:root {
    --navy: #10243e;
    --blue: #2d6cdf;
    --blue-dark: #1f53b4;
    --text: #253247;
    --muted: #667085;
    --border: #d7deea;
    --surface: #ffffff;
    --background: #f3f6fb;
    --danger-bg: #fff1f1;
    --danger: #b42318;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    min-height: 100vh;
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text);
    background:
        radial-gradient(circle at top left, rgba(45, 108, 223, 0.12), transparent 34%),
        var(--background);
}

.login-page {
    min-height: calc(100vh - 36px);
    display: grid;
    place-items: center;
    padding: 28px 18px;
}

.login-card {
    width: min(100%, 430px);
    padding: 38px;
    background: var(--surface);
    border: 1px solid rgba(16, 36, 62, 0.08);
    border-radius: 18px;
    box-shadow: 0 24px 60px rgba(16, 36, 62, 0.12);
}

.back-link {
    display: inline-block;
    margin-bottom: 28px;
    color: var(--muted);
    font-size: 14px;
    text-decoration: none;
}

.back-link:hover {
    color: var(--blue);
}

.login-header {
    margin-bottom: 28px;
}

.brand {
    display: block;
    margin-bottom: 10px;
    color: var(--blue);
    font-size: 13px;
    font-weight: 800;
    letter-spacing: 0.15em;
}

.login-header h1 {
    margin-bottom: 8px;
    color: var(--navy);
    font-size: clamp(28px, 5vw, 36px);
    line-height: 1.1;
}

.login-header p {
    color: var(--muted);
    line-height: 1.6;
}

.form-group {
    margin-bottom: 19px;
}

label {
    display: block;
    margin-bottom: 7px;
    color: var(--text);
    font-size: 14px;
    font-weight: 700;
}

input {
    width: 100%;
    padding: 13px 14px;
    border: 1px solid var(--border);
    border-radius: 10px;
    color: var(--text);
    background: #fff;
    font-size: 16px;
    transition: border-color 0.2s, box-shadow 0.2s;
}

input:focus {
    outline: none;
    border-color: var(--blue);
    box-shadow: 0 0 0 4px rgba(45, 108, 223, 0.12);
}

.btn-login {
    width: 100%;
    margin-top: 4px;
    padding: 14px;
    border: 0;
    border-radius: 10px;
    color: #fff;
    background: var(--blue);
    font-size: 16px;
    font-weight: 800;
    cursor: pointer;
    transition: background 0.2s, transform 0.2s;
}

.btn-login:hover {
    background: var(--blue-dark);
    transform: translateY(-1px);
}

.alert-error {
    margin-bottom: 20px;
    padding: 12px 14px;
    border-left: 4px solid var(--danger);
    border-radius: 8px;
    color: var(--danger);
    background: var(--danger-bg);
    font-size: 14px;
}

.footer-dev {
    height: 36px;
    color: #8993a4;
    text-align: center;
    font-size: 12px;
}

@media (max-width: 520px) {
    .login-card {
        padding: 28px 22px;
        border-radius: 14px;
    }
}