:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #dbeafe;
    --input-bg: #f8fafc;
    --text: #1e293b;
    --text-muted: #64748b;
    --border: #cbd5e1;
    --success: #22c55e;
    --error: #f87171;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background: linear-gradient(135deg, #1e40af 0%, #2563eb 60%, #3b82f6 100%);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 24px 16px;
}

.brand-header {
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-bottom: 24px;
}

.brand-header img {
    height: 52px;
    width: auto;
}

.brand-header h2 {
    color: #ffffff;
    font-size: 2.6rem;
    font-weight: 700;
    letter-spacing: 1px;
}

.brand-tagline {
    color: rgba(255, 255, 255, 0.75);
    font-size: 0.9rem;
    text-align: center;
    margin-bottom: 24px;
    letter-spacing: 0.3px;
}

.login-container {
    background: #fff;
    padding: 36px 32px 28px;
    border-radius: 16px;
    box-shadow: 0 20px 48px rgba(0, 0, 0, 0.18);
    max-width: 420px;
    width: 100%;
}

.login-container h1 {
    text-align: center;
    margin-bottom: 6px;
    color: var(--text);
    font-size: 1.6rem;
    font-weight: 700;
}

.form-subtitle {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-bottom: 28px;
}

.form-group {
    margin-bottom: 18px;
    position: relative;
}

.form-group label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 6px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-group input {
    width: 100%;
    padding: 12px 44px 12px 14px;
    border: 1.5px solid var(--border);
    border-radius: 10px;
    background: var(--input-bg);
    font-size: 0.95rem;
    color: var(--text);
    transition: border-color 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
    appearance: none;
    -moz-appearance: textfield;
}

.form-group input::-webkit-outer-spin-button,
.form-group input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.form-group input:focus {
    border-color: var(--primary);
    outline: none;
    background: #fff;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.input-correct {
    border-color: var(--success) !important;
    background: #f0fdf4 !important;
}

.input-incorrect {
    border-color: var(--error) !important;
    background: #fff5f5 !important;
}

.icon-eye {
    position: absolute;
    bottom: 12px;
    right: 13px;
    cursor: pointer;
    color: #94a3b8;
    transition: color 0.2s ease;
}

.icon-eye:hover {
    color: var(--primary);
}

.error-message {
    color: #dc2626;
    font-size: 0.8rem;
    margin-top: 5px;
    display: block;
}

/* Indicador de fortaleza de contraseña */
.strength-bar {
    display: flex;
    gap: 4px;
    margin-top: 6px;
}

.strength-bar span {
    flex: 1;
    height: 4px;
    border-radius: 2px;
    background: var(--border);
    transition: background 0.3s ease;
}

.strength-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 4px;
}

/* Checkbox de términos */
.terms-group {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    margin-bottom: 22px;
}

.terms-group input[type="checkbox"] {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
    margin-top: 2px;
    accent-color: var(--primary);
    cursor: pointer;
}

.terms-group label {
    font-size: 0.82rem;
    color: var(--text-muted);
    line-height: 1.5;
    cursor: pointer;
}

.terms-group label a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
}

.terms-group label a:hover {
    text-decoration: underline;
}

.btn-primary {
    width: 100%;
    background-color: var(--primary);
    color: #fff;
    border: none;
    padding: 13px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 10px;
    cursor: pointer;
    transition: background 0.2s ease, transform 0.15s ease, box-shadow 0.2s ease;
    letter-spacing: 0.3px;
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 6px 16px rgba(37, 99, 235, 0.35);
}

.btn-primary:active {
    transform: translateY(0);
}

.divider {
    text-align: center;
    margin: 20px 0 4px;
    color: var(--text-muted);
    font-size: 0.85rem;
}

.btn-link {
    display: block;
    text-align: center;
    margin-top: 10px;
    color: var(--primary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s ease;
}

.btn-link:hover {
    text-decoration: underline;
    color: var(--primary-dark);
}

/* ── Responsivo móvil ── */
@media (max-width: 480px) {
    body {
        padding: 20px 12px;
        justify-content: flex-start;
        padding-top: 32px;
    }

    .brand-header {
        gap: 10px;
        margin-bottom: 16px;
    }

    .brand-header img {
        height: 38px;
    }

    .brand-header h2 {
        font-size: 1.9rem;
    }

    .brand-tagline {
        font-size: 0.8rem;
        margin-bottom: 16px;
    }

    .login-container {
        padding: 24px 18px 20px;
        border-radius: 14px;
    }

    .login-container h1 {
        font-size: 1.35rem;
    }

    .form-subtitle {
        font-size: 0.8rem;
        margin-bottom: 20px;
    }

    .form-group {
        margin-bottom: 14px;
    }

    .form-group input {
        padding: 11px 42px 11px 13px;
        font-size: 1rem; /* evita zoom automático en iOS */
    }

    .btn-primary {
        padding: 14px;
        font-size: 1rem;
    }

    .terms-group label {
        font-size: 0.78rem;
    }
}

/* ── Pantallas muy pequeñas (≤360px) ── */
@media (max-width: 360px) {
    .brand-header h2 {
        font-size: 1.6rem;
    }

    .brand-header img {
        height: 32px;
    }

    .login-container {
        padding: 20px 14px 16px;
    }
}