/* RHP - Customer Research Single Page Site */
/* Typography: Instrument Serif (headings) + DM Sans (body) */
/* Palette: Deep navy, warm amber accents, clean neutrals */

:root {
    --color-bg: #0f172a;
    --color-bg-elevated: #1e293b;
    --color-text: #f1f5f9;
    --color-text-muted: #94a3b8;
    --color-accent: #f59e0b;
    --color-accent-hover: #fbbf24;
    --color-border: rgba(148, 163, 184, 0.2);
    --font-serif: 'Instrument Serif', Georgia, serif;
    --font-sans: 'DM Sans', system-ui, sans-serif;
    --max-width: 1200px;
    --section-padding: clamp(4rem, 10vw, 8rem);
}

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

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: var(--font-sans);
    font-size: 1.0625rem;
    line-height: 1.65;
    color: var(--color-text);
    background: var(--color-bg);
    -webkit-font-smoothing: antialiased;
}

/* Header & Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: 1.25rem 1.5rem;
    background: rgba(15, 23, 42, 0.85);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
}

.nav {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    color: var(--color-text);
}

.logo-svg {
    height: 40px;
    width: auto;
    display: block;
}

.logo-svg-footer {
    height: 32px;
    opacity: 0.9;
}

.footer-links {
    margin: 0 0 1rem;
}

.footer-links a {
    color: var(--color-text-muted);
    text-decoration: none;
}

.footer-links a:hover {
    color: var(--color-accent);
}

.nav-links {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 2rem;
}

.nav-links a {
    color: var(--color-text-muted);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9375rem;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--color-accent);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
}

/* Hero */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 8rem 1.5rem 4rem;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background-image: url('https://images.unsplash.com/photo-1552664730-d307ca884978?w=1920&q=80');
    background-size: cover;
    background-position: center;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(15, 23, 42, 0.92) 0%, rgba(15, 23, 42, 0.75) 100%);
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 720px;
    text-align: center;
}

.hero h1 {
    font-family: var(--font-serif);
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 400;
    line-height: 1.15;
    margin: 0 0 1.5rem;
    letter-spacing: -0.02em;
}

.hero h1 em {
    font-style: italic;
    color: var(--color-accent);
}

.hero-tagline {
    font-size: 1.25rem;
    color: var(--color-text-muted);
    margin: 0 0 2.5rem;
    max-width: 560px;
    margin-left: auto;
    margin-right: auto;
}

.btn {
    display: inline-block;
    padding: 1rem 2rem;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.2s;
    cursor: pointer;
}

.btn-primary {
    background: var(--color-accent);
    color: var(--color-bg);
}

.btn-primary:hover {
    background: var(--color-accent-hover);
    transform: translateY(-2px);
}

.btn-large {
    padding: 1.25rem 2.5rem;
    font-size: 1.125rem;
}

/* Section common */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem;
}

.section-title {
    font-family: var(--font-serif);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 400;
    margin: 0 0 1rem;
    letter-spacing: -0.02em;
}

.section-intro {
    font-size: 1.25rem;
    color: var(--color-text-muted);
    max-width: 640px;
    margin: 0 0 3rem;
}

/* Proof / Stats */
.proof {
    padding: var(--section-padding) 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

.stat-card {
    background: var(--color-bg-elevated);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 2rem;
    transition: border-color 0.2s, transform 0.2s;
}

.stat-card:hover {
    border-color: rgba(245, 158, 11, 0.4);
    transform: translateY(-4px);
}

.stat-number {
    display: block;
    font-family: var(--font-serif);
    font-size: 2.5rem;
    color: var(--color-accent);
    margin-bottom: 0.5rem;
}

.stat-label {
    margin: 0;
    font-size: 0.9375rem;
    color: var(--color-text-muted);
}

/* Methodologies */
.methodologies {
    padding: var(--section-padding) 0;
    background: var(--color-bg-elevated);
}

.methodology-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.methodology-card {
    background: var(--color-bg);
    border-radius: 12px;
    overflow: hidden;
    border: 1px solid var(--color-border);
    transition: border-color 0.2s, transform 0.2s;
}

.methodology-card:hover {
    border-color: rgba(245, 158, 11, 0.3);
    transform: translateY(-4px);
}

.methodology-image {
    aspect-ratio: 16/10;
    overflow: hidden;
}

.methodology-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s;
}

.methodology-card:hover .methodology-image img {
    transform: scale(1.05);
}

.methodology-content {
    padding: 1.75rem;
}

.methodology-content h3 {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 400;
    margin: 0 0 0.75rem;
}

.methodology-content p {
    margin: 0;
    color: var(--color-text-muted);
    font-size: 0.9375rem;
}

/* Approach */
.approach {
    position: relative;
    padding: var(--section-padding) 0;
    overflow: hidden;
}

.approach-bg {
    position: absolute;
    inset: 0;
    background-image: url('https://images.unsplash.com/photo-1522071820081-009f0129c71c?w=1920&q=80');
    background-size: cover;
    background-position: center;
}

.approach-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, rgba(15, 23, 42, 0.9) 0%, rgba(15, 23, 42, 0.95) 100%);
}

.approach-content {
    position: relative;
    z-index: 1;
}

.approach-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2.5rem;
    margin-top: 3rem;
}

.approach-step {
    padding: 1.5rem 0;
    border-top: 1px solid var(--color-border);
}

.step-number {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-accent);
    letter-spacing: 0.1em;
    margin-bottom: 0.75rem;
}

.approach-step h3 {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 400;
    margin: 0 0 0.5rem;
}

.approach-step p {
    margin: 0;
    color: var(--color-text-muted);
    font-size: 0.9375rem;
}

/* CTA */
.cta {
    padding: var(--section-padding) 0;
    text-align: center;
}

.cta .section-title {
    margin-bottom: 1rem;
}

.cta-text {
    font-size: 1.25rem;
    color: var(--color-text-muted);
    margin: 0 0 2rem;
    max-width: 560px;
    margin-left: auto;
    margin-right: auto;
}

/* Footer */
.footer {
    padding: 3rem 1.5rem;
    border-top: 1px solid var(--color-border);
}

.footer-content {
    max-width: var(--max-width);
    margin: 0 auto;
    text-align: center;
}

.logo-footer .logo-svg {
    height: 32px;
    margin: 0 auto 0.75rem;
}

.footer-tagline {
    font-size: 0.9375rem;
    color: var(--color-text-muted);
    margin: 0 0 1rem;
}

.footer-legal {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    opacity: 0.7;
    margin: 0;
}

/* Mobile */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .nav-toggle {
        display: flex;
    }

    .nav.nav-open .nav-links {
        display: flex;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--color-bg-elevated);
        padding: 1.5rem;
        gap: 1rem;
        border-bottom: 1px solid var(--color-border);
    }

    .hero {
        min-height: 90vh;
    }

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

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