/* ==============================================
   PUMS TOOLKIT — DESIGN TOKENS
   Sửa các giá trị ở đây để thay đổi toàn bộ giao diện
   ============================================== */

:root {
    /* --- Màu chính --- */
    --color-primary:        #4361ee;
    --color-primary-dark:   #3730a3;
    --color-primary-light:  #f0f3ff;
    --color-primary-hover:  #eef2ff;

    /* --- Màu nền --- */
    --color-bg-page:        #f5f7fa;
    --color-bg-sidebar:     #ffffff;
    --color-bg-card:        #ffffff;
    --color-bg-input:       #f8fafc;

    /* --- Màu chữ --- */
    --color-text-heading:   #1e293b;
    --color-text-body:      #334155;
    --color-text-muted:     #64748b;
    --color-text-disabled:  #cbd5e1;

    /* --- Màu border --- */
    --color-border:         #e8ecf0;
    --color-border-light:   #f0f2f5;
    --color-border-input:   #e2e8f0;

    /* --- Màu trạng thái nav active --- */
    --color-nav-active-bg:  #f0f3ff;
    --color-nav-active-txt: #4361ee;

    /* --- Màu label section "sắp có" --- */
    --color-label-muted:    #94a3b8;

    /* --- Typography --- */
    --font-family:          'Inter', sans-serif;
    --font-size-base:       0.875rem;
    --font-size-sm:         0.75rem;
    --font-size-xs:         0.68rem;
    --font-weight-normal:   400;
    --font-weight-semi:     600;
    --font-weight-bold:     800;

    /* --- Spacing --- */
    --spacing-xs:           0.25rem;
    --spacing-sm:           0.5rem;
    --spacing-md:           1rem;
    --spacing-lg:           1.5rem;
    --spacing-xl:           2rem;

    /* --- Border radius --- */
    --radius-sm:            6px;
    --radius-md:            10px;
    --radius-lg:            16px;
    --radius-xl:            20px;

    /* --- Shadow --- */
    --shadow-card:          0 1px 4px rgba(0,0,0,0.06), 0 4px 16px rgba(0,0,0,0.04);
    --shadow-btn:           0 4px 12px rgba(67, 97, 238, 0.25);

    /* --- Kích thước sidebar --- */
    --sidebar-width:        260px;
}

/* ==============================================
   BASE STYLES
   ============================================== */

body {
    background-color: var(--color-bg-page);
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    color: var(--color-text-body);
    display: flex;
    min-height: 100vh;
}

/* ==============================================
   SIDEBAR
   ============================================== */

.sidebar {
    width: var(--sidebar-width);
    background: var(--color-bg-sidebar);
    border-right: 1px solid var(--color-border);
    padding: var(--spacing-lg) calc(var(--spacing-lg) * 0.8);
    flex-shrink: 0;
}

/* --- Brand / Logo --- */
.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border-light);
}

.brand img {
    width: 36px;
    height: 36px;
    object-fit: contain;
    mix-blend-mode: multiply;
}

.brand-name {
    font-weight: var(--font-weight-bold);
    font-size: 0.95rem;
    color: var(--color-text-heading);
    letter-spacing: 0.04em;
}

/* --- Navigation --- */
.nav-link {
    padding: 0.65rem 0.9rem;
    border-radius: var(--radius-md);
    color: var(--color-text-muted);
    font-weight: var(--font-weight-semi);
    font-size: var(--font-size-base);
    margin-bottom: 0.2rem;
    transition: background 0.15s, color 0.15s;
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-link:hover {
    background: var(--color-bg-input);
    color: var(--color-text-heading);
}

.nav-link.active {
    background: var(--color-nav-active-bg);
    color: var(--color-nav-active-txt);
}

.nav-link i {
    width: 16px;
    font-size: 0.85rem;
}

/* --- Sub nav (children of a nav item) --- */
.nav-sub {
    padding-left: 1.5rem;
    border-left: 2px solid var(--color-border-light);
    margin-left: 1.2rem;
    margin-bottom: 0.2rem;
}

.nav-link-sub {
    font-size: 0.82rem;
    padding: 0.45rem 0.75rem;
    color: var(--color-text-muted);
}

.nav-link-sub.active {
    background: var(--color-nav-active-bg);
    color: var(--color-nav-active-txt);
    font-weight: var(--font-weight-semi);
}

/* --- Collapsible nav item --- */
.nav-link-collapsible {
    justify-content: space-between;
}

.nav-chevron {
    font-size: 0.7rem;
    transition: transform 0.2s ease;
    color: var(--color-text-disabled);
}

.nav-chevron.collapsed {
    transform: rotate(-90deg);
}

.nav-section-label {
    font-size: var(--font-size-xs);
    text-transform: uppercase;
    color: var(--color-label-muted);
    font-weight: var(--font-weight-semi);
    letter-spacing: 0.08em;
    padding: var(--spacing-md) 0.9rem 0.4rem;
}

.nav-link.disabled {
    color: var(--color-text-disabled);
    cursor: not-allowed;
    pointer-events: none;
}

/* ==============================================
   MAIN CONTENT
   ============================================== */

.main-content {
    flex-grow: 1;
    padding: var(--spacing-xl);
    max-width: 1200px;
    margin: 0 auto;
}

/* ==============================================
   CARD
   ============================================== */

.card-custom {
    border: none;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    background: var(--color-bg-card);
}

/* ==============================================
   BUTTONS
   ============================================== */

.btn-primary-custom {
    background: var(--color-primary);
    border: none;
    color: #ffffff;
    padding: 14px 40px;
    border-radius: var(--radius-md);
    font-weight: var(--font-weight-bold);
    font-size: var(--font-size-base);
    width: 100%;
    transition: background 0.2s, transform 0.2s, box-shadow 0.2s;
    cursor: pointer;
}

.btn-primary-custom:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-btn);
}

/* ==============================================
   FORM ELEMENTS
   ============================================== */

.form-control,
.form-select {
    border-color: var(--color-border-input);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
    background-color: var(--color-bg-card);
    color: var(--color-text-body);
    transition: border-color 0.15s, box-shadow 0.15s;
}

.form-control:focus,
.form-select:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
    outline: none;
}

.form-label {
    font-weight: var(--font-weight-semi);
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xs);
}

/* ==============================================
   FILE UPLOAD
   ============================================== */

.file-upload-wrapper {
    border: 2px dashed var(--color-border-input);
    border-radius: var(--radius-lg);
    padding: 40px;
    text-align: center;
    background: var(--color-bg-input);
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s;
}

.file-upload-wrapper:hover {
    border-color: var(--color-primary);
    background: var(--color-primary-hover);
}

/* ==============================================
   NAV PILLS (tabs)
   ============================================== */

.nav-pills .nav-link {
    border-radius: var(--radius-md);
    padding: 10px 20px;
    font-weight: var(--font-weight-semi);
    color: var(--color-text-muted);
    border: 1px solid transparent;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.nav-pills .nav-link:hover:not(.active) {
    background: var(--color-primary-light);
    color: var(--color-primary);
    border-color: var(--color-primary-light);
}

.nav-pills .nav-link.active {
    background-color: var(--color-primary);
    color: #ffffff;
    border-color: var(--color-primary);
    box-shadow: 0 2px 8px rgba(67, 97, 238, 0.25);
}

/* ==============================================
   SPINNER / LOADER
   ============================================== */

.loader-overlay {
    display: none;
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(255, 255, 255, 0.85);
    z-index: 1000;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

.spinner-pro {
    width: 48px;
    height: 48px;
    border: 4px solid var(--color-border);
    border-top: 4px solid var(--color-primary);
    border-radius: 50%;
    animation: spin 0.9s linear infinite;
}

@keyframes spin {
    0%   { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}