/* ============================================
   THE CLIMATE LEDGER — DESIGN SYSTEM V3
   Trainline Group Executive Architecture Theme
   Colors: Trainline Mint (#00a88f / #0fa98f),
   Deep Forest Teal (#002326), Pure White (#ffffff),
   Soft Executive Grey (#f4f6f5), Pitch Black (#000000)
   ============================================ */

/* --- CSS Custom Properties --- */
:root {
    /* Exact Trainline & Logo Colors */
    --bg-mint: #00a88f;
    --bg-mint-hover: #00876c;
    --bg-mint-dark: #002326;
    --bg-mint-deep: #00191c;
    --bg-mint-light: #e6faf6;
    --bg-mint-subtle: #f0fbf9;
    --bg-grey: #f4f6f5;
    --bg-grey-mid: #eeecec;
    --bg-white: #ffffff;
    --bg-black: #000000;

    /* Legacy compatibility tokens */
    --bg-primary: #ffffff;
    --bg-secondary: #f4f6f5;
    --bg-tertiary: #002326;
    --bg-card: #ffffff;

    --accent-emerald: #00a88f;
    --accent-emerald-light: #2dd4bf;
    --accent-emerald-dark: #00876c;
    --accent-teal: #00a88f;
    --accent-cyan: #00d4a4;
    --accent-mint: #2dd4bf;
    --accent-blue: #0284c7;
    --accent-gold: #f59e0b;

    /* Primary Brand Action Colors */
    --accent-main: #00a88f;
    --accent-main-hover: #00876c;
    --accent-main-light: #2dd4bf;
    --accent-main-rgb: 0, 168, 143;
    --accent-cyan-rgb: 0, 212, 164;

    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #00a88f 0%, #00876c 100%);
    --gradient-hero: linear-gradient(180deg, #002326 0%, #00191c 100%);
    --gradient-card: #ffffff;
    --gradient-glow: radial-gradient(ellipse at center, rgba(0, 168, 143, 0.15) 0%, transparent 70%);

    /* High-Definition Card System */
    --card-bg: #ffffff;
    --card-border: rgba(0, 168, 143, 0.25);
    --card-border-hover: #00a88f;
    --glass-bg: #ffffff;
    --glass-bg-hover: #fcfdfd;
    --glass-border: #e2e8f0;
    --glass-border-hover: #00a88f;

    /* Text */
    --text-primary: #111827;
    --text-heading: #002326;
    --text-secondary: #4b5563;
    --text-tertiary: #6b7280;
    --text-light: #ffffff;
    --text-mint: #00a88f;

    /* Typography */
    --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    --space-4xl: 6rem;
    --space-5xl: 8rem;

    /* Borders */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-2xl: 32px;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 35, 38, 0.06);
    --shadow-md: 0 4px 16px rgba(0, 35, 38, 0.08);
    --shadow-lg: 0 10px 30px rgba(0, 35, 38, 0.12);
    --shadow-xl: 0 20px 50px rgba(0, 35, 38, 0.16);
    --shadow-card: 0 8px 24px rgba(0, 35, 38, 0.08);

    /* Transitions */
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
    --duration-fast: 0.2s;
    --duration-normal: 0.35s;
    --duration-slow: 0.7s;

    /* Z-indexes */
    --z-canvas: -1;
    --z-content: 1;
    --z-navbar: 150;
    --z-mobile-menu: 100;
    --z-modal: 200;
    --z-widget: 300;
    --z-transition: 999;

    /* Container */
    --container-max: 1280px;
    --container-padding: 1.5rem;
}

/* --- Reset & Base --- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.7;
    color: var(--text-primary);
    background-color: #ffffff;
    overflow-x: hidden;
    min-height: 100vh;
    position: relative;
}

/* Three.js Canvas Background (subtle particle ambience behind hero) */
#three-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    z-index: 1;
    pointer-events: none;
    opacity: 0.75;
}

/* --- Trainline Section Utility Themes --- */
.background-mint {
    background-color: var(--bg-mint) !important;
    color: #ffffff !important;
}

.background-mint-dark {
    background-color: var(--bg-mint-dark) !important;
    color: #ffffff !important;
}

.background-white {
    background-color: #ffffff !important;
    color: var(--text-primary) !important;
}

.background-grey {
    background-color: var(--bg-grey) !important;
    color: var(--text-primary) !important;
}

.background-black {
    background-color: #000000 !important;
    color: #ffffff !important;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    line-height: 1.15;
    letter-spacing: -0.02em;
    color: var(--text-heading);
    font-weight: 700;
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4.25rem);
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.08;
}

h2 {
    font-size: clamp(1.85rem, 3.2vw, 2.65rem);
    font-weight: 700;
    letter-spacing: -0.02em;
}

h3 {
    font-size: clamp(1.25rem, 2vw, 1.6rem);
    font-weight: 700;
}

h4 {
    font-size: 1.15rem;
    font-weight: 600;
}

p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.7;
}

/* Text in dark sections */
.background-mint-dark h1,
.background-mint-dark h2,
.background-mint-dark h3,
.background-mint-dark h4,
.background-mint-dark p,
.background-mint-dark span,
.background-mint h1,
.background-mint h2,
.background-mint h3,
.background-mint h4,
.background-mint p,
.background-mint span,
.background-black h1,
.background-black h2,
.background-black h3,
.background-black h4,
.background-black p,
.background-black span {
    color: #ffffff;
}

.background-mint-dark h2.heading,
.background-mint-dark .section-heading-mint {
    color: #2dd4bf !important;
}

a {
    color: var(--accent-main);
    text-decoration: none;
    transition: all var(--duration-fast) var(--ease-out);
}

a:hover {
    color: var(--bg-mint-hover);
}

:focus-visible {
    outline: 2px solid var(--accent-main);
    outline-offset: 3px;
    border-radius: var(--radius-sm);
}

/* --- Trainline Universal Card Architecture --- */
.card,
.service-preview-card,
.service-card,
.service-card-full,
.article-card,
.spotlight-card,
.feature-card,
.padded-card,
.dashboard-card,
.modal-card,
.briefing-modal-card,
.dash-card,
.dash-booking-card,
.booking-form-section,
.booking-summary,
.contact-form-card,
.contact-channel,
.inquiry-card,
.about-console-card,
.about-quote-box,
.pillar-card-v2,
.value-card-v2,
.team-card-v2,
.category-score-card,
.expert-card,
.research-card {
    background: #ffffff !important;
    border: 1px solid #e2e8f0 !important;
    border-radius: var(--radius-lg) !important;
    box-shadow: var(--shadow-card) !important;
    color: var(--text-primary) !important;
    transition: transform var(--duration-normal) var(--ease-out),
                box-shadow var(--duration-normal) var(--ease-out),
                border-color var(--duration-fast) ease !important;
}

.card:hover,
.service-preview-card:hover,
.service-card:hover,
.article-card:hover,
.spotlight-card:hover,
.feature-card:hover,
.padded-card:hover,
.dash-card:hover,
.pillar-card-v2:hover,
.value-card-v2:hover,
.team-card-v2:hover,
.expert-card:hover {
    transform: translateY(-6px) !important;
    border-color: var(--accent-main) !important;
    box-shadow: 0 16px 36px rgba(0, 35, 38, 0.12) !important;
}

/* Headings inside white cards */
.card h1, .card h2, .card h3, .card h4,
.service-preview-card h3,
.service-card h3,
.article-card h3,
.spotlight-card h3,
.padded-card h3,
.padded-card .subheading,
.team-card-v2 h3,
.expert-card h3,
.contact-form-card h3,
.booking-form-section h3 {
    color: var(--text-heading) !important;
    font-weight: 700 !important;
}

/* Paragraphs inside white cards */
.card p,
.service-preview-card p,
.service-card p,
.article-card p,
.spotlight-card p,
.padded-card p,
.padded-card__content p,
.excerpt-text,
.team-card-v2 p,
.expert-card p,
.contact-form-card p {
    color: #4b5563 !important;
    line-height: 1.65 !important;
}

/* Meta, badges & read briefing link */
.article-read-time,
.spotlight-read-time,
.article-card-meta span {
    color: #6b7280 !important;
    font-size: 0.88rem !important;
    font-weight: 600 !important;
}

.btn-read-more,
.card-arrow,
.padded-card__link a {
    color: var(--accent-main) !important;
    font-weight: 700 !important;
    font-size: 0.95rem !important;
    display: inline-flex !important;
    align-items: center !important;
    gap: 8px !important;
    text-decoration: none !important;
    transition: gap 0.2s ease !important;
}

.btn-read-more:hover,
.card-arrow:hover,
.padded-card__link a:hover {
    color: var(--bg-mint-hover) !important;
    gap: 12px !important;
}

/* Universal High-Definition Form Inputs */
.form-input,
.form-select,
.form-textarea,
.esg-form-input,
.esg-form-select,
.footer-input {
    background: #ffffff !important;
    border: 1.5px solid #d1d5db !important;
    border-radius: var(--radius-sm) !important;
    color: #111827 !important;
    font-family: var(--font-body) !important;
    font-size: 0.98rem !important;
    font-weight: 500 !important;
    padding: 0.85rem 1.15rem !important;
    outline: none !important;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05) !important;
    transition: border-color 0.2s ease, box-shadow 0.2s ease !important;
    width: 100%;
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus,
.esg-form-input:focus,
.esg-form-select:focus {
    border-color: var(--accent-main) !important;
    box-shadow: 0 0 0 3px rgba(0, 168, 143, 0.2) !important;
}

.form-input::placeholder,
.form-textarea::placeholder {
    color: #9ca3af !important;
}

/* Layout */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

.main-content {
    position: relative;
    z-index: var(--z-content);
    min-height: 100vh;
}

.section {
    padding: 5rem 0;
    position: relative;
}

/* Trainline Universal Page Hero Banner */
.page-hero {
    background-color: var(--bg-mint-dark) !important;
    padding: 160px 0 70px !important;
    text-align: center;
    position: relative;
    color: #ffffff !important;
}

.page-hero h1 {
    font-size: clamp(2.4rem, 4.5vw, 3.8rem) !important;
    font-weight: 800 !important;
    color: #ffffff !important;
    margin-bottom: 1rem !important;
    letter-spacing: -0.02em !important;
}

.page-hero p {
    color: #e6faf6 !important;
    font-size: 1.15rem !important;
    max-width: 720px !important;
    margin: 0.75rem auto 0 !important;
    line-height: 1.7 !important;
}

.page-hero .section-label {
    display: inline-block;
    background: rgba(255, 255, 255, 0.15) !important;
    border: 1px solid rgba(255, 255, 255, 0.35) !important;
    color: #ffffff !important;
    font-weight: 700;
    border-radius: 9999px;
    padding: 0.35rem 1rem;
    font-size: 0.82rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 1rem;
}

.section-header {
    text-align: center;
    margin-bottom: 3.5rem;
}

.section-header .section-label {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--accent-main);
    text-transform: uppercase;
    letter-spacing: 0.12em;
    margin-bottom: var(--space-sm);
    padding: 0.35rem 1rem;
    border: 1px solid rgba(0, 168, 143, 0.3);
    border-radius: var(--radius-full);
    background: #e6faf6;
}

.background-mint-dark .section-header .section-label,
.background-mint .section-header .section-label {
    background: rgba(255, 255, 255, 0.15) !important;
    border-color: rgba(255, 255, 255, 0.4) !important;
    color: #ffffff !important;
}

.section-header h2 {
    margin-bottom: var(--space-md);
}

.section-header p {
    margin: 0 auto;
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 760px;
}

/* Grids */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--space-xl); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-xl); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-xl); }

@media (max-width: 1024px) {
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .section { padding: 3.5rem 0; }
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f5f9;
}

::-webkit-scrollbar-thumb {
    background: #cbd5e1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #94a3b8;
}

/* Selection */
::selection {
    background: rgba(0, 168, 143, 0.25);
    color: #002326;
}

/* Page Transition Overlay */
.page-transition {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #002326;
    z-index: var(--z-transition);
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.3s var(--ease-out);
}

.page-transition.active {
    opacity: 1;
    pointer-events: all;
}

/* Utilities */
.text-center { text-align: center; }
.text-accent { color: var(--accent-main); }
.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-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; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-gap { gap: var(--space-md); }
.flex-wrap { flex-wrap: wrap; }
.hidden { display: none !important; }