/* --- CSS Variables (Dark Theme) --- */
:root {
    --primary-color: #4a90e2;
    --primary-dark: #357abd;
    --secondary-color: #ecf0f1;
    --background-color: #121212;
    --card-bg: #1e1e1e;
    --text-main: #e0e0e0;
    --text-light: #a0a0a0;
    --error-color: #e74c3c;
    --border-color: #333333;
    --input-bg: #2d2d2d;
    --border-radius: 12px;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    --transition: all 0.3s ease;
}

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

body {
    background-color: var(--background-color);
    color: var(--text-main);
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

/* --- Background Decoration --- */
.bg-shape {
    position: absolute;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(74, 144, 226, 0.15) 0%, rgba(0,0,0,0) 70%);
    z-index: -1;
}

.shape-1 {
    width: 600px;
    height: 600px;
    top: -200px;
    left: -200px;
}

.shape-2 {
    width: 500px;
    height: 500px;
    bottom: -150px;
    right: -150px;
}

/* --- Login Card --- */
.login-card {
    background: var(--card-bg);
    width: 100%;
    max-width: 420px;
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: 0 15px 35px rgba(0,0,0,0.5);
    border: 1px solid var(--border-color);
    text-align: center;
}

.logo {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 10px;
    display: inline-flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    border-radius: 10px;
    display: grid;
    place-items: center;
    color: white;
    font-size: 1.5rem;
}

.subtitle {
    color: var(--text-light);
    margin-bottom: 30px;
    font-size: 0.95rem;
}

/* --- Form Elements --- */
.form-group {
    margin-bottom: 20px;
    text-align: left;
}

.form-label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-light);
    font-size: 0.9rem;
}

.form-input {
    width: 100%;
    padding: 12px 15px;
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-main);
    font-size: 1rem;
    outline: none;
    transition: var(--transition);
}

    .form-input:focus {
        border-color: var(--primary-color);
        box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.2);
    }

.btn-login {
    width: 100%;
    padding: 14px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    margin-top: 10px;
}

    .btn-login:hover {
        background: var(--primary-dark);
        transform: translateY(-2px);
    }

/* --- Extra Links --- */
.links {
    margin-top: 20px;
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
}

.link {
    color: var(--text-light);
    text-decoration: none;
    transition: var(--transition);
}

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

/* --- Social Login (Optional) --- */
.divider {
    margin: 25px 0;
    position: relative;
    text-align: center;
}

    .divider::before {
        content: '';
        position: absolute;
        top: 50%;
        left: 0;
        right: 0;
        height: 1px;
        background: var(--border-color);
        z-index: 0;
    }

    .divider span {
        position: relative;
        background: var(--card-bg);
        padding: 0 10px;
        color: var(--text-light);
        font-size: 0.85rem;
        z-index: 1;
    }

.social-login {
    display: flex;
    gap: 15px;
    justify-content: center;
}

.social-btn {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    background: var(--input-bg);
    display: grid;
    place-items: center;
    cursor: pointer;
    transition: var(--transition);
    font-size: 1.2rem;
}

    .social-btn:hover {
        background: rgba(255,255,255,0.05);
        border-color: var(--text-light);
    }

/* --- Simple Error Message --- */
.error-msg {
    color: var(--error-color);
    font-size: 0.85rem;
    margin-top: 10px;
    display: none;
    align-items: center;
    justify-content: center;
    gap: 5px;
}