:root {
    --bg-color: #f4f4f4;
    --container-bg: #ffffff;
    --header-bg: #ffffff;
    --accent-color: #00709d;
    --text-primary: #333333;
    --text-secondary: #555555;
    --border-color: #dddddd;
    --hover-bg: #f0f0f0;
}

[data-theme="dark"] {
    --bg-color: #191919;
    --container-bg: #262626;
    --header-bg: #1e1e1e;
    --accent-color: #00709d;
    --text-primary: #e0e0e0;
    --text-secondary: #b0b0b0;
    --border-color: #3d3d3d;
    --hover-bg: #333333;
}

body {
    margin: 0;
    padding: 80px 20px 50px;
    background-color: var(--bg-color);
    font-family: 'Roboto', Arial, sans-serif;
    color: var(--text-primary);
    display: flex;
    justify-content: center;
    transition: background-color 0.3s, color 0.3s;
    line-height: 1.6;
}

header {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: 60px;
    background-color: var(--header-bg);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 30px;
    z-index: 1000;
    transition: background-color 0.3s;
}

.header-brand { display: flex; align-items: center; gap: 12px; }
.header-logo { font-weight: bold; color: var(--accent-color); font-size: 18px; }
.header-controls { display: flex; align-items: center; gap: 10px; }

.header-brand-logo {
    height: 35px;
    width: auto;
}

.icon-btn {
    background: none; border: none; color: var(--text-primary);
    cursor: pointer; padding: 8px; border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    transition: background-color 0.2s, color 0.2s;
}

.icon-btn:hover { background-color: var(--hover-bg); color: var(--accent-color); }

[data-theme="dark"] .icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: block; }
[data-theme="light"] .icon-moon { display: block; }
[data-theme="light"] .icon-sun { display: none; }

.lang-dropdown { position: relative; }
.lang-menu {
    position: absolute; top: 100%; right: 0; margin-top: 10px;
    background-color: var(--container-bg); border: 1px solid var(--border-color);
    border-radius: 8px; box-shadow: 0 4px 15px rgba(0,0,0,0.2); width: 160px;
    opacity: 0; visibility: hidden; transform: translateY(-10px); transition: all 0.2s ease;
}
.lang-menu.show { opacity: 1; visibility: visible; transform: translateY(0); }
.lang-option {
    display: flex; align-items: center; gap: 10px; padding: 12px 15px;
    cursor: pointer; font-size: 14px; transition: background-color 0.2s;
}
.lang-option:hover { background-color: var(--hover-bg); }
.flag { font-size: 16px; line-height: 1; }

.container {
    background-color: var(--container-bg); padding: 40px; border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1); max-width: 800px; width: 100%;
    border: 1px solid var(--border-color); transition: background-color 0.3s;
}

h1 { color: var(--accent-color); font-size: 26px; margin-top: 0; margin-bottom: 25px; border-bottom: 2px solid var(--accent-color); padding-bottom: 10px; }
h2 { color: var(--accent-color); font-size: 18px; font-weight: bold; margin-top: 30px; margin-bottom: 12px; }
h3 { font-size: 16px; color: var(--text-primary); margin-top: 20px; }
p, li { color: var(--text-secondary); margin-bottom: 15px; font-size: 15px; }
ul { padding-left: 20px; margin-bottom: 20px; }

.highlight-box {
    background: rgba(0, 112, 157, 0.1); border-left: 4px solid var(--accent-color);
    padding: 15px 20px; margin: 25px 0;
}
.highlight-box p { margin-bottom: 0; color: var(--text-primary); font-style: italic; }

a { color: var(--accent-color); text-decoration: none; transition: color 0.3s; }
a:hover { color: #0090c7; text-decoration: underline; }

.footer-nav { margin-top: 50px; padding-top: 20px; border-top: 1px solid var(--border-color); text-align: center; }
.back-btn { font-size: 14px; font-weight: bold; color: var(--accent-color); text-decoration: none; }

@media (max-width: 600px) {
    header { padding: 0 15px; }
    .header-logo { font-size: 14px; }
    .header-brand-logo { height: 25px; }
    .container { padding: 20px; }
}