:root {
    --primary-color: #1e4d7b;
    --secondary-color: #0d2847;
    --accent-color: #ff6b35;
    --text-color: #333;
    --text-light: #555;
    --bg-color: #f4f4f4;
    --bg-light: #ffffff;
    --border-color: #ddd;
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-size-base: 16px;
    --line-height: 1.6;
    color-scheme: light;
}

:root[data-theme='dark'] {
    --primary-color: #7ab8ff;
    --secondary-color: #8db5ff;
    --accent-color: #ff9f68;
    --text-color: #f0f4ff;
    --text-light: #d1d9e6;
    --bg-color: #10131d;
    --bg-light: #171b2b;
    --border-color: #2d3a59;
    color-scheme: dark;
}

:root[data-theme='auto'] {
    color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
    :root[data-theme='auto'] {
        --primary-color: #7ab8ff;
        --secondary-color: #8db5ff;
        --accent-color: #ff9f68;
        --text-color: #f0f4ff;
        --text-light: #d1d9e6;
        --bg-color: #10131d;
        --bg-light: #171b2b;
        --border-color: #2d3a59;
    }
}

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

html, body {
    min-height: 100%;
}

body {
    font-family: var(--font-family);
    line-height: var(--line-height);
    color: var(--text-color);
    background-color: var(--bg-color);
    padding: 24px;
}

.theme-switcher {
    display: flex;
    gap: 10px;
    margin-bottom: 24px;
}

.theme-button {
    width: 42px;
    height: 42px;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    background: var(--bg-light);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: transform .15s ease, box-shadow .2s ease, border-color .2s ease, background .2s ease;
}

.theme-button:hover,
.theme-button:focus-visible {
    transform: translateY(-1px);
    box-shadow: 0 8px 20px rgba(0,0,0,.12);
    outline: none;
}

.theme-button.active {
    border-color: var(--accent-color);
    background: rgba(255, 107, 53, .12);
}

.theme-button img {
    width: 20px;
    height: 20px;
}

h1 {
    color: var(--primary-color);
    margin-top: 0;
    margin-bottom: 15px;
}

p {
    font-size: var(--font-size-base);
    color: var(--text-light);
    max-width: 860px;
    line-height: 1.8;
}