/* ==========================================================================
   STUDYBUDDY v4 - ULTRA-MINIMALIST LIGHT DESIGN SYSTEM
   Inspiration: thetinypod.com & Apple Hardware Design
   Characteristics: Pristine white, studio lighting, crisp typography, 
   restrained layout, cinematic photography + interactive 3D model.
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. VARIABLES & DESIGN TOKENS
   -------------------------------------------------------------------------- */
:root {
    --bg-main: #FFFFFF;
    --bg-secondary: #F5F5F7;
    --bg-card: #FFFFFF;
    --bg-hover: #ECECEE;
    
    --text-primary: #1D1D1F;     /* Deep Graphite */
    --text-secondary: #86868B;   /* Apple Muted Gray */
    --text-tertiary: #A1A1A6;
    
    --accent-mint: #3DD598;
    --accent-cyan: #38BDF8;
    
    --border-light: rgba(0, 0, 0, 0.08);
    --border-focus: #1D1D1F;
    
    --font-system: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Display', sans-serif;
    
    --radius-sm: 8px;
    --radius-md: 18px;
    --radius-lg: 32px;
    --radius-full: 9999px;
    
    --shadow-subtle: 0 4px 20px rgba(0, 0, 0, 0.04);
    --shadow-elevated: 0 20px 40px rgba(0, 0, 0, 0.06);
    --shadow-product: 0 30px 60px rgba(0, 0, 0, 0.08);

    --transition: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

/* --------------------------------------------------------------------------
   2. RESET & BASE
   -------------------------------------------------------------------------- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html.lenis {
    height: auto;
}

.lenis.lenis-smooth {
    scroll-behavior: auto !important;
}

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-family: var(--font-system);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

.container {
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 2rem;
}

.text-center { text-align: center; }

/* --------------------------------------------------------------------------
   3. TYPOGRAPHY & SHARED ELEMENTS
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5 {
    color: var(--text-primary);
    font-weight: 700;
    letter-spacing: -0.025em;
    line-height: 1.12;
}

p {
    color: var(--text-secondary);
}

a {
    color: inherit;
    text-decoration: none;
}

.eyebrow-pill {
    display: inline-block;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
    background: var(--bg-secondary);
    padding: 0.35rem 1rem;
    border-radius: var(--radius-full);
    margin-bottom: 1.5rem;
    letter-spacing: -0.01em;
}

.section-kicker {
    display: block;
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.section-headline {
    font-size: clamp(2.4rem, 4.5vw, 3.75rem);
    margin-bottom: 1rem;
}

.section-subheadline {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 620px;
    margin: 0 auto 4.5rem;
    line-height: 1.6;
}

/* Buttons (Apple / TinyPod Style) */
.btn-pill {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.6rem;
    border-radius: var(--radius-full);
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: -0.01em;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    outline: none;
    white-space: nowrap;
}

.btn-pill-dark {
    background: #000000;
    color: #FFFFFF;
}

.btn-pill-dark:hover {
    background: #2D2D2F;
    transform: translateY(-1px);
}

.btn-hero {
    padding: 1rem 2.2rem;
    font-size: 1rem;
}

.link-chevron {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    transition: var(--transition);
}

.link-chevron .arrow {
    transition: transform 0.2s ease;
}

.link-chevron:hover .arrow {
    transform: translateX(4px);
}

/* --------------------------------------------------------------------------
   4. STICKY HEADER
   -------------------------------------------------------------------------- */
header#site-header {
    position: sticky;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.82);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-light);
    padding: 1rem 0;
    transition: var(--transition);
}

.header-container {
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 1.25rem;
    font-weight: 800;
    letter-spacing: -0.03em;
}

.brand-logo-img {
    width: 34px;
    height: 34px;
    object-fit: contain;
    transition: transform var(--transition);
}

.brand-logo:hover .brand-logo-img {
    transform: scale(1.08) rotate(-3deg);
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-link {
    font-size: 0.88rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition);
}

.nav-link:hover {
    color: var(--text-primary);
}

/* --------------------------------------------------------------------------
   5. SECTION 1: HERO
   -------------------------------------------------------------------------- */
.hero-section {
    padding: 5rem 0 6rem;
    background: var(--bg-main);
}

.hero-title {
    font-size: clamp(3rem, 6.5vw, 5.2rem);
    max-width: 820px;
    margin: 0 auto 1.5rem;
    letter-spacing: -0.04em;
}

.hero-lead {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 680px;
    margin: 0 auto 2.5rem;
    line-height: 1.6;
}

.hero-actions-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 4rem;
}

/* Studio Product Media Frame */
.hero-media-wrapper {
    position: relative;
    max-width: 860px;
    margin: 0 auto 4rem;
}

.hero-product-img {
    width: 100%;
    display: block;
    filter: drop-shadow(0 30px 50px rgba(0, 0, 0, 0.08));
    transition: transform 0.5s ease-out;
}

/* Floating Callouts */
.hardware-callout {
    position: absolute;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    padding: 0.85rem 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.85rem;
    box-shadow: var(--shadow-subtle);
    pointer-events: none;
    text-align: left;
}

.hardware-callout .dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent-mint);
}

.callout-text strong {
    font-size: 0.82rem;
    color: var(--text-primary);
    display: block;
}

.callout-text span {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.callout-left { top: 22%; left: -3%; }
.callout-right { bottom: 25%; right: -3%; }

/* Minimal Specs Strip */
.hero-specs-strip {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
    max-width: 820px;
    margin: 0 auto;
    padding-top: 3rem;
    border-top: 1px solid var(--border-light);
}

.spec-col {
    display: flex;
    flex-direction: column;
}

.spec-big {
    font-size: 2.2rem;
    font-weight: 800;
    color: var(--text-primary);
    letter-spacing: -0.03em;
}

.spec-desc {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* --------------------------------------------------------------------------
   6. SECTION 2: PROBLEM CATERING
   -------------------------------------------------------------------------- */
.problem-section {
    padding: 8rem 0;
    background: var(--bg-secondary);
}

.problem-cards-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.narrative-card {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: 3rem 2.5rem;
    text-align: left;
    box-shadow: var(--shadow-subtle);
    border: 1px solid var(--border-light);
    transition: var(--transition);
}

.narrative-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-elevated);
}

.card-num {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-tertiary);
    margin-bottom: 1.5rem;
    display: block;
}

.narrative-card h3 {
    font-size: 1.45rem;
    margin-bottom: 0.75rem;
}

.narrative-card p {
    font-size: 0.98rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* --------------------------------------------------------------------------
   7. SECTION 3: FEATURE & HARDWARE
   -------------------------------------------------------------------------- */
.hardware-section {
    padding: 8rem 0;
    background: var(--bg-main);
}

.hardware-showcase-grid {
    display: grid;
    grid-template-columns: 1fr 1.15fr;
    gap: 4rem;
    align-items: center;
    margin-top: 4rem;
}

.hardware-feature-pane {
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
}

.feature-item h4 {
    font-size: 1.35rem;
    margin-bottom: 0.4rem;
}

.feature-item p {
    font-size: 0.98rem;
    line-height: 1.6;
}

.hardware-visual-pane {
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: var(--bg-secondary);
    padding: 1.5rem;
}

.desk-image-cutout {
    width: 100%;
    display: block;
    border-radius: calc(var(--radius-lg) - 1rem);
    box-shadow: var(--shadow-elevated);
}

/* --------------------------------------------------------------------------
   8. SECTION 4: PRODUCT DISPLAY (INTERACTIVE 3D MODEL)
   -------------------------------------------------------------------------- */
.display-3d-section {
    padding: 8rem 0;
    background: var(--bg-secondary);
}

.studio-3d-container {
    position: relative;
    max-width: 860px;
    height: 520px;
    margin: 0 auto;
    background: radial-gradient(circle at center, #FFFFFF 0%, #EAEAEF 100%);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-product);
    border: 1px solid rgba(0, 0, 0, 0.06);
    overflow: hidden;
}

#studio-3d-canvas {
    width: 100%;
    height: 100%;
    display: block;
    cursor: grab;
}

#studio-3d-canvas:active {
    cursor: grabbing;
}

/* Emotion Switch Bar */
.emotion-switch-bar {
    position: absolute;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-full);
    padding: 0.45rem 0.6rem 0.45rem 1.25rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    box-shadow: var(--shadow-subtle);
    z-index: 10;
}

.emotion-bar-title {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-secondary);
    letter-spacing: 0.06em;
}

.emotion-pills {
    display: flex;
    gap: 0.35rem;
}

.pill-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 0.4rem 1rem;
    border-radius: var(--radius-full);
    font-size: 0.82rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.pill-btn:hover {
    color: var(--text-primary);
}

.pill-btn.active {
    background: #000000;
    color: #FFFFFF;
}

.canvas-hint {
    position: absolute;
    top: 20px;
    right: 24px;
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-weight: 500;
    pointer-events: none;
}

/* --------------------------------------------------------------------------
   9. SECTION 5: WAITLIST
   -------------------------------------------------------------------------- */
.waitlist-section {
    padding: 8rem 0;
    background: var(--bg-main);
}

.waitlist-minimal-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: 6rem 3rem;
    max-width: 720px;
    margin: 0 auto;
}

.batch-badge {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    display: block;
    margin-bottom: 1rem;
}

.waitlist-heading {
    font-size: clamp(2.2rem, 4vw, 3rem);
    margin-bottom: 1rem;
}

.waitlist-text {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 520px;
    margin: 0 auto 3rem;
    line-height: 1.6;
}

.minimal-input-group {
    display: flex;
    gap: 0.75rem;
    max-width: 460px;
    margin: 0 auto 1.5rem;
}

.minimal-input-group input {
    flex: 1;
    padding: 0.85rem 1.25rem;
    border-radius: var(--radius-full);
    border: 1px solid rgba(0, 0, 0, 0.12);
    background: #FFFFFF;
    font-family: var(--font-system);
    font-size: 0.95rem;
    outline: none;
    transition: var(--transition);
}

.minimal-input-group input:focus {
    border-color: #000000;
}

.waitlist-footnotes {
    font-size: 0.82rem;
    color: var(--text-tertiary);
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(12px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.modal-overlay.show {
    opacity: 1;
    pointer-events: auto;
}

.modal-box {
    background: #FFFFFF;
    border-radius: var(--radius-md);
    padding: 3.5rem 3rem;
    max-width: 440px;
    box-shadow: var(--shadow-product);
    transform: scale(0.95);
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-overlay.show .modal-box {
    transform: scale(1);
}

.modal-box h3 {
    font-size: 1.75rem;
    margin-bottom: 0.75rem;
}

.modal-box p {
    font-size: 0.95rem;
    margin-bottom: 2rem;
}

/* --------------------------------------------------------------------------
   10. COMPANY FOOTER
   -------------------------------------------------------------------------- */
footer.site-footer {
    background: var(--bg-secondary);
    padding: 5rem 0 3rem;
    border-top: 1px solid var(--border-light);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 4rem;
    margin-bottom: 4rem;
}

.footer-brand-header {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    margin-bottom: 0.75rem;
}

.footer-logo-img {
    width: 30px;
    height: 30px;
    object-fit: contain;
}

.footer-brand-title {
    font-size: 1.2rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    display: inline-block;
    margin-bottom: 0;
}

.footer-brand-desc {
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
    max-width: 280px;
}

.footer-privacy-tag {
    font-size: 0.8rem;
    color: var(--text-tertiary);
}

.footer-col h5 {
    font-size: 0.82rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
    margin-bottom: 1.25rem;
}

.footer-col a {
    display: block;
    font-size: 0.88rem;
    color: var(--text-primary);
    margin-bottom: 0.65rem;
    transition: var(--transition);
}

.footer-col a:hover {
    color: var(--text-secondary);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    padding-top: 2rem;
    border-top: 1px solid var(--border-light);
    font-size: 0.82rem;
    color: var(--text-secondary);
}

/* --------------------------------------------------------------------------
   11. RESPONSIVENESS
   -------------------------------------------------------------------------- */
@media (max-width: 900px) {
    .problem-cards-grid, .hardware-showcase-grid, .hero-specs-strip {
        grid-template-columns: 1fr;
        gap: 2.5rem;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }

    .hardware-callout {
        display: none;
    }
}

@media (max-width: 600px) {
    .header-nav { display: none; }
    
    .hero-title { font-size: 2.5rem; }
    .section-headline { font-size: 2.1rem; }

    .minimal-input-group {
        flex-direction: column;
    }

    .studio-3d-container {
        height: 400px;
    }

    .emotion-switch-bar {
        width: 90%;
        padding: 0.35rem;
        justify-content: center;
    }

    .emotion-bar-title { display: none; }

    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
}