:root {
    --color-bg: #f5f5f5;
    --color-card: #fff;
    --color-card-shadow: rgba(0, 0, 0, 0.1);
    --color-heading: #333;
    --color-text: #555;
    --color-input-border: #ddd;
    --color-accent: #19b394;
    --color-accent-hover: #14a085;
    --color-error: #d32f2f;
    --color-btn-text: #fff;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: var(--color-bg);
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.card-container {
    background: var(--color-card);
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 2px 10px var(--color-card-shadow);
    width: 100%;
    max-width: 480px;
}

.card-container.home {
    text-align: center;
}

h1 {
    margin: 0 0 24px;
    font-size: 24px;
    color: var(--color-heading);
    text-align: center;
}

.form-group {
    margin-bottom: 16px;
}

label {
    display: block;
    margin-bottom: 4px;
    font-size: 14px;
    color: var(--color-text);
}

input[type="email"],
input[type="password"],
input[type="text"] {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--color-input-border);
    border-radius: 4px;
    font-size: 14px;
    box-sizing: border-box;
}

input[type="email"]:focus,
input[type="password"]:focus,
input[type="text"]:focus {
    border-color: var(--color-accent);
    outline: none;
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 16px;
}

.checkbox-group input {
    margin: 0;
}

.btn-primary {
    width: 100%;
    padding: 12px;
    background: var(--color-accent);
    color: var(--color-btn-text);
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
}

.btn-primary:hover {
    background: var(--color-accent-hover);
}

.validation-summary-errors {
    color: var(--color-error);
    margin-bottom: 16px;
    font-size: 13px;
}

.field-validation-error {
    color: var(--color-error);
    font-size: 12px;
}

.user-info {
    font-size: 14px;
    color: var(--color-text);
    margin-bottom: 24px;
}

.page-link {
    text-align: center;
    margin-top: 16px;
    font-size: 14px;
    color: var(--color-text);
}

.page-link a {
    color: var(--color-accent);
    text-decoration: none;
}

.page-link a:hover {
    text-decoration: underline;
}

/* External Login */
.external-login-separator {
    text-align: center;
    margin: 20px 0;
    position: relative;
}

.external-login-separator::before,
.external-login-separator::after {
    content: "";
    position: absolute;
    top: 50%;
    width: 40%;
    height: 1px;
    background: #ddd;
}

.external-login-separator::before { left: 0; }
.external-login-separator::after { right: 0; }

.external-login-separator span {
    background: #fff;
    padding: 0 10px;
    color: #888;
    font-size: 14px;
    vertical-align: text-top;
}

.external-login-buttons form {
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-external {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    border: 1px solid #ddd;
    border-radius: 6px;
    background: #fff;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: background 0.2s, border-color 0.2s;
}

.btn-external:hover {
    background: #f5f5f5;
    border-color: #bbb;
}

.btn-github { color: #24292e; }
.btn-facebook { color: #1877f2; }
.btn-twitter { color: #000; }
.btn-google { color: #4285f4; }