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

:root {
    color-scheme: light;
    --color-primary: #4f46e5;
    --color-primary-dark: #3730a3;
    --color-secondary: #111827;
    --color-accent: #0f766e;
    --color-success: #15803d;
    --color-warning: #a16207;
    --color-danger: #b42318;
    --color-text: #202939;
    --color-text-light: #667085;
    --color-bg: #f6f7fb;
    --color-surface: #ffffff;
    --color-border: #e4e7ec;
    --color-white: #ffffff;
    --layout-container-max: 1000px;
    --layout-container-padding: 20px;
    --layout-container-width: min(var(--layout-container-max), calc(100% - (var(--layout-container-padding) * 2)));
    --shadow-sm: 0 10px 30px rgba(16, 24, 40, 0.06);
    --shadow-md: 0 20px 48px rgba(16, 24, 40, 0.1);
    --border-radius: 12px;
    --border-radius-large: 20px;
    --transition: 180ms ease;
}

html {
    scroll-behavior: smooth;
}

body {
    min-width: 320px;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic UI", "Meiryo", sans-serif;
    font-size: 16px;
    line-height: 1.75;
    color: var(--color-text);
    background: var(--color-bg);
    -webkit-font-smoothing: antialiased;
}

button,
input,
textarea {
    font: inherit;
}

button,
a {
    -webkit-tap-highlight-color: transparent;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    line-height: 1.35;
    color: var(--color-secondary);
    font-weight: 700;
}

h1 {
    font-size: clamp(2rem, 5vw, 3.25rem);
}

h2 {
    font-size: clamp(1.55rem, 3.4vw, 2.15rem);
}

h3 {
    font-size: 1.25rem;
}

p {
    margin-bottom: 1rem;
}

a {
    color: var(--color-primary-dark);
    text-decoration: none;
    transition: color var(--transition), opacity var(--transition);
}

a:hover {
    color: var(--color-primary);
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
textarea:focus-visible {
    outline: 3px solid rgba(79, 70, 229, 0.3);
    outline-offset: 3px;
}

.container {
    width: var(--layout-container-width);
    margin: 0 auto;
}

.main-content {
    min-height: calc(100vh - 160px);
}

.pg-header {
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid rgba(228, 231, 236, 0.86);
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
}

.pg-header__container {
    display: flex;
    width: var(--layout-container-width);
    min-height: 68px;
    margin: 0 auto;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.pg-header__logo-link {
    display: inline-flex;
    flex: 0 0 auto;
    align-items: center;
    color: var(--color-secondary);
    font-size: 1.25rem;
    font-weight: 700;
}

.pg-header__logo-image {
    display: block;
    width: 204px;
    height: auto;
}

.pg-header__nav-list {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    list-style: none;
}

.pg-header__nav-link {
    position: relative;
    display: inline-flex;
    padding: 0.35rem 0;
    color: var(--color-text-light);
    font-size: 0.92rem;
    font-weight: 600;
    white-space: nowrap;
}

.pg-header__nav-link::after {
    position: absolute;
    right: 0;
    bottom: 0;
    left: 0;
    height: 2px;
    border-radius: 999px;
    background: var(--color-primary);
    content: '';
    opacity: 0;
    transform: scaleX(0.5);
    transition: opacity var(--transition), transform var(--transition);
}

.pg-header__nav-link:hover,
.pg-header__nav-link--active {
    color: var(--color-secondary);
}

.pg-header__nav-link:hover::after,
.pg-header__nav-link--active::after {
    opacity: 1;
    transform: scaleX(1);
}

.pg-footer {
    margin-top: 5rem;
    padding: 2.6rem 0;
    color: rgba(255, 255, 255, 0.78);
    background: #111827;
}

.pg-footer__container {
    width: var(--layout-container-width);
    margin: 0 auto;
    text-align: center;
}

.pg-static__container,
.pg-article-detail__container,
.notepad-app__frame,
.notepad-related__container,
.notepad-seo__container,
.notepad-seo__container--narrow {
    width: var(--layout-container-width) !important;
    margin-right: auto;
    margin-left: auto;
}

.notepad-app.is-fullscreen .notepad-app__frame {
    width: 100% !important;
}

@media (min-width: 1600px) {
    :root {
        --layout-container-width: min(1200px, calc(100vw - 644px));
    }
}

.pg-footer__links {
    display: flex;
    margin-bottom: 1.5rem;
    align-items: center;
    justify-content: center;
    gap: 0.75rem 1.2rem;
    flex-wrap: wrap;
}

.pg-footer__link {
    color: #ffffff;
    font-size: 0.9rem;
    font-weight: 600;
}

.pg-footer__link:hover {
    color: #c7d2fe;
}

.pg-footer__text {
    margin-bottom: 0.45rem;
}

.pg-footer__disclaimer {
    max-width: 720px;
    margin: 0 auto;
    color: rgba(255, 255, 255, 0.58);
    font-size: 0.82rem;
}

@media (max-width: 820px) {
    .pg-header__container {
        width: 100%;
        min-height: auto;
        padding: 0.75rem 14px;
        align-items: flex-start;
        flex-direction: column;
        gap: 0.55rem;
    }

    .pg-header__logo-image {
        width: 178px;
    }

    .pg-header__nav {
        width: 100%;
        overflow-x: auto;
        scrollbar-width: none;
    }

    .pg-header__nav::-webkit-scrollbar {
        display: none;
    }

    .pg-header__nav-list {
        width: max-content;
        gap: 1.15rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
    }
}