:root {
    --primary-color: #a28b6a;
    --bg-color: #f8f9fa;
    --text-color: #333;
    --card-bg: #fff;
    --border-color: #ddd;
}
[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --text-color: #fff;
    --card-bg: #2c2c2c;
    --border-color: #444;
}
body { 
    font-family: 'Arial', sans-serif; 
    margin: 0; 
    padding: 0; 
    background: var(--bg-color); 
    color: var(--text-color); 
    transition: background 0.3s, color 0.3s;
}
header { 
    background: linear-gradient(135deg, var(--primary-color), #c5cbd3); 
    color: white; 
    padding: 15px 20px; 
    display: flex; 
    justify-content: space-between; 
    align-items: center; 
    box-shadow: 0 2px 10px rgba(0,123,255,0.2);
}
.logo { font-size: 28px; font-weight: bold; }
nav ul { 
    list-style: none; 
    display: flex; 
    gap: 25px; 
    margin: 0; 
    padding: 0; 
}
nav a { 
    text-decoration: none; 
    color: white; 
    transition: color 0.3s; 
}
nav a:hover { color: #ffd700; }
.header-right { display: flex; align-items: center; gap: 15px; }
.search { 
    padding: 8px; 
    border: none; 
    border-radius: 20px; 
    width: 200px; 
}
.theme-toggle { background: rgba(255,255,255,0.2); border: none; color: white; padding: 5px 10px; border-radius: 20px; cursor: pointer; }
.container { 
    display: grid; 
    grid-template-columns: 1fr 3fr; 
    max-width: 1200px; 
    margin: 20px auto; 
    gap: 20px; 
    padding: 0 20px; 
}
.sidebar { 
    background: var(--card-bg); 
    padding: 20px; 
    border-radius: 10px; 
    box-shadow: 0 4px 8px rgba(0,0,0,0.1); 
    animation: fadeIn 0.5s ease-in;
}
.sidebar h3 { 
    color: var(--primary-color); 
    border-bottom: 2px solid var(--primary-color); 
    padding-bottom: 10px; 
    margin-top: 30px; 
}
.sidebar h3:first-child { margin-top: 0; }
.sidebar ul { list-style: none; padding: 0; }
.sidebar li { margin: 10px 0; }
.sidebar a { 
    display: block; 
    padding: 12px; 
    background: var(--bg-color); 
    border-radius: 6px; 
    text-decoration: none; 
    color: var(--text-color); 
    transition: transform 0.3s, background 0.3s; 
}
.sidebar a:hover { 
    background: var(--primary-color); 
    color: white; 
    transform: translateX(5px); 
}
.main { 
    background: var(--card-bg); 
    padding: 20px; 
    border-radius: 10px; 
    box-shadow: 0 4px 8px rgba(0,0,0,0.1); 
    animation: fadeIn 0.5s ease-in;
}
.main h1 { color: var(--primary-color); }
.back-btn { background: var(--primary-color); color: white; padding: 10px; border: none; border-radius: 5px; cursor: pointer; margin-bottom: 20px; }
.post { 
    border-bottom: 1px solid var(--border-color); 
    padding: 20px 0; 
    cursor: pointer; 
    transition: all 0.3s; 
}
.post:last-child { border-bottom: none; }
.post h2 { 
    color: var(--primary-color); 
    margin: 0 0 10px; 
    font-size: 20px; 
}
.post-meta { 
    font-size: 14px; 
    color: #666; 
    margin-bottom: 10px; 
}
.post:hover { 
    background: var(--bg-color); 
    padding-left: 15px; 
    border-radius: 5px; 
}
.pagination { 
    display: flex; 
    justify-content: center; 
    gap: 10px; 
    margin-top: 20px; 
}
.pagination button { 
    padding: 8px 12px; 
    border: 1px solid var(--primary-color); 
    background: var(--card-bg); 
    color: var(--primary-color); 
    cursor: pointer; 
    border-radius: 4px; 
    transition: background 0.3s; 
}
.pagination button:hover, .pagination button.active { 
    background: var(--primary-color); 
    color: white; 
}
footer { 
    background: #333; 
    color: white; 
    text-align: center; 
    padding: 20px; 
    margin-top: 40px; 
}
/* Modal */
.modal { 
    display: none; 
    position: fixed; 
    z-index: 1000; 
    left: 0; 
    top: 0; 
    width: 100%; 
    height: 100%; 
    background: rgba(0,0,0,0.5); 
    animation: fadeIn 0.3s; 
}
.modal-content { 
    background: var(--card-bg); 
    margin: 10% auto; 
    padding: 20px; 
    border-radius: 10px; 
    width: 80%; 
    max-width: 600px; 
    color: var(--text-color); 
}
.close { 
    color: #aaa; 
    float: right; 
    font-size: 28px; 
    font-weight: bold; 
    cursor: pointer; 
}
/* Grid Card Layout cho page con */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin: 20px 0;
}
.card {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    cursor: pointer;
    position: relative;
    border: 1px solid var(--border-color);
}
.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.2);
}
.card-icon {
    font-size: 40px;
    margin-bottom: 10px;
    text-align: center;
}
.card-diagram {
    background: #f0f8ff; /* Nền nhẹ cho sơ đồ */
    padding: 10px;
    border-radius: 5px;
    margin: 10px 0;
    font-size: 12px;
    text-align: center;
    min-height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px dashed var(--primary-color);
}
.card h3 {
    color: var(--primary-color);
    margin: 10px 0;
    font-size: 18px;
}
.card-meta {
    font-size: 12px;
    color: #666;
    margin-bottom: 10px;
}

/* Phần phụ (như CI/CD) */
.sub-section {
    margin-top: 40px;
    padding-top: 20px;
    border-top: 2px solid var(--primary-color);
}
.sub-section h2 {
    color: var(--primary-color);
    text-align: center;
}

/* Form upload trong sidebar */
.sidebar .upload-form {
    margin-top: 20px;
    padding: 15px;
    background: var(--bg-color);
    border-radius: 8px;
}

/* Responsive cho grid */
@media (max-width: 768px) {
    .card-grid {
        grid-template-columns: 1fr;
    }
}

/* Audio Player trong Card */
.audio-card {
    position: relative;
}
.card audio {
    width: 100%;
    margin-top: 10px;
    border-radius: 5px;
}
.audio-controls {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-top: 10px;
}
.play-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 8px 12px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 16px;
    transition: background 0.3s;
}
.play-btn:hover {
    background: #218838;
}
.play-btn.playing {
    background: #dc3545; /* Đỏ khi đang phát */
}

/* Responsive audio */
@media (max-width: 768px) {
    .card audio {
        width: 100%;
    }
}
/* Page Chi Tiết Bài Viết */
.detail-page {
    background: linear-gradient(to bottom, #f0f8ff 0%, var(--bg-color) 50%);
    min-height: 100vh;
}
.detail-header {
    position: relative;
    padding: 20px;
    text-align: center;
}
.decor-image {
    position: absolute;
    top: 20px;
    left: 20px;
    width: 120px;
    height: auto;
    z-index: 1;
    opacity: 0.8;
}
.detail-title {
    font-size: 32px;
    color: var(--primary-color);
    margin: 20px 0;
    z-index: 2;
    position: relative;
}
.detail-subtitle {
    font-size: 18px;
    color: #666;
    margin-bottom: 20px;
}
.detail-content {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    line-height: 1.6;
    background: var(--card-bg);
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}
.detail-meta {
    text-align: center;
    font-size: 14px;
    color: #666;
    margin: 10px 0;
}
.back-btn-detail {
    background: var(--primary-color);
    color: white;
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    display: block;
    margin: 20px auto;
    text-align: center;
}
.sidebar-detail {
    width: 250px;
    background: var(--bg-color);
    padding: 20px;
    border-radius: 10px;
    margin: 20px;
}
.container-detail {
    display: flex;
    max-width: 1200px;
    margin: 0 auto;
    gap: 20px;
    padding: 20px;
}
@media (max-width: 768px) {
    .container-detail {
        flex-direction: column;
    }
    .decor-image {
        width: 80px;
        top: 10px;
        left: 10px;
    }
    .detail-title {
        font-size: 24px;
    }
}

        /* Thêm phần CSS điều chỉnh ảnh đầu trang */
        .detail-header {
            position: relative;
            text-align: center;
            color: white;
            margin-bottom: 30px;
        }

        .header-image {
            width: 100%;
            height: 180px;            /* Giảm chiều cao ảnh */
            object-fit: cover;        /* Giúp ảnh trải đều, không méo */
            border-radius: 12px;      /* Bo nhẹ góc cho mềm mại */
            box-shadow: 0 4px 12px rgba(0,0,0,0.3); /* Bóng mờ nhẹ */
        }

        .detail-title {
            margin-top: 15px;
            font-size: 28px;
            color: #222;
        }

        .detail-subtitle {
            color: #555;
            font-size: 16px;
            margin-bottom: 8px;
        }

        .detail-meta {
            color: #777;
            font-size: 14px;
        }
    
        /* Topics Grid - Làm đẹp, trong suốt, mượt mà */
.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-top: 40px;
}
.topic-card {
    background: rgba(255, 255, 255, 0.1); /* Trong suốt hơn */
    backdrop-filter: blur(10px); /* Hiệu ứng kính mờ, làm mượt mà */
    border: 1px solid rgba(255, 255, 255, 0.2); /* Viền mờ */
    padding: 25px 20px; /* Padding đều hơn */
    border-radius: 15px; /* Bo góc mềm mại */
    transition: all 0.3s ease; /* Smooth transition */
    text-align: center;
}
.topic-card:hover {
    background: rgba(255, 255, 255, 0.2); /* Tăng opacity khi hover */
    transform: translateY(-5px); /* Nâng nhẹ */
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2); /* Shadow mượt */
}
.topic-card h3 {
    color: var(--primary-color);
    margin-bottom: 10px;
    font-size: 20px;
}
.topic-card p {
    font-style: italic; /* Italic để tinh tế */
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 15px;
    font-size: 14px;
}
.topic-link {
    text-decoration: none; /* Không gạch chân */
    color: var(--primary-color);
    font-weight: bold;
    font-size: 14px;
    position: relative;
    display: inline-block;
    padding: 8px 15px;
    border: 1px solid rgba(255, 255, 255, 0.3); /* Viền mờ cho link */
    border-radius: 20px; /* Bo tròn như button */
    transition: all 0.3s ease;
    background: rgba(255, 255, 255, 0.1);
}
.topic-link::after {
    content: ' →'; /* Mũi tên mượt, thay vì text thô */
    opacity: 0;
    transition: opacity 0.3s ease;
}
.topic-link:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateX(5px); /* Slide nhẹ sang phải */
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}
.topic-link:hover::after {
    opacity: 1; /* Hiện mũi tên khi hover */
}

footer a { transition: all 0.3s ease; }
footer a:hover { transform: scale(1.1); }
.social-link svg { transition: transform 0.3s ease; }
.social-link:hover svg { transform: rotate(10deg); } /* Quay nhẹ icon khi hover */
@media (max-width: 768px) {
    .social-links { gap: 10px; }
    footer { padding: 30px 15px 15px; }
    .social-link { font-size: 20px; }
}


/* Responsive */
@media (max-width: 768px) {
    .topics-grid { grid-template-columns: repeat(2, 1fr); gap: 15px; } /* 2 cột mobile */
    .topic-card { padding: 20px 15px; }
}

.close:hover { color: var(--primary-color); }
@keyframes fadeIn { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
/* Responsive */
@media (max-width: 768px) {
    .container { grid-template-columns: 1fr; }
    nav ul { flex-direction: column; gap: 10px; }
    .header-right { flex-direction: column; width: 100%; }
    .search { width: 100%; margin-bottom: 10px; }
}
.logo-img:hover {
    transform: scale(1.1); 
}
nav a:hover {
    color: #ffd700; 
.header-right input::placeholder {
    color: rgba(255,255,255,0.7);
}}
@media (max-width: 768px) {
    header { flex-direction: column; gap: 10px; }
    nav ul { flex-direction: column; gap: 10px; text-align: center; }
    .header-right { width: 100%; justify-content: center; }
    .header-right input { width: 100%; max-width: 250px; }
    .logo-container span { display: none; } /* Ẩn text logo trên mobile để gọn */
}
#header {
    transition: background 0.3s ease, box-shadow 0.3s ease;
}

/* Slider Container */
.slider-container {
    position: relative;
    overflow: hidden;
    border-radius: 20px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.1);
    margin-bottom: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* Slider */
.slider {
    display: flex;
    transition: transform 0.6s ease;
    width: 100%;
}

/* Mỗi slide */
.art-slide {
    flex: 0 0 100%;
    display: flex;
    flex-direction: column;
    align-items: center;         /* Căn giữa ngang */
    justify-content: center;     /* Căn giữa dọc */
    background: white;
    padding: 40px 0;
    box-sizing: border-box;
}

/* Ảnh luôn ở giữa và không bị kéo lệch */
.art-img {
    max-width: 100%;
    max-height: 400px;
    width: auto;
    height: auto;
    object-fit: contain;         /* Không cắt ảnh, giữ nguyên tỉ lệ */
    border-radius: 15px;
    margin: 0 auto 20px;
    transition: transform 0.4s ease;
    cursor: pointer;
    display: block;
}

/* Khi hover vẫn phóng to nhẹ mà không lệch vị trí */
.art-img:hover {
    transform: scale(1.05);
}
.slider-container, .art-slide {
    min-height: 500px; /* hoặc tuỳ theo chiều cao mong muốn */
}
#header {
    transition: background 0.3s ease, box-shadow 0.3s ease;
}
#header:hover {
    background: rgba(201, 91, 1, 0.15); /* Tăng opacity nhẹ khi hover toàn header */
    box-shadow: 0 4px 20px rgba(201,91,1,0.3);
}

/* Hiệu ứng nhún nhảy + lóe sáng khi hover nav items */
nav a {
    position: relative;
}
nav a::before {
    content: '';
    position: absolute; bottom: -2px; left: 50%; width: 0; height: 2px; background: #fff; transition: width 0.3s ease, left 0.3s ease;
}
nav a:hover {
    transform: translateY(-2px); /* Nhún nhảy lên */
    text-shadow: 0 0 10px #fff, 0 0 20px #c95b01; /* Lóe sáng white + orange glow */
    color: #fff;
}
nav a:hover::before {
    width: 100%; left: 0; /* Underline glow */
    box-shadow: 0 0 5px #fff;
}

/* Hiệu ứng logo */
.logo-img:hover {
    transform: scale(1.1) rotate(5deg); /* Rotate nhẹ cho vui */
    box-shadow: 0 4px 15px rgba(201,91,1,0.4), 0 0 20px #c95b01;
}

/* Hiệu ứng theme toggle */
.theme-toggle {
    position: relative;
    overflow: hidden;
}
.theme-toggle::before {
    content: '';
    position: absolute; top: 0; left: -100%; width: 100%; height: 100%; background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent); transition: left 0.5s;
}
.theme-toggle:hover::before {
    left: 100%;
}
.theme-toggle:hover {
    background: rgba(255,255,255,0.3);
    box-shadow: 0 0 15px #c95b01;
    transform: scale(1.1);
}
.logo-container span, nav a {
    font-size: 18px; /* Tăng size to hơn */
    opacity: 0.9; /* Trong suốt hơn */
    text-shadow: 0 0 10px #fff, 0 0 20px var(--primary-color); /* Glow anime-style */
    font-family: 'Bangers', cursive; /* Anime comic font */
    transition: all 0.3s ease;
}
nav a:hover {
    transform: translateY(-2px) scale(1.05); /* Nhún nhảy anime bounce */
    text-shadow: 0 0 15px #fff, 0 0 30px var(--primary-color); /* Lóe sáng mạnh hơn */
    opacity: 1;
}
.theme-toggle {
    opacity: 0.9;
    transition: all 0.3s ease;
}
.theme-toggle:hover {
    opacity: 1;
    text-shadow: 0 0 10px #ffffff;
    transform: scale(1.1);
}

/* Responsive */
@media (max-width: 768px) {
    header { flex-direction: column; gap: 10px; }
    nav ul { flex-direction: column; gap: 10px; text-align: center; }
    .header-right { width: 100%; justify-content: center; }
    .logo-container span { font-size: 20px; }
    nav a:hover { transform: translateY(-1px); } /* Giảm bounce mobile */
}
body {
    margin: 0;
    font-family: 'Poppins', sans-serif;
    background: #fafafa;
    color: #333;
}

.header {
    text-align: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, #ffb6c1, #f9c5d1);
    color: #fff;
    border-bottom: 5px solid #f07ea0;
}

.header h1 {
    font-size: 2.5em;
    margin: 0;
}

.header p {
    margin-top: 10px;
    font-weight: 300;
}

.gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    padding: 30px;
    max-width: 1200px;
    margin: auto;
}

.item {
    position: relative;
    cursor: pointer;
    overflow: hidden;
    border-radius: 15px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

.item img,
.item video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.item:hover {
    transform: scale(1.05);
}

/* Lightbox */
.lightbox {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.8);
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.lightbox-content {
    position: relative;
    max-width: 90%;
    max-height: 90%;
}

.lightbox img, .lightbox video {
    width: 100%;
    border-radius: 10px;
}

.close {
    position: absolute;
    top: 20px;
    right: 40px;
    font-size: 40px;
    color: white;
    cursor: pointer;
}
.horizontal-container {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: 30px; 
  flex-wrap: wrap; 
  padding: 20px 0;
}

.vn-clock-card,
.vn-crypto-card,
.vn-weather-card {
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  cursor: pointer;
}

.vn-clock-card:hover,
.vn-crypto-card:hover,
.vn-weather-card:hover {
  transform: translateY(-5px) scale(1.02);
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.25);
  z-index: 2; 
}


.vn-clock-card,
.vn-crypto-card,
.vn-weather-card {
  background: rgba(230, 226, 226, 0.09); /* Trong suốt hơn ban đầu */
  backdrop-filter: blur(12px);
  transition: all 0.35s ease;
  cursor: pointer;
}


.vn-clock-card:hover,
.vn-crypto-card:hover,
.vn-weather-card:hover {
  background: rgba(255, 255, 255, 0.5); 
  backdrop-filter: blur(20px); 
  transform: translateY(-5px) scale(1.02);
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.25);
  z-index: 2;
}