/* --- Biến màu sắc --- */
:root {
    --bg-dark: #0d1117;
    --card-bg: #161b22;
    --color-grass: #4ade80;
    --color-royal: #4169e1;
    --text-white: #ffffff;
    --text-gray: #8b949e;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-white);
    display: block;
    justify-content: center;
    align-items: center;
    height: auto;
    overflow: hidden;
}

/* Nút quay lại */
.back-home {
    position: absolute;
    top: 20px;
    left: 20px;
    color: var(--color-grass);
    text-decoration: none;
    font-size: 14px;
    transition: 0.3s;
}

.back-home:hover {
    letter-spacing: 1px;
}

/* Auth Card */
.auth-wrapper {
    width: 100%;
    max-width: 420px;
    padding: 20px;
    /* Đảm bảo form nằm giữa màn hình bên dưới navbar */
    margin: 0 auto; 
    display: flex;
    align-items: center;
    min-height: calc(100vh - 80px); /* 80px là chiều cao trung bình của navbar */
}

.auth-card {
    background-color: var(--card-bg);
    padding: 45px;
    border-radius: 20px;
    border: 1px solid #30363d;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    transition: all 0.3s ease;
}

.auth-card:hover {
    border-color: var(--color-grass);
}

.auth-header {
    text-align: center;
    margin-bottom: 35px;
}

.auth-header h2 {
    color: var(--color-grass);
    font-size: 30px;
    font-weight: 800;
    margin-bottom: 8px;
}

.auth-header p {
    color: var(--text-gray);
    font-size: 14px;
}

/* Form Groups */
.input-group {
    margin-bottom: 25px;
}

.input-group label {
    display: block;
    color: var(--text-gray);
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.input-group input {
    width: 100%;
    padding: 14px 16px;
    border-radius: 10px;
    border: 2px solid #30363d;
    background-color: #0d1117;
    color: white;
    font-size: 15px;
    outline: none;
    transition: 0.3s;
}

.input-group input:focus {
    border-color: var(--color-royal);
    box-shadow: 0 0 10px rgba(65, 105, 225, 0.2);
}

/* Button */
.btn-primary {
    width: 100%;
    padding: 16px;
    border: none;
    border-radius: 10px;
    background-color: var(--color-royal);
    color: white;
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    margin-top: 10px;
}

.btn-primary:hover {
    background-color: #3457c1;
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(65, 105, 225, 0.4);
}

/* Footer */
.auth-footer {
    margin-top: 30px;
    text-align: center;
    font-size: 14px;
    color: var(--text-gray);
}

.auth-footer a {
    color: var(--color-grass);
    text-decoration: none;
    font-weight: 700;
    margin-left: 5px;
}

.auth-footer a:hover {
    text-decoration: underline;
}