/* ==========================================================================
   Nathan Guion — Personal Site
   ========================================================================== */

/* ---------- Reset ---------- */

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

/* ---------- Custom Properties ---------- */

:root {
    --color-bg: #faf8f5;
    --color-text: #1a1816;
    --color-text-secondary: #635e58;
    --color-accent: #746a5b;
    --color-accent-hover: #5c5347;
    --color-link: #1a1816;
    --color-link-hover: #8a7d6b;
    --color-border: #d8d3cc;
    --color-card-border: #d8d3cc;
    --color-card-border-hover: #8a7d6b;
    --color-toggle-bg: transparent;
    --color-toggle-border: #d8d3cc;
    --color-selection-bg: rgba(138, 125, 107, 0.15);
    --color-focus-ring: rgba(138, 125, 107, 0.5);
    --color-result-border: rgba(138, 125, 107, 0.2);

    --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Text",
        "SF Pro Display", "Helvetica Neue", Arial, sans-serif;

    --container-max: 680px;
    --container-padding: 24px;
}

html.dark {
    --color-bg: #151312;
    --color-text: #ede8e3;
    --color-text-secondary: #8a847c;
    --color-accent: #b8a07a;
    --color-accent-hover: #d4bc96;
    --color-link: #ede8e3;
    --color-link-hover: #b8a07a;
    --color-border: #2e2a26;
    --color-card-border: #2e2a26;
    --color-card-border-hover: #b8a07a;
    --color-toggle-border: #3d3832;
    --color-selection-bg: rgba(184, 160, 122, 0.2);
    --color-focus-ring: rgba(184, 160, 122, 0.4);
    --color-result-border: rgba(184, 160, 122, 0.15);
}

/* ---------- Global ---------- */

html {
    font-size: 17px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.5;
    font-weight: 400;
    letter-spacing: 0;
    transition: background-color 0.3s ease, color 0.3s ease;
}

::selection {
    background: var(--color-selection-bg);
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    * { transition: none !important; animation: none !important; }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ---------- Focus ---------- */

:focus-visible {
    outline: 2px solid var(--color-focus-ring);
    outline-offset: 3px;
}

/* ---------- Layout ---------- */

.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--container-padding);
    min-height: 100vh;
    min-height: 100dvh;
    display: flex;
    flex-direction: column;
    animation: fadeIn 0.4s ease both;
}

/* ---------- Skip Link ---------- */

.skip-link {
    position: absolute;
    top: 10px;
    left: 10px;
    padding: 10px 12px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    color: var(--color-text);
    text-decoration: none;
    transform: translateY(-200%);
    transition: transform 0.15s ease;
    z-index: 999;
}

.skip-link:focus-visible {
    transform: translateY(0);
}

/* ---------- Header ---------- */

header {
    padding-top: 80px;
    padding-bottom: 8px;
}

.header-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

h1 {
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--color-text);
}

.site-title a {
    color: var(--color-text);
    text-decoration: none;
    border-bottom: none;
    padding-bottom: 0;
}

.site-title a:hover {
    color: var(--color-text);
    border-bottom: none;
}

/* ---------- Theme Toggle ---------- */

.theme-toggle {
    background: var(--color-toggle-bg);
    border: 1.5px solid var(--color-toggle-border);
    border-radius: 50%;
    width: 44px;
    height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--color-text-secondary);
    transition: color 0.2s ease, border-color 0.2s ease;
    flex-shrink: 0;
}

.theme-toggle:hover {
    color: var(--color-text);
    border-color: var(--color-accent);
}

.icon-sun { display: none; }
.icon-moon { display: block; }
html.dark .icon-sun { display: block; }
html.dark .icon-moon { display: none; }

/* ---------- Main ---------- */

main {
    flex: 1;
    padding-top: 48px;
}

/* ---------- Sections ---------- */

.section {
    padding-bottom: 56px;
}

.section:last-child {
    padding-bottom: 40px;
}

.section h2 {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-secondary);
    margin-bottom: 20px;
}

.section p {
    margin-bottom: 20px;
}

.section p:last-child {
    margin-bottom: 0;
}

/* ---------- Hero ---------- */

.hero {
    padding-bottom: 64px;
}

.lead {
    font-size: 2.1rem;
    font-weight: 700;
    letter-spacing: -0.035em;
    line-height: 1.15;
    margin-bottom: 40px;
}

/* ---------- Coda ---------- */

.coda p:first-child {
    font-size: 1.05rem;
    letter-spacing: -0.01em;
}

.coda p:first-child a {
    color: var(--color-accent);
    border-bottom-color: var(--color-accent);
}

.coda p:first-child a:hover {
    color: var(--color-accent-hover);
    border-bottom-color: var(--color-accent-hover);
}

.fine-print {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    margin-top: 16px;
}

.fine-print a {
    color: var(--color-text-secondary);
}

.fine-print a:hover {
    color: var(--color-link-hover);
}

/* ---------- Links ---------- */

a {
    color: var(--color-link);
    text-decoration: none;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 1px;
    transition: color 0.2s ease, border-color 0.2s ease;
}

a:hover {
    color: var(--color-link-hover);
    border-bottom-color: var(--color-link-hover);
}

.link-sep {
    margin: 0 8px;
    color: var(--color-text-secondary);
}


/* ---------- Case Study Cards ---------- */

.case-study-card {
    border-radius: 0;
    margin-bottom: 0;
    background: transparent;
    border: none;
    border-left: 2px solid var(--color-border);
    padding-left: 24px;
    margin-left: 2px;
    transition: border-color 0.2s ease;
}

.case-study-card + .case-study-card {
    margin-top: 20px;
}

.case-study-card:last-of-type {
    margin-bottom: 0;
}

.case-study-card:hover {
    border-left-color: var(--color-accent);
}

.case-study-card[open] {
    border-left-color: var(--color-accent);
}

.case-study-card summary {
    cursor: pointer;
    padding: 8px 0;
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 4px;
    border-bottom: none;
    -webkit-user-select: none;
    user-select: none;
    position: relative;
}

.case-study-card summary::-webkit-details-marker { display: none; }
.case-study-card summary::marker { content: ""; }

.case-study-card summary::after {
    content: "+";
    position: absolute;
    right: 0;
    top: 12px;
    font-size: 1.1rem;
    font-weight: 300;
    color: var(--color-text-secondary);
    transition: color 0.2s ease;
    line-height: 1;
}

.case-study-card:hover summary::after {
    color: var(--color-accent);
}

.case-study-card[open] summary::after {
    content: "\2212";
    color: var(--color-accent);
}

.card-title {
    font-size: 1.05rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    color: var(--color-text);
    padding-right: 36px;
}

.card-subtitle {
    font-size: 0.88rem;
    color: var(--color-text-secondary);
    padding-right: 36px;
    line-height: 1.5;
    letter-spacing: 0;
}

.card-body {
    padding: 12px 0 8px;
}

.card-body p {
    margin-bottom: 14px;
    font-size: 0.94rem;
    line-height: 1.55;
    color: var(--color-text);
}

.card-body p:last-child {
    margin-bottom: 0;
}

.card-body .result {
    font-weight: 500;
    color: var(--color-accent);
    margin-top: 20px;
    padding-top: 16px;
    border-top: 1px solid var(--color-result-border);
}

/* ---------- Footer ---------- */

footer {
    padding-top: 24px;
    padding-bottom: 32px;
    border-top: 1px solid var(--color-border);
    margin-top: auto;
}

footer p {
    font-size: 0.8rem;
    color: var(--color-text-secondary);
    letter-spacing: 0;
}

/* ---------- Responsive ---------- */

@media (max-width: 640px) {
    :root {
        --container-padding: 20px;
    }

    header {
        padding-top: 48px;
    }

    h1 {
        font-size: 1rem;
    }

    .lead {
        font-size: 1.9rem;
    }

    main {
        padding-top: 36px;
    }

    .hero {
        padding-bottom: 48px;
    }

    .section {
        padding-bottom: 44px;
    }

    .case-study-card {
        padding-left: 20px;
    }

    .case-study-card summary::after {
        right: 0;
    }
}

@media (max-width: 380px) {
    :root {
        --container-padding: 16px;
    }

    h1 {
        font-size: 0.9rem;
    }

    .lead {
        font-size: 1.8rem;
    }
}

/* ---------- Print ---------- */

@media print {
    .theme-toggle,
    .skip-link {
        display: none !important;
    }

    body {
        background: white;
        color: black;
    }

    a {
        border-bottom: none;
        text-decoration: underline;
    }

    main a::after {
        content: " (" attr(href) ")";
        font-size: 0.85rem;
        color: #666;
    }

    .case-study-card {
        border-left: 2px solid #999;
    }

    details {
        display: block;
    }

    details[open],
    details:not([open]) {
        display: block;
    }

    details > summary {
        display: block;
        pointer-events: none;
    }

    details > summary::after {
        display: none !important;
    }

    details > .card-body {
        display: block !important;
    }
}