/* ================================================================
   UX PSYCHOLOGY — Gestalt Principles & Cognitive Laws (White Mode)
   ================================================================ */

/* ---------- Custom Properties ---------- */
:root {
    --font-heading: 'Space Grotesk', system-ui, sans-serif;
    --font-body: 'Inter', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

    --clr-bg: #f8f9fc;
    --clr-surface: #ffffff;
    --clr-text: #1a1a2e;
    --clr-text-muted: #475569;
    --clr-indigo: #6366f1;
    --clr-indigo-deep: #4338ca;
    --clr-sky: #0ea5e9;
    --clr-emerald: #10b981;
    --clr-amber: #f59e0b;
    --clr-red: #ef4444;
    --clr-pink: #ec4899;
    --clr-purple: #8b5cf6;
    --clr-border: rgba(0,0,0,0.08);
    --clr-border-strong: rgba(0,0,0,0.15);

    --slide-transition: 0.8s cubic-bezier(.4, 0, .15, 1);
    --bubble-bg: rgba(255,255,255,0.85);
    --bubble-border: rgba(0,0,0,0.08);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.1);
    --shadow-xl: 0 16px 48px rgba(0,0,0,0.12);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.hidden { display: none !important; }

html, body {
    height: 100%;
    overflow: hidden;
    font-family: var(--font-body);
    color: var(--clr-text);
    background: var(--clr-bg);
    -webkit-font-smoothing: antialiased;
}

/* ---------- Presentation Container ---------- */
.presentation {
    position: relative;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
}

/* ---------- Progress Bar ---------- */
.progress-bar {
    position: fixed;
    top: 0; left: 0;
    width: 100%;
    height: 3px;
    background: rgba(0,0,0,0.04);
    z-index: 100;
}
.progress-fill {
    height: 100%;
    width: 8.33%;
    background: linear-gradient(90deg, var(--clr-indigo), var(--clr-sky));
    transition: width 0.7s cubic-bezier(.4,0,.2,1);
    border-radius: 0 2px 2px 0;
    box-shadow: 0 0 12px rgba(99,102,241,0.3);
}

/* ---------- Slides Base ---------- */
.slide {
    position: absolute;
    inset: 0 0 90px 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--slide-transition), transform var(--slide-transition), filter var(--slide-transition);
    transform: translateX(60px) scale(0.98);
    filter: blur(4px);
    z-index: 1;
}
.slide.active {
    opacity: 1;
    pointer-events: auto;
    transform: translateX(0) scale(1);
    filter: blur(0);
    z-index: 10;
}
.slide.exit-left {
    opacity: 0;
    transform: translateX(-60px) scale(0.98);
    filter: blur(4px);
}
.slide.exit-right {
    opacity: 0;
    transform: translateX(60px) scale(0.98);
    filter: blur(4px);
}

.slide-content {
    width: 100%;
    height: 100%;
    padding: 48px 5vw 20px;
    display: flex;
    flex-direction: column;
    position: relative;
    z-index: 2;
    overflow: hidden;
}

/* ---------- Slide Tag / Label ---------- */
.slide-tag {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--clr-indigo);
    background: rgba(99,102,241,0.08);
    border: 1px solid rgba(99,102,241,0.2);
    border-radius: 20px;
    padding: 5px 16px;
    margin-bottom: 14px;
    width: fit-content;
}

/* ---------- Navigation ---------- */
.slide-nav {
    position: fixed;
    bottom: 28px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 12px;
    z-index: 200;
    background: rgba(255,255,255,0.8);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border: 1px solid var(--clr-border);
    border-radius: 50px;
    padding: 8px 12px;
    box-shadow: var(--shadow-lg);
}

.nav-arrow {
    width: 38px;
    height: 38px;
    border-radius: 50%;
    border: 1.5px solid var(--clr-border-strong);
    background: var(--clr-surface);
    color: var(--clr-text);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s cubic-bezier(.4,0,.2,1);
    flex-shrink: 0;
}
.nav-arrow svg { width: 18px; height: 18px; }
.nav-arrow:hover {
    background: rgba(99,102,241,0.1);
    border-color: var(--clr-indigo);
    transform: scale(1.12);
    box-shadow: 0 0 16px rgba(99,102,241,0.2);
}
.nav-arrow:active { transform: scale(0.92); }
.nav-arrow.disabled { opacity: 0.25; pointer-events: none; }

.slide-dots { display: flex; gap: 6px; }
.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    border: 1.5px solid rgba(0,0,0,0.15);
    background: transparent;
    cursor: pointer;
    transition: all 0.4s cubic-bezier(.4,0,.2,1);
    position: relative;
}
.dot.active {
    background: var(--clr-indigo);
    border-color: var(--clr-indigo);
    width: 24px;
    border-radius: 10px;
    box-shadow: 0 0 12px rgba(99,102,241,0.4);
}
.dot:hover { border-color: var(--clr-sky); }

.dot-tooltip {
    position: absolute;
    bottom: calc(100% + 10px);
    left: 50%;
    transform: translateX(-50%) translateY(4px);
    background: var(--clr-text);
    color: white;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    padding: 4px 10px;
    border-radius: 6px;
    white-space: nowrap;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.25s, transform 0.25s;
}
.dot:hover .dot-tooltip { opacity: 1; transform: translateX(-50%) translateY(0); }

.slide-counter {
    position: fixed;
    bottom: 32px;
    right: 30px;
    font-size: 0.82rem;
    color: var(--clr-text-muted);
    font-family: var(--font-mono);
    z-index: 200;
    letter-spacing: 1px;
}

/* ---------- Animation Primitives ---------- */
.anim {
    opacity: 0;
    transition: opacity 0.8s ease, transform 0.8s cubic-bezier(.4,0,.2,1);
}
.slide.active .anim { opacity: 1; transform: none; }

.anim-fade-down  { transform: translateY(-35px); }
.anim-fade-up    { transform: translateY(35px); }
.anim-fade-left  { transform: translateX(-45px); }
.anim-fade-right { transform: translateX(45px); }
.anim-pop        { transform: scale(0.4); }

/* ---------- Step Items ---------- */
.step-item {
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 0.5s ease, transform 0.5s cubic-bezier(.4,0,.2,1);
    pointer-events: none;
}
.step-item.step-visible {
    opacity: 1;
    transform: none;
    pointer-events: auto;
}

/* ---------- Owl Mascot ---------- */
.owl-wrap {
    display: inline-block;
    position: relative;
}
.owl-placeholder {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Owl character images */
.owl-img {
    width: 120px;
    height: auto;
    filter: drop-shadow(0 6px 20px rgba(99,102,241,0.25));
    animation: owlFloat 3.5s ease-in-out infinite, owlBreath 6s ease-in-out infinite;
    transform-origin: center bottom;
    transition: filter 0.4s ease;
}
.owl-img:hover {
    filter: drop-shadow(0 8px 28px rgba(99,102,241,0.4));
}

.owl-img-sm {
    width: 42px;
    height: 42px;
    object-fit: contain;
    flex-shrink: 0;
}

.owl-img-lg {
    width: 100px;
    height: auto;
    filter: drop-shadow(0 6px 20px rgba(99,102,241,0.25));
    transform-origin: center bottom;
    opacity: 0;
    transform: translateY(30px) scale(0.5);
    transition: none;
}
.slide.active .owl-img-lg {
    animation: owlCelebrate 0.9s cubic-bezier(.34,1.56,.64,1) forwards, owlFloat 3s ease-in-out 1s infinite, owlBreath 5s ease-in-out 1s infinite;
}

/* ---- Owl hover speech bubble (side-positioned) ---- */
.owl-bubble {
    position: absolute;
    top: 50%;
    left: calc(100% + 18px);
    transform: translateY(-50%) translateX(10px);
    width: 240px;
    background: #fff;
    border: 1.5px solid var(--clr-indigo);
    border-radius: 14px;
    padding: 14px 18px;
    box-shadow: 0 8px 32px rgba(99,102,241,0.15);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.35s ease, transform 0.35s ease, visibility 0.35s;
    z-index: 100;
    text-align: left;
}
.owl-bubble::after {
    content: '';
    position: absolute;
    top: 50%;
    right: 100%;
    transform: translateY(-50%);
    border: 8px solid transparent;
    border-right-color: var(--clr-indigo);
}
.owl-bubble p {
    font-size: 0.82rem;
    line-height: 1.6;
    margin: 0;
    color: var(--clr-text);
    font-family: var(--font-body);
}
.owl-wrap:hover .owl-bubble {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateY(-50%) translateX(0);
}

/* ---------- Key Diff Callout ---------- */
.key-diff {
    display: flex;
    align-items: center;
    gap: 12px;
    background: rgba(99,102,241,0.06);
    border: 1px solid rgba(99,102,241,0.18);
    border-left: 3px solid var(--clr-indigo);
    border-radius: 10px;
    padding: 12px 18px;
    margin-top: 12px;
    max-width: 680px;
    flex-shrink: 0;
}
.key-diff-wide {
    max-width: 100%;
    margin: 8px auto 0;
}
.kd-icon { font-size: 1.3rem; flex-shrink: 0; }
.kd-text {
    font-size: 0.85rem;
    line-height: 1.55;
    color: var(--clr-text-muted);
}
.kd-text strong { color: var(--clr-indigo); }
.kd-text em { color: var(--clr-sky); font-style: italic; }

/* ---------- Slide Sub/Def ---------- */
.slide-sub {
    font-size: 1rem;
    color: var(--clr-text-muted);
    line-height: 1.55;
}
.slide-sub em { color: var(--clr-indigo); font-style: italic; }
.slide-sub strong { color: var(--clr-text); }

.principle-def {
    font-size: 0.95rem;
    color: var(--clr-text-muted);
    line-height: 1.65;
    max-width: 480px;
}
.principle-def strong { color: var(--clr-text); }

.heading-amp {
    color: var(--clr-text-muted);
    font-weight: 400;
    margin: 0 0.15em;
}

/* ================================================================
   SLIDE 1 — Title
   ================================================================ */
.slide-title {
    background: linear-gradient(135deg, #f0f0ff 0%, #e8f4f8 40%, #faf5ff 100%);
}

.stitle-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    gap: 14px;
    text-align: center;
}

.stitle-heading {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.15;
    letter-spacing: -0.02em;
}
.stitle-line1 {
    display: block;
    font-size: clamp(2.2rem, 5vw, 3.8rem);
    background: linear-gradient(135deg, var(--clr-indigo), var(--clr-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.stitle-line2 {
    display: block;
    font-size: clamp(1rem, 2.2vw, 1.5rem);
    color: var(--clr-text-muted);
    -webkit-text-fill-color: var(--clr-text-muted);
    font-weight: 500;
    letter-spacing: 0;
    margin-top: 4px;
}

.stitle-sub {
    font-size: 1.05rem;
    color: var(--clr-text-muted);
    font-weight: 400;
}

.stitle-author {
    font-family: var(--font-heading);
    font-size: 1.15rem;
    font-weight: 500;
    color: var(--clr-text);
    letter-spacing: 0.5px;
}

.stitle-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--clr-indigo);
    text-decoration: none;
    font-family: var(--font-mono);
    font-size: 0.82rem;
    padding: 6px 16px;
    border-radius: 20px;
    border: 1px solid rgba(99,102,241,0.25);
    background: rgba(99,102,241,0.06);
    transition: all 0.3s ease;
}
.stitle-link:hover {
    background: rgba(99,102,241,0.12);
    border-color: rgba(99,102,241,0.45);
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(99,102,241,0.15);
}
.stitle-link svg { flex-shrink: 0; }

/* ================================================================
   SLIDE 2 — Gestalt Intro
   ================================================================ */
.slide-gestalt-intro {
    background: linear-gradient(160deg, #f8f9fc 0%, #f0f0ff 50%, #e8f4f8 100%);
}

.sintro-content {
    align-items: center;
    justify-content: center;
    gap: 24px;
    text-align: center;
}

.sintro-header {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}
.sintro-header h1 {
    font-family: var(--font-heading);
    font-size: clamp(1.6rem, 3.5vw, 2.6rem);
    font-weight: 700;
    line-height: 1.2;
    color: var(--clr-text);
}

.sintro-bigquote {
    max-width: 600px;
    margin: 0 auto;
    padding: 24px 32px;
    background: var(--clr-surface);
    border-radius: 16px;
    border: 1px solid var(--clr-border);
    box-shadow: var(--shadow-md);
    position: relative;
}
.bigquote-mark {
    position: absolute;
    top: -8px;
    left: 20px;
    font-size: 3rem;
    color: var(--clr-indigo);
    line-height: 1;
    font-family: Georgia, serif;
}
.sintro-bigquote p {
    font-size: 1.1rem;
    line-height: 1.7;
    color: var(--clr-text);
}
.sintro-bigquote strong {
    color: var(--clr-indigo);
    font-weight: 600;
}

.sintro-cards {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    justify-content: center;
    max-width: 800px;
}
.sintro-card {
    flex: 1;
    min-width: 200px;
    max-width: 240px;
    background: var(--clr-surface);
    border: 1px solid var(--clr-border);
    border-radius: 14px;
    padding: 20px 18px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.sintro-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}
.sintro-card-icon {
    font-size: 1.8rem;
    display: block;
    margin-bottom: 8px;
}
.sintro-card h3 {
    font-family: var(--font-heading);
    font-size: 0.92rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--clr-text);
}
.sintro-card p {
    font-size: 0.8rem;
    color: var(--clr-text-muted);
    line-height: 1.5;
}

/* ================================================================
   PRINCIPLE LAYOUTS
   ================================================================ */

/* Two-column layout: text left, demo right */
.principle-layout {
    flex-direction: row;
    align-items: center;
    gap: 40px;
    padding-top: 60px;
}
.principle-text {
    flex: 1;
    max-width: 420px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.principle-text h1 {
    font-family: var(--font-heading);
    font-size: clamp(1.8rem, 3vw, 2.8rem);
    font-weight: 700;
    color: var(--clr-text);
    line-height: 1.15;
}

.principle-quote {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    background: rgba(99,102,241,0.04);
    border-radius: 12px;
    padding: 12px 16px;
    margin-top: 4px;
}
.principle-quote p {
    font-size: 0.88rem;
    line-height: 1.55;
    color: var(--clr-text-muted);
    font-style: italic;
}

.principle-demo {
    flex: 1.2;
    display: flex;
    justify-content: center;
}

/* Stacked layout (dual/triple panels) */
.principle-layout-stacked {
    align-items: center;
    gap: 20px;
    padding-top: 48px;
}
.principle-header-wide {
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}
.principle-header-wide h1 {
    font-family: var(--font-heading);
    font-size: clamp(1.5rem, 3vw, 2.2rem);
    font-weight: 700;
    color: var(--clr-text);
}

/* Dual demo panels */
.dual-demo {
    display: flex;
    gap: 24px;
    width: 100%;
    max-width: 960px;
    margin: 0 auto;
    flex-wrap: wrap;
    justify-content: center;
}
.dual-panel {
    flex: 1;
    min-width: 380px;
    max-width: 460px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.dual-panel-header {
    display: flex;
    align-items: center;
    gap: 10px;
}
.dual-num {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--clr-indigo);
    background: rgba(99,102,241,0.08);
    border-radius: 8px;
    padding: 3px 10px;
    min-width: 36px;
    text-align: center;
}
.dual-panel-header h2 {
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--clr-text);
}
.dual-def {
    font-size: 0.82rem;
    color: var(--clr-text-muted);
    line-height: 1.55;
}
.dual-def strong { color: var(--clr-text); }

/* Triple demo panels */
.triple-demo {
    display: flex;
    gap: 18px;
    width: 100%;
    max-width: 960px;
    margin: 0 auto;
    flex-wrap: wrap;
    justify-content: center;
}
.triple-panel {
    flex: 1;
    min-width: 260px;
    max-width: 310px;
    background: var(--clr-surface);
    border: 1px solid var(--clr-border);
    border-radius: 14px;
    padding: 18px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    box-shadow: var(--shadow-sm);
}
.triple-header {
    display: flex;
    align-items: center;
    gap: 8px;
}
.triple-icon { font-size: 1.4rem; }
.triple-header h3 {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 600;
    color: var(--clr-text);
}
.triple-def {
    font-size: 0.78rem;
    color: var(--clr-text-muted);
    line-height: 1.5;
}
.triple-def strong { color: var(--clr-text); }

/* ================================================================
   APP WINDOW MOCKUP (Shared)
   ================================================================ */
.app-window {
    background: var(--clr-surface);
    border: 1px solid var(--clr-border);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 480px;
}
.app-window-sm { max-width: 100%; }

.window-titlebar {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    background: #f1f3f5;
    border-bottom: 1px solid var(--clr-border);
}
.window-dots {
    display: flex;
    gap: 6px;
}
.window-dots span {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}
.window-dots span:nth-child(1) { background: #ff5f57; }
.window-dots span:nth-child(2) { background: #febc2e; }
.window-dots span:nth-child(3) { background: #28c840; }

.window-title {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--clr-text-muted);
    letter-spacing: 0.5px;
}
.window-body {
    padding: 16px;
}

/* ================================================================
   SLIDE 3 — Proximity Demo
   ================================================================ */
.slide-proximity {
    background: linear-gradient(160deg, #f8f9fc 0%, #faf5ff 50%, #f0f0ff 100%);
}
.demo-proximity {
    display: flex;
    gap: 16px;
}
.demo-col {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.demo-label {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    padding: 3px 10px;
    border-radius: 6px;
    width: fit-content;
}
.demo-label-bad {
    color: var(--clr-red);
    background: rgba(239,68,68,0.08);
}
.demo-label-good {
    color: var(--clr-emerald);
    background: rgba(16,185,129,0.08);
}

.form-mock {
    display: flex;
    flex-direction: column;
}
.form-label {
    font-size: 0.75rem;
    color: var(--clr-text-muted);
    font-weight: 500;
}
.form-input {
    height: 28px;
    background: #f1f3f5;
    border: 1px solid var(--clr-border);
    border-radius: 6px;
}
.form-scattered .form-label { margin-top: 14px; }
.form-scattered .form-input { margin-top: 2px; }

.form-grouped .form-group {
    margin-bottom: 12px;
    padding: 10px;
    background: rgba(99,102,241,0.03);
    border: 1px dashed rgba(99,102,241,0.15);
    border-radius: 8px;
}
.form-group-label {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--clr-indigo);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 6px;
    font-weight: 600;
}
.form-grouped .form-label { margin-top: 6px; }
.form-grouped .form-input { margin-top: 2px; }

/* ================================================================
   SLIDE 4 — Similarity Demo
   ================================================================ */
.slide-similarity {
    background: linear-gradient(160deg, #f8f9fc 0%, #e8f4f8 50%, #f0f0ff 100%);
}
.demo-similarity {
    display: flex;
    flex-direction: column;
    gap: 12px;
}
.product-grid {
    display: flex;
    gap: 12px;
}
.product-card {
    flex: 1;
    background: var(--clr-bg);
    border: 1px solid var(--clr-border);
    border-radius: 10px;
    padding: 10px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}
.product-img {
    height: 50px;
    background: linear-gradient(135deg, #e0e7ff, #c7d2fe);
    border-radius: 6px;
}
.product-img.img-2 { background: linear-gradient(135deg, #ccfbf1, #99f6e4); }
.product-img.img-3 { background: linear-gradient(135deg, #fef3c7, #fde68a); }
.product-name { font-size: 0.78rem; font-weight: 600; color: var(--clr-text); }
.product-price { font-size: 0.72rem; color: var(--clr-text-muted); font-family: var(--font-mono); }
.product-actions { display: flex; gap: 6px; margin-top: auto; }

.btn-primary {
    flex: 1;
    padding: 5px 8px;
    font-size: 0.68rem;
    font-weight: 600;
    color: white;
    background: var(--clr-indigo);
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
}
.btn-primary:hover { background: var(--clr-indigo-deep); }
.btn-secondary {
    padding: 5px 8px;
    font-size: 0.68rem;
    color: var(--clr-text-muted);
    background: transparent;
    border: 1px solid var(--clr-border);
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
}
.btn-secondary:hover { border-color: var(--clr-indigo); color: var(--clr-indigo); }
.btn-danger {
    padding: 5px 8px;
    font-size: 0.68rem;
    color: white;
    background: var(--clr-red);
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
}
.btn-danger:hover { background: #dc2626; }

.similarity-annotation {
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding: 10px 12px;
    background: rgba(99,102,241,0.04);
    border-radius: 8px;
}
.anno-line {
    height: 3px;
    border-radius: 2px;
    width: 60%;
}
.anno-primary { background: var(--clr-indigo); }
.anno-danger { background: var(--clr-red); width: 40%; }
.anno-label {
    font-size: 0.7rem;
    font-family: var(--font-mono);
}
.anno-label-primary { color: var(--clr-indigo); }
.anno-label-danger { color: var(--clr-red); }

/* ================================================================
   SLIDE 5 — Continuity & Closure Demo
   ================================================================ */
.slide-cont-closure {
    background: linear-gradient(160deg, #f8f9fc 0%, #f0fff4 50%, #e8f4f8 100%);
}
.demo-continuity {
    display: flex;
    flex-direction: column;
    gap: 8px;
    overflow: hidden;
}
.scroll-cards {
    display: flex;
    gap: 10px;
    overflow: hidden;
}
.scroll-card {
    min-width: 80px;
    height: 90px;
    border-radius: 10px;
    flex-shrink: 0;
}
.sc-1 { background: linear-gradient(135deg, #c7d2fe, #a5b4fc); }
.sc-2 { background: linear-gradient(135deg, #99f6e4, #5eead4); }
.sc-3 { background: linear-gradient(135deg, #fde68a, #fbbf24); }
.sc-4 {
    background: linear-gradient(135deg, #fecaca, #fca5a5);
    /* Deliberately cut off */
    margin-right: -40px;
}
.scroll-hint {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.72rem;
    color: var(--clr-text-muted);
}
.scroll-arrow {
    color: var(--clr-indigo);
    font-size: 1.2rem;
    animation: arrowPulse 1.5s ease-in-out infinite;
}
@keyframes arrowPulse {
    0%, 100% { transform: translateX(0); opacity: 1; }
    50%      { transform: translateX(6px); opacity: 0.5; }
}

.demo-closure {
    display: flex;
    justify-content: center;
    padding: 12px 0;
}
.closure-examples {
    display: flex;
    gap: 16px;
    align-items: center;
}
.closure-shape {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}
.closure-svg { width: 60px; height: 60px; }
.closure-svg-wide { width: 75px; }
.closure-shape span {
    font-size: 0.68rem;
    color: var(--clr-text-muted);
    font-family: var(--font-mono);
    text-align: center;
}

/* ================================================================
   SLIDE 6 — Figure/Ground Demo
   ================================================================ */
.slide-figure-ground {
    background: linear-gradient(160deg, #f8f9fc 0%, #faf5ff 50%, #f0f0ff 100%);
}
.demo-figureground {
    position: relative;
    min-height: 240px;
    overflow: hidden;
    border-radius: 0 0 11px 11px;
    padding: 0;
}
.fg-ground {
    padding: 12px;
    transition: filter 0.5s ease;
}
.fg-overlay.step-visible ~ .fg-labels .fg-label-ground,
.fg-overlay.step-visible ~ .fg-labels .fg-label-figure { opacity: 1; }
.fg-navbar {
    display: flex;
    gap: 16px;
    padding: 8px 12px;
    background: #f1f3f5;
    border-radius: 8px;
    font-size: 0.72rem;
    color: var(--clr-text-muted);
    margin-bottom: 12px;
}
.fg-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}
.fg-card {
    height: 50px;
    background: #f1f3f5;
    border-radius: 8px;
    border: 1px solid var(--clr-border);
}
.fg-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(2px);
    -webkit-backdrop-filter: blur(2px);
    z-index: 5;
}
.fg-modal {
    background: var(--clr-surface);
    border-radius: 14px;
    padding: 24px;
    box-shadow: var(--shadow-xl);
    text-align: center;
    max-width: 260px;
    animation: modalBounce 0.4s cubic-bezier(.34,1.56,.64,1);
}
@keyframes modalBounce {
    0% { transform: scale(0.8); opacity: 0; }
    100% { transform: scale(1); opacity: 1; }
}
.fg-modal-title {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 6px;
}
.fg-modal-text {
    font-size: 0.8rem;
    color: var(--clr-text-muted);
    margin-bottom: 14px;
}
.fg-modal-actions {
    display: flex;
    gap: 10px;
    justify-content: center;
}
.fg-btn-confirm {
    padding: 8px 20px;
    background: var(--clr-indigo);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}
.fg-btn-confirm:hover { background: var(--clr-indigo-deep); }
.fg-btn-cancel {
    padding: 8px 20px;
    background: transparent;
    color: var(--clr-text-muted);
    border: 1px solid var(--clr-border);
    border-radius: 8px;
    font-size: 0.8rem;
    cursor: pointer;
    transition: all 0.2s;
}
.fg-btn-cancel:hover { border-color: var(--clr-red); color: var(--clr-red); }
.fg-labels {
    position: absolute;
    bottom: 6px;
    left: 12px;
    right: 12px;
    display: flex;
    justify-content: space-between;
    z-index: 10;
}
.fg-label-figure, .fg-label-ground {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    color: white;
    background: rgba(0,0,0,0.5);
    padding: 3px 8px;
    border-radius: 4px;
}

/* ================================================================
   SLIDE 7 — Common Fate Demo
   ================================================================ */
.slide-common-fate {
    background: linear-gradient(160deg, #f8f9fc 0%, #e8f4f8 50%, #f0fff4 100%);
}
.demo-commonfate {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.cf-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding: 10px;
    border-radius: 10px;
    transition: transform 0.5s cubic-bezier(.4,0,.2,1);
    position: relative;
}
.cf-group-a { background: rgba(99,102,241,0.05); border: 1px dashed rgba(99,102,241,0.2); }
.cf-group-b { background: rgba(245,158,11,0.05); border: 1px dashed rgba(245,158,11,0.2); }
.cf-item {
    font-size: 0.78rem;
    padding: 6px 10px;
    background: var(--clr-surface);
    border: 1px solid var(--clr-border);
    border-radius: 6px;
    transition: transform 0.5s cubic-bezier(.4,0,.2,1);
}
.cf-item-b { border-color: rgba(245,158,11,0.2); }
.cf-group-label {
    font-size: 0.68rem;
    font-family: var(--font-mono);
    color: var(--clr-text-muted);
    text-align: right;
    opacity: 0;
    transition: opacity 0.4s;
}
.cf-separator {
    height: 1px;
    background: var(--clr-border);
    margin: 4px 0;
}
.cf-trigger {
    align-self: center;
    padding: 8px 20px;
    background: var(--clr-indigo);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    font-family: var(--font-body);
}
.cf-trigger:hover { background: var(--clr-indigo-deep); transform: scale(1.05); }

/* Common Fate Animation */
.cf-group.cf-animate-a {
    animation: cfSlideRight 1s ease-in-out;
}
.cf-group.cf-animate-b {
    animation: cfSlideLeft 1s ease-in-out;
}
.cf-group.cf-animate-a .cf-group-label,
.cf-group.cf-animate-b .cf-group-label {
    opacity: 1;
}
@keyframes cfSlideRight {
    0%, 100% { transform: translateX(0); }
    50% { transform: translateX(20px); }
}
@keyframes cfSlideLeft {
    0%, 100% { transform: translateX(0); }
    50% { transform: translateX(-20px); }
}

/* ================================================================
   SLIDE 8 — Hick's & Fitts's Law Demo
   ================================================================ */
.slide-hick-fitts {
    background: linear-gradient(160deg, #f8f9fc 0%, #fef3c7 30%, #f0f0ff 100%);
}
.demo-hick {
    display: flex;
    gap: 12px;
}
.hick-side { flex: 1; }
.hick-label {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 600;
    margin-bottom: 8px;
}
.hick-items {
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
}
.hick-items span {
    padding: 4px 8px;
    background: #f1f3f5;
    border: 1px solid var(--clr-border);
    border-radius: 4px;
    font-size: 0.68rem;
    color: var(--clr-text-muted);
}
.hick-categories {
    display: flex;
    flex-direction: column;
    gap: 6px;
}
.hick-cat {
    padding: 6px 10px;
    background: rgba(99,102,241,0.04);
    border: 1px solid rgba(99,102,241,0.12);
    border-radius: 8px;
    font-size: 0.72rem;
}
.hick-cat strong {
    display: block;
    color: var(--clr-text);
    margin-bottom: 2px;
}
.hick-cat span { color: var(--clr-text-muted); }

.demo-fitts {
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.fitts-bad, .fitts-good { display: flex; flex-direction: column; gap: 6px; }
.fitts-label {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 600;
}
.fitts-area {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px;
    background: #f9fafb;
    border-radius: 8px;
    position: relative;
}
.fitts-cursor { font-size: 1.2rem; flex-shrink: 0; }
.fitts-distance-line {
    flex: 1;
    height: 2px;
    background: repeating-linear-gradient(90deg, var(--clr-red), var(--clr-red) 4px, transparent 4px, transparent 8px);
}
.fitts-btn-small {
    padding: 3px 8px;
    font-size: 0.62rem;
    background: #e5e7eb;
    border: 1px solid var(--clr-border);
    border-radius: 3px;
    color: var(--clr-text-muted);
    cursor: pointer;
}
.fitts-btn-large {
    padding: 10px 24px;
    font-size: 0.82rem;
    font-weight: 600;
    background: var(--clr-indigo);
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(99,102,241,0.3);
    transition: all 0.2s;
}
.fitts-btn-large:hover { transform: scale(1.05); box-shadow: 0 4px 16px rgba(99,102,241,0.4); }

/* ================================================================
   SLIDE 9 — Miller's Law & Serial Position Demo
   ================================================================ */
.slide-miller-serial {
    background: linear-gradient(160deg, #f8f9fc 0%, #f0f0ff 50%, #e8f4f8 100%);
}
.demo-miller {
    display: flex;
    flex-direction: column;
    gap: 14px;
}
.miller-example {
    display: flex;
    gap: 16px;
}
.miller-bad, .miller-good {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.miller-label {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 600;
}
.miller-number {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    padding: 8px 12px;
    background: #f1f3f5;
    border-radius: 6px;
    border: 1px solid var(--clr-border);
    color: var(--clr-text);
    letter-spacing: 1px;
}
.miller-phone {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--clr-text-muted);
    padding: 4px 12px;
}
.miller-good .miller-number {
    color: var(--clr-indigo);
    border-color: rgba(99,102,241,0.2);
    background: rgba(99,102,241,0.04);
}
.miller-good .miller-phone { color: var(--clr-indigo); }

.demo-serial {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}
.serial-phone {
    width: 220px;
    background: var(--clr-surface);
    border: 2px solid var(--clr-border-strong);
    border-radius: 20px;
    overflow: hidden;
}
.serial-screen {
    height: 90px;
    background: #f9fafb;
}
.serial-content-area {
    height: 100%;
    background: repeating-linear-gradient(
        0deg,
        transparent,
        transparent 12px,
        #e5e7eb 12px,
        #e5e7eb 13px
    );
    margin: 10px 16px;
    opacity: 0.5;
}
.serial-navbar {
    display: flex;
    justify-content: space-around;
    padding: 8px 4px;
    border-top: 1px solid var(--clr-border);
    background: white;
}
.serial-nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    font-size: 0.72rem;
    position: relative;
    padding: 2px 6px;
    border-radius: 6px;
    transition: all 0.3s;
}
.serial-icon { font-size: 1rem; }
.serial-label { font-size: 0.58rem; color: var(--clr-text-muted); }
.serial-first, .serial-last {
    background: rgba(99,102,241,0.08);
}
.serial-highlight {
    position: absolute;
    bottom: -2px;
    width: 16px;
    height: 2px;
    background: var(--clr-indigo);
    border-radius: 2px;
}
.serial-annotation {
    display: flex;
    justify-content: space-between;
    width: 220px;
    font-family: var(--font-mono);
    font-size: 0.68rem;
    font-weight: 600;
}
.serial-arrow-first { color: var(--clr-indigo); }
.serial-arrow-last { color: var(--clr-emerald); }

/* ================================================================
   SLIDE 10 — Affordance & Cognitive Load Demo
   ================================================================ */
.slide-afford-cogload {
    background: linear-gradient(160deg, #f8f9fc 0%, #faf5ff 50%, #f0fff4 100%);
}
.demo-affordance {
    display: flex;
    justify-content: center;
}
.afford-example {
    display: flex;
    gap: 20px;
    width: 100%;
}
.afford-bad, .afford-good {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 16px;
}
.afford-label {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 600;
}
.afford-flat {
    font-size: 0.85rem;
    color: var(--clr-text-muted);
    padding: 8px 0;
}
.afford-btn {
    padding: 10px 28px;
    background: var(--clr-indigo);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 3px 0 var(--clr-indigo-deep), 0 4px 12px rgba(99,102,241,0.3);
    transition: all 0.15s;
}
.afford-btn:hover { transform: translateY(-1px); box-shadow: 0 4px 0 var(--clr-indigo-deep), 0 6px 16px rgba(99,102,241,0.35); }
.afford-btn:active { transform: translateY(2px); box-shadow: 0 1px 0 var(--clr-indigo-deep); }
.afford-hint {
    font-size: 0.72rem;
    color: var(--clr-text-muted);
    font-family: var(--font-mono);
}

.demo-cogload {
    display: flex;
    gap: 12px;
}
.cogload-bad, .cogload-good { flex: 1; }
.cogload-label {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 600;
    margin-bottom: 8px;
}
.cogload-form-heavy, .cogload-form-light {
    display: flex;
    flex-direction: column;
    gap: 4px;
}
.cl-row {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.68rem;
    color: var(--clr-text-muted);
}
.cl-row span { min-width: 48px; text-align: right; font-weight: 500; }
.cl-input {
    flex: 1;
    height: 22px;
    background: #f1f3f5;
    border: 1px solid var(--clr-border);
    border-radius: 4px;
}
.cl-step-indicator {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    color: var(--clr-indigo);
    text-align: center;
    margin-bottom: 6px;
    font-weight: 600;
}
.cl-next-btn {
    margin-top: 6px;
    padding: 6px 16px;
    background: var(--clr-indigo);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 0.7rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}
.cl-next-btn:hover { background: var(--clr-indigo-deep); }

/* ================================================================
   SLIDE 11 — Mental Model / Symmetry / Prägnanz Demo
   ================================================================ */
.slide-mental-advanced {
    background: linear-gradient(160deg, #f8f9fc 0%, #e8f4f8 50%, #faf5ff 100%);
}
.mental-model-demo {
    background: var(--clr-bg);
    border: 1px solid var(--clr-border);
    border-radius: 8px;
    padding: 8px;
    margin-top: 6px;
}
.mm-navbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 6px 10px;
    background: var(--clr-surface);
    border-radius: 6px;
    font-size: 0.72rem;
}
.mm-logo { font-weight: 600; }
.mm-cart-expected { margin-left: auto; }
.mm-note {
    font-size: 0.68rem;
    font-family: var(--font-mono);
    color: var(--clr-emerald);
    text-align: center;
    margin-top: 4px;
}
.mm-note-bad { color: var(--clr-red); }
.mm-wrong .mm-navbar { border: 1px solid rgba(239,68,68,0.3); }

.symmetry-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    margin-top: 6px;
}
.sym-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px;
    width: 100px;
}
.sym-box {
    width: 100%;
    aspect-ratio: 1;
    background: var(--clr-indigo);
    border-radius: 6px;
    opacity: 0.7;
}
.sym-off { transform: translateY(8px); }
.sym-off2 { transform: translateY(-6px) rotate(5deg); }
.sym-label {
    font-size: 0.68rem;
    font-family: var(--font-mono);
    color: var(--clr-emerald);
}
.sym-label-bad { color: var(--clr-red); }

.pragnanz-demo {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    margin-top: 8px;
}
.prag-svg { width: 100px; }
.prag-label {
    font-size: 0.68rem;
    font-family: var(--font-mono);
    color: var(--clr-text-muted);
    text-align: center;
    line-height: 1.4;
}

/* ---------- Compact overrides for Slides 10 & 11 (fit viewport without scroll) ---------- */
.slide-afford-cogload .slide-content,
.slide-mental-advanced .slide-content {
    padding-top: 20px;
    gap: 0;
}
.slide-afford-cogload .principle-layout-stacked,
.slide-mental-advanced .principle-layout-stacked {
    gap: 8px;
    padding-top: 12px;
}
.slide-afford-cogload .principle-header-wide,
.slide-mental-advanced .principle-header-wide {
    gap: 2px;
}
.slide-afford-cogload .dual-demo { gap: 14px; }
.slide-afford-cogload .dual-panel { gap: 4px; }
.slide-afford-cogload .dual-def { font-size: 0.76rem; line-height: 1.4; }
.slide-afford-cogload .window-body { padding: 8px 12px; }
.slide-afford-cogload .afford-bad,
.slide-afford-cogload .afford-good { gap: 6px; padding: 8px; }
.slide-afford-cogload .afford-btn { padding: 7px 22px; font-size: 0.8rem; }
.slide-afford-cogload .cogload-label { margin-bottom: 4px; }
.slide-afford-cogload .cogload-form-heavy,
.slide-afford-cogload .cogload-form-light { gap: 2px; }
.slide-afford-cogload .cl-input { height: 18px; }
.slide-afford-cogload .cl-next-btn { margin-top: 4px; padding: 5px 14px; }
.slide-afford-cogload .key-diff { padding: 8px 14px; margin-top: auto; }

.slide-mental-advanced .triple-demo { gap: 12px; }
.slide-mental-advanced .triple-panel { padding: 12px 14px; gap: 4px; }
.slide-mental-advanced .triple-def { font-size: 0.72rem; line-height: 1.4; }
.slide-mental-advanced .mental-model-demo { padding: 5px; margin-top: 3px; }
.slide-mental-advanced .mm-navbar { padding: 4px 8px; }
.slide-mental-advanced .mm-note { margin-top: 2px; }
.slide-mental-advanced .symmetry-demo { gap: 3px; margin-top: 3px; }
.slide-mental-advanced .sym-grid { width: 72px; gap: 4px; }
.slide-mental-advanced .pragnanz-demo { gap: 4px; margin-top: 4px; }
.slide-mental-advanced .prag-svg { width: 80px; }
.slide-mental-advanced .key-diff { padding: 8px 14px; margin-top: auto; }

/* ================================================================
   SLIDE 12 — Summary
   ================================================================ */
.slide-summary {
    background: linear-gradient(135deg, #f0f0ff 0%, #e8f4f8 40%, #f0fff4 100%);
}
.ssummary-content {
    align-items: center;
    justify-content: center;
    gap: 16px;
    text-align: center;
}
.ssummary-content h1 {
    font-family: var(--font-heading);
    font-size: clamp(1.6rem, 3.5vw, 2.6rem);
    font-weight: 700;
    color: var(--clr-text);
}
.ssummary-sub {
    font-size: 1rem;
    color: var(--clr-text-muted);
    max-width: 600px;
    line-height: 1.65;
}
.ssummary-sub em { color: var(--clr-text-muted); font-style: italic; }
.ssummary-sub strong { color: var(--clr-indigo); }

.ssummary-grid {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    justify-content: center;
    max-width: 800px;
}
.ssummary-item {
    flex: 1;
    min-width: 160px;
    max-width: 180px;
    background: var(--clr-surface);
    border: 1px solid var(--clr-border);
    border-radius: 14px;
    padding: 18px 16px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.ssummary-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}
.ssummary-num {
    font-family: var(--font-mono);
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--clr-indigo);
    display: block;
    margin-bottom: 8px;
}
.ssummary-item h3 {
    font-family: var(--font-heading);
    font-size: 0.88rem;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--clr-text);
}
.ssummary-item p {
    font-size: 0.82rem;
    color: var(--clr-text-muted);
    line-height: 1.5;
}

.ssummary-cta {
    margin-top: 12px;
}

/* ================================================================
   KEYFRAME ANIMATIONS
   ================================================================ */
@keyframes ghostFloat {
    0%, 100% { transform: translateY(0); }
    50%      { transform: translateY(-10px); }
}
@keyframes subtleZoom {
    0%   { transform: scale(1); }
    100% { transform: scale(1.05); }
}

/* ================================================================
   RESPONSIVE
   ================================================================ */
@media (max-width: 860px) {
    .slide-content { overflow-y: auto; }

    .principle-layout {
        flex-direction: column;
        gap: 24px;
        padding-top: 48px;
    }
    .principle-text { max-width: 100%; }
    .principle-demo { width: 100%; }
    .app-window { max-width: 100%; }

    .dual-demo { flex-direction: column; align-items: center; }
    .dual-panel { min-width: 100%; max-width: 100%; }
    .triple-demo { flex-direction: column; align-items: center; }
    .triple-panel { min-width: 100%; max-width: 100%; }

    .sintro-cards { flex-direction: column; align-items: center; }
    .sintro-card { max-width: 100%; }

    .ssummary-grid { flex-direction: column; align-items: center; }
    .ssummary-item { max-width: 100%; }

    .demo-proximity { flex-direction: column; }
    .demo-hick { flex-direction: column; }
    .demo-cogload { flex-direction: column; }
    .miller-example { flex-direction: column; }
    .afford-example { flex-direction: column; }
}

@media (max-width: 600px) {
    .slide-content { padding: 32px 4vw 16px; }
    .slide-nav { gap: 8px; padding: 6px 10px; }
    .product-grid { flex-direction: column; }
    .stitle-heading .stitle-line1 { font-size: 2rem; }
}