(to right, var(--primary-neon), #fff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.brand p {
    color: var(--text-dim);
    font-size: 0.9rem;
    margin-bottom: 30px;
}

.input-group {
    text-align: left;
    margin-bottom: 20px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.85rem;
    color: var(--text-dim);
}

.input-group input {
    width: 100%;
    padding: 12px 15px;
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    color: white;
    font-family: inherit;
    box-sizing: border-box;
    transition: 0.3s;
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-neon);
    box-shadow: 0 0 15px rgba(0, 210, 255, 0.2);
}

.btn-primary {
    width: 100%;
    padding: 15px;
    background: linear-gradient(45deg, var(--secondary-neon), var(--primary-neon));
    color: white;
    border: none;
    border-radius: 12px;
    font-weight: bold;
    font-size: 1rem;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0, 210, 255, 0.3);
    margin-top: 10px;
    transition: transform 0.2s;
}

.btn-primary:active {
    transform: scale(0.97);
}

.error-hidden {
    display: none;
}

.error-visible {
    display: block;
    color: var(--accent-red);
    font-size: 0.85rem;
    margin-bottom: 15px;
    font-weight: bold;
}