/* File: public/css/style.css */

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #64748b;
    --success: #16a34a;
    --danger: #dc2626;
    --bg-body: #f1f5f9;
    --bg-card: #ffffff;
    --border: #e2e8f0;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: var(--bg-body);
    color: var(--text-main);
    line-height: 1.5;
    font-size: 15px;
}

/* HEADER */
.app-header {
    background: var(--bg-card);
    padding: 1rem 0;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    position: sticky; top: 0; z-index: 100;
}
.header-content {
    max-width: 900px; margin: 0 auto; padding: 0 20px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.logo-icon {
    width: 40px; height: 40px; background: var(--primary);
    color: white; border-radius: 10px; display: flex;
    align-items: center; justify-content: center; font-size: 1.2rem;
}
.brand-text h1 { font-size: 1.25rem; font-weight: 700; color: var(--text-main); margin: 0; }
.badge {
    background: #dbeafe; color: var(--primary);
    font-size: 0.75rem; padding: 2px 8px; border-radius: 4px; font-weight: 600;
}
/* --- BẮT ĐẦU ĐOẠN CẦN THÊM --- */

/* Class này giúp đẩy Logo sang trái và Menu sang phải */
.header-inner {
    display: flex;              /* Kích hoạt Flexbox */
    align-items: center;        /* Căn giữa dọc */
    width: 100%;               /* QUAN TRỌNG: Bắt buộc khung phải rộng 100% */
    max-width: 1200px;         /* (Tùy chọn) Giới hạn chiều rộng cho đẹp */
    margin: 0 auto;            /* Căn giữa màn hình */
    }
.nav-area {
    margin-left: auto; /* QUYỀN LỰC NHẤT: Tự động đẩy toàn bộ khối này sang phải cùng */
    display: flex;     /* Để các nút con bên trong nằm ngang */
    align-items: center;
}
/* Tinh chỉnh khu vực chứa các nút Menu (Trang chủ, Hướng dẫn) */
.nav-area {
    display: flex;
    align-items: center;
}

/* Tạo khoảng cách giữa các nút và làm đẹp link */
.nav-link {
    margin-left: 24px;          /* Khoảng cách giữa các nút */
    text-decoration: none;      /* Bỏ gạch chân */
    color: var(--text-muted);   /* Màu chữ mặc định */
    font-weight: 600;           /* Chữ đậm vừa */
    transition: color 0.2s;     /* Hiệu ứng chuyển màu mượt */
    display: flex;
    align-items: center;
    gap: 6px;                   /* Khoảng cách giữa icon và chữ */
}

.nav-link:hover, .nav-link.active {
    color: var(--primary);      /* Đổi màu xanh khi di chuột vào */
}

/* --- KẾT THÚC ĐOẠN CẦN THÊM --- */

/* MAIN LAYOUT */
.main-container { max-width: 900px; margin: 0 auto; padding: 40px 20px; }

.intro-section { text-align: center; margin-bottom: 30px; }
.intro-section h2 { font-size: 2rem; font-weight: 800; color: var(--text-main); margin-bottom: 0.5rem; }
.intro-section p { color: var(--text-muted); font-size: 1.1rem; }

/* CARDS */
.card {
    background: var(--bg-card); border-radius: var(--radius);
    box-shadow: var(--shadow); margin-bottom: 24px; overflow: hidden;
    border: 1px solid var(--border);
}
.card-header {
    padding: 16px 24px; background: #f8fafc; border-bottom: 1px solid var(--border);
    font-weight: 600; color: var(--text-main); font-size: 1.1rem;
    display: flex; align-items: center; gap: 10px;
}
.card-header i { color: var(--primary); }
.card-body { padding: 24px; }

/* GRID SYSTEM */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.grid-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 20px; }

/* FORMS */
.form-group { margin-bottom: 15px; }
.form-group label { display: block; font-weight: 500; margin-bottom: 6px; font-size: 0.95rem; }
input[type="text"], input[type="number"], select, textarea {
    width: 100%; padding: 10px 12px; border: 1px solid #cbd5e1;
    border-radius: 8px; font-size: 15px; transition: border 0.2s, box-shadow 0.2s;
    font-family: inherit;
}
input:focus, select:focus, textarea:focus {
    border-color: var(--primary); outline: none;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}
textarea { resize: vertical; min-height: 80px; }

/* TOPIC ITEM */
.topic-item {
    background: #f8fafc; border: 1px solid var(--border);
    border-radius: 8px; padding: 16px; margin-bottom: 16px;
    position: relative; transition: transform 0.2s;
}
.topic-item:hover { border-color: #cbd5e1; }
.topic-header { display: flex; justify-content: space-between; margin-bottom: 10px; font-size: 0.85rem; font-weight: 600; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.5px; }
.btn-icon-danger { background: none; border: none; color: #ef4444; cursor: pointer; padding: 4px; font-size: 1rem; opacity: 0.7; }
.btn-icon-danger:hover { opacity: 1; transform: scale(1.1); }

/* BUTTONS */
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 10px 20px; border-radius: 8px; font-weight: 600; cursor: pointer;
    transition: all 0.2s; border: none; font-size: 1rem; gap: 8px;
}
.btn-primary { background: var(--primary); color: white; width: 100%; }
.btn-primary:hover { background: var(--primary-dark); transform: translateY(-1px); }
.btn-outline { background: white; border: 1px dashed #cbd5e1; color: var(--text-muted); width: 100%; }
.btn-outline:hover { border-color: var(--primary); color: var(--primary); background: #f0f9ff; }
.btn-success { background: var(--success); color: white; }
.btn-success:hover { background: #15803d; }
.btn-lg { height: 56px; font-size: 1.1rem; }

/* LICENSE CARD */
.license-card {
    background: linear-gradient(135deg, #eff6ff 0%, #ffffff 100%);
    border: 2px solid #bfdbfe; border-radius: var(--radius);
    padding: 24px; margin-bottom: 30px;
    display: flex; align-items: center; gap: 20px;
}
.license-icon {
    width: 50px; height: 50px; background: #dbeafe; color: var(--primary);
    border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 1.5rem;
}
.license-input { flex: 1; }
.license-input input {
    font-family: monospace; font-size: 1.25rem; font-weight: 700;
    text-align: center; color: var(--primary-dark); letter-spacing: 2px;
    border-color: #60a5fa; height: 50px;
}

/* UTILS */
.hidden { display: none !important; }
.highlight-box {
    background: #fff7ed; border: 1px dashed #fdba74; padding: 16px;
    border-radius: 8px; margin-top: 15px;
}
.box-title { font-weight: 600; color: #c2410c; margin-bottom: 12px; font-size: 0.9rem; }

/* LOADING */
.loading-state { text-align: center; margin-top: 20px; color: var(--text-muted); }
.spinner {
    width: 30px; height: 30px; border: 3px solid #e2e8f0;
    border-top-color: var(--primary); border-radius: 50%;
    margin: 0 auto 10px; animation: spin 1s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* PREVIEW TABLE CSS (QUAN TRỌNG CHO BẢNG) */
.preview-content {
    font-family: "Times New Roman", serif; /* Giống Word */
    background: white; padding: 20px; border: 1px solid #e2e8f0;
    max-height: 600px; overflow: auto;
}
.preview-content table {
    width: 100%; border-collapse: collapse; margin-bottom: 20px;
}
.preview-content th, .preview-content td {
    border: 1px solid #000 !important; /* Ép viền đen */
    padding: 6px; font-size: 14px; text-align: left; vertical-align: top;
}
.preview-content th { background: #f3f4f6; text-align: center; font-weight: bold; }
.preview-content h2, .preview-content h3 { 
    text-align: center; color: #000; margin: 20px 0 10px; font-weight: bold;
}

/* RESPONSIVE */
@media (max-width: 768px) {
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
    .license-card { flex-direction: column; text-align: center; }
    .container { padding: 20px 15px; }
}
/* === FOOTER STYLES === */
.app-footer {
    background-color: #1e293b; /* Màu nền tối sang trọng */
    color: #f8fafc;
    padding-top: 40px;
    margin-top: 50px;
}

.footer-content {
    max-width: 1000px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr 1fr; /* Chia 3 cột đều nhau */
    gap: 30px;
    padding: 0 20px 40px;
}

.footer-section h3 {
    color: #38bdf8; /* Màu xanh sáng cho tiêu đề */
    font-size: 1.1rem;
    margin-bottom: 15px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.footer-section p {
    color: #94a3b8;
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 10px;
}

/* Social Links */
.social-link {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #f8fafc;
    text-decoration: none;
    margin-bottom: 12px;
    font-weight: 500;
    transition: all 0.2s;
    padding: 8px 12px;
    border-radius: 6px;
    background: rgba(255,255,255,0.05);
}

.social-link:hover {
    background: rgba(255,255,255,0.15);
    transform: translateX(5px);
}

.social-link.facebook i { color: #1877f2; font-size: 1.2rem; }
.social-link.messenger i { color: #0084ff; font-size: 1.2rem; }

/* Zalo QR */
.qr-box {
    text-align: center;
    background: white;
    padding: 10px;
    border-radius: 8px;
    display: inline-block;
}

.qr-box img {
    width: 120px;
    height: 120px;
    display: block;
}

.qr-box p {
    color: #0f172a;
    font-size: 0.8rem;
    font-weight: 600;
    margin: 5px 0 0;
}

/* Footer Bottom */
.footer-bottom {
    background: #0f172a;
    text-align: center;
    padding: 15px;
    font-size: 0.85rem;
    color: #64748b;
    border-top: 1px solid #334155;
}

/* Responsive cho Mobile */
@media (max-width: 768px) {
    .footer-content {
        grid-template-columns: 1fr; /* Về 1 cột trên điện thoại */
        text-align: center;
    }
    
    .social-link {
        justify-content: center;
    }
}
/* File: public/css/style.css */

/* ... (CSS cũ giữ nguyên) ... */

/* === HEADER FLEX & COPY BUTTON === */
.header-flex {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #f0fdf4 !important; /* Màu nền xanh nhẹ */
    border-bottom: 1px solid #bbf7d0 !important;
}

.header-title {
    color: #166534;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Nút Copy Chuyên nghiệp */
.btn-copy {
    background-color: white;
    border: 1px solid #cbd5e1;
    color: #475569;
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s ease;
    box-shadow: 0 1px 2px rgba(0,0,0,0.05);
}

.btn-copy:hover {
    background-color: #f1f5f9;
    color: #2563eb;
    border-color: #2563eb;
    transform: translateY(-1px);
}

.btn-copy:active {
    transform: translateY(0);
    box-shadow: none;
}

.btn-copy i {
    font-size: 1rem;
}

/* Trạng thái sau khi copy thành công (dùng JS để toggle class này) */
.btn-copy.copied {
    background-color: #16a34a;
    color: white;
    border-color: #16a34a;
}