/* ============================================================
   LAYOUT.CSS - Grid system, containers, responsive layouts
   ============================================================ */

/* Container */
.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--khoang-cach-md);
}

@media (min-width: 768px) {
    .container {
        padding: 0 var(--khoang-cach-lg);
    }
}

@media (min-width: 1024px) {
    .container {
        padding: 0 var(--khoang-cach-xl);
    }
}

/* Section */
.section {
    display: none;
    height: 100%;
    overflow: hidden;
}

.section--active {
    display: block;
}

#trang-chu {
    padding: 0;
}

#gop-y,
#gioi-thieu,
#tin-tuc,
#quan-ly {
    padding: var(--khoang-cach-lg);
    overflow-y: auto;
}

.section__title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--mau-chu-chinh);
    margin-bottom: var(--khoang-cach-lg);
    text-align: center;
}

/* Grid System */
.grid {
    display: grid;
    gap: var(--khoang-cach-md);
}

/* 1 cột (mobile default) */
.grid-cols-1 {
    grid-template-columns: 1fr;
}

/* 2 cột (tablet) */
@media (min-width: 768px) {
    .grid-cols-md-2 {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* 3 cột (desktop) */
@media (min-width: 1024px) {
    .grid-cols-lg-3 {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* 4 cột (large desktop) */
@media (min-width: 1280px) {
    .grid-cols-xl-4 {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* Flexbox Utilities */
.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.flex-wrap {
    flex-wrap: wrap;
}

.items-center {
    align-items: center;
}

.items-start {
    align-items: flex-start;
}

.items-end {
    align-items: flex-end;
}

.justify-center {
    justify-content: center;
}

.justify-between {
    justify-content: space-between;
}

.justify-end {
    justify-content: flex-end;
}

.gap-sm { gap: var(--khoang-cach-sm); }
.gap-md { gap: var(--khoang-cach-md); }
.gap-lg { gap: var(--khoang-cach-lg); }

/* Main Layout */
.main {
    height: calc(100% - 70px);
    overflow: hidden;
}

@media (min-width: 768px) {
    .main {
        height: calc(100% - 80px);
    }
}

/* Responsive Utilities */
@media (max-width: 767px) {
    .an-mobile { display: none !important; }
}

@media (min-width: 768px) {
    .an-tablet { display: none !important; }
}

@media (min-width: 1024px) {
    .an-desktop { display: none !important; }
}

/* Show only on specific breakpoints */
.hien-mobile { display: block !important; }

@media (min-width: 768px) {
    .hien-mobile { display: none !important; }
    .hien-tablet { display: block !important; }
}

@media (min-width: 1024px) {
    .hien-tablet { display: none !important; }
    .hien-desktop { display: block !important; }
}