/* Toronto Skyline Notes — sheet.css
   City-at-dusk palette: deep navy #0e1a2b, warm amber #d99b3f, concrete #4a5568.
   Unique namespace tsn-*, system fonts only, no external frameworks. */

:root {
    --tsn-navy:       #0e1a2b;
    --tsn-navy-2:     #142338;
    --tsn-navy-3:     #1e2f47;
    --tsn-amber:      #d99b3f;
    --tsn-amber-2:    #b57e2a;
    --tsn-amber-soft: #f3d9a4;
    --tsn-concrete:   #4a5568;
    --tsn-concrete-2: #6b7684;
    --tsn-paper:      #f4f0e6;
    --tsn-paper-2:    #ebe4d1;
    --tsn-ink:        #1a2130;
    --tsn-line:       #d4cdb9;
    --tsn-line-soft:  #e8e2d1;
    --tsn-ok:         #2f6b3f;
    --tsn-err:        #a92828;

    --tsn-font-body: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --tsn-font-head: Georgia, "Times New Roman", Times, serif;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body.tsn-body {
    margin: 0;
    padding: 0;
    background: var(--tsn-paper);
    color: var(--tsn-ink);
    font-family: var(--tsn-font-body);
    font-size: 17px;
    line-height: 1.62;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}
a { color: var(--tsn-navy); text-underline-offset: 3px; }
a:hover { color: var(--tsn-amber-2); }

.tsn-shell {
    max-width: 1080px;
    margin: 0 auto;
    padding-left: 24px;
    padding-right: 24px;
}
@media (max-width: 640px) {
    .tsn-shell { padding-left: 18px; padding-right: 18px; }
    body.tsn-body { font-size: 16px; }
}

/* Top disclosure strip */
.tsn-disclose-strip {
    background: var(--tsn-navy);
    color: #d7d3c7;
    font-size: 12.5px;
    line-height: 1.45;
    padding: 8px 0;
    letter-spacing: 0.01em;
}
.tsn-disclose-strip .tsn-shell {
    text-align: center;
}

/* Top bar */
.tsn-topbar {
    background: var(--tsn-paper-2);
    border-bottom: 1px solid var(--tsn-line);
}
.tsn-topbar-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding-top: 18px;
    padding-bottom: 18px;
    flex-wrap: wrap;
}
.tsn-brand {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--tsn-navy);
}
.tsn-brand-mark {
    width: 34px;
    height: 34px;
    display: inline-block;
    background: linear-gradient(180deg, var(--tsn-navy) 0%, var(--tsn-navy-2) 55%, var(--tsn-amber) 55%, var(--tsn-amber) 100%);
    border-radius: 3px;
    position: relative;
    box-shadow: 0 0 0 1px var(--tsn-line) inset;
}
.tsn-brand-mark::after {
    content: "";
    position: absolute;
    top: 4px; left: 15px;
    width: 4px; height: 15px;
    background: var(--tsn-amber);
    border-radius: 1px;
}
.tsn-brand-text { line-height: 1.15; }
.tsn-brand-name {
    display: block;
    font-family: var(--tsn-font-head);
    font-weight: 700;
    font-size: 20px;
    letter-spacing: 0.005em;
}
.tsn-brand-tag {
    display: block;
    font-size: 11.5px;
    color: var(--tsn-concrete);
    letter-spacing: 0.02em;
    text-transform: uppercase;
    margin-top: 2px;
}
.tsn-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 4px 20px;
    align-items: center;
}
.tsn-nav-link {
    color: var(--tsn-concrete);
    text-decoration: none;
    font-size: 14.5px;
    font-weight: 500;
    padding: 6px 4px;
    border-bottom: 2px solid transparent;
    letter-spacing: 0.01em;
    transition: color .12s, border-color .12s;
}
.tsn-nav-link:hover {
    color: var(--tsn-navy);
    border-bottom-color: var(--tsn-amber);
}
.tsn-nav-link.is-active {
    color: var(--tsn-navy);
    border-bottom-color: var(--tsn-amber);
}
@media (max-width: 720px) {
    .tsn-topbar-row { gap: 12px; }
    .tsn-nav { width: 100%; justify-content: flex-start; gap: 4px 14px; }
    .tsn-brand-tag { display: none; }
}

/* Kickers / lede / headings */
.tsn-kicker {
    font-size: 12px;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    font-weight: 700;
    color: var(--tsn-amber-2);
    margin: 0 0 10px;
}
.tsn-h1 {
    font-family: var(--tsn-font-head);
    font-size: clamp(30px, 4.6vw, 46px);
    line-height: 1.08;
    margin: 0 0 16px;
    color: var(--tsn-navy);
    font-weight: 700;
    letter-spacing: -0.005em;
}
.tsn-h2 {
    font-family: var(--tsn-font-head);
    font-size: clamp(22px, 2.6vw, 28px);
    line-height: 1.2;
    margin: 32px 0 12px;
    color: var(--tsn-navy);
    font-weight: 700;
}
.tsn-lede {
    font-size: 18px;
    line-height: 1.55;
    color: var(--tsn-concrete);
    margin: 0 0 20px;
}

/* Page containers */
.tsn-page { padding-bottom: 60px; }
.tsn-page-article { padding-top: 32px; }

/* Hero */
.tsn-hero {
    padding: 44px 0 32px;
    background:
        linear-gradient(180deg, transparent 0%, rgba(14,26,43,0.02) 100%),
        var(--tsn-paper);
    border-bottom: 1px solid var(--tsn-line-soft);
}
.tsn-hero-grid {
    display: grid;
    grid-template-columns: 1.4fr 1fr;
    gap: 48px;
    align-items: center;
}
.tsn-hero-copy .tsn-h1 { margin-bottom: 18px; }
.tsn-hero-cta {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin: 22px 0 0;
}
@media (max-width: 820px) {
    .tsn-hero-grid { grid-template-columns: 1fr; gap: 30px; }
    .tsn-hero-side { order: -1; }
}

/* Buttons */
.tsn-btn {
    display: inline-block;
    background: var(--tsn-navy);
    color: #f7f3e6;
    text-decoration: none;
    padding: 12px 22px;
    border: 1px solid var(--tsn-navy);
    border-radius: 4px;
    font-weight: 600;
    font-size: 15px;
    letter-spacing: 0.02em;
    cursor: pointer;
    transition: transform .1s, background .12s, color .12s;
}
.tsn-btn:hover {
    background: var(--tsn-amber);
    color: var(--tsn-navy);
    border-color: var(--tsn-amber);
}
.tsn-btn-ghost {
    background: transparent;
    color: var(--tsn-navy);
    border-color: var(--tsn-navy);
}
.tsn-btn-ghost:hover {
    background: var(--tsn-navy);
    color: #f7f3e6;
    border-color: var(--tsn-navy);
}

/* Bands / sections */
.tsn-band { padding: 40px 0; }
.tsn-band-amber {
    background: var(--tsn-navy);
    color: #eee5cf;
}
.tsn-band-amber .tsn-h2 { color: var(--tsn-amber-soft); }
.tsn-band-amber a { color: var(--tsn-amber-soft); }

/* Open essay */
.tsn-open-essay {
    max-width: 780px;
    padding-top: 40px;
    padding-bottom: 40px;
}
.tsn-prose p { margin: 0 0 18px; }
.tsn-prose h2:first-child { margin-top: 0; }
.tsn-prose ul { padding-left: 22px; }
.tsn-prose ul li { margin: 6px 0; }

/* Card grid */
.tsn-card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 20px;
    margin-top: 22px;
}
.tsn-card {
    display: block;
    background: #fbf7ea;
    color: var(--tsn-navy);
    border: 1px solid var(--tsn-line-soft);
    border-radius: 6px;
    padding: 22px 22px 20px;
    text-decoration: none;
    transition: transform .12s, box-shadow .12s, border-color .12s;
}
.tsn-card:hover {
    border-color: var(--tsn-amber);
    box-shadow: 0 8px 20px rgba(14, 26, 43, 0.08);
    transform: translateY(-2px);
}
.tsn-card-eyebrow {
    font-size: 11.5px;
    text-transform: uppercase;
    letter-spacing: 0.14em;
    color: var(--tsn-amber-2);
    margin: 0 0 6px;
    font-weight: 700;
}
.tsn-card-title {
    font-family: var(--tsn-font-head);
    font-size: 22px;
    margin: 0 0 8px;
    color: var(--tsn-navy);
}
.tsn-card-body {
    color: var(--tsn-concrete);
    font-size: 15.5px;
    margin: 0 0 14px;
    line-height: 1.55;
}
.tsn-card-cta {
    color: var(--tsn-amber-2);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.03em;
    text-transform: uppercase;
}

/* Lessons list */
.tsn-lessons { max-width: 780px; }
.tsn-lesson-list {
    list-style: none;
    padding: 0;
    margin: 18px 0 0;
    border-top: 1px solid var(--tsn-line-soft);
}
.tsn-lesson-list li {
    padding: 14px 0;
    border-bottom: 1px solid var(--tsn-line-soft);
    font-size: 16px;
    line-height: 1.55;
}
.tsn-lesson-list li strong { color: var(--tsn-navy); }

/* CTA band */
.tsn-cta-band {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 32px;
    flex-wrap: wrap;
}
.tsn-cta-band > div { flex: 1 1 60%; }
.tsn-cta-h { margin: 0 0 8px; }
.tsn-cta-body { margin: 0; color: #d3c9ac; }
.tsn-cta-btn { margin: 0; flex-shrink: 0; }

/* Author box */
.tsn-author-box {
    display: flex;
    gap: 18px;
    align-items: flex-start;
    padding: 22px;
    border: 1px solid var(--tsn-line);
    border-left: 4px solid var(--tsn-amber);
    background: #fbf7ea;
    border-radius: 4px;
    margin-top: 40px;
}
.tsn-author-photo {
    flex-shrink: 0;
    width: 72px;
    height: 72px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--tsn-navy), var(--tsn-navy-3));
    color: var(--tsn-amber-soft);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--tsn-font-head);
    font-weight: 700;
    font-size: 24px;
    letter-spacing: 0.02em;
}
.tsn-author-name {
    font-family: var(--tsn-font-head);
    font-weight: 700;
    font-size: 16px;
    margin: 0 0 4px;
    color: var(--tsn-navy);
}
.tsn-author-bio {
    margin: 0;
    font-size: 14.5px;
    color: var(--tsn-concrete);
    line-height: 1.55;
}

/* Article body */
.tsn-article {
    max-width: 780px;
}
.tsn-article-head { margin-bottom: 26px; }

/* Figures with real photos */
.tsn-fig {
    margin: 26px 0;
}
.tsn-fig-img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 4px;
    background: var(--tsn-paper-2);
    box-shadow: 0 4px 16px rgba(14, 26, 43, 0.10);
}
.tsn-fig-wide .tsn-fig-img { aspect-ratio: 16 / 10; object-fit: cover; }
.tsn-fig-portrait .tsn-fig-img { aspect-ratio: 4 / 5; object-fit: cover; }
.tsn-fig-square .tsn-fig-img { aspect-ratio: 1 / 1; object-fit: cover; }
.tsn-fig figcaption {
    margin-top: 8px;
    font-size: 13.5px;
    color: var(--tsn-concrete);
    line-height: 1.5;
    font-style: italic;
}
.tsn-fig-credit {
    display: block;
    margin-top: 4px;
    font-size: 11.5px;
    color: var(--tsn-concrete-2);
    font-style: normal;
    letter-spacing: 0.01em;
}
.tsn-fig-credit a { color: var(--tsn-concrete-2); }

/* Inline CTA (end of article) */
.tsn-inline-cta {
    margin: 30px 0 8px;
    padding: 16px 18px;
    border-top: 1px solid var(--tsn-line-soft);
    border-bottom: 1px solid var(--tsn-line-soft);
    color: var(--tsn-concrete);
    font-size: 15px;
}

/* FAQ */
.tsn-faq-list { margin: 20px 0 30px; }
.tsn-faq-item {
    border-bottom: 1px solid var(--tsn-line-soft);
    padding: 14px 0;
}
.tsn-faq-item summary {
    cursor: pointer;
    list-style: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    font-family: var(--tsn-font-head);
    font-weight: 700;
    font-size: 18px;
    color: var(--tsn-navy);
    padding: 4px 0;
}
.tsn-faq-item summary::-webkit-details-marker { display: none; }
.tsn-faq-item summary::after {
    content: "+";
    color: var(--tsn-amber-2);
    font-size: 22px;
    font-weight: 700;
    line-height: 1;
    padding-left: 8px;
}
.tsn-faq-item[open] summary::after { content: "\2212"; }
.tsn-faq-a { padding: 10px 0 4px; color: var(--tsn-concrete); }
.tsn-faq-a p { margin: 0; line-height: 1.6; }

/* Form */
.tsn-form { max-width: 620px; margin: 20px 0 24px; }
.tsn-field { display: block; margin-bottom: 16px; }
.tsn-field-label {
    display: block;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--tsn-concrete);
    margin-bottom: 6px;
}
.tsn-form input[type="text"],
.tsn-form input[type="email"],
.tsn-form textarea {
    width: 100%;
    padding: 12px 14px;
    background: #fbf7ea;
    border: 1px solid var(--tsn-line);
    border-radius: 4px;
    font: inherit;
    color: var(--tsn-ink);
}
.tsn-form input:focus, .tsn-form textarea:focus {
    outline: 2px solid var(--tsn-amber);
    outline-offset: 1px;
    background: #fff;
}
.tsn-form-note {
    font-size: 13px;
    color: var(--tsn-concrete);
    margin: -4px 0 12px;
}
.tsn-alert {
    padding: 14px 18px;
    border-radius: 4px;
    margin: 16px 0;
    font-size: 15px;
}
.tsn-alert p { margin: 0 0 6px; }
.tsn-alert ul { margin: 6px 0 0 20px; }
.tsn-alert-ok { background: #e5efe4; border: 1px solid var(--tsn-ok); color: var(--tsn-ok); }
.tsn-alert-err { background: #f5e0dd; border: 1px solid var(--tsn-err); color: var(--tsn-err); }

/* Footer */
.tsn-foot {
    background: var(--tsn-navy);
    color: #c8c1ab;
    padding: 32px 0 26px;
    font-size: 14px;
    line-height: 1.6;
    margin-top: 40px;
}
.tsn-foot-disclose {
    color: #eee5cf;
    font-size: 13.5px;
    margin: 0 0 16px;
    text-align: center;
    line-height: 1.55;
}
.tsn-foot-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 6px 20px;
    margin-bottom: 14px;
}
.tsn-foot-nav a {
    color: var(--tsn-amber-soft);
    text-decoration: none;
    font-size: 13.5px;
    padding: 3px 2px;
}
.tsn-foot-nav a:hover { color: #fff; text-decoration: underline; }
.tsn-foot-meta {
    text-align: center;
    font-size: 12.5px;
    color: #9d9683;
    margin: 6px 0 0;
    letter-spacing: 0.02em;
}