* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
    color: #f8fafc;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 16px;
}

.auth-container {
    width: 100%;
    max-width: 420px;
    animation: fadeUp 0.5s ease-out;
}

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.auth-box {
    background: #1e293b;
    padding: 40px 32px;
    border-radius: 16px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(56, 189, 248, 0.1);
    position: relative;
    overflow: hidden;
}

.auth-box::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #3b82f6, #38bdf8, #059669);
}

.brand {
    text-align: center;
    margin-bottom: 28px;
}

.brand h1 {
    font-size: 28px;
    font-weight: 700;
    background: linear-gradient(135deg, #38bdf8, #3b82f6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

.brand p {
    color: #94a3b8;
    font-size: 14px;
    margin-top: 4px;
}

h2 {
    font-size: 22px;
    margin-bottom: 4px;
    text-align: center;
    font-weight: 600;
}

.subtitle {
    color: #94a3b8;
    font-size: 13px;
    text-align: center;
    margin-bottom: 28px;
}

.input-group {
    margin-bottom: 18px;
}

.input-group label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: #94a3b8;
    margin-bottom: 6px;
}

.input-group input {
    width: 100%;
    padding: 12px 16px;
    background-color: #0f172a;
    border: 1px solid #334155;
    border-radius: 10px;
    color: #f8fafc;
    font-size: 15px;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.input-group input:focus {
    outline: none;
    border-color: #38bdf8;
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.15);
}

.input-group input::placeholder {
    color: #475569;
}

button {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #3b82f6, #2563eb);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s, transform 0.15s;
    letter-spacing: 0.3px;
    margin-top: 4px;
}

button:hover {
    opacity: 0.9;
}

button:active {
    transform: scale(0.98);
}

.auth-toggle {
    margin-top: 24px;
    text-align: center;
    font-size: 14px;
    color: #94a3b8;
}

#btn-toggle {
    color: #38bdf8;
    cursor: pointer;
    font-weight: 600;
    transition: color 0.2s;
}

#btn-toggle:hover {
    color: #7dd3fc;
    text-decoration: underline;
}

@media (max-width: 480px) {
    .auth-box {
        padding: 32px 20px;
        border-radius: 12px;
    }

    .brand h1 {
        font-size: 24px;
    }

    h2 {
        font-size: 20px;
    }
}