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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.7;
    color: #333;
    background-color: #f8f9fa;
}

header {
    background: linear-gradient(135deg, #0077b6, #00b4d8);
    color: white;
    padding: 15px 0;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
    position: sticky;
    top: 0;
    z-index: 100;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
}

header .logo {
    font-size: 1.4rem;
    font-weight: 700;
    text-decoration: none;
    color: white;
}

header .logo span {
    color: #caf0f8;
}

nav {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

nav a {
    color: white;
    text-decoration: none;
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.9rem;
    transition: background 0.2s;
}

nav a:hover,
nav a.active {
    background: rgba(255, 255, 255, 0.25);
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

.hero {
    background: linear-gradient(135deg, #0077b6, #00b4d8);
    color: white;
    padding: 50px 20px;
    text-align: center;
}

.hero h1 {
    font-size: 2.2rem;
    margin-bottom: 15px;
}

.hero p {
    font-size: 1.15rem;
    max-width: 650px;
    margin: 0 auto;
    opacity: 0.95;
}

main {
    padding: 40px 20px;
}

main .container {
    background: white;
    border-radius: 12px;
    padding: 40px;
    box-shadow: 0 1px 6px rgba(0, 0, 0, 0.08);
}

h1 {
    color: #0077b6;
    margin-bottom: 20px;
    font-size: 2rem;
}

h2 {
    color: #023e8a;
    margin-top: 35px;
    margin-bottom: 15px;
    font-size: 1.4rem;
    border-bottom: 2px solid #caf0f8;
    padding-bottom: 6px;
}

h3 {
    color: #0077b6;
    margin-top: 25px;
    margin-bottom: 10px;
    font-size: 1.15rem;
}

p {
    margin-bottom: 16px;
    color: #444;
}

ul, ol {
    margin: 10px 0 20px 25px;
}

li {
    margin-bottom: 8px;
    color: #444;
}

strong {
    color: #333;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 25px;
    margin: 30px 0;
}

.card {
    background: white;
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    text-decoration: none;
    color: inherit;
    transition: transform 0.2s, box-shadow 0.2s;
    display: block;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
}

.card h3 {
    margin-top: 15px;
    color: #0077b6;
}

.card p {
    font-size: 0.95rem;
}

.card img {
    width: 100%;
    height: 140px;
    object-fit: cover;
    border-radius: 8px;
}

.tip-box {
    background: #e8f4f8;
    border-left: 4px solid #0077b6;
    padding: 18px 22px;
    border-radius: 0 8px 8px 0;
    margin: 20px 0;
}

.tip-box strong {
    color: #0077b6;
}

.warning-box {
    background: #fff3cd;
    border-left: 4px solid #ffc107;
    padding: 18px 22px;
    border-radius: 0 8px 8px 0;
    margin: 20px 0;
}

.warning-box strong {
    color: #856404;
}

.icon-img {
    display: block;
    max-width: 100%;
    height: auto;
    margin: 20px auto;
    border-radius: 10px;
}

.content-img {
    display: block;
    max-width: 100%;
    height: auto;
    margin: 25px auto;
    border-radius: 10px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

th, td {
    text-align: left;
    padding: 12px 16px;
    border-bottom: 1px solid #e0e0e0;
}

th {
    background: #0077b6;
    color: white;
    font-weight: 600;
}

tr:nth-child(even) {
    background: #f8f9fa;
}

footer {
    background: #023e8a;
    color: #caf0f8;
    text-align: center;
    padding: 30px 20px;
    margin-top: 50px;
    font-size: 0.9rem;
}

footer a {
    color: #90e0ef;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

@media (max-width: 600px) {
    .hero h1 {
        font-size: 1.6rem;
    }

    main .container {
        padding: 25px 18px;
    }

    header .container {
        flex-direction: column;
        text-align: center;
    }

    nav {
        justify-content: center;
    }
}