:root {
    --su-bg: #0f172a;
    --su-card-bg: #ffffff;
    --su-text: #111827;
    --su-muted: #6b7280;
    --su-primary: #ea580c;
    --su-primary-hover: #c2410c;
    --su-success-bg: #ecfdf3;
    --su-success: #15803d;
    --su-error-bg: #fef2f2;
    --su-error: #b91c1c;
    --su-border: #e5e7eb;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    min-height: 100vh;
    font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: linear-gradient(160deg, var(--su-bg), #1e293b);
    color: var(--su-text);
}

.signup-wrap {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
}

.signup-card {
    background: var(--su-card-bg);
    border-radius: 16px;
    padding: 2rem 1.5rem;
    max-width: 440px;
    width: 100%;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
}

h1 {
    font-size: 1.5rem;
    margin: 0 0 0.4rem;
    text-align: center;
}
.signup-subtitle {
    text-align: center;
    color: var(--su-muted);
    margin: 0 0 1.5rem;
    font-size: 0.95rem;
}

label {
    display: block;
    font-weight: 600;
    font-size: 0.9rem;
    margin: 1rem 0 0.35rem;
}

input[type="text"], input[type="email"] {
    width: 100%;
    padding: 0.75rem 0.9rem;
    border: 1px solid var(--su-border);
    border-radius: 8px;
    font-size: 1rem;
}
input:focus { outline: 2px solid var(--su-primary); outline-offset: 1px; }

.signup-domain-field {
    display: flex;
    align-items: center;
    border: 1px solid var(--su-border);
    border-radius: 8px;
    overflow: hidden;
}
.signup-domain-field input {
    border: none;
    flex: 1;
    min-width: 0;
}
.signup-domain-field input:focus { outline: none; }
.signup-domain-suffix {
    padding: 0 0.9rem;
    color: var(--su-muted);
    font-size: 0.9rem;
    white-space: nowrap;
}

.signup-hint { color: var(--su-muted); font-size: 0.78rem; margin: 0.3rem 0 0; }

.signup-honeypot {
    position: absolute;
    left: -9999px;
    width: 1px;
    height: 1px;
    overflow: hidden;
}

.g-recaptcha { margin: 1.2rem 0; display: flex; justify-content: center; transform-origin: center; }

button[type="submit"] {
    width: 100%;
    background: var(--su-primary);
    color: #fff;
    border: none;
    padding: 0.9rem;
    border-radius: 8px;
    font-size: 1.05rem;
    font-weight: 600;
    cursor: pointer;
    margin-top: 0.5rem;
}
button[type="submit"]:hover { background: var(--su-primary-hover); }

.signup-alert {
    background: var(--su-error-bg);
    color: var(--su-error);
    padding: 0.7rem 0.9rem;
    border-radius: 8px;
    font-size: 0.88rem;
    margin-bottom: 0.5rem;
}

.signup-success { text-align: center; }
.signup-success h2 { margin-top: 0; }
.signup-success p { color: var(--su-muted); }

@media (prefers-color-scheme: dark) {
    :root {
        --su-card-bg: #171a21;
        --su-text: #e5e7eb;
        --su-muted: #9ca3af;
        --su-border: #2a2e38;
    }
}