:root {
    --primary: #4361ee;
    --primary-hover: #3a0ca3;
    --secondary: #4cc9f0;
    --bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
    --card-bg: rgba(255, 255, 255, 0.95);
}

body {
    font-family: 'Inter', sans-serif;
    background: var(--bg-gradient);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    color: #334155;
}

.auth-container {
    width: 100%;
    max-width: 460px;
}

.auth-card {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3), 0 0 0 1px rgba(255, 255, 255, 0.1);
    padding: 40px 35px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    position: relative;
    overflow: hidden;
}

.auth-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: linear-gradient(90deg, #4361ee, #4cc9f0, #7209b7);
}

.brand-logo {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, #4361ee, #4cc9f0);
    color: white;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    margin: 0 auto 16px;
    box-shadow: 0 8px 16px rgba(67, 97, 238, 0.35);
}

.auth-tabs {
    background: #f1f5f9;
    padding: 4px;
    border-radius: 12px;
    display: flex;
    margin-bottom: 24px;
}

.auth-tab-btn {
    flex: 1;
    padding: 10px;
    border: none;
    background: transparent;
    font-weight: 600;
    color: #64748b;
    border-radius: 9px;
    transition: all 0.2s ease;
    font-size: 0.95rem;
}

.auth-tab-btn.active {
    background: #ffffff;
    color: var(--primary);
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
}

.form-floating > .form-control {
    border-radius: 12px;
    border: 1.5px solid #e2e8f0;
    font-size: 0.95rem;
}

.form-floating > .form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(67, 97, 238, 0.15);
}

.btn-auth-submit {
    background: linear-gradient(135deg, #4361ee, #3a0ca3);
    border: none;
    color: white;
    font-weight: 600;
    padding: 13px;
    border-radius: 12px;
    font-size: 1rem;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(67, 97, 238, 0.3);
}

.btn-auth-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 18px rgba(67, 97, 238, 0.45);
    color: white;
}

.demo-box {
    background: #f8fafc;
    border: 1px dashed #cbd5e1;
    border-radius: 12px;
    padding: 12px 16px;
    font-size: 0.85rem;
    color: #475569;
    margin-top: 20px;
}

.demo-box strong {
    color: #1e293b;
}

.btn-quick-fill {
    cursor: pointer;
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
}

.btn-quick-fill:hover {
    text-decoration: underline;
}