/**
 * roiAI — Site Shell Design System
 * roiAI_Doc_0 §2 (Design System) | §4 (Site Architecture) | §4.4 (Footer)
 *
 * Rules:
 *  - All colors via CSS custom properties only — no hardcoded hex in selectors
 *  - Fonts self-hosted via @font-face — zero external CDN requests
 *  - Instrument-grade aesthetic: no rounded pills, no gradients, no animations
 *  - Max widths: 1200px marketing, 900px content/evidence, 700px form flows
 */

/* ==========================================================================
   SELF-HOSTED FONTS — @font-face
   Font files placed by Bob in /assets/fonts/ before acceptance test runs.
   ========================================================================== */

@font-face {
    font-family: 'Cormorant Garamond';
    src: url('/assets/fonts/cormorant-garamond-400.woff2') format('woff2');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Cormorant Garamond';
    src: url('/assets/fonts/cormorant-garamond-500.woff2') format('woff2');
    font-weight: 500;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Nunito Sans';
    src: url('/assets/fonts/nunito-sans-400.woff2') format('woff2');
    font-weight: 400;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Nunito Sans';
    src: url('/assets/fonts/nunito-sans-600.woff2') format('woff2');
    font-weight: 600;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Nunito Sans';
    src: url('/assets/fonts/nunito-sans-800.woff2') format('woff2');
    font-weight: 800;
    font-style: normal;
    font-display: swap;
}

/* ==========================================================================
   CSS CUSTOM PROPERTIES — Design System Tokens
   Source: roiAI_Doc_0 §2.1
   ALL colors are defined here. No hex values appear in any rule below.
   ========================================================================== */

:root {
    /* --- Color palette --- */
    --color-charcoal:         #1A1A1A;
    --color-charcoal-mid:     #222222;
    --color-charcoal-light:   #2A2A2A;
    --color-teal:             #00C9A7;
    --color-teal-hover:       #00B096;
    --color-gold:             #D8A24A;
    --color-gold-light:       #C4901A;
    --color-white:            #FFFFFF;
    --color-text-primary:     #F0F4F8;
    --color-text-secondary:   #A0A8B0;
    --color-text-muted:       #666E78;
    --color-border:           #2E2E2E;
    --color-border-light:     #E5E7EB;
    --color-bg-light:         #F5F3EE;
    --color-error:            #C62828;
    --color-success:          #2E7D32;

    /* --- Indicator colors (profiler retrofit, WCAG AA verified) --- */
    --color-high:             #E65100;

    /* --- Typography --- */
    --font-serif:             'Cormorant Garamond', Georgia, serif;
    --font-sans:              'Nunito Sans', 'Segoe UI', Arial, sans-serif;

    /* --- Spacing scale --- */
    --space-xs:               0.5rem;
    --space-sm:               1rem;
    --space-md:               1.5rem;
    --space-lg:               2rem;
    --space-xl:               3rem;
    --space-2xl:              5rem;

    /* --- Layout widths --- */
    --max-width-marketing:    1200px;
    --max-width-content:      900px;
    --max-width-form:         700px;

    /* --- Section padding --- */
    --section-pad-desktop:    80px;
    --section-pad-mobile:     48px;

    /* --- Card grid gap --- */
    --grid-gap:               24px;

    /* --- Border radius (instrument aesthetic — no pills) --- */
    --radius-btn:             3px;
    --radius-card:            4px;

    /* --- Header height --- */
    --header-height:          64px;
}

/* ==========================================================================
   RESET & BASE
   ========================================================================== */

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    background-color: var(--color-charcoal);
    color: var(--color-text-primary);
    font-family: var(--font-sans);
    font-weight: 400;
    font-size: 1rem;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

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

a:hover {
    color: var(--color-teal-hover);
}

/* ==========================================================================
   TYPOGRAPHY SCALE
   Source: roiAI_Doc_0 §2.2
   ========================================================================== */

/* Display / Hero — 48–72px Cormorant Garamond 500 */
.text-display {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(48px, 6vw, 72px);
    line-height: 1.1;
    letter-spacing: -0.01em;
}

/* Section Heading — 32–40px Cormorant Garamond 500 */
.text-section-heading,
h2.section-heading {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(32px, 3.5vw, 40px);
    line-height: 1.2;
}

/* Subheading — 18–24px Nunito Sans 600 */
.text-subheading,
h3.subheading {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: clamp(18px, 2vw, 24px);
    line-height: 1.3;
}

/* Body — 16px Nunito Sans 400, line-height 1.7 */
.text-body,
p {
    font-family: var(--font-sans);
    font-weight: 400;
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text-primary);
}

/* Navigation — 14px Nunito Sans 600, all-caps, letter-spacing 1.5px */
.text-nav {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 1.5px;
}

/* Label / Meta — 12–13px Nunito Sans 400 */
.text-meta {
    font-family: var(--font-sans);
    font-weight: 400;
    font-size: 13px;
    color: var(--color-text-muted);
}

/* ==========================================================================
   LAYOUT CONTAINERS
   ========================================================================== */

.container {
    width: 100%;
    max-width: var(--max-width-marketing);
    margin-inline: auto;
    padding-inline: 24px;
}

.container--content {
    max-width: var(--max-width-content);
}

.container--form {
    max-width: var(--max-width-form);
}

.section {
    padding-block: var(--section-pad-desktop);
}

/* ==========================================================================
   HEADER
   Source: roiAI_Doc_0 §4.2
   ========================================================================== */

.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    height: var(--header-height);
    background-color: var(--color-charcoal);
    border-bottom: 1px solid var(--color-border);
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    max-width: var(--max-width-marketing);
    margin-inline: auto;
    padding-inline: 24px;
}

.site-header__brand {
    display: flex;
    align-items: baseline;
    gap: 8px;
    text-decoration: none;
}

/* CSS logo placeholder — replaced by roiai-wordmark-dark.svg when delivered */
.site-header__logo-text {
    display: inline-flex;
    align-items: baseline;
    line-height: 1;
}

.site-header__logo-roi {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 26px;
    color: var(--color-gold);
    letter-spacing: -0.02em;
}

.site-header__logo-ai {
    font-family: var(--font-sans);
    font-weight: 800;
    font-size: 22px;
    color: var(--color-teal);
    letter-spacing: 0;
}

.site-header__tagline {
    font-family: var(--font-sans);
    font-weight: 400;
    font-size: 12px;
    color: var(--color-text-muted);
    white-space: nowrap;
}

/* When SVG logo is delivered, swap in via this class */
.site-header__logo-svg {
    height: 32px;
    width: auto;
}

.site-header__actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.site-header__account-name {
    font-family: var(--font-sans);
    font-size: 14px;
    color: var(--color-text-secondary);
}

/* ==========================================================================
   FOOTER
   Source: roiAI_Doc_0 §4.4
   ========================================================================== */

.site-footer {
    background-color: var(--color-charcoal-mid);
    border-top: 1px solid var(--color-border);
    padding-block: var(--space-2xl);
}

.site-footer__inner {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-lg);
    max-width: var(--max-width-marketing);
    margin-inline: auto;
    padding-inline: 24px;
}

.site-footer__brand {
    display: flex;
    align-items: baseline;
    gap: 8px;
}

.site-footer__logo-roi {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 20px;
    color: var(--color-gold);
    letter-spacing: -0.02em;
}

.site-footer__logo-ai {
    font-family: var(--font-sans);
    font-weight: 800;
    font-size: 17px;
    color: var(--color-teal);
}

.site-footer__tagline {
    font-family: var(--font-sans);
    font-size: 12px;
    color: var(--color-text-muted);
}

.site-footer__nav {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 24px;
    list-style: none;
}

.site-footer__nav a {
    font-family: var(--font-sans);
    font-size: 14px;
    color: var(--color-text-secondary);
    text-decoration: none;
}

.site-footer__nav a:hover {
    color: var(--color-text-primary);
}

.site-footer__legal {
    font-size: 13px;
    color: var(--color-text-muted);
}

.site-footer__disclaimer {
    font-size: 12px;
    color: var(--color-text-muted);
    font-style: italic;
    max-width: 640px;
    line-height: 1.6;
}

/* ==========================================================================
   BUTTONS
   Source: roiAI_Doc_0 §2.3
   All buttons: border-radius 3px. No pill buttons.
   ========================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 14px;
    letter-spacing: 0.5px;
    border-radius: var(--radius-btn);
    border: 1px solid transparent;
    cursor: pointer;
    text-decoration: none;
    transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
    white-space: nowrap;
}

/* Primary CTA — teal background, dark text */
.btn--primary {
    background-color: var(--color-teal);
    color: var(--color-charcoal);
    border-color: var(--color-teal);
}

.btn--primary:hover {
    background-color: var(--color-teal-hover);
    border-color: var(--color-teal-hover);
    color: var(--color-charcoal);
}

/* Secondary CTA — transparent, teal border + text */
.btn--secondary {
    background-color: transparent;
    color: var(--color-teal);
    border-color: var(--color-teal);
}

.btn--secondary:hover {
    background-color: var(--color-teal);
    color: var(--color-charcoal);
}

/* Gold CTA — gold background, dark text */
.btn--gold {
    background-color: var(--color-gold);
    color: var(--color-charcoal);
    border-color: var(--color-gold);
}

.btn--gold:hover {
    background-color: var(--color-gold-light);
    border-color: var(--color-gold-light);
    color: var(--color-charcoal);
}

/* Ghost — transparent, border, primary text */
.btn--ghost {
    background-color: transparent;
    color: var(--color-text-primary);
    border-color: var(--color-border);
}

.btn--ghost:hover {
    border-color: var(--color-text-secondary);
    color: var(--color-white);
}

.btn--sm {
    padding: 8px 16px;
    font-size: 13px;
}

.btn--lg {
    padding: 16px 32px;
    font-size: 16px;
}

/* ==========================================================================
   CARDS
   Source: roiAI_Doc_0 §2.3
   ========================================================================== */

/* Product card */
.card {
    background-color: var(--color-charcoal-mid);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-card);
    padding: 32px;
}

/* Feature card — teal left accent */
.card--feature {
    background-color: var(--color-charcoal-mid);
    border: 1px solid var(--color-border);
    border-left: 3px solid var(--color-teal);
    border-radius: var(--radius-card);
    padding: 32px;
}

/* Stat card */
.card--stat {
    background-color: var(--color-charcoal-light);
    border-radius: var(--radius-card);
    padding: 32px;
}

/* Gold accent card (About page metrics, evidence-base findings) */
.card--gold {
    background-color: var(--color-charcoal-mid);
    border: 1px solid var(--color-border);
    border-left: 3px solid var(--color-gold);
    border-radius: var(--radius-card);
    padding: 32px;
}

/* ==========================================================================
   CARD GRID
   ========================================================================== */

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: var(--grid-gap);
}

.card-grid--2 {
    grid-template-columns: repeat(2, 1fr);
}

.card-grid--3 {
    grid-template-columns: repeat(3, 1fr);
}

.card-grid--4 {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

/* ==========================================================================
   STAT CARD SPECIFICS (Home page "Problem in Numbers")
   ========================================================================== */

.stat-card__number {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(40px, 5vw, 56px);
    color: var(--color-gold);
    line-height: 1;
    margin-bottom: 12px;
}

.stat-card__label {
    font-family: var(--font-sans);
    font-weight: 400;
    font-size: 16px;
    color: var(--color-text-primary);
    line-height: 1.5;
}

.stat-card__source {
    margin-top: 12px;
    font-size: 12px;
    color: var(--color-text-muted);
    font-style: italic;
}

.stat-card__subnote {
    margin-top: 8px;
    font-size: 11px;
    color: var(--color-text-muted);
    font-style: italic;
    border-top: 1px solid var(--color-border);
    padding-top: 8px;
}

/* ==========================================================================
   PRODUCT ECOSYSTEM CARDS (Home page)
   ========================================================================== */

.product-card {
    background-color: var(--color-charcoal-mid);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-card);
    padding: 28px 32px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

/* Free tools: teal left accent */
.product-card--free {
    border-left: 3px solid var(--color-teal);
}

/* Paid tools: gold left accent */
.product-card--paid {
    border-left: 3px solid var(--color-gold);
}

.product-card__badge {
    display: inline-block;
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 1px;
    padding: 3px 8px;
    border-radius: var(--radius-btn);
}

.product-card__badge--free {
    background-color: rgba(0, 201, 167, 0.15);
    color: var(--color-teal);
    border: 1px solid rgba(0, 201, 167, 0.3);
}

.product-card__badge--paid {
    background-color: rgba(216, 162, 74, 0.15);
    color: var(--color-gold);
    border: 1px solid rgba(216, 162, 74, 0.3);
}

.product-card__title {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 18px;
    color: var(--color-text-primary);
}

.product-card__access {
    font-size: 13px;
    color: var(--color-text-secondary);
}

.product-card__cta {
    margin-top: auto;
}

.product-card__cta .btn {
    width: 100%;
    white-space: normal;
    text-align: center;
    box-sizing: border-box;
}

/* ==========================================================================
   HERO SECTIONS
   ========================================================================== */

.hero {
    background-color: var(--color-charcoal);
    padding-block: var(--section-pad-desktop);
}

.hero__headline {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(40px, 5vw, 56px);
    line-height: 1.15;
    color: var(--color-text-primary);
    max-width: 820px;
    margin-bottom: 20px;
}

.hero__subhead {
    font-family: var(--font-sans);
    font-weight: 400;
    font-size: 20px;
    color: var(--color-text-secondary);
    max-width: 640px;
    line-height: 1.6;
    margin-bottom: 40px;
}

.hero__supporting {
    font-family: var(--font-sans);
    font-weight: 400;
    font-size: 18px;
    color: var(--color-text-muted);
    max-width: 680px;
    line-height: 1.7;
    margin-bottom: 40px;
}

.hero__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: center;
}

/* Methodology page hero — no illustration, receptacle only */
.hero-methodology {
    background-color: var(--color-charcoal);
    min-height: 280px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding-block: var(--section-pad-desktop);
    /* Asset slot: roiai-hero-methodology.svg placed here by Bob */
    /* CSS class ready; asset delivered separately per Doc_0 §3.5 build gate */
}

/* ==========================================================================
   PULL QUOTES
   Source: roiAI_About_Page_Content, roiAI_Methodology_Page_Content
   ========================================================================== */

blockquote.pull-quote {
    font-family: var(--font-serif);
    font-weight: 400;
    font-size: 22px;
    color: var(--color-gold);
    border-left: 3px solid var(--color-gold);
    margin-left: 40px;
    padding: 24px 32px;
    line-height: 1.5;
    font-style: italic;
}

/* Methodology page uses 24px per content spec */
.methodology-page blockquote.pull-quote {
    font-size: 24px;
}

/* ==========================================================================
   CREDIBILITY STATEMENT
   Source: roiAI_About_Page_Content v1.6; roiAI_Methodology_Page_Content v1.7
   Distinct from pull-quote (no left border, centered, near-white).
   Distinct from value-callout (serif, not sans; not teal; not commercial).
   Reserved for governance-of-development claims on Methodology page only.
   Never used for thesis statements or commercial signals.
   ========================================================================== */

.credibility-statement {
    font-family: var(--font-serif);
    font-weight: 400;
    font-style: italic;
    font-size: 20px;
    color: var(--color-text-light);
    text-align: center;
    padding-top: 48px;
    padding-bottom: 48px;
    max-width: 760px;
    margin: 0 auto;
    line-height: 1.6;
}

/* ==========================================================================
   VALUE CALLOUTS
   Source: roiAI_Methodology_Page_Content v1.6 Section 6
   Distinct from pull-quote: sans-serif, teal, not italic, not gold.
   Never use pull-quote class on these elements.
   ========================================================================== */

.value-callout {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 18px;
    color: var(--color-teal);
    border-left: 3px solid var(--color-teal);
    padding: 16px 24px;
    margin-bottom: 24px;
    line-height: 1.5;
}

/* ==========================================================================
   PRE-VALIDATION LANGUAGE
   Source: roiAI_Doc_0 §0 (IP Protection); Doc_6 AT-6.8 and constraint C4
   ========================================================================== */

.pre-validation {
    font-family: var(--font-sans);
    font-weight: 400;
    font-size: 14px;
    color: var(--color-text-muted);
    font-style: italic;
    line-height: 1.6;
    margin-top: 12px;
}

/* ==========================================================================
   SECTION DIVIDERS
   ========================================================================== */

.section-divider {
    border: none;
    border-top: 1px solid var(--color-border);
    margin-block: 0;
}

/* ==========================================================================
   METHODOLOGY DIFFERENTIATOR SECTION SPECIFICS
   ========================================================================== */

.differentiator-card__number {
    font-family: var(--font-serif);
    font-weight: 400;
    font-size: 14px;
    color: var(--color-teal);
    letter-spacing: 2px;
    text-transform: uppercase;
    margin-bottom: 8px;
}

/* ==========================================================================
   PRICING PAGE
   ========================================================================== */

.pricing-table {
    width: 100%;
    border-collapse: collapse;
}

.pricing-table th,
.pricing-table td {
    padding: 16px 20px;
    text-align: left;
    border-bottom: 1px solid var(--color-border);
    font-family: var(--font-sans);
    font-size: 15px;
}

.pricing-table th {
    font-weight: 600;
    color: var(--color-text-secondary);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.pricing-table td {
    color: var(--color-text-primary);
    vertical-align: top;
}

.pricing-table tr:last-child td {
    border-bottom: none;
}

.pricing-table__price {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 24px;
    color: var(--color-gold);
    white-space: nowrap;
}

.pricing-table__product {
    font-weight: 600;
    font-size: 16px;
    color: var(--color-text-primary);
    margin-bottom: 4px;
}

.pricing-table__note {
    font-size: 13px;
    color: var(--color-text-secondary);
    margin-top: 4px;
}

/* ==========================================================================
   EVIDENCE BASE PAGE — Finding Blocks
   Source: roiAI_Doc_0 §5.6
   ========================================================================== */

.finding-block {
    background-color: var(--color-charcoal-mid);
    border-left: 3px solid var(--color-gold);
    border-radius: var(--radius-card);
    padding: 28px 32px;
    margin-bottom: 24px;
}

.finding-block h3 {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 18px;
    color: var(--color-text-primary);
    margin-bottom: 12px;
}

.finding-citation {
    font-family: var(--font-sans);
    font-weight: 400;
    font-size: 13px;
    color: var(--color-text-muted);
    line-height: 1.6;
    margin-top: 16px;
    border-top: 1px solid var(--color-border);
    padding-top: 12px;
}

.finding-qualifier {
    font-size: 12px;
    color: var(--color-text-muted);
    font-style: italic;
    margin-top: 8px;
}

/* ==========================================================================
   ABOUT PAGE — Outcome Metrics Card
   Source: roiAI_About_Page_Content
   ========================================================================== */

.metrics-card {
    background-color: var(--color-charcoal-mid);
    border-left: 3px solid var(--color-gold);
    border-radius: var(--radius-card);
    padding: 32px;
    margin-block: 32px;
}

.metrics-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 16px;
}

.metrics-table th,
.metrics-table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--color-border);
    font-family: var(--font-sans);
    font-size: 15px;
}

.metrics-table th {
    font-weight: 600;
    color: var(--color-gold);
    font-size: 13px;
}

.metrics-table td {
    color: var(--color-text-primary);
}

.metrics-table tr:last-child td {
    border-bottom: none;
}

/* ==========================================================================
   PAGE-SPECIFIC TYPOGRAPHY (About, Methodology)
   ========================================================================== */

/* About page opening H1 */
.page-opening-h1 {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 40px;
    color: var(--color-text-primary);
    padding-top: 80px;
    margin-bottom: 32px;
}

/* Methodology page H2 — 36px per content spec */
.methodology-page h2 {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 36px;
    color: var(--color-text-primary);
    margin-bottom: 20px;
}

/* Methodology page body — line-height 1.8 per content spec */
.methodology-page p,
.about-page p {
    line-height: 1.8;
    margin-bottom: 20px;
}

/* About page larger opening paragraph */
.about-page .opening-para {
    font-size: 18px;
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: 40px;
}

/* ==========================================================================
   SECTION HEADING UTILITY
   ========================================================================== */

.section-header {
    margin-bottom: var(--space-xl);
}

.section-header h2 {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 36px;
    color: var(--color-text-primary);
    margin-bottom: 12px;
}

.section-header p {
    font-size: 18px;
    color: var(--color-text-secondary);
    max-width: 600px;
}

/* ==========================================================================
   STAT CARDS FOOTNOTE + SOURCES LINK
   ========================================================================== */

.stat-footnote {
    font-size: 13px;
    color: var(--color-text-muted);
    font-style: italic;
    margin-top: 16px;
    line-height: 1.6;
}

.stat-sources-link {
    display: inline-block;
    font-size: 14px;
    color: var(--color-teal);
    margin-top: 8px;
    text-decoration: none;
}

.stat-sources-link:hover {
    color: var(--color-teal-hover);
    text-decoration: underline;
}

.bridge-copy {
    font-size: 18px;
    color: var(--color-text-secondary);
    line-height: 1.7;
    max-width: 760px;
    margin-top: 24px;
}

/* ==========================================================================
   PLACEHOLDER / AUTH PAGES
   ========================================================================== */

.placeholder-page {
    min-height: 60vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: var(--section-pad-desktop) 24px;
}

.placeholder-page h1 {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 36px;
    margin-bottom: 16px;
    color: var(--color-text-primary);
}

.placeholder-page p {
    color: var(--color-text-secondary);
    max-width: 480px;
}

/* ==========================================================================
   FORM ELEMENTS (stubs — full spec in auth build sessions)
   ========================================================================== */

.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 14px;
    color: var(--color-text-secondary);
    margin-bottom: 6px;
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    background-color: var(--color-charcoal-mid);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-btn);
    color: var(--color-text-primary);
    font-family: var(--font-sans);
    font-size: 15px;
    transition: border-color 0.15s ease;
}

.form-input:focus {
    outline: none;
    border-color: var(--color-teal);
}

.form-error {
    font-size: 13px;
    color: var(--color-error);
    margin-top: 4px;
}

/* ==========================================================================
   RESPONSIVE — Mobile breakpoint 768px
   Source: roiAI_Doc_0 §2.4
   ========================================================================== */

@media (max-width: 768px) {
    .section {
        padding-block: var(--section-pad-mobile);
    }

    .card-grid--2,
    .card-grid--3 {
        grid-template-columns: 1fr;
    }

    .hero__headline {
        font-size: 36px;
    }

    .hero__subhead {
        font-size: 17px;
    }

    .hero__actions {
        flex-direction: column;
        align-items: flex-start;
    }

    blockquote.pull-quote {
        margin-left: 0;
        padding-left: 20px;
        font-size: 18px;
    }

    .site-header__actions .btn--ghost {
        display: none;  /* "Sign In" becomes text link on mobile */
    }

    .pricing-table {
        font-size: 14px;
    }

    .pricing-table th,
    .pricing-table td {
        padding: 12px 12px;
    }
}

@media (max-width: 480px) {
    .site-header__tagline {
        display: none;
    }

    .hero__headline {
        font-size: 30px;
    }
}

/* ==========================================================================
   UTILITY CLASSES
   ========================================================================== */

.text-gold   { color: var(--color-gold); }
.text-teal   { color: var(--color-teal); }
.text-muted  { color: var(--color-text-muted); }
.text-secondary { color: var(--color-text-secondary); }
.text-center { text-align: center; }
.mt-sm  { margin-top: var(--space-sm); }
.mt-md  { margin-top: var(--space-md); }
.mt-lg  { margin-top: var(--space-lg); }
.mt-xl  { margin-top: var(--space-xl); }
.mb-sm  { margin-bottom: var(--space-sm); }
.mb-md  { margin-bottom: var(--space-md); }
.mb-lg  { margin-bottom: var(--space-lg); }
.mb-xl  { margin-bottom: var(--space-xl); }
.flex   { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.gap-md { gap: var(--space-md); }
.gap-sm { gap: var(--space-sm); }
.cta-group {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: center;
    margin-top: var(--space-xl);
}
.cta-group--centered {
    justify-content: center;
}

/* ==========================================================================
   AUTH PAGES — register, login, verify-email, password reset
   Source: roiAI_Doc_0 §5.7, §9.1, §12.3; R1-S4
   ========================================================================== */

/* Outer wrapper — centers auth card vertically on short pages */
.auth-page {
    min-height: calc(100vh - 140px);
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 48px 16px;
}

/* Auth card container */
.auth-container {
    width: 100%;
    max-width: 460px;
}

/* Auth headings */
.auth-heading {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(24px, 3vw, 32px);
    color: var(--color-text-primary);
    margin-bottom: 8px;
}

.auth-subhead {
    font-size: 15px;
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: 0;
}

.auth-header {
    margin-bottom: 28px;
}

/* Body text inside auth cards */
.auth-body {
    font-size: 15px;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: 12px;
}

/* Form hint text (inline after label) */
.form-hint {
    font-weight: 400;
    color: var(--color-text-muted);
    font-size: 13px;
    margin-left: 4px;
}

/* Form link style */
.form-link {
    font-size: 13px;
    color: var(--color-teal);
    text-decoration: none;
}
.form-link:hover {
    text-decoration: underline;
}

/* Error box */
.auth-error {
    background-color: rgba(220, 53, 69, 0.12);
    border: 1px solid rgba(220, 53, 69, 0.35);
    border-radius: var(--radius-card);
    color: #f8a4ab;
    font-size: 14px;
    line-height: 1.5;
    padding: 14px 16px;
    margin-bottom: 20px;
}

/* Notice box (informational — e.g., "Your email has been verified") */
.auth-notice {
    background-color: rgba(0, 168, 150, 0.10);
    border: 1px solid rgba(0, 168, 150, 0.30);
    border-radius: var(--radius-card);
    color: var(--color-teal);
    font-size: 14px;
    line-height: 1.5;
    padding: 14px 16px;
    margin-bottom: 20px;
}

/* Success card (e.g., "Check Your Inbox") */
.auth-success-card {
    background-color: var(--color-charcoal-mid);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-card);
    padding: 32px 28px;
    text-align: left;
}
.auth-success-card .auth-heading {
    margin-bottom: 16px;
}
.auth-success-card .btn {
    margin-top: 24px;
}

/* Full-width button modifier */
.btn--full {
    width: 100%;
    justify-content: center;
}

/* Footer link below auth forms */
.auth-footer-link {
    font-size: 14px;
    color: var(--color-text-muted);
    text-align: center;
    margin-top: 20px;
}
.auth-footer-link a {
    color: var(--color-teal);
    text-decoration: none;
}
.auth-footer-link a:hover {
    text-decoration: underline;
}

/* Auth form spacing */
.auth-form {
    display: flex;
    flex-direction: column;
}

/* ==========================================================================
   TERMS GATE — enforced on Prescriber entry
   Source: roiAI_Doc_0 §12.3; R1-S4 terms gate architecture
   ========================================================================== */

.terms-gate {
    width: 100%;
    padding: 40px 16px 64px;
}

.terms-gate__body {
    background-color: var(--color-charcoal-mid);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-card);
    padding: 28px;
    margin-bottom: 28px;
}

.terms-gate__section {
    margin-bottom: 24px;
}
.terms-gate__section:last-child {
    margin-bottom: 0;
}

.terms-gate__section-heading {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 14px;
    color: var(--color-text-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 10px;
}

.terms-gate__section p {
    font-size: 14px;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: 10px;
}
.terms-gate__section p:last-child {
    margin-bottom: 0;
}

.terms-gate__disclaimer {
    font-size: 13px;
    color: var(--color-text-muted);
    font-style: italic;
}

.terms-gate__acceptance {
    margin-bottom: 4px;
}

.terms-gate__checkbox-label {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    font-size: 14px;
    color: var(--color-text-secondary);
    line-height: 1.6;
    cursor: pointer;
}
.terms-gate__checkbox-label input[type="checkbox"] {
    margin-top: 3px;
    flex-shrink: 0;
    accent-color: var(--color-teal);
    width: 16px;
    height: 16px;
}
.terms-gate__checkbox-label a {
    color: var(--color-teal);
    text-decoration: none;
}
.terms-gate__checkbox-label a:hover {
    text-decoration: underline;
}

/* Auth mobile overrides */
@media (max-width: 480px) {
    .auth-page {
        padding: 32px 12px;
    }
    .auth-success-card {
        padding: 24px 20px;
    }
    .terms-gate__body {
        padding: 20px;
    }
}