/* ─── Variables ─── */
:root {
    --bg: #F2F5F0;
    --surface: #FFFFFF;
    --primary: #1B4332;
    --action: #40916C;
    --accent: #D8EAE0;
    --text: #1a1a1a;
    --text-muted: #4a6a52;
    --border: #d0ddd0;
    --font-serif: 'Fraunces', Georgia, serif;
    --font-sans: 'DM Sans', system-ui, sans-serif;
    --font-persona: 'Playfair Display', Georgia, serif;
    --radius: 12px;
    --max-w: 1200px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--font-sans); background: var(--bg); color: var(--text); line-height: 1.7; font-size: 16px; }
a { text-decoration: none; color: inherit; }

/* ─── Nav ─── */
nav { background: var(--primary); position: sticky; top: 0; z-index: 100; }
.nav-inner { max-width: var(--max-w); margin: 0 auto; padding: 0 2.5rem; height: 64px; display: flex; align-items: center; justify-content: space-between; }
.nav-logo { font-family: var(--font-serif); font-size: 1.0625rem; font-weight: 400; color: var(--bg); }
.nav-links { list-style: none; display: flex; gap: 2rem; }
.nav-links a { font-size: 0.875rem; color: rgba(242,245,240,0.75); transition: color 0.2s; }
.nav-links a:hover { color: var(--bg); }

/* ─── Container ─── */
.container { max-width: var(--max-w); margin: 0 auto; padding: 0 2.5rem; }

/* ─── Hero ─── */
.cs-hero { background: var(--primary); padding: 3rem 2.5rem 1.5rem; }

.cs-hero-meta {
    display: flex;
    align-items: center;
    gap: 2rem;
    margin-bottom: 2.5rem;
}

.back-link { font-size: 0.875rem; color: rgba(242,245,240,0.65); transition: color 0.2s; }
.back-link:hover { color: var(--bg); }

.cs-type { font-size: 0.6875rem; letter-spacing: 0.15em; text-transform: uppercase; color: #74c69d; font-weight: 500; }

.cs-title {
    font-family: var(--font-serif);
    font-size: clamp(2.5rem, 5vw, 4.25rem);
    font-weight: 300;
    color: var(--bg);
    line-height: 1.08;
    letter-spacing: -0.5px;
    margin-bottom: 1.75rem;
}

.cs-subtitle {
    font-size: 1.08rem;
    color: rgba(242,245,240,0.7);
    line-height: 1.75;
    max-width: none;
    margin-bottom: 3rem;
}

.cs-stats { display: flex; gap: 1rem; flex-wrap: wrap; justify-content: center; }

.stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: rgba(255,255,255,0.10);
    border: 1px solid rgba(255,255,255,0.18);
    border-radius: 50%;
    width: 116px;
    height: 116px;
    gap: 4px;
}

.stat-num { font-family: var(--font-serif); font-size: 2rem; font-weight: 300; color: var(--bg); line-height: 1; }
.stat-label { font-size: 0.625rem; color: rgba(242,245,240,0.55); text-align: center; letter-spacing: 0.05em; padding: 0 8px; line-height: 1.3; }

/* ─── Overview strip ─── */
.cs-overview { background: var(--surface); border-bottom: 1px solid var(--border); padding: 1.75rem 2.5rem; }
.overview-grid { max-width: var(--max-w); margin: 0 auto; display: grid; grid-template-columns: repeat(4, 1fr); gap: 2rem; }
.overview-label { display: block; font-size: 0.6875rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--action); font-weight: 500; margin-bottom: 6px; }
.overview-value { font-size: 0.9375rem; color: var(--text); line-height: 1.5; }

/* ─── Main ─── */
.cs-main { padding: 3rem 0 0; }

/* ─── Sections ─── */
.cs-section { margin-bottom: 4.5rem; }

.cs-section-inner {
    display: grid;
    grid-template-columns: 180px 1fr;
    gap: 4rem;
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 2.5rem;
}

.cs-section-label { font-size: 0.6875rem; letter-spacing: 0.15em; text-transform: uppercase; color: var(--action); font-weight: 500; padding-top: 6px; line-height: 1.4; }
.cs-section-label-inline { display: block; font-size: 0.6875rem; letter-spacing: 0.15em; text-transform: uppercase; color: var(--action); font-weight: 500; margin-bottom: 1.5rem; }

.cs-section-content p { font-size: 1rem; color: var(--text); opacity: 0.8; line-height: 1.85; margin-bottom: 1.25rem; }
.cs-section-content p:last-child { margin-bottom: 0; }

.cs-heading { font-family: var(--font-serif); font-size: clamp(1.25rem, 2.5vw, 1.75rem); font-weight: 300; color: var(--text); line-height: 1.3; margin-bottom: 1.25rem; letter-spacing: -0.2px; }

/* ─── Callout ─── */
.callout { background: var(--accent); padding: 1.5rem 1.75rem; margin-top: 1.75rem; border-left: 3px solid var(--action); border-radius: 0 var(--radius) var(--radius) 0; }
.callout-label { display: block; font-size: 0.6875rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--action); font-weight: 500; margin-bottom: 0.625rem; }
.callout p { font-size: 0.9375rem; color: var(--text); opacity: 0.85; line-height: 1.75; margin: 0 !important; }

/* ─── Personas ─── */
.personas-section { background: var(--surface); padding: 3.5rem 2.5rem; margin-bottom: 4.5rem; border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }

.tab-row { display: grid; grid-template-columns: repeat(5,1fr); border: 0.5px solid var(--border); border-radius: var(--radius); overflow: hidden; margin-bottom: 1.5rem; }
.tab-btn { background: transparent; border: none; border-right: 0.5px solid var(--border); padding: 14px 12px; cursor: pointer; text-align: left; font-family: var(--font-sans); transition: background 0.15s; }
.tab-btn:last-child { border-right: none; }
.tab-btn:hover { background: var(--bg); }
.tab-btn.active { background: var(--bg); }
.tab-num { display: block; font-size: 10px; color: var(--text-muted); letter-spacing: 1px; margin-bottom: 4px; }
.tab-name { display: block; font-family: var(--font-persona); font-size: 15px; color: var(--text); margin-bottom: 3px; }
.tab-arch { display: block; font-size: 10px; color: var(--text-muted); line-height: 1.3; }
.tab-bar { height: 2px; width: 100%; margin-top: 10px; border-radius: 1px; }

.persona-card { background: var(--bg); border: 0.5px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.persona-card-top { display: grid; grid-template-columns: 1fr 1fr; border-bottom: 0.5px solid var(--border); }
.persona-identity { padding: 24px; border-right: 0.5px solid var(--border); }
.persona-num { font-size: 10px; color: var(--text-muted); letter-spacing: 2px; margin-bottom: 10px; }
.persona-name { font-family: var(--font-persona); font-size: 36px; font-weight: 400; color: var(--text); line-height: 1.0; margin-bottom: 6px; }
.persona-meta { font-size: 12px; color: var(--text-muted); margin-bottom: 14px; }
.persona-pill { display: inline-block; border: 0.5px solid var(--border); border-radius: 20px; padding: 4px 14px; font-size: 11px; color: var(--text-muted); }
.persona-pattern { padding: 24px; }
.pattern-label { font-size: 10px; letter-spacing: 2px; text-transform: uppercase; color: var(--text-muted); margin-bottom: 6px; }
.pattern-value { font-family: var(--font-persona); font-style: italic; font-size: 16px; color: var(--text); line-height: 1.3; margin-bottom: 16px; }
.risk-label { font-size: 10px; letter-spacing: 2px; text-transform: uppercase; color: var(--text-muted); margin-bottom: 6px; }
.risk-value { font-size: 13px; color: var(--text); opacity: 0.8; line-height: 1.5; }
.persona-quote-wrap { padding: 18px 24px; border-bottom: 0.5px solid var(--border); }
.persona-quote { font-family: var(--font-persona); font-style: italic; font-size: 14px; color: var(--text); line-height: 1.6; padding-left: 16px; border-left: 2px solid var(--border); }
.persona-card-bottom { display: grid; grid-template-columns: repeat(3,1fr); border-bottom: 0.5px solid var(--border); }
.persona-col { padding: 18px 24px; }
.persona-col:not(:last-child) { border-right: 0.5px solid var(--border); }
.col-label { font-size: 10px; letter-spacing: 2px; text-transform: uppercase; color: var(--action); margin-bottom: 10px; }
.col-item { font-size: 12px; color: var(--text); opacity: 0.8; line-height: 1.5; padding: 5px 0; border-bottom: 0.5px solid var(--border); }
.col-item:last-child { border-bottom: none; }
.persona-bars { display: flex; gap: 2rem; padding: 16px 24px; background: var(--surface); }
.bar-item { flex: 1; }
.bar-label-row { display: flex; justify-content: space-between; margin-bottom: 6px; }
.bar-label-text { font-size: 10px; letter-spacing: 1px; text-transform: uppercase; color: var(--text-muted); }
.bar-val { font-size: 11px; color: var(--text); }
.bar-bg { height: 4px; background: var(--border); border-radius: 2px; overflow: hidden; }
.bar-fill { height: 100%; border-radius: 2px; transition: width 0.4s; }
.persona-nav { display: flex; justify-content: space-between; margin-top: 1rem; }
.persona-nav-btn { font-size: 12px; color: var(--text-muted); background: none; border: 0.5px solid var(--border); border-radius: 8px; padding: 7px 16px; cursor: pointer; font-family: var(--font-sans); transition: all 0.15s; }
.persona-nav-btn:hover { background: var(--bg); color: var(--text); }

/* ─── Findings grid ─── */
.findings-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; margin-top: 1.75rem; }
.finding-card { background: var(--surface); border: 0.5px solid var(--border); border-radius: var(--radius); padding: 1.5rem; }
.finding-num { font-size: 0.6875rem; letter-spacing: 0.12em; color: var(--action); margin-bottom: 0.75rem; font-weight: 500; }
.finding-title { font-family: var(--font-serif); font-size: 1.0625rem; font-weight: 400; color: var(--text); margin-bottom: 0.75rem; line-height: 1.3; }
.finding-card p { font-size: 0.875rem; color: var(--text); opacity: 0.75; line-height: 1.75; margin: 0; }

/* ─── Implications ─── */
.implication { background: var(--surface); border: 0.5px solid var(--border); border-radius: var(--radius); padding: 2rem; margin-top: 1.5rem; }
.implication-header { margin-bottom: 1rem; }
.implication-num { font-size: 0.6875rem; letter-spacing: 0.12em; text-transform: uppercase; color: var(--action); font-weight: 500; display: block; margin-bottom: 0.4rem; }
.implication-title { font-family: var(--font-serif); font-size: 1.25rem; font-weight: 400; color: var(--text); line-height: 1.3; }
.implication p { font-size: 0.9375rem; color: var(--text); opacity: 0.8; line-height: 1.8; margin-top: 0.875rem; }

/* ─── Design screens ─── */
.screens-section { padding: 2rem 2.5rem 5rem; max-width: var(--max-w); margin: 0 auto; }
.screen-item { display: grid; grid-template-columns: 1fr 2fr; gap: 3rem; align-items: center; margin-bottom: 5rem; }
.screen-item.reverse { grid-template-columns: 2fr 1fr; }
.screen-item.reverse .screen-meta { order: 2; }
.screen-item.reverse .screen-image { order: 1; }
.screen-num { display: block; font-size: 0.6875rem; letter-spacing: 0.15em; text-transform: uppercase; color: var(--action); margin-bottom: 0.5rem; font-weight: 500; }
.screen-title { display: block; font-family: var(--font-serif); font-size: 1.5rem; font-weight: 300; color: var(--text); margin-bottom: 0.875rem; }
.screen-desc { font-size: 0.9375rem; color: var(--text); opacity: 0.75; line-height: 1.75; }
.screen-image img { width: 100%; border-radius: var(--radius); border: 1px solid var(--border); box-shadow: 0 8px 32px rgba(27,67,50,0.08); }

/* ─── Blockquote ─── */
.cs-blockquote { font-family: var(--font-serif); font-style: italic; font-size: 1.125rem; color: var(--primary); line-height: 1.7; border-left: 3px solid var(--action); padding-left: 1.5rem; margin: 1.5rem 0 0; }

/* ─── Next project ─── */
.next-project { background: var(--surface); border-top: 1px solid var(--border); padding: 3rem 2.5rem; }
.next-link { font-family: var(--font-serif); font-size: clamp(1.25rem, 3vw, 2rem); font-weight: 300; color: var(--primary); display: block; margin-top: 0.5rem; transition: color 0.2s; }
.next-link:hover { color: var(--action); }

/* ─── Footer ─── */
footer { background: var(--bg); border-top: 1px solid var(--border); padding: 1.5rem 2.5rem; }
.footer-inner { max-width: var(--max-w); margin: 0 auto; display: flex; justify-content: space-between; align-items: center; }
.footer-name { font-family: var(--font-serif); font-size: 0.9375rem; color: var(--primary); }
.footer-copy { font-size: 0.8125rem; color: var(--text-muted); }

/* ─── Back to top ─── */
#back-to-top { position: fixed; bottom: 2rem; right: 2rem; width: 44px; height: 44px; background: var(--primary); color: var(--bg); border: none; border-radius: 50%; font-size: 1.125rem; cursor: pointer; opacity: 0; visibility: hidden; transition: all 0.3s; z-index: 99; }
#back-to-top.show { opacity: 1; visibility: visible; }
#back-to-top:hover { background: var(--action); }

/* ─── Animations ─── */
.fade-up { opacity: 0; transform: translateY(20px); transition: opacity 0.6s ease, transform 0.6s ease; }
.fade-up.visible { opacity: 1; transform: translateY(0); }

/* ─── Focus ─── */
a:focus-visible, button:focus-visible { outline: 2px solid var(--action); outline-offset: 3px; border-radius: 3px; }

/* ─── Responsive ─── */
@media (max-width: 900px) {
    .cs-section-inner { grid-template-columns: 1fr; gap: 1rem; }
    .persona-card-top { grid-template-columns: 1fr; }
    .persona-identity { border-right: none; border-bottom: 0.5px solid var(--border); }
    .persona-card-bottom { grid-template-columns: 1fr; }
    .persona-col:not(:last-child) { border-right: none; border-bottom: 0.5px solid var(--border); }
    .tab-row { grid-template-columns: 1fr 1fr; }
    .findings-grid { grid-template-columns: 1fr; }
    .screen-item, .screen-item.reverse { grid-template-columns: 1fr; }
    .screen-item.reverse .screen-meta { order: 1; }
    .screen-item.reverse .screen-image { order: 2; }
    .overview-grid { grid-template-columns: 1fr 1fr; gap: 1rem; }
    .cs-stats { gap: 0.75rem; }
    .stat { width: 100px; height: 100px; }
}

@media (max-width: 600px) {
    .cs-hero { padding: 3rem 1.5rem; }
    .cs-hero-meta { flex-direction: column; align-items: flex-start; gap: 0.75rem; }
    .overview-grid { grid-template-columns: 1fr; }
    .tab-row { grid-template-columns: 1fr; }
    .screens-section { padding: 2rem 1.5rem 3rem; }
}