:root {
    --stu: #0069a8;
    --stu-dark: #004879;
    --stu-light: #eaf6ff;
    --red: #d71920;
    --yellow: #ffd23f;
    --text: #17233a;
    --line: #c9d8e6;
    --bg: #f4f8fb;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: Arial, Helvetica, sans-serif;
    font-size: 14px;
}

a {
    text-decoration: none;
    color: var(--stu);
}

a:hover {
    text-decoration: underline;
}

.wrap {
    width: 100%;
    max-width: none;
    padding-left: 6.5%;
    padding-right: 6.5%;
}


/* thanh tren cung */

.top-line {
    height: 32px;
    background: var(--stu-dark);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 13px;
}

.top-line a {
    color: #fff;
    margin-left: 14px;
}


/* header va logo */

.site-header {
    height: 138px;
    background: linear-gradient(90deg, #0071b8 0%, #0071b8 52%, #d9edf7 52%, #d9edf7 100%);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 25px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 18px;
}

.brand img {
    width: 180px;
    height: 82px;
    object-fit: contain;
    background: transparent;
    padding: 0;
}

.brand h1 {
    margin: 0 0 8px;
    color: #fff;
    font-size: 31px;
    letter-spacing: 1px;
    font-weight: 600;
}

.brand p {
    margin: 0;
    color: rgb(255, 0, 0);
    font-size: 22px;
    font-weight: 800;
    letter-spacing: 1.5px;
}

.header-photo {
    height: 135px;
    width: 60%;
    min-width: 430px;
    background: transparent;
    border: none;
    box-shadow: none;
    overflow: hidden;
}

.header-photo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center center;
    display: block;
}


/* thanh menu va dropdown */

.main-nav {
    background: #0069a8;
    border-bottom: 3px solid var(--yellow);
    position: relative;
    z-index: 10;
}

.main-nav ul {
    margin: 0;
    padding: 0;
    list-style: none;
    display: flex;
    align-items: stretch;
    flex-wrap: wrap;
}

.main-nav li {
    position: relative;
}

.main-nav li>a {
    display: block;
    color: #fff;
    text-transform: uppercase;
    font-weight: 700;
    font-size: 13px;
    padding: 14px 18px;
    border-right: 1px solid rgba(255, 255, 255, .16);
    transition: background .22s, color .22s, transform .22s;
}

.main-nav li.active>a,
.main-nav li:hover>a {
    background: var(--yellow);
    color: #003b67;
    text-decoration: none;
}

.main-nav li:hover>a {
    transform: translateY(-1px);
}

.main-nav .right {
    margin-left: auto;
}


/* menu so xuong */

.dropdown-menu-stu {
    display: block;
    visibility: hidden;
    opacity: 0;
    transform: translateY(12px);
    position: absolute;
    left: 0;
    top: 100%;
    min-width: 245px;
    background: #fff;
    border: 1px solid #c6d6e2;
    box-shadow: 0 10px 20px rgba(0, 0, 0, .18);
    transition: opacity .25s ease, transform .25s ease, visibility .25s;
    z-index: 99;
}

.has-dropdown:hover .dropdown-menu-stu {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
}

.dropdown-menu-stu a {
    display: block;
    padding: 11px 15px;
    color: #123;
    border-bottom: 1px solid #eef3f7;
    text-transform: none;
    font-weight: 600;
}

.dropdown-menu-stu a:hover {
    background: #e9f6ff;
    color: var(--red);
    text-decoration: none;
    padding-left: 20px;
}


/* thanh tim kiem nhanh */

.search-strip {
    display: grid;
    grid-template-columns: 250px 1fr 135px 135px;
    gap: 8px;
    background: #e8f3fa;
    padding-top: 10px;
    padding-bottom: 10px;
    border-bottom: 1px solid #cdddea;
}

.search-strip input,
.search-strip select {
    height: 37px;
    border: 1px solid #9eb7c9;
    padding: 0 12px;
}

.btn-stu,
.search-strip button {
    height: 37px;
    border: 0;
    background: #007d75;
    color: #fff;
    font-weight: 700;
    padding: 0 14px;
    border-radius: 2px;
    cursor: pointer;
}

.btn-stu:hover,
.search-strip button:hover {
    background: #005f59;
}

.btn-yellow {
    background: var(--yellow);
    color: #0b4469;
}

.btn-red {
    background: var(--red);
    color: #fff;
}


/* thong bao chu chay */

.marquee-box {
    display: flex;
    align-items: center;
    background: #fff;
    border-bottom: 1px solid #d5e1ea;
}

.marquee-label {
    background: var(--yellow);
    color: #004879;
    padding: 11px 20px;
    font-weight: 800;
}

.marquee-box marquee {
    color: var(--red);
    font-weight: 700;
    padding-left: 10px;
}


/* cac o chuc nang nhanh */

.quick-actions {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 12px;
    padding-top: 14px;
    padding-bottom: 14px;
}

.quick-card {
    display: flex;
    align-items: center;
    gap: 12px;
    background: #fff;
    border: 1px solid #cfe0ec;
    border-left: 5px solid var(--stu);
    padding: 15px;
    min-height: 84px;
    transition: .25s;
}

.quick-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 87, 140, .16);
    text-decoration: none;
}

.quick-card i {
    font-size: 28px;
    color: var(--stu);
}

.quick-card b {
    display: block;
    color: #003e67;
}

.quick-card span {
    display: block;
    color: #475569;
    font-size: 13px;
    margin-top: 4px;
}


/* noi dung chinh */

.main-wrap {
    padding-top: 0;
    padding-bottom: 30px;
}

.top-grid {
    display: grid;
    grid-template-columns: 2.1fr .95fr;
    gap: 13px;
}


/* slideshow */

.hero {
    position: relative;
    background: #ddd;
    min-height: 390px;
    overflow: hidden;
    border: 1px solid #c9d8e6;
}

.hero img {
    width: 100%;
    height: 430px;
    object-fit: cover;
    object-position: center;
    display: block;
    transition: opacity .3s;
}

.hero-caption {
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(transparent, rgba(0, 0, 0, .72));
    color: #fff;
    padding: 58px 25px 22px;
}

.hero-caption strong {
    display: block;
    font-size: 25px;
    letter-spacing: 1px;
}

.hero-caption span {
    font-size: 15px;
}


/* cot phai slideshow */

.side-banners {
    display: grid;
    grid-template-rows: 1fr 1fr;
    gap: 13px;
}

.service-panel {
    background: linear-gradient(135deg, #0084bd, #005c8d);
    color: #fff;
    min-height: 205px;
    padding: 28px;
    position: relative;
    overflow: hidden;
}

.service-panel:after {
    content: "";
    position: absolute;
    right: -35px;
    bottom: -35px;
    width: 180px;
    height: 180px;
    background: rgba(255, 255, 255, .17);
    border-radius: 50%;
}

.service-panel h3 {
    color: var(--yellow);
    font-weight: 900;
    letter-spacing: 2px;
}

.service-panel p {
    font-size: 17px;
}

.library-photo-card {
    position: relative;
    min-height: 205px;
    overflow: hidden;
}

.library-photo-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    filter: brightness(.77);
}

.library-photo-card div {
    position: absolute;
    left: 24px;
    bottom: 20px;
    color: #fff;
}

.library-photo-card h3 {
    font-weight: 900;
    letter-spacing: 1px;
}


/* bo cuc noi dung */

.content-grid {
    display: grid;
    grid-template-columns: 2fr .9fr;
    gap: 13px;
    margin-top: 13px;
}

.three-cols {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 13px;
}


/* hop noi dung */

.box {
    background: #fff;
    border: 1px solid #cfdce7;
    margin-bottom: 13px;
}

.box-title {
    height: 39px;
    border-bottom: 1px solid #dbe7ef;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 14px;
    border-left: 5px solid var(--stu);
}

.box-title h2 {
    margin: 0;
    color: #004879;
    text-transform: uppercase;
    font-size: 18px;
    font-weight: 900;
}

.box-title .more {
    font-size: 12px;
}


/* hien thi danh sach sach */

.books {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    padding: 18px;
}

.book-card {
    position: relative;
    text-align: center;
    border: 1px solid #e1eaf1;
    padding: 12px 8px;
    background: #fff;
    min-height: 282px;
    transition: .2s;
}

.book-card:hover {
    box-shadow: 0 6px 15px rgba(0, 0, 0, .12);
    transform: translateY(-2px);
}

.book-card img {
    width: 95px;
    height: 135px;
    object-fit: cover;
    margin-bottom: 8px;
    border: 1px solid #ddd;
}

.book-card b {
    display: block;
    min-height: 38px;
    color: #004879;
    font-size: 13px;
}

.book-card span {
    display: block;
    color: #555;
    font-size: 12px;
    margin-top: 4px;
}

.book-card .status {
    display: inline-block;
    border-radius: 20px;
    padding: 3px 8px;
    margin: 7px 0;
    font-size: 11px;
    background: #e9f7ef;
    color: #0c6b35;
}

.book-actions {
    display: flex;
    justify-content: center;
    gap: 5px;
    flex-wrap: wrap;
}

.book-actions button {
    border: 0;
    border-radius: 2px;
    padding: 5px 7px;
    font-size: 11px;
    background: #e7f1fb;
    color: #004879;
    font-weight: 700;
}

.book-actions button:hover {
    background: var(--yellow);
}


/* danh sach link */

.list-links {
    padding: 10px 15px;
}

.list-links a {
    display: block;
    border-bottom: 1px dotted #c6d5df;
    padding: 8px 0;
    color: #00558d;
}

.list-links a:before {
    content: "◉";
    font-size: 10px;
    color: var(--stu);
    margin-right: 8px;
}


/* tin tuc */

.news-list {
    padding: 12px 15px;
}

.news-item {
    display: grid;
    grid-template-columns: 86px 1fr;
    gap: 11px;
    border-bottom: 1px solid #e3edf4;
    padding: 9px 0;
}

.news-item img {
    width: 86px;
    height: 58px;
    object-fit: cover;
}

.news-item b {
    color: #00558d;
}

.news-item span {
    display: block;
    font-size: 12px;
    color: #667;
}


/* thong bao */

.notice-list {
    padding: 12px 16px;
}

.notice-list li {
    margin: 8px 0;
}

.notice-list i {
    color: var(--red);
    margin-right: 7px;
}


/* tien ich */

.tool-panel {
    padding: 16px;
}

.tool-panel .btn-stu {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    margin: 4px 4px 6px 0;
    min-width: 145px;
}


/* footer va ban do */

.footer {
    background: #0069a8;
    color: #fff;
    margin-top: 28px;
}

.footer-main {
    display: grid;
    grid-template-columns: 1fr 1.5fr 1fr;
    gap: 28px;
    padding-top: 24px;
    padding-bottom: 24px;
}

.footer h3 {
    font-size: 16px;
    color: #fff;
    border-bottom: 1px solid rgba(255, 255, 255, .35);
    padding-bottom: 8px;
}

.footer p {
    margin: 7px 0;
}

.footer iframe {
    width: 100%;
    height: 170px;
    border: 0;
}

.footer-bottom {
    background: #004879;
    display: flex;
    justify-content: space-between;
    padding-top: 11px;
    padding-bottom: 11px;
}


/* tieu de trang con */

.page-title {
    background: #fff;
    border-left: 5px solid var(--stu);
    padding: 16px 18px;
    margin: 18px 0 13px;
}

.page-title h1 {
    font-size: 25px;
    margin: 0;
    color: #004879;
}


/* form nhap lieu */

.form-box {
    background: #fff;
    border: 1px solid #cfdce7;
    padding: 18px;
}

.form-row {
    margin-bottom: 13px;
}

.form-row label {
    font-weight: 700;
    margin-bottom: 5px;
    display: block;
}

.form-row input,
.form-row textarea,
.form-row select {
    width: 100%;
    border: 1px solid #b5c8d7;
    padding: 9px;
}


/* thanh loc du lieu */

.catalog-toolbar {
    background: #fff;
    border: 1px solid #cfdce7;
    padding: 14px;
    margin-bottom: 13px;
    display: grid;
    grid-template-columns: 1fr 210px 150px;
    gap: 10px;
}

.catalog-toolbar input,
.catalog-toolbar select {
    border: 1px solid #b5c8d7;
    padding: 9px;
}


/* bang du lieu */

.table-wrap {
    background: #fff;
    border: 1px solid #cfdce7;
    padding: 14px;
    overflow: auto;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
}

.data-table th {
    background: #0069a8;
    color: #fff;
}

.data-table th,
.data-table td {
    border: 1px solid #d8e3eb;
    padding: 9px;
}

.data-table input,
.data-table select {
    width: 100%;
    padding: 6px;
    border: 1px solid #9fb3c0;
}


/* so luong gio */

.cart-badge {
    background: var(--red);
    color: #fff;
    border-radius: 50%;
    font-size: 11px;
    padding: 2px 6px;
    margin-left: 4px;
}


/* giao dien admin */

.admin-layout {
    display: grid;
    grid-template-columns: 235px 1fr;
    min-height: 100vh;
    align-items: stretch;
}


/* boc menu admin de mau nen keo dai het trang */

#menuAdmin {
    background: #004879;
}

.admin-sidebar {
    background: #004879;
    color: #fff;
    padding: 18px;
    min-height: 100vh;
    height: 100%;
}

.admin-sidebar h4 {
    font-weight: 800;
    margin-bottom: 12px;
}

.admin-sidebar a {
    display: block;
    color: #fff;
    border-bottom: 1px solid rgba(255, 255, 255, .18);
    padding: 11px;
}

.admin-sidebar a:hover,
.admin-sidebar .active {
    background: #0069a8;
    text-decoration: none;
}

.admin-main {
    padding: 20px;
    background: #f4f8fb;
}

.admin-main h2 {
    margin-bottom: 16px;
    color: #004879;
    font-weight: 800;
}

.admin-cards {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 14px;
    margin-bottom: 18px;
}

.admin-card {
    background: #fff;
    border-left: 5px solid #0069a8;
    padding: 18px;
    box-shadow: 0 1px 3px #ccd;
}

.admin-card b {
    font-size: 27px;
    color: #0069a8;
}


/* form dang nhap admin */

.login-wrap {
    max-width: 410px;
    margin: 75px auto;
    background: #fff;
    border-top: 7px solid var(--stu);
    box-shadow: 0 5px 25px rgba(0, 0, 0, .15);
    padding: 26px;
}


/* thong bao */

.alert {
    margin: 12px 0;
}

.alert-success {
    display: none;
    background: #e4f7ec;
    border: 1px solid #9fd7b4;
    color: #0f6b35;
    padding: 10px;
    margin-bottom: 12px;
}


/* nut trong bang admin */

.btn-small {
    display: inline-block;
    padding: 5px 9px;
    border: 0;
    margin: 2px;
    cursor: pointer;
    border-radius: 2px;
    text-decoration: none !important;
}

.btn-small:hover {
    text-decoration: none !important;
    opacity: .9;
}

.btn-edit {
    background: var(--yellow);
    color: #123;
}

.btn-del {
    background: #dc3545;
    color: #fff;
}

.btn-ok {
    background: #198754;
    color: #fff;
}

.btn-return {
    background: #0d6efd;
    color: #fff;
}

.btn-renew {
    background: #17a2b8;
    color: #fff;
}


/* trang chi tiet sach */

.detail-box {
    display: flex;
    gap: 24px;
    padding: 20px;
    align-items: flex-start;
}

.detail-box img {
    width: 150px;
    height: 210px;
    object-fit: cover;
    border: 1px solid #ddd;
}

.form-box .row {
    align-items: end;
}


/* responsive cho tablet */

@media(max-width:1200px) {
    .wrap {
        padding-left: 18px;
        padding-right: 18px;
    }
    .books {
        grid-template-columns: repeat(4, 1fr);
    }
    .header-photo {
        width: 38%;
        min-width: 340px;
    }
    .brand h1 {
        font-size: 25px;
    }
    .brand p {
        font-size: 18px;
    }
    .content-grid,
    .top-grid,
    .three-cols,
    .footer-main {
        grid-template-columns: 1fr;
    }
    .side-banners {
        grid-template-columns: 1fr 1fr;
        grid-template-rows: auto;
    }
    .hero img {
        height: 390px;
    }
    .admin-cards {
        grid-template-columns: repeat(2, 1fr);
    }
}


/* responsive cho dien thoai */

@media(max-width:760px) {
    .top-line,
    .site-header,
    .footer-bottom {
        height: auto;
        display: block;
        padding-top: 8px;
        padding-bottom: 8px;
    }
    .brand {
        margin-bottom: 10px;
    }
    .brand img {
        width: 90px;
    }
    .brand h1 {
        font-size: 18px;
    }
    .brand p {
        font-size: 15px;
    }
    .header-photo {
        width: 100%;
        min-width: 0;
        height: 120px;
    }
    .main-nav ul {
        display: block;
    }
    .main-nav .right {
        margin-left: 0;
    }
    .dropdown-menu-stu {
        position: static;
        visibility: visible;
        opacity: 1;
        transform: none;
        display: none;
    }
    .has-dropdown:hover .dropdown-menu-stu {
        display: block;
    }
    .search-strip,
    .quick-actions,
    .catalog-toolbar,
    .admin-layout {
        grid-template-columns: 1fr;
    }
    #menuAdmin,
    .admin-sidebar {
        min-height: auto;
        height: auto;
    }
    .books {
        grid-template-columns: repeat(2, 1fr);
    }
    .side-banners {
        grid-template-columns: 1fr;
    }
    .hero img {
        height: 270px;
    }
    .quick-card {
        min-height: auto;
    }
    .footer-main {
        gap: 10px;
    }
    .admin-cards {
        grid-template-columns: 1fr;
    }
    .detail-box {
        display: block;
    }
    .detail-box img {
        margin-bottom: 15px;
    }
}


/* =========================
   Phần bổ sung cho bản HTML nhập môn
   ========================= */

.noi-dung-rong {
    padding: 18px;
    background: #fff;
    border: 1px solid #cfdce7;
    line-height: 1.7;
}

.ghi-chu-code {
    background: #fffbe8;
    border-left: 5px solid #ffd23f;
    padding: 12px;
    margin: 12px 0;
}

.search-strip button {
    border: 0;
}

.alert-success {
    display: block;
}

.toast-message {
    position: fixed;
    top: 18px;
    right: 18px;
    z-index: 9999;
    width: min(420px, calc(100% - 36px));
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 16px;
    border-radius: 12px;
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.18);
    background: #fff;
    border-left: 6px solid #198754;
}

.toast-success {
    border-left-color: #198754;
}

.toast-info {
    border-left-color: #0d6efd;
}

.toast-warning {
    border-left-color: #ffc107;
}

.toast-error {
    border-left-color: #dc3545;
}

.toast-icon {
    font-size: 22px;
    line-height: 1;
}

.toast-success .toast-icon {
    color: #198754;
}

.toast-info .toast-icon {
    color: #0d6efd;
}

.toast-warning .toast-icon {
    color: #b58100;
}

.toast-error .toast-icon {
    color: #dc3545;
}

.toast-text {
    flex: 1;
    color: #222;
    font-weight: 600;
    line-height: 1.45;
}

.toast-close {
    border: 0;
    background: transparent;
    font-size: 24px;
    line-height: 1;
    cursor: pointer;
    color: #777;
}

.nut-phu {
    background: #eef6ff;
    color: #004879;
    border: 1px solid #bcd8ec;
    padding: 8px 12px;
}

.admin-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.badge-huong-dan {
    display: inline-block;
    background: #eaf6ff;
    color: #004879;
    padding: 4px 8px;
    border-radius: 999px;
    font-weight: 700;
}


/* giữ chân trang luôn nằm cuối màn hình */

html,
body {
    min-height: 100%;
}

body {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

#phancuoitrang {
    margin-top: auto;
}

.main-wrap,
.admin-main {
    flex: 1 0 auto;
}

.user-panel {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 18px;
}

.account-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 12px;
    padding: 18px;
}

.account-card h3 {
    color: var(--stu-dark);
    font-weight: 700;
}

.admin-section-title {
    margin: 25px 0 12px;
    color: var(--stu-dark);
    font-weight: 700;
}

.nut-phu {
    border: 1px solid var(--line);
    background: #fff;
    border-radius: 8px;
    padding: 8px 12px;
}

@media(max-width: 800px) {
    .user-panel {
        grid-template-columns: 1fr;
    }
}