/* =========================================
   1. VARIABLES & RESET
   ========================================= */
:root {
    --primary-color: #0056b3; 
    --secondary-color: #6c757d;
    --success-color: #2fb344;
    --warning-color: #f59f00;
    --danger-color: #d63939;
    --info-color: #4299e1;
    --card-bg: #ffffff;
    --body-bg: #f4f6f8;
    --text-main: #2c3e50;
    --text-muted: #95a5a6;
    --border-radius: 12px;
    --header-height: 70px; /* Định nghĩa chiều cao header để dùng chung */
    --sidebar-width: 250px;
    --sidebar-collapsed-width: 80px;
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-hover: 0 10px 25px rgba(0, 0, 0, 0.08);
}

body {
    background-color: var(--body-bg);
    color: var(--text-main);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    padding: 0;
    overflow-x: hidden; /* Ngăn thanh cuộn ngang không mong muốn */
}

/* =========================================
   2. LAYOUT CORE (HEADER & PAGE STRUCTURE)
   ========================================= */

/* --- Header (Fixed) --- */
.app-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: #ffffff;
    z-index: 1030; /* Cao hơn nội dung */
    box-shadow: 0 0.25rem 1rem rgba(0, 0, 0, 0.05);
    border-bottom: 1px solid rgba(0,0,0,0.05);
    transition: margin-left 0.3s ease;
}

/* --- Page Content Wrapper --- */
.page {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    /* FIX LỖI HEADER CHE NỘI DUNG: Đẩy xuống bằng chiều cao header + khoảng hở */
    padding-top: calc(var(--header-height) + 20px) !important; 
    position: relative;
}

/* Khu vực chứa nội dung chính */
.page-content {
    width: 100%;
    padding: 0 1.5rem;
    transition: margin-left 0.3s ease, width 0.3s ease; /* Hiệu ứng trượt mượt */
}

/* =========================================
   3. SIDEBAR STYLING
   ========================================= */
.app-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: var(--sidebar-width);
    height: 100vh;
    background-color: #ffffff;
    border-right: 1px solid rgba(0, 0, 0, 0.06);
    box-shadow: 2px 0 12px rgba(0, 0, 0, 0.02);
    z-index: 1040; /* Cao hơn header một chút để phủ lên nếu cần, hoặc thấp hơn tùy design */
    padding-top: var(--header-height); /* Để nội dung menu không bị logo che nếu logo nằm trên header */
    transition: left 0.3s ease, width 0.3s ease;
    overflow-y: auto;
}

/* Logo thương hiệu trong Sidebar (nếu có) hoặc Header */
.navbar-brand {
    font-family: 'Inter', sans-serif;
    font-weight: 800;
    font-size: 1.5rem;
    color: var(--primary-color) !important;
    padding: 1rem 0;
    display: block;
    text-align: center;
}

/* Menu Items */
.navbar-nav .nav-item { margin-bottom: 0.25rem; }

.navbar-nav .nav-link {
    color: #64748b;
    font-weight: 500;
    padding: 0.75rem 1.25rem;
    margin: 0 0.75rem;
    border-radius: 8px;
    transition: all 0.25s ease;
    display: flex;
    align-items: center;
    white-space: nowrap; /* Ngăn chữ xuống dòng khi thu nhỏ */
}

.nav-link-icon {
    width: 24px;
    font-size: 1.1rem;
    color: #94a3b8;
    margin-right: 0.75rem;
    text-align: center;
    transition: color 0.2s, transform 0.2s;
}

.navbar-nav .nav-link:hover {
    background-color: rgba(0, 86, 179, 0.06);
    color: var(--primary-color);
}

.navbar-nav .nav-link:hover .nav-link-icon {
    color: var(--primary-color);
    transform: translateX(2px);
}

.navbar-nav .nav-link.active {
    background-color: var(--primary-color);
    color: #ffffff;
    font-weight: 600;
    box-shadow: 0 4px 6px rgba(0, 86, 179, 0.2);
}

.navbar-nav .nav-link.active .nav-link-icon { color: #ffffff; }

/* =========================================
   4. TOGGLE LOGIC (FIX LỖI DƯ TRÁI & MOBILE)
   ========================================= */

/* --- DESKTOP (Màn hình > 992px) --- */
@media (min-width: 992px) {
    /* 1. Trạng thái MỞ (Mặc định hoặc data-toggled="open") */
    /* Sidebar hiện full, nội dung bị đẩy sang phải */
    html:not([data-toggled="close"]):not([data-toggled="icon-overlay"]) .app-sidebar {
        width: var(--sidebar-width);
        left: 0;
    }
    html:not([data-toggled="close"]):not([data-toggled="icon-overlay"]) .page-content,
    html:not([data-toggled="close"]):not([data-toggled="icon-overlay"]) .app-header {
        margin-left: var(--sidebar-width);
        width: calc(100% - var(--sidebar-width));
    }

    /* 2. Trạng thái ĐÓNG HOÀN TOÀN (data-toggled="close") */
    /* Sidebar ẩn sang trái, nội dung tràn full màn hình -> FIX LỖI DƯ TRÁI */
    html[data-toggled="close"] .app-sidebar {
        left: calc(var(--sidebar-width) * -1); /* Đẩy hẳn ra ngoài */
    }
    html[data-toggled="close"] .page-content,
    html[data-toggled="close"] .app-header {
        margin-left: 0 !important;
        width: 100% !important;
    }

    /* 3. Trạng thái ICON (data-toggled="icon-overlay") - Tùy chọn */
    html[data-toggled="icon-overlay"] .app-sidebar {
        width: var(--sidebar-collapsed-width);
        left: 0;
    }
    html[data-toggled="icon-overlay"] .app-sidebar .nav-link span {
        display: none; /* Ẩn chữ */
    }
    html[data-toggled="icon-overlay"] .page-content,
    html[data-toggled="icon-overlay"] .app-header {
        margin-left: var(--sidebar-collapsed-width);
        width: calc(100% - var(--sidebar-collapsed-width));
    }
}

/* --- MOBILE (Màn hình < 992px) --- */
@media (max-width: 991.98px) {
    /* Mặc định trên mobile: Sidebar ẩn */
    .app-sidebar {
        left: -100%; /* Ẩn hẳn */
        width: var(--sidebar-width);
        z-index: 1050; /* Rất cao để đè lên mọi thứ */
        box-shadow: 0 0 15px rgba(0,0,0,0.2);
    }
    
    .page-content, .app-header {
        margin-left: 0 !important;
        width: 100% !important;
    }

    /* Khi mở menu trên mobile (data-toggled="open") */
    html[data-toggled="open"] .app-sidebar {
        left: 0 !important;
    }

    /* Lớp phủ đen mờ khi mở menu mobile */
    #responsive-overlay {
        display: none;
        position: fixed;
        top: 0; right: 0; bottom: 0; left: 0;
        background: rgba(0,0,0,0.5);
        z-index: 1045; /* Thấp hơn sidebar (1050) nhưng cao hơn header (1030) */
    }
    html[data-toggled="open"] #responsive-overlay {
        display: block;
    }
}

/* =========================================
   5. COMPONENT STYLING (Card, Button, Form)
   ========================================= */

/* --- Card Styles --- */
.card {
    background: var(--card-bg);
    border: none;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    margin-bottom: 1.5rem;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.card-header {
    background-color: transparent;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    padding: 1.25rem 1.5rem;
}

.card-title {
    font-size: 1.1rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin: 0;
    display: flex;
    align-items: center;
}

.card-body { padding: 1.5rem; }

/* Avatar & Icons */
.avatar {
    width: 3.5rem;
    height: 3.5rem;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    transition: transform 0.3s;
}
.avatar.bg-success { background: rgba(47, 179, 68, 0.1) !important; color: var(--success-color) !important; }
.avatar.bg-info { background: rgba(66, 153, 225, 0.1) !important; color: var(--info-color) !important; }
.avatar.bg-warning { background: rgba(245, 159, 0, 0.1) !important; color: var(--warning-color) !important; }

.card:hover .avatar { transform: scale(1.1); }

/* Buttons */
.btn {
    border-radius: 8px;
    font-weight: 600;
    padding: 0.6rem 1.25rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    box-shadow: 0 4px 6px rgba(0, 86, 179, 0.25);
}
.btn-primary:hover {
    background-color: #004494;
    transform: translateY(-2px);
    box-shadow: 0 8px 15px rgba(0, 86, 179, 0.3);
}
.btn-danger {
    background-color: var(--danger-color);
    border-color: var(--danger-color);
    box-shadow: 0 4px 6px rgba(214, 57, 57, 0.25);
}

/* Forms */
.form-label {
    font-weight: 600;
    color: var(--text-main);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}
.form-control, .form-select {
    background-color: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 10px;
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
    color: #334155;
    transition: all 0.2s ease-in-out;
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
}
.form-control:focus, .form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(0, 86, 179, 0.15);
    background-color: #fff;
    transform: translateY(-1px);
}
.input-group-text {
    background-color: #f8fafc;
    border: 1px solid #e2e8f0;
    border-right: none;
    color: #64748b;
    border-radius: 10px 0 0 10px;
}
.input-group .form-control {
    border-left: none;
    border-radius: 0 10px 10px 0;
}
.input-group:focus-within .input-group-text {
    border-color: var(--primary-color);
    background-color: #fff;
    color: var(--primary-color);
}

/* Scroll to top */
.scrollToTop {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--primary-color);
    color: #fff;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    z-index: 999;
    transition: all 0.3s;
    opacity: 0.8;
}
.scrollToTop:hover {
    transform: translateY(-3px);
    opacity: 1;
}