/* Reset cơ bản */

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


/* Container / reset cơ bản */

.btn-back {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.45rem 0.8rem;
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
    font-size: 0.95rem;
    line-height: 1;
    color: #0f172a;
    /* text color */
    background: #f1f5f9;
    /* light background */
    border: 1px solid rgba(15, 23, 42, 0.06);
    border-radius: 10px;
    cursor: pointer;
    user-select: none;
    transition: transform 120ms ease, box-shadow 120ms ease, background 120ms ease;
    box-shadow: 0 1px 0 rgba(15, 23, 42, 0.03);
}


/* Arrow icon styling */

.btn-back .icon {
    display: inline-block;
    font-weight: 600;
    font-size: 1.05rem;
    transform-origin: center;
}


/* Smaller variant (optional) */

.btn-back.small {
    padding: 0.25rem 0.5rem;
    font-size: 0.85rem;
    border-radius: 8px;
}


/* Hover / focus */

.btn-back:hover,
.btn-back:focus {
    transform: translateX(-3px);
    /* slight left movement for 'back' feeling */
    background: #e2e8f0;
    box-shadow: 0 6px 18px rgba(15, 23, 42, 0.08);
    outline: none;
}


/* Active (mouse down) */

.btn-back:active {
    transform: translateX(-1px) scale(0.995);
    box-shadow: 0 4px 10px rgba(15, 23, 42, 0.06);
}


/* Keyboard accessibility focus ring */

.btn-back:focus-visible {
    box-shadow: 0 0 0 4px rgba(59, 130, 246, 0.12), 0 6px 18px rgba(15, 23, 42, 0.06);
}


/* Optional small icon-only style */

.btn-back.icon-only {
    padding: 0.45rem;
    width: 40px;
    justify-content: center;
}

.btn-back.icon-only .label {
    display: none;
}


/* Dark mode friendly (simple) */

@media (prefers-color-scheme: dark) {
    .btn-back {
        color: #e6eef8;
        background: #28a745;
        border-color: rgba(255, 255, 255, 0.06);
        box-shadow: 0 1px 0 rgba(255, 255, 255, 0.02);
    }
    .btn-back:hover {
        background: #28a650;
        box-shadow: 0 6px 18px rgba(2, 6, 23, 0.6);
    }
}


/* Nền xanh nhạt toàn màn hình */

body {
    background: linear-gradient(135deg, #e8fff2, #dffff1);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}


/* Container chính */

.login-container {
    width: 100%;
    max-width: 400px;
}


/* Hộp đăng nhập */

.login-box {
    background: white;
    padding: 40px 50px;
    border-radius: 14px;
    box-shadow: 0 6px 15px rgba(0, 0, 0, 0.08);
    text-align: center;
    width: 100%;
}


/* Icon khiên */

.login-icon {
    background-color: #00b56a;
    width: 70px;
    height: 70px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0 auto 15px;
}

.login-icon i {
    font-size: 28px;
    color: white;
}


/* Tiêu đề */

.login-box h2 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 5px;
    color: #333;
}

.login-box p {
    font-size: 14px;
    color: #555;
    margin-bottom: 20px;
}


/* Label */

.login-box label {
    display: block;
    text-align: left;
    font-size: 14px;
    font-weight: 500;
    color: #333;
    margin-bottom: 6px;
}


/* Nhóm input - DÀI RA NHƯ ẢNH */

.input-group {
    display: flex;
    align-items: center;
    background-color: #f6f6f6;
    border-radius: 8px;
    margin-bottom: 15px;
    padding: 10px 12px;
    border: 1px solid transparent;
    transition: border 0.2s;
    width: 100%;
    /* <-- THÊM DÒNG NÀY */
}

.input-group:focus-within {
    border-color: #0040c1;
}

.input-group i {
    color: #888;
    margin-right: 8px;
    font-size: 15px;
    flex-shrink: 0;
}

.input-group input {
    border: none;
    outline: none;
    flex: 1;
    background: none;
    font-size: 15px;
    color: #333;
    width: 100%;
    /* <-- THÊM DÒNG NÀY */
}

.input-group input::placeholder {
    color: #aaa;
}


/* Nút */

button {
    width: 100%;
    background-color: #0040c1;
    color: white;
    border: none;
    padding: 12px;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    margin-top: 5px;
    transition: background-color 0.2s;
}

button:hover {
    background-color: #0030a1;
}

button:active {
    transform: translateY(1px);
}


/* Gợi ý */

.hint {
    font-size: 12px;
    color: #777;
    margin-top: 15px;
    line-height: 1.5;
}

.hint strong {
    color: #0040c1;
}


/* Responsive */

@media (max-width: 480px) {
    .login-box {
        padding: 30px 35px;
    }
    .login-container {
        max-width: 340px;
    }
}