/* course.css — one stylesheet for tayweid.github.io and every course site.
   No external requests: fonts are self-hosted in ./fonts, icons are inline SVG.

   Sections: tokens · fonts · base · layout · nav · type · cards/carousel ·
             course home (0150) · projects (0150) · icons · mobile */

/* ---------- tokens ---------- */

:root {
    --bg: #212121;
    --bg-hover: #181818;
    --fg: #C8C8C8;
    --mid: #333333;
    --rule: #444;
    --white: #fff;
    --cool-white: #D1D1D1;
    --link: #4C72B0;
    --blue: #4284F2;

    --column: 860px;   /* card width; the content column and arrows follow it */

    --font-serif: "CMU Serif", "Computer Modern Serif", Georgia, serif;
    --font-sans: "Source Sans 3", "Source Sans Pro", system-ui, sans-serif;
    --font-heading: var(--font-serif);
    --font-body: var(--font-sans);

    /* legacy names, still used by inline styles in generated pages */
    --main-bg-color: var(--bg);
    --main-fg-color: var(--fg);
    --main-md-color: var(--mid);
    --main-link-color: var(--link);
    --main-cool-white: var(--cool-white);
    --main-cool-blue: var(--blue);
}

/* ---------- fonts ---------- */

@font-face { font-family: "CMU Serif"; src: url("fonts/CMUSerif-Roman.woff2") format("woff2"); font-weight: 400; font-style: normal; font-display: swap; }
@font-face { font-family: "CMU Serif"; src: url("fonts/CMUSerif-Bold.woff2") format("woff2"); font-weight: 700; font-style: normal; font-display: swap; }
@font-face { font-family: "CMU Serif"; src: url("fonts/CMUSerif-Italic.woff2") format("woff2"); font-weight: 400; font-style: italic; font-display: swap; }
@font-face { font-family: "Source Sans 3"; src: url("fonts/SourceSans3-Light.woff2") format("woff2"); font-weight: 300; font-style: normal; font-display: swap; }
@font-face { font-family: "Source Sans 3"; src: url("fonts/SourceSans3-Semibold.woff2") format("woff2"); font-weight: 600; font-style: normal; font-display: swap; }
@font-face { font-family: "Source Sans 3"; src: url("fonts/SourceSans3-LightItalic.woff2") format("woff2"); font-weight: 300; font-style: italic; font-display: swap; }

/* ---------- base ---------- */

* { box-sizing: border-box; }

body {
    margin: 0;
    padding: 0;
    background: var(--bg);
    color: var(--fg);
    font-family: var(--font-body);
    font-weight: 300;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a { color: var(--link); text-decoration: none; }

hr { border: 0; border-top: 1px solid var(--fg); }

p {
    font-size: clamp(16px, 2vw, 20px);
    line-height: 1.4;
    transition: color 0.3s ease;
}
p:hover { color: var(--white); }

h1, h2, h3, h4, h5, h6 { font-family: var(--font-heading); font-weight: 400; }
h3, h4 { color: var(--fg); }

/* ---------- layout: left nav · content · (optional) right nav ---------- */

.wrapper {
    width: 100%;
    max-width: 1420px;
    margin: 0 auto;
    display: flex;
    gap: 10px;
    min-height: 100vh;
}

.left_div { width: 150px; flex-shrink: 0; margin-left: 20px; }
.course-econ-0150 .left_div { width: 200px; }
.right_div { width: 200px; flex-shrink: 0; }

.left_div > nav { position: sticky; top: 50px; text-align: right; }
.right_div > nav { position: sticky; top: 50px; text-align: left; }

.content { flex: 1; min-width: 0; max-width: calc(var(--column) + 30px); margin: 0 auto; padding: 50px 15px; }
.content > div { margin: 0 0 40px 0; max-width: 100%; }

/* ---------- nav ---------- */

nav ul { list-style: none; padding: 0; margin: 0; overflow: hidden; }

/* nameplate: <span>MICRO</span><span>-ECON</span>, or <a class="brand">…</a> lines */
nav ul > span,
nav ul > a.brand {
    display: block;
    margin: 5% 0 2%;
    font-family: var(--font-heading);
    font-size: 36px;
    line-height: 0.8;
    color: var(--white);
}
nav ul > span + span,
nav ul > a.brand + a.brand { margin-top: 0; }

nav li a {
    display: block;
    padding: 4px;
    color: var(--fg);
    font-family: var(--font-heading);
    font-size: 20px;
}
nav li a:hover { color: var(--cool-white); }
nav li a.active { color: var(--blue); }
.right_div .active { font-size: 18px; }
.nav-link-right { font-size: 18px; }

.nav-hr { width: 40%; margin: 20px 0 10px auto; }
.nav-hr-top { width: 40%; margin: 10px 0 10px auto; }
.nav-hr-right { width: 40%; margin: 20px 0 10px 0; }
.nav-item-no-margin { margin: 0; }

/* right-nav scroll indicator (built by course.js) */
.right_div ul { position: relative; overflow: visible; }
.scroll-indicator {
    position: absolute;
    left: -8px;
    width: 3px;
    background: var(--blue);
    border-radius: 2px;
    transition: top 0.3s ease, height 0.3s ease;
    pointer-events: none;
}

/* ---------- type ---------- */


.title {
    font-size: clamp(32px, 4vw, 40px);
    margin: 0 0 2%;
    color: var(--white);
}
.title.title-tight { margin-bottom: 0; line-height: 1.1; }

.subtitle-text {
    display: block;
    font-family: var(--font-heading);
    font-size: 20px;
    margin: -4px 0 0;   /* tucked under the title */
}
.title-rule { width: 48px; margin: 16px 0 26px; border-top: 1px solid var(--fg); }

.subtitle {
    font-size: clamp(22px, 2.8vw, 28px);
    margin: 5px 0 0;
    color: var(--white);
}
.subtitle + p { margin-top: 5px; }

.block-description {
    margin: 10px 0 20px;
    font-size: clamp(16px, 2vw, 20px);
    line-height: 1.4;
}

.btn { border: none; cursor: pointer; font-size: 26px; color: var(--fg); font-family: var(--font-heading); }
.btn:hover { color: var(--blue); }

.section-divider { border: none; border-top: 1px solid var(--rule); margin: 0.7em 0; }
.section-heading { margin: 0.5em 0 0.3em; font-size: 1.3em; }
.bottom-spacer { margin-bottom: 50%; }

.hr-with-text { display: flex; align-items: center; gap: 12px; }
.hr-with-text .section-divider { flex: 1; margin: 0; }
.hr-with-text .btn { white-space: nowrap; }

/* ---------- carousel ---------- */

.carousel-container { position: relative; margin: 0; max-width: 100%; }

.carousel { position: relative; display: flex; align-items: center; border-radius: 15px; min-width: 0; }

.carousel-track {
    flex: 1;
    min-width: 0;
    display: flex;
    align-items: flex-start;
    gap: 40px;
    padding: 15px calc(50% - min(var(--column) / 2, 45vw));
    overflow-x: auto;
    scroll-behavior: smooth;
    scroll-snap-type: x mandatory;
    scroll-snap-stop: always;
    scrollbar-width: none;
}
.carousel-track::-webkit-scrollbar { display: none; }

.carousel-card {
    flex: 0 0 auto;
    width: var(--column);
    max-width: 100%;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    border: 1px solid var(--mid);
    border-radius: 15px;
    background: var(--bg);
    cursor: pointer;
    scroll-snap-align: center;
    scroll-snap-stop: always;
    transition: background-color 0.3s ease;
}
.carousel-card:hover { background: var(--bg-hover); }

.carousel-card.livestream-card { opacity: 0.7; }
.carousel-card.livestream-card:hover { opacity: 1; }

.carousel-card.placeholder { opacity: 0.3; cursor: default; pointer-events: none; }
.carousel-card.placeholder:hover { background: var(--bg); }

.carousel-card.standalone-card { margin: 20px auto; cursor: default; }

.card-video {
    position: relative;
    height: 0;
    padding-bottom: 56%;
    overflow: hidden;
    border-radius: 13px 13px 0 0;
    background: var(--mid);
    cursor: pointer;
}
.card-video img {
    position: absolute; inset: 0;
    width: 100%; height: 100%;
    object-fit: cover;
}
img.placeholder-bg { display: none; }
.card-video:has(img.placeholder-bg)::after {
    content: "Video not yet available";
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    color: var(--white);
    font-size: 20px;
    font-weight: 600;
    white-space: nowrap;
}

.play-button {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    width: 60px; height: 60px;
    display: flex; align-items: center; justify-content: center;
    border-radius: 50%;
    background: rgba(0, 0, 0, 0.7);
    color: var(--white);
    font-size: 24px;
    pointer-events: none;
    transition: background 0.3s ease, transform 0.2s ease;
}
.card-video:hover .play-button { background: rgba(0, 0, 0, 0.9); transform: translate(-50%, -50%) scale(1.1); }

.card-content { flex-grow: 1; display: flex; flex-direction: column; padding: 20px; }

.card-title {
    margin: 0 0 5px;
    font-size: clamp(16px, 2vw, 20px);
    line-height: 1.2;
    color: var(--white);
}
.chapter-topic { color: var(--fg); }

.card-description {
    flex-grow: 1;
    margin: 0;
    font-size: clamp(14px, 1.8vw, 18px);
    line-height: 1.4;
    font-style: italic;
    color: var(--fg);
}

.card-downloads {
    display: flex; flex-wrap: wrap; align-items: center;
    gap: 12px;
    min-height: 40px;
    margin-top: 10px; padding-top: 10px;
    border-top: 1px solid var(--mid);
}

.download-link, .practice-link {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 3px 8px;
    border-radius: 4px;
    background: var(--mid);
    color: var(--fg);
    font-family: var(--font-body);
    font-size: 14px;
    transition: background 0.2s ease, color 0.2s ease;
}
.practice-link { margin-right: 8px; }
.download-link:hover, .practice-link:hover { background: var(--link); color: var(--white); }

/* arrows */
.carousel-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    z-index: 10;
    width: 50px; height: 50px;
    display: flex; align-items: center; justify-content: center;
    border: none; border-radius: 50%;
    background: rgba(0, 0, 0, 0.5);
    color: var(--white);
    font-size: 24px;
    cursor: pointer;
    transition: background 0.3s ease;
}
.carousel-arrow:hover { background: rgba(0, 0, 0, 0.7); }
.carousel-arrow-left { left: calc(50% - var(--column) / 2 + 20px); }
.carousel-arrow-right { right: calc(50% - var(--column) / 2 + 20px); }

/* indicator dots (built by course.js) */
.carousel-indicator {
    position: absolute;
    top: 35px; left: 50%;
    transform: translateX(-50%);
    z-index: 20;
    display: flex; justify-content: center;
    pointer-events: none;
}
.indicator-track {
    display: flex; align-items: center;
    gap: 20px;
    padding: 4px 14px;
    border-radius: 20px;
    background: rgba(0, 0, 0, 0.85);
    pointer-events: auto;
    transition: background 0.3s ease;
}
.indicator-track:hover { background: rgba(0, 0, 0, 0.95); }

.indicator-tab {
    position: relative;
    height: 30px;
    display: flex; align-items: center; justify-content: center;
    padding: 0; border: none; background: transparent;
    cursor: pointer;
    transition: all 0.3s ease;
}
.indicator-tab::before {
    content: "";
    display: block;
    width: 12px; height: 12px;
    border: 2px solid rgba(255, 255, 255, 0.5);
    border-radius: 50%;
    transition: all 0.3s ease;
}
.indicator-tab:hover::before { border-color: rgba(255, 255, 255, 0.7); }
.indicator-tab.active::before {
    width: 32px;
    border-radius: 6px;
    background: rgba(66, 132, 242, 0.7);
}
/* exercise: short connector to the previous dot */
.indicator-tab.exercise-indicator::after {
    content: "";
    position: absolute;
    right: 100%; top: 50%;
    width: 12px; height: 1px;
    margin-right: 4px;
    background: rgba(255, 255, 255, 0.5);
    transform: translateY(-50%);
}
/* homework: vertical separator before it */
.indicator-tab + .indicator-tab.homework-indicator::after {
    content: "";
    position: absolute;
    right: 100%; top: 50%;
    width: 2px; height: 18px;
    margin-right: 9px;
    background: rgba(255, 255, 255, 0.5);
    transform: translateY(-50%);
}
/* livestream: hidden camera glyph, revealed when active */
.indicator-tab.livestream-indicator { width: 0; opacity: 0; overflow: hidden; margin-right: -20px; }
.indicator-tab.livestream-indicator.revealed { width: auto; opacity: 1; margin-right: 0; }
.indicator-tab.livestream-indicator::before {
    width: 14px; height: 14px;
    border: none; border-radius: 0;
    background: rgba(255, 255, 255, 0.5);
    -webkit-mask: var(--icon-video) center / contain no-repeat;
    mask: var(--icon-video) center / contain no-repeat;
}
.indicator-tab.livestream-indicator.active::before { background: var(--blue); }


/* ---------- block path: episode left, three practice steps right ---------- */

.block { margin-bottom: 40px; }

.path {
    display: flex;
    border: 1px solid var(--mid);
    border-radius: 15px;
    background: var(--bg);
    overflow: hidden;
}

.path-episode {
    width: 470px;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    padding-bottom: 12px;
    border-right: 1px solid var(--mid);
}
.path-episode .card-video { border-radius: 0; }
.path-episode .card-video:has(img.placeholder-bg) { padding-bottom: 56%; }
.path-episode > .path-name { margin: 10px 16px 0; }
.path-episode > .path-links { margin: 8px 16px 0; }

.path-name {
    margin: 0;
    font-family: var(--font-heading);
    font-size: 19px;
    line-height: 1.3;
    color: var(--white);
}
.path-desc { font-family: var(--font-body); font-size: 16px; font-style: italic; color: var(--fg); }
.path-where {
    margin-left: 6px;
    font-family: var(--font-body);
    font-size: 13px;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: #8a8a8a;
}
.path-due { margin: 0; font-size: 14px; font-style: italic; color: #8a8a8a; }
.path-sub { margin: 0; font-size: 16px; font-style: italic; }                    /* a step's own title (0150 exercises) */
.path-brief { margin: 8px 0 0; padding-left: 1.3em; font-size: 16px; line-height: 1.45; }   /* project deliverables */
.path-brief li { margin: 6px 0; }

/* a text-only face (no video): the final project's prompts */
.path-text { padding: 18px 20px 16px; gap: 10px; }
.path-text .project-detail { margin: 0; padding: 0; font-size: 16px; line-height: 1.4; }
.path-text .project-detail .project-label { display: block; margin: 0; font-family: var(--font-heading); font-weight: 400; font-size: 18px; color: var(--white); }
.path-text .project-detail i { color: var(--fg); }
.path-text > .path-links { margin: 8px 0 0; }
/* project rail: a single node; the line drops straight in and stops there */
.path-project { justify-content: center; padding-top: 16px; }
.path-project .path-step-checkpoint { margin-top: 0; }
.path-project .path-links { margin-top: 12px; }
.path-project .path-step:first-child::after { display: none; }
.path-project .path-step:first-child::before { border-right: 0; }   /* one line, not two */
.path-project .path-step-checkpoint::before { left: 5px; width: 0; top: -600px; height: 622px; border-top: 0; border-radius: 0; }
.path-links { display: flex; flex-wrap: wrap; gap: 8px; }

.path-steps {
    flex: 1;
    min-width: 0;
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    margin: 0;
    padding: 100px 20px 16px 28px;
    list-style: none;
}
.path-step {
    position: relative;
    display: flex;
    gap: 14px;
    align-items: flex-start;
    padding: 9px 0;
}
/* dashed rail: drops in from the top, bends into the episode, comes back out below
   it, and runs down through the steps and off the bottom — one line, card to card */
.path-steps::before {
    content: "";
    position: absolute;
    left: 0;
    width: 33px;
    top: -10px;
    height: 56px;
    border-right: 2px dashed rgba(255, 255, 255, 0.28);
    border-bottom: 2px dashed rgba(255, 255, 255, 0.28);
    border-bottom-right-radius: 16px;
}
.path-steps::after {
    content: "";
    position: absolute;
    left: 0;
    width: 33px;
    top: 82px;
    bottom: 0;
    border-top: 2px dashed rgba(255, 255, 255, 0.28);
    border-right: 2px dashed rgba(255, 255, 255, 0.28);
    border-top-right-radius: 16px;
}
.path-step > div { display: flex; flex-direction: column; gap: 5px; flex: 1; min-width: 0; }
.path-dot {
    position: relative;
    z-index: 1;
    flex-shrink: 0;
    width: 12px;
    height: 12px;
    margin-top: 7px;
    border-radius: 50%;
    border: 2px solid rgba(255, 255, 255, 0.55);
    background: var(--bg);
}
/* checkpoint: rail enters to the Demo node, swings into the video, swings back out
   to a big solid Checkpoint node, and hangs the optional Reattempt below it */
/* the first block of a part has nothing above it: no drop-in, the line starts at the episode */
.description + .block .path-steps::before { display: none; }
.description + .block .path-steps::after { top: 28px; }
.description + .block .path-steps { padding-top: 46px; }
.path-checkpoint::before, .path-checkpoint::after { display: none; }
.path-checkpoint { padding-top: 40px; }
.path-checkpoint .path-step:first-child::before {                             /* straight drop from the top to the Demo dot */
    content: "";
    position: absolute;
    left: 5px;
    top: -600px;
    height: 622px;
    border-left: 2px dashed rgba(255, 255, 255, 0.28);
}
.path-checkpoint .path-step:first-child::after {                              /* past the Demo dot, then bends into the video */
    content: "";
    position: absolute;
    left: -28px;
    width: 33px;
    top: 22px;
    height: 30px;
    border-right: 2px dashed rgba(255, 255, 255, 0.28);
    border-bottom: 2px dashed rgba(255, 255, 255, 0.28);
    border-bottom-right-radius: 16px;
}
.path-step-checkpoint, .path-checkpoint .path-step-bend { margin-top: 56px; }
.path-step-checkpoint::before, .path-step-bend::before {                     /* out of the video → down to the next dot */
    content: "";
    position: absolute;
    left: -28px;
    width: 33px;
    top: -30px;
    height: 52px;
    border-top: 2px dashed rgba(255, 255, 255, 0.28);
    border-right: 2px dashed rgba(255, 255, 255, 0.28);
    border-top-right-radius: 16px;
}
/* checkpoint preceded by extra demos: the extra carries the line down to the next dot */
.path-checkpoint .path-step-cont { margin-top: 0; }
.path-step-cont::before { display: none; }
.path-checkpoint .path-step-bend::after, .path-checkpoint .path-step-extra::after {
    content: "";
    position: absolute;
    left: 5px;
    top: 22px;
    bottom: -22px;
    border-left: 2px dashed rgba(255, 255, 255, 0.28);
}
.path-dot-big { width: 16px; height: 16px; margin: 5px -2px 0; border: none; background: rgba(255, 255, 255, 0.85); }
.path-step.current > .path-dot-big { background: var(--blue); }
.path-step-alt { margin-top: 8px; }
.path-steps:not(.path-checkpoint) .path-step-alt { margin-top: 0; }
.path-steps:not(.path-checkpoint) .path-step-alt::before { display: none; }
.path-step-alt::before {                                                      /* faint, sparse stub from the Checkpoint dot */
    content: "";
    position: absolute;
    left: 5px;
    width: 2px;
    top: -52px;
    height: 68px;
    background: repeating-linear-gradient(to bottom, rgba(255, 255, 255, 0.18) 0 4px, transparent 4px 12px);
}
/* an extra demo between the walkthrough and the Checkpoint rides the main rail, not the faint stub */
.path-checkpoint .path-step-bend::before {
    left: -28px;
    width: 33px;
    top: -30px;
    height: 52px;
    background: none;
    border-top: 2px dashed rgba(255, 255, 255, 0.28);
    border-right: 2px dashed rgba(255, 255, 255, 0.28);
    border-top-right-radius: 16px;
}
.path-dot-alt { border-style: dashed; border-color: rgba(255, 255, 255, 0.25); }
.path-step-alt .path-name { color: #8a8a8a; }
.path-step-alt .path-where { color: #666; }

/* optional extra on a block: sits on the drop-in segment above the episode bend,
   small thumbnail to the right of the text */
.path-step-extra {
    position: absolute;
    top: 4px;
    left: 28px;
    right: 20px;
    padding: 9px 0;
}
.description + .block:has(.path-step-extra) .path-steps::before { display: block; }   /* first block: keep the segment the node sits on */
.description + .block:has(.path-step-extra) .path-steps::after { top: 82px; }
.description + .block:has(.path-step-extra) .path-steps { padding-top: 100px; }

.path-thumb {
    flex-shrink: 0;
    width: 96px;
    height: 54px;
    margin-top: 2px;
    border-radius: 6px;
    overflow: hidden;
    background: var(--mid);
    opacity: 0.75;
    transition: opacity 0.2s ease;
}
.path-thumb:hover { opacity: 1; }
.path-thumb img { width: 100%; height: 100%; object-fit: cover; display: block; }

/* after the MiniExam: a faint stub down to the next part, half-clipped at the card's edge */
.path-step-next {
    position: absolute;
    left: 28px;
    bottom: -22px;
    padding: 9px 0;
    color: #8a8a8a;
}
.path-step-next .path-name { color: #8a8a8a; }
.path-step-next .path-dot { border-color: rgba(255, 255, 255, 0.3); }
.path-checkpoint .path-step-checkpoint::after {
    content: "";
    position: absolute;
    left: 5px;
    width: 2px;
    top: 22px;
    bottom: -600px;
    background: repeating-linear-gradient(to bottom, rgba(255, 255, 255, 0.18) 0 4px, transparent 4px 12px);
}

/* set by course.js from data-date: where the student is this week */
.path-step.past > .path-dot:first-child { background: rgba(255, 255, 255, 0.35); border-color: transparent; }
.path-step.current > .path-dot:first-child { background: rgba(66, 132, 242, 0.85); border-color: rgba(255, 255, 255, 0.6); }

/* ---------- course home (part boxes, 0150) ---------- */

.course-overview { margin-top: 1em; }
.course-part-link { display: block; margin-bottom: 0.5em; }

.course-part-box {
    margin: 3px 0;
    padding: 0.7em;
    border: 2px solid var(--mid);
    border-radius: 15px;
    background: var(--bg);
    cursor: pointer;
    transition: background-color 0.2s;
}
.course-part-box:hover { background: var(--bg-hover); }
.course-part-box .part-title { margin: 0; font-size: 26px; line-height: 1.1; color: var(--white); }
.course-part-box .part-description { margin: 0; font-size: 0.9em; font-style: italic; color: var(--fg); }

.course-links { display: flex; flex-wrap: wrap; align-items: center; gap: 0.5em; margin: 0.5em 0; font-size: 1.1em; }
.course-links .separator { color: var(--fg); }

.info-list { margin-top: 0.3em; padding-left: 1.2em; list-style: disc; }
.info-list li { margin-bottom: 0.3em; font-size: 0.95em; }
.info-columns { display: flex; gap: 2em; margin: 0.5em 0; }
.info-column { flex: 1; }

/* part-0 mini card hanging on the right of a part box */
.course-part-box:has(.part0-card-container) { position: relative; padding-right: 270px; min-height: 140px; }
.part0-card-container { position: absolute; top: -1px; right: -1px; bottom: -1px; width: 250px; }
.part0-card { height: 100%; }
.part0-card .card-video { height: 100%; padding-bottom: 0; border-radius: 0 13px 13px 0; }

/* ---------- projects (0150) ---------- */

.topic-toggle { cursor: pointer; }
.topic-cards.collapsed { display: none; }

.project-card {
    margin: 0.5em 0;
    padding: 1.2em;
    border: 2px solid var(--mid);
    border-radius: 15px;
    background: var(--bg);
    transition: background-color 0.2s;
}
.project-card:hover { background: var(--bg-hover); }
.project-card h2 { margin: 0 0 0.4em; font-size: 1.4em; color: var(--white); }
.project-card-highlighted { position: relative; margin-bottom: 0.5em !important; }
.project-card-highlighted::after {
    content: "";
    position: absolute;
    top: 10px; right: 12px;
    width: 18px; height: 18px;
    background: var(--blue);
    opacity: 0.7;
    -webkit-mask: var(--icon-star) center / contain no-repeat;
    mask: var(--icon-star) center / contain no-repeat;
}

.project-detail { margin: 0.2em 0; padding-left: 1.5em; line-height: 1.3; }
.project-detail i { color: var(--fg); }
.project-label { margin-right: 0.3em; font-weight: 600; }
.project-label.research { color: #4CAF50; }
.project-label.data { color: #2196F3; }
.project-label.methods { color: #FF9800; }
.project-label.finding { color: #E91E63; }


/* ---------- home page (tayweid.github.io) ---------- */

.home .content { max-width: calc(var(--column) + 30px); }

/* header: portrait left, everything else beside it */
#header { display: flex; gap: 28px; align-items: flex-start; margin-bottom: 36px; }
#portrait { flex: 0 0 220px; }
#portrait img { width: 100%; display: block; opacity: 0.9; border-radius: 12px; }
#biograph { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 8px; }
.name_text { margin: 0; font-family: var(--font-heading); font-size: 34px; line-height: 1.1; color: var(--white); }
.email { margin: 0; font-size: 18px; }
.bio { margin: 10px 0 0; font-size: 19px; line-height: 1.45; }

.home .section { margin: 0 0 36px; }
.home hr { margin: 0 0 22px; }
.home h2 { margin: 0; font-size: 32px; line-height: 1.1; color: var(--white); }
.home .lead { margin: 4px 0 14px; font-size: 19px; }

.cards { display: flex; flex-direction: column; gap: 6px; }
.card {
    padding: 14px 18px 16px;
    border: 1px solid var(--mid);
    border-radius: 15px;
    background: var(--bg);
    transition: background-color 0.2s;
}
.card:hover { background: var(--bg-hover); }
.card-head { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; }
.card-head .path-links { margin: 0; flex-shrink: 0; }
.card h3 { margin: 0; font-size: 24px; line-height: 1.25; color: var(--white); }
.card .subtitle-line { margin: 2px 0 0; font-size: 16px; color: #8a8a8a; }
.card p { margin: 6px 0 0; font-size: 18px; line-height: 1.45; }
.card .coauthors { font-size: 16px; font-style: italic; margin-left: 1.2em; }
.card .coauthors a { color: var(--fg); }
.card .coauthors a:hover { color: var(--white); }
.card .path-links { margin-top: 10px; }
.meta {
    margin-left: 8px;
    font-family: var(--font-body);
    font-size: 13px;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: #8a8a8a;
    white-space: nowrap;
}
.card-list { margin: 8px 0 0; padding-left: 18px; font-size: 18px; line-height: 1.5; }
.card-list li { margin: 4px 0; }
.card-list .meta { margin: 0 6px 0 4px; }
.card-list .download-link { vertical-align: 1px; }

/* project cards: text left, screenshot right (Images/projects/<name>.png) */
.card-shot { display: flex; gap: 20px; align-items: flex-start; }
.card-shot .card-text { flex: 1; min-width: 0; }
.card-shot .shot { flex: 0 0 220px; height: 132px; object-fit: cover; border-radius: 8px; background: var(--mid); opacity: 0.85; }
.card-shot .shot:not([src$=".png"]), .card-shot .shot[src=""] { display: none; }

.home .footer { margin-top: 60px; }
.home .footer hr { margin-bottom: 12px; }
.home .footer p { display: flex; align-items: center; justify-content: center; gap: 10px; margin: 0; font-size: 13px; color: #8a8a8a; }
.home .footer a { color: #8a8a8a; font-size: 16px; line-height: 1; }
.home .footer a:hover { color: var(--fg); }

@media (max-width: 768px) {
    #header { flex-direction: column; }
    #portrait { flex-basis: auto; width: 180px; }
    .card-shot { flex-direction: column; }
    .card-shot .shot { flex-basis: auto; width: 100%; height: auto; }
}

/* ---------- icons ---------- */
/* Keeps the <i class="fa fa-…"> markup; each glyph is an inline SVG mask. */

:root {
    --icon-file: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="black" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M14 3H6a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V9z"/><path d="M14 3v6h6"/></svg>');
    --icon-file-text: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="black" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M14 3H6a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V9z"/><path d="M14 3v6h6M8 13h8M8 17h8"/></svg>');
    --icon-file-code: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="black" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M14 3H6a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V9z"/><path d="M14 3v6h6M10 13l-2 2.5 2 2.5M14 13l2 2.5-2 2.5"/></svg>');
    --icon-file-slides: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="black" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M14 3H6a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V9z"/><path d="M14 3v6h6"/><rect x="8" y="12" width="8" height="6" rx="1"/></svg>');
    --icon-pencil: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="black" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M17 3a2.8 2.8 0 1 1 4 4L7.5 20.5 2 22l1.5-5.5z"/></svg>');
    --icon-external: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="black" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M18 13v6a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V8a2 2 0 0 1 2-2h6M15 3h6v6M10 14L21 3"/></svg>');
    --icon-desktop: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="black" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><rect x="2" y="3" width="20" height="14" rx="2"/><path d="M8 21h8M12 17v4"/></svg>');
    --icon-video: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="black" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><path d="M23 7l-7 5 7 5z"/><rect x="1" y="5" width="15" height="14" rx="2"/></svg>');
    --icon-github: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16" fill="black"><path d="M8 0C3.58 0 0 3.58 0 8c0 3.54 2.29 6.53 5.47 7.59.4.07.55-.17.55-.38 0-.19-.01-.82-.01-1.49-2.01.37-2.53-.49-2.69-.94-.09-.23-.48-.94-.82-1.13-.28-.15-.68-.52-.01-.53.63-.01 1.08.58 1.23.82.72 1.21 1.87.87 2.33.66.07-.52.28-.87.51-1.07-1.78-.2-3.64-.89-3.64-3.95 0-.87.31-1.59.82-2.15-.08-.2-.36-1.02.08-2.12 0 0 .67-.21 2.2.82.64-.18 1.32-.27 2-.27.68 0 1.36.09 2 .27 1.53-1.04 2.2-.82 2.2-.82.44 1.1.16 1.92.08 2.12.51.56.82 1.27.82 2.15 0 3.07-1.87 3.75-3.65 3.95.29.25.54.73.54 1.48 0 1.07-.01 1.93-.01 2.2 0 .21.15.46.55.38A8.013 8.013 0 0 0 16 8c0-4.42-3.58-8-8-8z"/></svg>');
    --icon-star: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="black"><path d="M12 2l3 6.6 7 .8-5.2 4.9 1.4 7L12 17.8 5.8 21.3l1.4-7L2 9.4l7-.8z"/></svg>');
}

i.fa {
    display: inline-block;
    width: 1em; height: 1em;
    vertical-align: -0.15em;
    background: currentColor;
    -webkit-mask: var(--icon-file) center / contain no-repeat;
    mask: var(--icon-file) center / contain no-repeat;
}
i.fa-file-pdf-o        { --icon-file: var(--icon-file-text); }
i.fa-file-text-o       { --icon-file: var(--icon-file-text); }
i.fa-file-code-o       { --icon-file: var(--icon-file-code); }
i.fa-file-powerpoint-o { --icon-file: var(--icon-file-slides); }
i.fa-pencil            { --icon-file: var(--icon-pencil); }
i.fa-external-link     { --icon-file: var(--icon-external); }
i.fa-desktop           { --icon-file: var(--icon-desktop); }
i.fa-video-camera      { --icon-file: var(--icon-video); }
i.fa-github            { --icon-file: var(--icon-github); }

/* ---------- responsive ---------- */

@media (max-width: 1000px) {
    .wrapper { max-width: 100%; padding: 0 20px; }
    .right_div { display: none; }
    .content { max-width: 610px; margin: 0 auto; padding: 50px 30px; }
    p:hover { color: var(--fg); }

    .carousel-arrow { display: none; }
    .carousel-card { width: 100%; }
    .carousel-track { padding: 15px 0; gap: 30px; }
    .card-content { padding: 15px; }
}

@media (max-width: 768px) {
    .info-columns { flex-direction: column; gap: 1em; }
    .path { flex-direction: column; }
    .path-episode { width: 100%; border-right: 0; border-bottom: 1px solid var(--mid); }
    .path-steps { padding: 10px 20px 10px 28px; }
    .path-steps::before { display: none; }
    .path-steps::after { top: 0; border-top: 0; border-radius: 0; }
}

@media (max-width: 650px) {
    .wrapper { padding: 0 10px; justify-content: center; }
    .left_div { display: none; }
    .content { max-width: 100%; padding: 20px 10px; }

    .course-part-box:has(.part0-card-container) { padding-right: 0.7em; padding-top: 120px; }
    .part0-card-container { top: 0; right: 0; bottom: auto; left: 0; width: auto; height: 120px; }
    .part0-card .card-video { border-radius: 13px 13px 0 0; }

    /* bottom pill nav (built by course.js) */
    .mobile-nav-bar {
        position: fixed;
        bottom: 24px; left: 50%;
        transform: translateX(-50%);
        z-index: 1000;
        display: flex; align-items: center;
        border-radius: 50px;
        background: rgba(60, 60, 60, 0.9);
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
    }
    .mobile-nav-bar a {
        display: flex; align-items: center; justify-content: center;
        padding: 10px 16px;
        color: rgba(255, 255, 255, 0.7);
        font-family: var(--font-heading);
        font-size: 24px;
        transition: color 0.2s ease;
    }
    .mobile-nav-bar a:hover { color: var(--white); }
    .mobile-nav-bar a.disabled { opacity: 0.3; pointer-events: none; }
    .mobile-nav-label { display: flex; align-items: center; padding: 10px 18px; color: rgba(255, 255, 255, 0.9); font-family: var(--font-heading); font-size: 18px; white-space: nowrap; }
    .mobile-nav-divider { width: 1px; height: 18px; background: rgba(255, 255, 255, 0.25); }
}

@media (min-width: 651px) {
    .mobile-nav-bar { display: none; }
}