:root {
    --color-bg: #f6f8fa;
    --color-surface: #ffffff;
    --color-primary: #66859a;
    --color-primary-dark: #3e5d70;
    --color-text: #34444e;
    --color-muted: #7a8992;
    --color-border: #dfe7eb;
    --color-tag: #edf3f6;
    --color-danger: #a65353;
    --color-danger-bg: #fbf1f1;
    --shadow-soft: 0 12px 32px rgba(62, 93, 112, 0.06);
    --radius-sm: 8px;
    --radius-md: 14px;
    --content-width: 1180px;
    --reading-width: 800px;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    color-scheme: light;
    scroll-behavior: smooth;
}

body {
    min-height: 100vh;
    margin: 0;
    display: flex;
    flex-direction: column;
    background: var(--color-bg);
    color: var(--color-text);
    font-family:
        Inter, "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic",
        Meiryo, sans-serif;
    font-size: 16px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--color-primary-dark);
    text-decoration-color: rgba(62, 93, 112, 0.4);
    text-underline-offset: 0.2em;
}

a:hover {
    color: #2f4c5e;
    text-decoration-color: currentColor;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
    outline: 3px solid rgba(102, 133, 154, 0.34);
    outline-offset: 3px;
}

button,
input,
textarea,
select {
    font: inherit;
}

.site-header {
    background: rgba(255, 255, 255, 0.92);
    border-bottom: 1px solid var(--color-border);
}

.site-header__inner {
    width: min(calc(100% - 40px), var(--content-width));
    min-height: 68px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 28px;
}

.site-brand {
    color: var(--color-primary-dark);
    font-size: 1.2rem;
    font-weight: 750;
    letter-spacing: 0.025em;
    text-decoration: none;
}

.site-nav {
    display: flex;
    align-items: center;
    margin-right: auto;
}

.site-nav a,
.admin-nav a {
    color: var(--color-muted);
    font-size: 0.9rem;
    font-weight: 600;
    text-decoration: none;
}

.site-nav a:hover,
.admin-nav a:hover {
    color: var(--color-primary-dark);
}

.admin-nav {
    display: flex;
    align-items: center;
    gap: 16px;
}

.admin-nav__label {
    color: #9aa6ad;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.site-main {
    width: min(calc(100% - 40px), var(--content-width));
    margin: 0 auto;
    flex: 1;
    padding: 64px 0 80px;
}

.site-footer {
    padding: 28px 20px 36px;
    color: var(--color-muted);
    font-size: 0.82rem;
    text-align: center;
}

.site-footer p {
    margin: 0;
}

.page-heading {
    margin-bottom: 32px;
}

.page-heading__eyebrow {
    margin: 0 0 6px;
    color: var(--color-primary);
    font-size: 0.76rem;
    font-weight: 750;
    letter-spacing: 0.14em;
    text-transform: uppercase;
}

.page-heading h1 {
    margin: 0;
    color: var(--color-primary-dark);
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    line-height: 1.25;
    letter-spacing: -0.025em;
}

.page-heading p {
    margin: 10px 0 0;
    color: var(--color-muted);
}

.blog-hero {
    padding: 24px 0 52px;
}

.blog-hero__title {
    margin: 0;
    color: var(--color-primary-dark);
    font-size: clamp(2.5rem, 7vw, 4.6rem);
    font-weight: 750;
    line-height: 1.08;
    letter-spacing: -0.045em;
}

.blog-hero__description {
    margin: 16px 0 0;
    color: var(--color-muted);
    font-size: clamp(1rem, 2vw, 1.12rem);
}

.section-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 20px;
    margin-bottom: 18px;
}

.section-title {
    margin: 0;
    color: var(--color-primary-dark);
    font-size: 1.35rem;
    letter-spacing: -0.015em;
}

.tag-filter,
.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tag-filter {
    margin-bottom: 28px;
}

.tag-chip {
    display: inline-flex;
    align-items: center;
    min-height: 30px;
    padding: 4px 11px;
    border: 1px solid transparent;
    border-radius: 999px;
    background: var(--color-tag);
    color: var(--color-primary-dark);
    font-size: 0.78rem;
    font-weight: 650;
    line-height: 1.2;
    text-decoration: none;
}

a.tag-chip:hover {
    border-color: #cbd9e0;
    background: #e5eef2;
    color: #2f4c5e;
}

.tag-chip--all {
    background: var(--color-primary-dark);
    color: #ffffff;
}

a.tag-chip--all:hover {
    background: #2f4c5e;
    color: #ffffff;
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
}

.article-card {
    min-width: 0;
    padding: 24px;
    display: flex;
    flex-direction: column;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    box-shadow: var(--shadow-soft);
}

.article-card__pinned {
    align-self: flex-start;
    margin: 0 0 10px;
    color: var(--color-primary);
    font-size: 0.68rem;
    font-weight: 800;
    letter-spacing: 0.13em;
}

.article-card__title {
    margin: 0;
    font-size: 1.22rem;
    line-height: 1.45;
    letter-spacing: -0.01em;
}

.article-card__title a {
    color: var(--color-primary-dark);
    text-decoration: none;
}

.article-card__title a:hover {
    text-decoration: underline;
    text-decoration-color: rgba(62, 93, 112, 0.35);
}

.article-card__summary {
    min-height: calc(1.7em * 3);
    margin: 14px 0 18px;
    display: -webkit-box;
    overflow: hidden;
    color: var(--color-text);
    font-size: 0.92rem;
    line-height: 1.7;
    -webkit-box-orient: vertical;
    -webkit-line-clamp: 3;
}

.article-card__tags {
    margin-bottom: 20px;
}

.article-card__footer {
    margin-top: auto;
    padding-top: 17px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    border-top: 1px solid #edf1f3;
}

.article-card__date {
    color: var(--color-muted);
    font-size: 0.76rem;
    letter-spacing: 0.025em;
}

.article-card__more {
    font-size: 0.83rem;
    font-weight: 700;
    text-decoration: none;
}

.article-card__admin {
    margin-top: 14px;
    display: flex;
    justify-content: flex-end;
    gap: 14px;
    font-size: 0.76rem;
}

.article-card__admin a {
    color: var(--color-muted);
}

.article-card__admin .danger-link {
    color: var(--color-danger);
}

.empty-state {
    grid-column: 1 / -1;
    padding: 56px 24px;
    border: 1px dashed #cbd8de;
    border-radius: var(--radius-md);
    color: var(--color-muted);
    text-align: center;
}

.reading-layout {
    width: min(100%, var(--reading-width));
    margin: 0 auto;
}

.back-link {
    display: inline-flex;
    margin-bottom: 40px;
    color: var(--color-muted);
    font-size: 0.88rem;
    text-decoration: none;
}

.back-link:hover {
    color: var(--color-primary-dark);
}

.article-header {
    margin-bottom: 42px;
    padding-bottom: 28px;
    border-bottom: 1px solid var(--color-border);
}

.article-header h1 {
    margin: 0 0 18px;
    color: var(--color-primary-dark);
    font-size: clamp(2rem, 6vw, 3.25rem);
    line-height: 1.25;
    letter-spacing: -0.035em;
}

.markdown-body {
    font-size: 1.02rem;
    line-height: 1.9;
    overflow-wrap: anywhere;
}

.markdown-body > :first-child,
.markdown-preview > :first-child {
    margin-top: 0;
}

.markdown-body > :last-child,
.markdown-preview > :last-child {
    margin-bottom: 0;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6,
.markdown-preview h1,
.markdown-preview h2,
.markdown-preview h3,
.markdown-preview h4,
.markdown-preview h5,
.markdown-preview h6 {
    color: var(--color-primary-dark);
    line-height: 1.4;
}

.markdown-body h1,
.markdown-preview h1 {
    margin: 2.4em 0 0.8em;
    font-size: 2rem;
}

.markdown-body h2,
.markdown-preview h2 {
    margin: 2.2em 0 0.75em;
    padding-bottom: 0.35em;
    border-bottom: 1px solid var(--color-border);
    font-size: 1.55rem;
}

.markdown-body h3,
.markdown-preview h3 {
    margin: 2em 0 0.65em;
    font-size: 1.25rem;
}

.markdown-body h4,
.markdown-body h5,
.markdown-body h6,
.markdown-preview h4,
.markdown-preview h5,
.markdown-preview h6 {
    margin: 1.8em 0 0.6em;
    font-size: 1.05rem;
}

.markdown-body p,
.markdown-preview p {
    margin: 0 0 1.35em;
}

.markdown-body ul,
.markdown-body ol,
.markdown-preview ul,
.markdown-preview ol {
    margin: 0 0 1.4em;
    padding-left: 1.6em;
}

.markdown-body li + li,
.markdown-preview li + li {
    margin-top: 0.35em;
}

.markdown-body blockquote,
.markdown-preview blockquote {
    margin: 1.8em 0;
    padding: 0.35em 0 0.35em 1.25em;
    border-left: 3px solid #9bb1bf;
    color: #596b76;
}

.markdown-body blockquote p,
.markdown-preview blockquote p {
    margin: 0;
}

.markdown-body code,
.markdown-preview code {
    padding: 0.16em 0.38em;
    border: 1px solid #dde6ea;
    border-radius: 5px;
    background: #edf3f6;
    color: #304d5d;
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
    font-size: 0.9em;
}

.markdown-body pre,
.markdown-preview pre {
    margin: 1.7em 0;
    padding: 18px 20px;
    overflow-x: auto;
    border: 1px solid #d9e2e7;
    border-radius: var(--radius-sm);
    background: #263944;
    color: #edf3f6;
    line-height: 1.65;
    tab-size: 4;
}

.markdown-body pre code,
.markdown-preview pre code {
    padding: 0;
    border: 0;
    background: transparent;
    color: inherit;
    font-size: 0.88rem;
}

.markdown-body a,
.markdown-preview a {
    color: var(--color-primary-dark);
    font-weight: 600;
}

.form-layout {
    width: min(100%, 1080px);
    margin: 0 auto;
}

.form-card,
.compact-card,
.danger-card {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    box-shadow: var(--shadow-soft);
}

.form-card {
    padding: clamp(24px, 4vw, 42px);
}

.compact-card,
.danger-card {
    width: min(100%, 520px);
    margin: 5vh auto 0;
    padding: clamp(26px, 5vw, 42px);
}

.field-group {
    margin-bottom: 26px;
}

.field-label,
.editor-panel__label {
    display: block;
    margin-bottom: 8px;
    color: var(--color-primary-dark);
    font-size: 0.85rem;
    font-weight: 750;
}

.field-hint {
    margin: 7px 0 0;
    color: var(--color-muted);
    font-size: 0.78rem;
}

.title-field-row {
    position: relative;
}

#title-count {
    display: block;
    margin-top: 7px;
    color: var(--color-muted);
    font-size: 0.76rem;
    text-align: right;
}

input[type="text"],
textarea,
select {
    width: 100%;
    border: 1px solid #cdd9df;
    border-radius: var(--radius-sm);
    background: #fbfcfd;
    color: var(--color-text);
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

input[type="text"] {
    min-height: 46px;
    padding: 10px 13px;
}

textarea {
    padding: 16px;
    resize: vertical;
}

input[type="text"]:focus,
textarea:focus,
select:focus {
    border-color: var(--color-primary);
    background: #ffffff;
    box-shadow: 0 0 0 4px rgba(102, 133, 154, 0.11);
    outline: none;
}

.editor-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 18px;
}

.editor-panel {
    min-width: 0;
}

.editor-panel textarea,
.markdown-preview {
    height: 520px;
    min-height: 520px;
}

.editor-panel textarea {
    display: block;
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
    font-size: 0.9rem;
    line-height: 1.7;
}

.markdown-preview {
    padding: 18px 20px;
    overflow: auto;
    border: 1px solid #d9e2e7;
    border-radius: var(--radius-sm);
    background: #fbfcfd;
    font-size: 0.92rem;
    line-height: 1.75;
}

#tag-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

#tag-buttons button {
    min-height: 32px;
    padding: 5px 12px;
    border: 1px solid #d7e2e7;
    border-radius: 999px;
    background: var(--color-tag);
    color: var(--color-primary-dark);
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 650;
}

#tag-buttons button:hover {
    border-color: var(--color-primary);
    background: #e5eef2;
}

.checkbox-row {
    display: flex;
    align-items: flex-start;
    gap: 10px;
}

.checkbox-row input {
    width: 17px;
    height: 17px;
    margin-top: 4px;
    accent-color: var(--color-primary-dark);
}

.checkbox-row label {
    font-weight: 650;
}

.checkbox-row input:disabled + label {
    color: var(--color-muted);
}

.error-list,
.errorlist {
    margin: 8px 0 0;
    padding: 0;
    color: var(--color-danger);
    font-size: 0.82rem;
    list-style: none;
}

.form-actions {
    margin-top: 32px;
    display: flex;
    align-items: center;
    gap: 18px;
}

.button {
    min-height: 42px;
    padding: 9px 19px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 700;
    line-height: 1.2;
    text-decoration: none;
}

.button--primary {
    background: var(--color-primary-dark);
    color: #ffffff;
}

.button--primary:hover {
    background: #2f4c5e;
    color: #ffffff;
}

.button--danger {
    background: var(--color-danger);
    color: #ffffff;
}

.button--danger:hover {
    background: #8d4242;
    color: #ffffff;
}

.cancel-link {
    color: var(--color-muted);
    font-size: 0.88rem;
}

.danger-card {
    border-color: #ecdada;
}

.danger-card__label {
    color: var(--color-danger);
    font-size: 0.73rem;
    font-weight: 800;
    letter-spacing: 0.12em;
}

.danger-card h1,
.compact-card h1 {
    margin: 7px 0 14px;
    color: var(--color-primary-dark);
    font-size: 1.65rem;
}

.danger-card p,
.compact-card p {
    color: var(--color-muted);
}

@media (max-width: 900px) {
    .article-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .editor-grid {
        grid-template-columns: 1fr;
    }

    .editor-panel textarea,
    .markdown-preview {
        height: 420px;
        min-height: 420px;
    }
}

@media (max-width: 680px) {
    .site-header__inner {
        width: min(calc(100% - 28px), var(--content-width));
        padding: 14px 0;
        flex-wrap: wrap;
        gap: 8px 20px;
    }

    .site-nav {
        margin-right: 0;
    }

    .admin-nav {
        width: 100%;
        padding-top: 10px;
        justify-content: flex-start;
        border-top: 1px solid var(--color-border);
    }

    .site-main {
        width: min(calc(100% - 28px), var(--content-width));
        padding: 42px 0 60px;
    }

    .blog-hero {
        padding: 12px 0 38px;
    }

    .article-grid {
        grid-template-columns: 1fr;
    }

    .article-card {
        padding: 21px;
    }

    .article-card__summary {
        min-height: auto;
    }

    .article-header {
        margin-bottom: 32px;
    }

    .markdown-body {
        font-size: 0.98rem;
        line-height: 1.85;
    }

    .form-card {
        padding: 22px 18px;
    }

    .editor-panel textarea,
    .markdown-preview {
        height: 360px;
        min-height: 360px;
    }

    .form-actions {
        align-items: stretch;
        flex-direction: column;
    }

    .form-actions .button,
    .form-actions .cancel-link {
        width: 100%;
        text-align: center;
    }

    .compact-card,
    .danger-card {
        margin-top: 0;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
    }
}