@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+JP:wght@400;500;700&display=swap');

:root {
    --paper: #FAF9F6;
    --ink: #2C2B29;
    --subtle: #8C8A85;
    --border: #E8E6E1;
    --accent: #D3543A;
    --font-serif: 'Noto Serif JP', "Hiragino Mincho ProN", "Yu Mincho", YuMincho, serif;
    --font-sans: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
    --max-w: 800px;
}

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

::selection {
    background-color: var(--ink);
    color: var(--paper);
}

body {
    background-color: var(--paper);
    color: var(--ink);
    font-family: var(--font-sans);
    line-height: 1.9;
    letter-spacing: 0.03em;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    margin: 0;
}

a { color: inherit; }

/* --- Nav --- */
.site-nav {
    width: 100%;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    justify-content: space-between;
    align-items: center;
    background-color: rgba(250, 249, 246, 0.9);
    backdrop-filter: blur(8px);
    position: sticky;
    top: 0;
    z-index: 50;
    border-bottom: 1px solid rgba(232, 230, 225, 0.5);
}

@media (min-width: 768px) {
    .site-nav {
        flex-direction: row;
        gap: 0;
        padding: 24px 48px;
    }
}

.site-nav-logo {
    font-family: var(--font-serif);
    font-size: 18px;
    letter-spacing: 0.05em;
    color: var(--ink);
    font-weight: bold;
    text-decoration: none;
    transition: opacity 0.2s;
}

.site-nav-logo:hover { opacity: 0.7; }

.site-nav-logo-sub {
    font-family: var(--font-sans);
    font-size: 11px;
    font-weight: normal;
    letter-spacing: 0.12em;
    color: var(--subtle);
    margin-left: 10px;
}

.site-nav-links {
    display: flex;
    gap: 24px;
    font-family: var(--font-sans);
    font-size: 12px;
    letter-spacing: 0.05em;
    color: var(--ink);
    font-weight: 500;
}

@media (min-width: 768px) {
    .site-nav-links {
        gap: 32px;
        font-size: 14px;
    }
}

.site-nav-links a {
    text-decoration: none;
    transition: opacity 0.2s;
}

.site-nav-links a:hover { opacity: 0.7; }

/* --- Main / Footer --- */
.site-main {
    flex-grow: 1;
    width: 100%;
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 64px 24px;
}

@media (min-width: 768px) {
    .site-main { padding: 96px 48px; }
}

.site-footer {
    width: 100%;
    padding: 64px 24px;
    margin-top: 64px;
    border-top: 1px solid var(--border);
}

@media (min-width: 768px) {
    .site-footer { padding: 64px 48px; }
}

.site-footer-inner {
    max-width: var(--max-w);
    margin: 0 auto;
    text-align: center;
}

/* --- Buttons --- */
.btn-primary {
    background-color: var(--accent);
    color: var(--paper);
    padding: 16px 40px;
    border-radius: 8px;
    font-family: var(--font-sans);
    font-size: 16px;
    font-weight: 500;
    letter-spacing: 0.1em;
    transition: all 0.3s ease;
    display: inline-block;
    box-shadow: 0 4px 12px rgba(211, 84, 58, 0.3);
    text-decoration: none;
}

.btn-primary:hover {
    background-color: #B84730;
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(211, 84, 58, 0.4);
    color: var(--paper);
}

.btn-primary--block {
    display: block;
    width: 100%;
    text-align: center;
    padding-top: 16px;
    padding-bottom: 16px;
    font-size: 18px;
}

.btn-ghost {
    background-color: transparent;
    color: var(--ink);
    padding: 14px 40px;
    border: 2px solid var(--ink);
    border-radius: 8px;
    font-family: var(--font-sans);
    font-size: 16px;
    font-weight: 500;
    letter-spacing: 0.1em;
    transition: all 0.3s ease;
    display: inline-block;
    text-decoration: none;
}

.btn-ghost:hover {
    color: var(--paper);
    background-color: var(--ink);
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(44, 43, 41, 0.15);
}

.btn-choice {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 24px;
    border: 2px solid var(--border);
    border-radius: 12px;
    background-color: #ffffff;
    color: var(--ink);
    text-align: center;
    transition: all 0.3s ease;
    text-decoration: none;
    flex: 1;
}

.btn-choice:hover {
    border-color: var(--accent);
    box-shadow: 0 8px 24px rgba(211, 84, 58, 0.1);
    transform: translateY(-2px);
}

.btn-choice .choice-label {
    color: var(--subtle);
    font-size: 12px;
    letter-spacing: 0.1em;
    margin-bottom: 8px;
    font-weight: 500;
}

.btn-choice .choice-title {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 8px;
}

.btn-choice .choice-action {
    font-size: 14px;
    font-weight: 700;
    color: var(--accent);
    transition: transform 0.3s ease;
    display: flex;
    align-items: center;
    gap: 4px;
}

.btn-choice:hover .choice-action { transform: translateX(4px); }

/* --- Markdown content --- */
.markdown-content {
    max-width: 65ch;
    margin: 0 auto;
}

.markdown-content h1,
.markdown-content h2,
.markdown-content h3 {
    font-family: var(--font-serif);
    font-weight: 500;
    color: var(--ink);
    margin-top: 3.5em;
    margin-bottom: 1.5em;
    line-height: 1.4;
}

.markdown-content h2 {
    font-size: 24px;
    border-bottom: 1px solid var(--border);
    padding-bottom: 0.5em;
}

.markdown-content h3 { font-size: 20px; }

.markdown-content p {
    margin-bottom: 2em;
    color: #3D3B38;
    letter-spacing: 0.03em;
    font-size: 16px;
}

.markdown-content a {
    color: var(--ink);
    text-decoration: underline;
    text-decoration-color: var(--ink);
    text-underline-offset: 4px;
    text-decoration-thickness: 1px;
    transition: color 0.2s, text-decoration-color 0.2s;
}

.markdown-content a:hover {
    color: #6C6A65;
    text-decoration-color: #6C6A65;
}

.markdown-content ul,
.markdown-content ol {
    margin-bottom: 2em;
    padding-left: 1.5em;
    color: #3D3B38;
}

.markdown-content li { margin-bottom: 0.5em; }
.markdown-content ul { list-style-type: circle; }
.markdown-content ol { list-style-type: decimal; }

.markdown-content blockquote {
    border-left: 2px solid #D0CEC9;
    padding-left: 1.5em;
    margin: 2em 0;
    color: #6C6A65;
    font-style: italic;
}

.markdown-content a.cta-button {
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #ffffff;
    color: var(--ink);
    border: 2px solid var(--accent);
    padding: 24px 32px;
    margin: 48px 0;
    border-radius: 12px;
    text-decoration: none;
    font-family: var(--font-sans);
    font-weight: 500;
    font-size: 17px;
    letter-spacing: 0.05em;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(211, 84, 58, 0.1);
    position: relative;
}

.markdown-content a.cta-button::after {
    content: '→';
    position: absolute;
    right: 32px;
    color: var(--accent);
    transition: transform 0.3s ease;
    font-weight: bold;
}

.markdown-content a.cta-button:hover {
    background-color: var(--accent);
    color: var(--paper);
    border-color: var(--accent);
    box-shadow: 0 8px 24px rgba(211, 84, 58, 0.25);
    transform: translateY(-2px);
}

.markdown-content a.cta-button:hover::after {
    color: var(--paper);
    transform: translateX(6px);
}

/* ========================
   Index Page
   ======================== */

.hero {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    min-height: 40vh;
    margin-bottom: 96px;
}

.hero-title {
    font-size: 30px;
    line-height: 1.8;
    margin-bottom: 32px;
    font-family: var(--font-serif);
    font-weight: 300;
    color: var(--ink);
}

@media (min-width: 768px) {
    .hero-title { font-size: 36px; }
}

.hero-desc {
    color: var(--ink);
    font-size: 16px;
    margin-bottom: 48px;
    font-family: var(--font-sans);
    letter-spacing: 0.05em;
    line-height: 2;
}

@media (min-width: 768px) {
    .hero-desc { font-size: 18px; }
}

.hero-choice {
    margin-top: 32px;
    width: 100%;
    border-top: 1px solid rgba(232, 230, 225, 0.5);
    padding-top: 40px;
}

.hero-choice-label {
    color: var(--ink);
    font-family: var(--font-sans);
    font-weight: bold;
    margin-bottom: 24px;
    font-size: 18px;
}

.choice-buttons {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 16px;
    width: 100%;
}

@media (min-width: 768px) {
    .choice-buttons { flex-direction: row; }
}

.md-only { display: none; }

@media (min-width: 768px) {
    .md-only { display: inline; }
}

/* Series */
.series {
    padding-top: 64px;
    border-top: 1px solid var(--border);
    scroll-margin-top: 128px;
}

.section-heading {
    font-family: var(--font-sans);
    font-size: 12px;
    letter-spacing: 0.2em;
    margin-bottom: 48px;
    color: var(--ink);
    font-weight: bold;
    text-transform: uppercase;
}

.series-phases {
    display: flex;
    flex-direction: column;
    gap: 64px;
}

.series-phase-title {
    font-family: var(--font-sans);
    font-size: 20px;
    color: var(--ink);
    font-weight: bold;
    margin-bottom: 32px;
    display: flex;
    align-items: center;
    gap: 16px;
}

.series-phase-line {
    width: 32px;
    height: 2px;
    background-color: rgba(44, 43, 41, 0.6);
    display: inline-block;
    flex-shrink: 0;
}

.series-article-list {
    display: flex;
    flex-direction: column;
    gap: 40px;
    padding-left: 24px;
    border-left: 2px solid var(--border);
    position: relative;
}

@media (min-width: 768px) {
    .series-article-list { padding-left: 48px; }
}

.series-article {
    display: block;
    position: relative;
    text-decoration: none;
    color: inherit;
}

.series-article-dot {
    position: absolute;
    left: -36px;
    top: 8px;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--border);
    transition: background-color 0.2s;
}

@media (min-width: 768px) {
    .series-article-dot { left: -60px; }
}

.series-article:hover .series-article-dot { background-color: var(--ink); }

.series-article-title {
    font-size: 20px;
    margin-bottom: 12px;
    color: var(--ink);
    font-family: var(--font-serif);
    font-weight: 500;
    transition: opacity 0.2s;
    line-height: 1.4;
}

@media (min-width: 768px) {
    .series-article-title { font-size: 24px; }
}

.series-article:hover .series-article-title { opacity: 0.7; }

.series-article-desc {
    color: var(--ink);
    font-family: var(--font-sans);
    font-size: 14px;
    line-height: 1.8;
    margin-bottom: 16px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

@media (min-width: 768px) {
    .series-article-desc { font-size: 16px; }
}

.series-article-cta {
    font-family: var(--font-sans);
    font-size: 12px;
    letter-spacing: 0.1em;
    color: var(--ink);
    font-weight: bold;
    transition: opacity 0.2s;
}

.series-article:hover .series-article-cta { opacity: 0.7; }

/* Habits */
.habits {
    padding-top: 96px;
    margin-top: 96px;
    border-top: 1px solid var(--border);
    scroll-margin-top: 128px;
}

.habits-intro {
    margin-bottom: 64px;
    padding: 32px;
    background-color: #ffffff;
    border: 2px solid rgba(211, 84, 58, 0.2);
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
}

@media (min-width: 768px) {
    .habits-intro { padding: 40px; }
}

.habits-intro-title {
    font-size: 24px;
    font-family: var(--font-serif);
    font-weight: bold;
    color: var(--ink);
    margin-bottom: 16px;
}

.habits-intro-lead {
    font-size: 18px;
    font-family: var(--font-sans);
    color: var(--ink);
    font-weight: 500;
    margin-bottom: 32px;
}

.habits-list {
    display: flex;
    flex-direction: column;
    gap: 32px;
    font-family: var(--font-sans);
    font-size: 18px;
    color: var(--ink);
    font-weight: 500;
    list-style: none;
    padding: 0;
    margin: 0;
}

.habits-list-note {
    font-size: 14px;
    color: var(--subtle);
    font-weight: normal;
    margin-top: 4px;
    display: block;
}

.habits-list-link {
    font-size: 14px;
    text-decoration: underline;
    text-decoration-color: var(--accent);
    text-underline-offset: 4px;
    color: var(--ink);
    margin-top: 8px;
    display: inline-block;
    transition: opacity 0.2s;
}

.habits-list-link:hover { opacity: 0.7; }

.habits-alt-box {
    margin-top: 16px;
    padding: 20px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 14px;
    background-color: rgba(250, 249, 246, 0.5);
}

.habits-alt-box a {
    text-decoration: underline;
    font-weight: bold;
    color: var(--accent);
}

.habits-cards {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

@media (min-width: 768px) {
    .habits-cards { gap: 32px; }
}

.habits-card {
    display: block;
    padding: 32px;
    background-color: #ffffff;
    border: 2px solid var(--border);
    border-radius: 12px;
    position: relative;
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    box-shadow: 0 4px 20px rgba(44, 43, 41, 0.02);
    transition: border-color 0.2s, box-shadow 0.2s;
}

@media (min-width: 768px) {
    .habits-card { padding: 40px; }
}

.habits-card:hover {
    border-color: var(--ink);
    box-shadow: 0 8px 30px rgba(44, 43, 41, 0.06);
}

.habits-card-title {
    font-size: 20px;
    margin-bottom: 16px;
    color: var(--ink);
    font-family: var(--font-serif);
    font-weight: 500;
    line-height: 1.4;
}

@media (min-width: 768px) {
    .habits-card-title { font-size: 24px; }
}

.habits-card-desc {
    color: var(--ink);
    font-family: var(--font-sans);
    font-size: 14px;
    line-height: 1.8;
    margin-bottom: 32px;
}

@media (min-width: 768px) {
    .habits-card-desc { font-size: 16px; }
}

.habits-card-cta {
    font-family: var(--font-sans);
    font-size: 12px;
    letter-spacing: 0.1em;
    color: var(--ink);
    font-weight: bold;
    display: flex;
    align-items: center;
}

.habits-card-cta-arrow {
    margin-left: 8px;
    display: inline-block;
    transition: transform 0.2s;
}

.habits-card:hover .habits-card-cta-arrow { transform: translateX(4px); }

/* ========================
   Article Page
   ======================== */

.article-header {
    margin-bottom: 80px;
    padding-bottom: 48px;
    border-bottom: 1px solid var(--border);
}

.article-title {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 30px;
    line-height: 1.3;
    margin-bottom: 32px;
    color: var(--ink);
}

@media (min-width: 768px) {
    .article-title { font-size: 36px; }
}

.article-desc {
    color: rgba(44, 43, 41, 0.8);
    font-size: 16px;
    font-family: var(--font-sans);
    line-height: 1.8;
}

.article-next {
    margin-top: 96px;
    padding: 32px;
    background-color: #ffffff;
    border: 2px solid rgba(211, 84, 58, 0.2);
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    max-width: 65ch;
    margin-left: auto;
    margin-right: auto;
}

@media (min-width: 768px) {
    .article-next { padding: 40px; }
}

.article-next-title {
    font-size: 20px;
    font-family: var(--font-serif);
    font-weight: bold;
    color: var(--ink);
    margin-bottom: 24px;
    line-height: 1.6;
}

@media (min-width: 768px) {
    .article-next-title { font-size: 24px; }
}

.article-next-lead {
    font-size: 18px;
    font-family: var(--font-sans);
    color: var(--ink);
    font-weight: 500;
    margin-bottom: 16px;
}

.article-next-sub {
    font-size: 16px;
    font-family: var(--font-sans);
    color: rgba(44, 43, 41, 0.8);
    margin-bottom: 32px;
}

.article-back {
    margin-top: 96px;
    padding-top: 64px;
    border-top: 1px solid var(--border);
    text-align: center;
}

/* Author bio */
.author-bio {
    margin-top: 80px;
    padding: 32px;
    border: 1px solid var(--border);
    border-radius: 12px;
    max-width: 65ch;
    margin-left: auto;
    margin-right: auto;
}

.author-bio-label {
    font-family: var(--font-sans);
    font-size: 11px;
    letter-spacing: 0.18em;
    color: var(--subtle);
    text-transform: uppercase;
    font-weight: bold;
    margin-bottom: 20px;
}

.author-bio p {
    font-family: var(--font-sans);
    font-size: 15px;
    color: var(--ink);
    line-height: 1.9;
    margin-bottom: 12px;
}

.author-bio-link {
    display: inline-block;
    margin-top: 8px;
    font-family: var(--font-sans);
    font-size: 13px;
    color: var(--subtle);
    text-decoration: underline;
    text-underline-offset: 4px;
    text-decoration-color: var(--border);
    transition: color 0.2s;
}

.author-bio-link:hover { color: var(--ink); }

/* About page */
.about-body {
    max-width: 65ch;
    margin: 0 auto;
}

.about-body p {
    font-family: var(--font-sans);
    font-size: 17px;
    line-height: 2;
    color: var(--ink);
    margin-bottom: 1.8em;
}

/* Contact form */
.contact-form-wrap {
    margin: 0 auto;
    max-width: 65ch;
}

.contact-form-wrap iframe {
    display: block;
    width: 100%;
    border: none;
}

/* Footer links */
.footer-links {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.footer-links a {
    font-family: var(--font-sans);
    font-size: 12px;
    color: var(--subtle);
    text-decoration: none;
    letter-spacing: 0.05em;
    transition: color 0.2s;
}

.footer-links a:hover { color: var(--ink); }

.footer-copy {
    font-family: var(--font-sans);
    font-size: 12px;
    color: var(--subtle);
    letter-spacing: 0.1em;
    margin: 0;
}