body {
    background: #f6f7fb;
    font-family: 'Segoe UI', sans-serif;
}

/* avatar */
.avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
}

/* container */
.list-container {
    max-width: 900px;
    margin: auto;
}

/* card */
.wide-card {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-radius: 20px;
    margin-bottom: 20px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
    transition: 0.2s;
}

.wide-card:hover {
    transform: translateY(-5px);
}

/* màu nền từng card */
.card-orange { background: #fff3e0; }
.card-blue { background: #e3f2fd; }
.card-green { background: #e8f5e9; }

/* left */
.left {
    display: flex;
    align-items: center;
    gap: 15px;
}

/* icon */
.icon {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.orange { background: #ffe0b2; color: orange; }
.blue { background: #bbdefb; color: #2196f3; }
.green { background: #c8e6c9; color: #4caf50; }

/* text */
.tag {
    font-size: 12px;
    color: #666;
    font-weight: bold;
}

.blue-text { color: #2196f3; }
.green-text { color: #4caf50; }

h5 {
    margin: 3px 0;
    font-weight: bold;
}

p {
    margin: 0;
    color: #555;
    font-size: 14px;
}

/* right */
.right {
    text-align: right;
}

/* icon phải */
.play {
    font-size: 26px;
    color: orange;
}

.arrow {
    font-size: 18px;
    color: #555;
}

/* card đang học */
.active {
    border: 2px solid #ffd54f;
}
/* HEADER container */
.fancy-header {
    position: relative;
    padding: 20px 0;
}

/* TEXT gradient + glow */
.glow-text {
    font-size: 42px;
    background: linear-gradient(90deg, #ff9800, #ffcc80);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    position: relative;
}

/* glow nhẹ */
.glow-text::after {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    filter: blur(20px);
    opacity: 0.4;
    background: linear-gradient(90deg, #ff9800, #ffd54f);
    z-index: -1;
}

/* subtitle mượt */
.subtitle {
    font-size: 16px;
    opacity: 0.8;
    animation: fadeIn 1s ease;
}

/* sparkle effect */
.fancy-header::before {
    content: '';
    position: absolute;
    top: 10px;
    left: 30%;
    width: 6px;
    height: 6px;
    background: gold;
    border-radius: 50%;
    box-shadow: 0 0 10px gold, 0 0 20px gold;
    animation: sparkle 2s infinite;
}

.fancy-header::after {
    content: '';
    position: absolute;
    top: 40px;
    left: 60%;
    width: 4px;
    height: 4px;
    background: #ffd54f;
    border-radius: 50%;
    box-shadow: 0 0 10px #ffd54f;
    animation: sparkle 3s infinite;
}

/* animation */
@keyframes sparkle {
    0% { transform: scale(1) translateY(0); opacity: 1; }
    50% { transform: scale(1.5) translateY(-5px); opacity: 0.6; }
    100% { transform: scale(1) translateY(0); opacity: 1; }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 0.8; transform: translateY(0); }
}
.fancy-header {
    max-width: 700px;
    margin: 0 auto;
}

/* nền login */
.login-bg {
    background: linear-gradient(135deg, #fff8e1, #f3e5f5);
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* container */
.login-container {
    width: 100%;
    display: flex;
    justify-content: center;
}

/* box */
.login-box {
    background: white;
    padding: 30px;
    border-radius: 20px;
    width: 350px;
    box-shadow: 0 15px 30px rgba(0,0,0,0.1);
    animation: fadeUp 0.5s ease;
}

/* hover input */
.login-box input:focus {
    box-shadow: 0 0 5px #ffc107;
}

/* animation */
@keyframes fadeUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}
.main-bg {
    background: linear-gradient(135deg, #fff8e1, #f3e5f5);
    min-height: 100vh;
}
.wide-card {
    cursor: pointer;
}

/* answer hover */
.answer {
    cursor: pointer;
    transition: 0.2s;
}

.answer:hover {
    transform: scale(1.02);
    background: #fff8e1;
}

/* chọn đáp án */
.answer.active {
    border: 2px solid #ffc107;
    background: #fff3cd;
}

/* đúng sai */
.correct {
    background: #d4edda !important;
    border: 2px solid #28a745;
}

.wrong {
    background: #f8d7da !important;
    border: 2px solid #dc3545;
}

button.btn {
    border-radius: 10px;
    transition: 0.2s;
}

button.btn:hover {
    transform: translateY(-2px);
}
.bg-soft-primary { background-color: #e7f1ff; color: #0d6efd; }
.rounded-4 { border-radius: 1.2rem !important; }
/* Đảm bảo Font Awesome hoạt động */
@import url('https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.0.0/css/all.min.css');
.nav-btn-custom {
    display: inline-flex;
    align-items: center;
    padding: 10px 25px;
    background-color: #ffffff;
    color: #4e73df;
    border: 2px solid #4e73df;
    border-radius: 50px; /* Bo tròn viên thuốc */
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px rgba(78, 115, 223, 0.1);
}

.nav-btn-custom:hover {
    background-color: #4e73df;
    color: #ffffff;
    transform: translateY(-2px); /* Hiệu ứng nổi lên */
    box-shadow: 0 6px 12px rgba(78, 115, 223, 0.2);
}

.nav-btn-custom i {
    font-size: 1.1rem;
    margin-right: 10px; /* Khoảng cách icon và chữ */
}