/* ==========================================================================
   Design System & Styling Variables
   ========================================================================== */
:root {
    /* Fonts */
    --font-heading: 'Prompt', sans-serif;
    --font-body: 'Sarabun', sans-serif;

    /* Color Palette */
    --color-bg-primary: #ffffff;
    --color-bg-secondary: #f8fafc; /* Slate 50 - extremely light cool gray */
    --color-text-primary: #0f172a; /* Slate 900 - dark charcoal */
    --color-text-secondary: #334155; /* Slate 700 - medium dark gray */
    --color-text-muted: #64748b; /* Slate 500 - gray for supporting text */
    
    /* Accents */
    --color-accent-indigo: #4f46e5; /* Indigo 600 */
    --color-accent-indigo-hover: #4338ca; /* Indigo 700 */
    --color-accent-cyan: #0891b2; /* Cyan 600 */
    
    /* UI Structure */
    --color-border: #e2e8f0; /* Slate 200 */
    --color-border-light: rgba(226, 232, 240, 0.5);
    
    /* Transition Systems */
    --transition-fast: 0.2s ease;
    --transition-medium: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Layout Constants */
    --max-width: 1200px;
    --max-width-narrow: 800px;
    --header-height: 80px;
    
    /* Shadows - extremely light to preserve minimal feel */
    --shadow-subtle: 0 1px 3px 0 rgba(0, 0, 0, 0.05), 0 1px 2px 0 rgba(0, 0, 0, 0.03);
    --shadow-card-hover: 0 10px 25px -5px rgba(15, 23, 42, 0.04), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
}

/* ==========================================================================
   Global Resets & Base Styles
   ========================================================================== */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
    scroll-padding-top: var(--header-height);
}

body {
    font-family: var(--font-body);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

/* Headings */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--color-text-primary);
    font-weight: 600;
    line-height: 1.3;
}

/* Utility Containers */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin-left: auto;
    margin-right: auto;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
}

.container-narrow {
    width: 100%;
    max-width: var(--max-width-narrow);
    margin-left: auto;
    margin-right: auto;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
}

.section-padding {
    padding-top: 6rem;
    padding-bottom: 6rem;
}

.alt-bg {
    background-color: var(--color-bg-secondary);
}

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

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.75rem;
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 500;
    border-radius: 8px;
    border: 1px solid transparent;
    cursor: pointer;
    text-decoration: none;
    transition: all var(--transition-fast);
}

.btn-primary {
    background-color: var(--color-accent-indigo);
    color: #ffffff;
}

.btn-primary:hover {
    background-color: var(--color-accent-indigo-hover);
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: var(--color-bg-secondary);
    color: var(--color-text-primary);
    border-color: var(--color-border);
}

.btn-secondary:hover {
    background-color: #f1f5f9;
    border-color: #cbd5e1;
    transform: translateY(-1px);
}

.btn-outline {
    background-color: transparent;
    color: var(--color-text-primary);
    border-color: var(--color-border);
}

.btn-outline:hover {
    background-color: var(--color-bg-secondary);
    border-color: var(--color-text-muted);
    transform: translateY(-1px);
}

.btn-large {
    padding: 0.9rem 2.25rem;
    font-size: 1.05rem;
    border-radius: 10px;
}

/* ==========================================================================
   Header / Navigation Menu
   ========================================================================== */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border-light);
    z-index: 1000;
    transition: all var(--transition-fast);
}

.site-header.is-scrolled {
    background-color: rgba(255, 255, 255, 0.95);
    box-shadow: 0 4px 20px -5px rgba(15, 23, 42, 0.03);
    border-bottom: 1px solid var(--color-border);
}

.header-container {
    height: 100%;
    max-width: var(--max-width);
    margin-left: auto;
    margin-right: auto;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-logo {
    font-family: var(--font-heading);
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--color-text-primary);
    text-decoration: none;
    letter-spacing: -0.01em;
}

.logo-accent {
    color: var(--color-accent-indigo);
}

.nav-list {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 2.25rem;
}

.nav-link {
    font-family: var(--font-heading);
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    text-decoration: none;
    padding: 0.5rem 0;
    position: relative;
    transition: color var(--transition-fast);
}

.nav-link:hover {
    color: var(--color-accent-indigo);
}

/* Active Nav Indicator Link */
.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--color-accent-indigo);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform var(--transition-fast);
}

.nav-link.active {
    color: var(--color-accent-indigo);
}

.nav-link.active::after {
    transform: scaleX(1);
    transform-origin: left;
}

/* Hamburger toggle for mobile */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: transparent;
    border: none;
    cursor: pointer;
    z-index: 1001;
}

.hamburger-bar {
    width: 100%;
    height: 2px;
    background-color: var(--color-text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
    padding-top: calc(var(--header-height) + 4rem);
    display: flex;
    align-items: center;
    min-height: 90vh;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.15fr 0.85fr;
    gap: 4.5rem;
    align-items: center;
}

.hero-content {
    display: flex;
    flex-direction: column;
}

.tagline {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-accent-cyan);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    margin-bottom: 1.25rem;
}

.headline {
    font-size: 2.85rem;
    line-height: 1.25;
    font-weight: 700;
    margin-bottom: 1.5rem;
    letter-spacing: -0.015em;
}

.subtitle-wrap {
    margin-bottom: 1.75rem;
}

.subtitle-name {
    font-family: var(--font-heading);
    font-size: 1.4rem;
    font-weight: 500;
    color: var(--color-text-primary);
    display: block;
    margin-bottom: 0.25rem;
}

.subtitle-position {
    font-family: var(--font-heading);
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--color-accent-indigo);
}

.description {
    font-size: 1.05rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: 2.5rem;
}

.hero-actions {
    display: flex;
    gap: 1.25rem;
    align-items: center;
}

.hero-image-container {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-image-wrapper {
    position: relative;
    width: 100%;
    max-width: 400px;
    aspect-ratio: 4 / 5;
    border-radius: 20px;
    overflow: hidden;
    border: 1px solid var(--color-border);
    background-color: var(--color-bg-secondary);
    box-shadow: var(--shadow-subtle);
}

.hero-portrait {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* ==========================================================================
   Section Headers
   ========================================================================== */
.section-title {
    font-size: 2.15rem;
    font-weight: 700;
    margin-bottom: 1.75rem;
    letter-spacing: -0.01em;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    display: block;
    width: 40px;
    height: 3px;
    background-color: var(--color-accent-indigo);
    margin-top: 0.75rem;
}

.section-title.text-center::after {
    margin-left: auto;
    margin-right: auto;
}

.subsection-title {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 1.25rem;
}

/* ==========================================================================
   About Section
   ========================================================================== */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 5rem;
    align-items: start;
}

.highlight-paragraph {
    font-size: 1.15rem;
    font-weight: 500;
    color: var(--color-text-primary);
    line-height: 1.75;
    margin-bottom: 1.5rem;
}

.bio-text {
    font-size: 1rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: 1.25rem;
}

.bio-text:last-child {
    margin-bottom: 0;
}

.about-expertise {
    padding-top: 0.5rem;
}

.expertise-tags {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem 0.5rem;
}

.tag-pill {
    display: inline-flex;
    align-items: center;
    padding: 0.5rem 1.15rem;
    background-color: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    border-radius: 50px;
    font-family: var(--font-heading);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: all var(--transition-fast);
}

.tag-pill:hover {
    border-color: var(--color-accent-cyan);
    color: var(--color-text-primary);
    transform: translateY(-1px);
}

.pill-dot {
    display: inline-block;
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background-color: var(--color-accent-cyan);
    margin-right: 0.65rem;
}

/* ==========================================================================
   Services Section
   ========================================================================== */
.services-grid {
    display: grid;
    grid-template-columns: 0.9fr 1.1fr;
    gap: 5rem;
    align-items: start;
}

.services-intro {
    font-size: 1.05rem;
    color: var(--color-text-secondary);
    line-height: 1.75;
}

.services-list {
    list-style: none;
    display: flex;
    flex-direction: column;
}

.service-item {
    display: flex;
    align-items: flex-start;
    gap: 1.25rem;
    padding: 1.25rem 0;
    border-bottom: 1px solid var(--color-border);
}

.service-item:first-child {
    padding-top: 0;
}

.service-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.service-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--color-accent-indigo);
    width: 24px;
    height: 24px;
    flex-shrink: 0;
    margin-top: 0.15rem;
}

.service-icon svg {
    width: 100%;
    height: 100%;
}

.service-text {
    font-family: var(--font-heading);
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--color-text-primary);
}

/* ==========================================================================
   Core Idea Section
   ========================================================================== */
.core-idea-header {
    margin-bottom: 4.5rem;
}

.core-statement {
    font-size: 1.4rem;
    line-height: 1.65;
    font-weight: 500;
    color: var(--color-text-primary);
    margin-top: 1.5rem;
    margin-bottom: 1.5rem;
}

.core-explain {
    font-size: 1.05rem;
    color: var(--color-text-muted);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.roadmap-wrapper {
    margin-top: 2rem;
}

.roadmap-title {
    font-size: 1.2rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    margin-bottom: 3rem;
}

.roadmap-flow {
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
    width: 100%;
}

.roadmap-step {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    position: relative;
    z-index: 2;
    flex-shrink: 0;
}

.step-number {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background-color: var(--color-accent-indigo);
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 1.1rem;
    border: 4px solid var(--color-bg-secondary);
    box-shadow: 0 0 0 1px var(--color-border);
    margin-bottom: 1rem;
    transition: all var(--transition-fast);
}

.roadmap-step:hover .step-number {
    transform: scale(1.1);
    background-color: var(--color-accent-indigo-hover);
}

.step-label {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    width: 130px;
    line-height: 1.4;
}

.roadmap-connector {
    flex-grow: 1;
    height: 2px;
    background-color: var(--color-border);
    margin-top: -2.5rem; /* Offsets positioning relative to step labels */
    z-index: 1;
}

/* ==========================================================================
   Knowledge Hub Section
   ========================================================================== */
.knowledge-header {
    margin-bottom: 4rem;
}

.section-intro {
    font-size: 1.05rem;
    color: var(--color-text-secondary);
    max-width: 650px;
    margin-left: auto;
    margin-right: auto;
    margin-top: 1.25rem;
}

.knowledge-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2.25rem;
}

.knowledge-card {
    background-color: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    border-radius: 16px;
    padding: 2.75rem 2.25rem;
    display: flex;
    flex-direction: column;
    transition: all var(--transition-medium);
}

.knowledge-card:hover {
    transform: translateY(-4px);
    border-color: var(--color-accent-indigo);
    box-shadow: var(--shadow-card-hover);
}

.card-icon {
    color: var(--color-accent-cyan);
    margin-bottom: 1.75rem;
    width: 36px;
    height: 36px;
}

.card-icon svg {
    width: 100%;
    height: 100%;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--color-text-primary);
}

.card-description {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    line-height: 1.65;
    margin-bottom: 1.25rem;
    flex-grow: 1;
}

.card-source {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    margin-bottom: 1.75rem;
    font-style: italic;
}

.card-link {
    margin-top: auto;
    font-family: var(--font-heading);
    color: var(--color-accent-indigo);
    font-size: 0.95rem;
    font-weight: 600;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: color var(--transition-fast);
}

.card-link:hover {
    color: var(--color-accent-indigo-hover);
}

.arrow-icon {
    width: 18px;
    height: 18px;
    transition: transform var(--transition-fast);
}

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

/* ==========================================================================
   Contact Section
   ========================================================================== */
.contact-description {
    font-size: 1.15rem;
    color: var(--color-text-secondary);
    margin-top: 1.25rem;
    margin-bottom: 3rem;
}

.contact-actions {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    align-items: center;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
    background-color: var(--color-bg-secondary);
    border-top: 1px solid var(--color-border);
    padding: 4.5rem 0 2.5rem 0;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.footer-logo {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: 0.5rem;
}

.footer-subtitle {
    font-family: var(--font-heading);
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--color-text-primary);
    margin-bottom: 0.25rem;
}

.footer-desc {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-bottom: 1.5rem;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.5rem 1.5rem;
    margin-bottom: 1.75rem;
}

.footer-links a {
    font-family: var(--font-heading);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

.footer-divider {
    width: 80px;
    height: 1px;
    background-color: var(--color-border);
    margin-bottom: 1.75rem;
}

.footer-copy {
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

/* ==========================================================================
   Responsive Breakpoints & Layout Adapters
   ========================================================================== */

/* Tablet and Smaller Screen Rules */
@media (max-width: 992px) {
    .section-padding {
        padding-top: 4.5rem;
        padding-bottom: 4.5rem;
    }
    
    /* Hero Adjustments */
    .hero-section {
        padding-top: calc(var(--header-height) + 2rem);
        min-height: auto;
    }
    
    .hero-grid {
        grid-template-columns: 1fr;
        gap: 3.5rem;
        text-align: center;
    }
    
    .hero-image-container {
        order: -1; /* Display portrait above content on smaller screens */
    }
    
    .hero-image-wrapper {
        max-width: 300px;
    }
    
    .headline {
        font-size: 2.25rem;
    }
    
    .description {
        max-width: 600px;
        margin-left: auto;
        margin-right: auto;
        margin-bottom: 2rem;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    /* About & Services Adjustments */
    .about-grid,
    .services-grid {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    
    .services-intro {
        margin-bottom: 1.5rem;
    }
    
    /* Knowledge Hub Cards Layout */
    .knowledge-grid {
        grid-template-columns: 1fr;
        gap: 1.75rem;
        max-width: 450px;
        margin-left: auto;
        margin-right: auto;
    }
    
    /* Roadmap Responsive Layout (Horizontal -> Vertical Timeline) */
    .roadmap-flow {
        flex-direction: column;
        align-items: flex-start;
        gap: 2rem;
        padding-left: 2rem;
    }
    
    .roadmap-flow::before {
        content: '';
        position: absolute;
        left: calc(2rem + 22px);
        top: 0;
        bottom: 0;
        width: 2px;
        background-color: var(--color-border);
        z-index: 1;
    }
    
    .roadmap-step {
        flex-direction: row;
        text-align: left;
        gap: 1.5rem;
        width: 100%;
    }
    
    .step-number {
        margin-bottom: 0;
        border: 4px solid var(--color-bg-secondary);
        box-shadow: 0 0 0 1px var(--color-border);
    }
    
    .step-label {
        width: auto;
        font-size: 0.95rem;
        padding-top: 0.25rem;
    }
    
    .roadmap-connector {
        display: none;
    }
}

/* Mobile & Menu Drawer Toggle Rules */
@media (max-width: 768px) {
    /* Header & Navigation drawer rules */
    .menu-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: var(--header-height);
        right: -100%;
        width: 80%;
        max-width: 300px;
        height: calc(100vh - var(--header-height));
        background-color: var(--color-bg-primary);
        box-shadow: -8px 10px 30px rgba(15, 23, 42, 0.05);
        padding: 3rem 2.25rem;
        transition: right var(--transition-medium);
        z-index: 999;
    }
    
    .nav-menu.is-active {
        right: 0;
    }
    
    .nav-list {
        flex-direction: column;
        align-items: flex-start;
        gap: 2rem;
    }
    
    .nav-link {
        font-size: 1.1rem;
        width: 100%;
        display: block;
    }
    
    /* Toggle Close State animation */
    .menu-toggle.is-active .hamburger-bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }
    
    .menu-toggle.is-active .hamburger-bar:nth-child(2) {
        opacity: 0;
    }
    
    .menu-toggle.is-active .hamburger-bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }
    
    /* Contact and Actions on small screen */
    .contact-actions {
        flex-direction: column;
        gap: 1rem;
    }
    
    .contact-actions .btn {
        width: 100%;
    }
}
.current-roles-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: 0.45rem;
}

.current-roles-list li {
    color: var(--text-main);
    line-height: 1.7;
}