/* ==========================================================================
   DESIGN SYSTEM & VARIABLES
   ========================================================================== */
:root {
    /* Color Palette - Modern Minimalist Warm Light */
    --color-bg-primary: #fafaf9;
    --color-bg-secondary: #f5f5f4;
    --color-text-primary: #1c1917;
    --color-text-muted: #78716c;
    --color-accent-indigo: #475569;
    --color-accent-indigo-hover: #1e293b;
    --color-accent-soft: #f1f5f9;
    --color-border: #e7e5e4;
    --color-white: #ffffff;
    
    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-serif: 'Playfair Display', Georgia, Cambria, "Times New Roman", serif;
    
    /* Spacing System */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2.5rem;
    --space-xl: 4rem;
    --space-xxl: 6rem;
    
    /* Grid & Layout */
    --max-width: 1140px;
    --max-width-md: 760px;
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 16px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.04), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
    --shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.06), 0 8px 10px -6px rgba(0, 0, 0, 0.06);
    
    /* Transitions */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

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

a {
    color: inherit;
    text-decoration: none;
    transition: var(--transition-fast);
}

ul {
    list-style: none;
}

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

input, textarea, button {
    font-family: inherit;
    font-size: inherit;
    color: inherit;
    outline: none;
    border: none;
}

/* ==========================================================================
   REUSABLE UTILITIES
   ========================================================================== */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin-left: auto;
    margin-right: auto;
    padding-left: var(--space-md);
    padding-right: var(--space-md);
}

.max-width-md {
    max-width: var(--max-width-md);
}

.grid-2 {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-lg);
}

.grid-3 {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-lg);
}

@media (min-width: 768px) {
    .grid-2 {
        grid-template-columns: repeat(2, 1fr);
    }
    .grid-3 {
        grid-template-columns: repeat(3, 1fr);
    }
}

.section-spacing {
    padding-top: var(--space-xxl);
    padding-bottom: var(--space-xxl);
}

.border-top {
    border-top: 1px solid var(--color-border);
}

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

.text-serif {
    font-family: var(--font-serif);
    font-style: italic;
    font-weight: 400;
}

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

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

/* ==========================================================================
   BUTTONS
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius-sm);
    font-weight: 500;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition-fast);
}

.btn-primary {
    background-color: var(--color-text-primary);
    color: var(--color-bg-primary);
    border: 1px solid var(--color-text-primary);
}

.btn-primary:hover {
    background-color: var(--color-accent-indigo);
    border-color: var(--color-accent-indigo);
    color: var(--color-white);
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-text-primary);
    border: 1px solid var(--color-border);
}

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

.btn-outline {
    background-color: transparent;
    color: var(--color-text-primary);
    border: 1px solid var(--color-text-primary);
}

.btn-outline:hover {
    background-color: var(--color-text-primary);
    color: var(--color-bg-primary);
}

.btn-block {
    display: flex;
    width: 100%;
}

/* ==========================================================================
   HEADER / NAVIGATION
   ========================================================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: rgba(250, 250, 249, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(231, 229, 228, 0.5);
    transition: var(--transition-normal);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    font-family: var(--font-sans);
    font-weight: 700;
    font-size: 1.3rem;
    letter-spacing: -0.5px;
    display: flex;
    align-items: center;
}

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

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

.nav-menu {
    display: none; /* Hidden on mobile by default */
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--color-text-muted);
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.lang-switcher {
    display: inline-flex;
    align-items: center;
    border: 1px solid var(--color-border);
    padding: 2px;
    border-radius: var(--border-radius-sm);
    background-color: var(--color-bg-secondary);
}

.lang-btn {
    background: transparent;
    cursor: pointer;
    color: var(--color-text-muted);
    padding: 2px 6px;
    border-radius: 2px;
    transition: var(--transition-fast);
    font-size: 0.7rem;
    font-weight: 700;
}

.lang-btn.active {
    color: var(--color-text-primary);
    background-color: var(--color-white);
    box-shadow: var(--shadow-sm);
}

.lang-btn:hover:not(.active) {
    color: var(--color-text-primary);
}

/* Language Visibility & Typography Rules */
html[lang="en"] .lang-th {
    display: none !important;
}
html[lang="th"] .lang-en {
    display: none !important;
}
html[lang="th"] {
    --font-sans: 'Noto Sans Thai', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-serif: 'Chonburi', var(--font-sans);
}

/* Mobile Nav Toggle Icon */
.nav-toggle {
    display: block;
    background: transparent;
    cursor: pointer;
}

.nav-toggle .bar {
    display: block;
    width: 24px;
    height: 2px;
    margin: 5px auto;
    background-color: var(--color-text-primary);
    transition: var(--transition-fast);
}

/* Header state on scroll (extra shadow/compact) */
.header-scrolled {
    height: 60px;
    box-shadow: var(--shadow-sm);
}

.header-scrolled .nav {
    height: 60px;
}

/* Mobile Menu Open State */
@media (max-width: 767px) {
    .nav-menu.active {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background-color: var(--color-bg-primary);
        border-bottom: 1px solid var(--color-border);
        padding: var(--space-md) var(--space-md) var(--space-lg);
        gap: var(--space-md);
        box-shadow: var(--shadow-lg);
        animation: slideDown var(--transition-normal);
    }
    
    .nav-toggle.active .bar:nth-child(2) {
        opacity: 0;
    }
    
    .nav-toggle.active .bar:nth-child(1) {
        transform: translateY(7px) rotate(45deg);
    }
    
    .nav-toggle.active .bar:nth-child(3) {
        transform: translateY(-7px) rotate(-45deg);
    }
}

/* Desktop Navigation */
@media (min-width: 768px) {
    .nav-menu {
        display: flex;
        align-items: center;
        gap: var(--space-lg);
    }
    
    .nav-toggle {
        display: none;
    }
    
    .nav-btn {
        padding: 0.5rem 1rem;
        font-size: 0.85rem;
    }
}

/* ==========================================================================
   HERO SECTION
   ========================================================================== */
.hero {
    display: flex;
    flex-direction: column-reverse;
    justify-content: center;
    min-height: 100vh;
    padding-top: 100px;
    padding-bottom: var(--space-xl);
    gap: var(--space-lg);
}

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

.hero-subtitle {
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--color-accent-indigo);
    margin-bottom: var(--space-xs);
}

.hero-title {
    font-size: 2.5rem;
    line-height: 1.15;
    font-weight: 700;
    margin-bottom: var(--space-md);
    letter-spacing: -1px;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--color-text-muted);
    margin-bottom: var(--space-lg);
    max-width: 580px;
}

.hero-actions {
    display: flex;
    gap: var(--space-sm);
}

.hero-visual {
    display: flex;
    align-items: center;
    justify-content: center;
    max-width: 300px;
    margin: 0 auto;
}

.profile-image-wrapper {
    position: relative;
    width: 280px;
    height: 280px;
    margin: 0 auto;
}

.profile-image-backdrop {
    position: absolute;
    top: 15px;
    left: 15px;
    width: 100%;
    height: 100%;
    border: 2px solid var(--color-accent-indigo);
    border-radius: var(--border-radius-md);
    z-index: 1;
    transition: var(--transition-normal);
}

.profile-image-container {
    position: relative;
    width: 100%;
    height: 100%;
    border-radius: var(--border-radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    border: 4px solid var(--color-white);
    z-index: 2;
}

.profile-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition-slow);
}

.profile-image-wrapper:hover .profile-image {
    transform: scale(1.05);
}

.profile-image-wrapper:hover .profile-image-backdrop {
    transform: translate(-8px, -8px);
}

@media (min-width: 768px) {
    .hero {
        flex-direction: row;
        align-items: center;
        gap: var(--space-xl);
    }
    
    .hero-content {
        flex: 1.2;
    }
    
    .hero-visual {
        flex: 0.8;
        max-width: 100%;
    }
    
    .hero-title {
        font-size: 3.8rem;
    }
}

/* ==========================================================================
   ABOUT SECTION
   ========================================================================== */
.section-title {
    font-family: var(--font-serif);
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: var(--space-lg);
    position: relative;
}

.about-lead {
    font-size: 1.2rem;
    font-weight: 500;
    margin-bottom: var(--space-md);
    color: var(--color-text-primary);
}

.about-text p {
    margin-bottom: var(--space-md);
}

.about-illustration {
    display: flex;
    align-items: center;
    justify-content: center;
}

.illustration-wrapper {
    position: relative;
    width: 100%;
    max-width: 420px;
    aspect-ratio: 4 / 3;
}

.illustration-backdrop {
    position: absolute;
    top: 15px;
    left: 15px;
    width: 100%;
    height: 100%;
    border: 2px solid var(--color-accent-indigo);
    border-radius: var(--border-radius-md);
    z-index: 1;
    transition: var(--transition-normal);
}

.illustration-container {
    position: relative;
    width: 100%;
    height: 100%;
    border-radius: var(--border-radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    border: 4px solid var(--color-white);
    z-index: 2;
    background-color: var(--color-bg-secondary);
}

.illustration-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition-slow);
}

.illustration-wrapper:hover .illustration-image {
    transform: scale(1.03);
}

.illustration-wrapper:hover .illustration-backdrop {
    transform: translate(-8px, -8px);
}

/* ==========================================================================
   EXPERIENCE (TIMELINE)
   ========================================================================== */
.timeline {
    position: relative;
    padding-left: 1.5rem;
    margin-top: var(--space-xl);
}

.timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 4px;
    width: 2px;
    height: 100%;
    background-color: var(--color-border);
}

.timeline-item {
    position: relative;
    margin-bottom: var(--space-xl);
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-marker {
    position: absolute;
    top: 6px;
    left: -1.5rem;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: var(--color-bg-secondary);
    border: 2px solid var(--color-accent-indigo);
    transition: var(--transition-fast);
}

.timeline-item:hover .timeline-marker {
    background-color: var(--color-accent-indigo);
    transform: scale(1.3);
}

.timeline-content {
    background-color: var(--color-white);
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
}

.timeline-date {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--color-accent-indigo);
    letter-spacing: 0.5px;
    display: inline-block;
    margin-bottom: var(--space-xs);
}

.timeline-role {
    font-size: 1.25rem;
    font-weight: 600;
}

.timeline-company {
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 500;
    font-style: italic;
    color: var(--color-text-muted);
    margin-bottom: var(--space-sm);
}

.timeline-desc {
    color: var(--color-text-muted);
    font-size: 0.95rem;
    margin-bottom: var(--space-md);
}

.timeline-bullets {
    list-style-type: none;
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

.timeline-bullets li {
    position: relative;
    padding-left: 1.2rem;
    margin-bottom: 0.5rem;
}

.timeline-bullets li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--color-accent-indigo);
}

/* ==========================================================================
   PROJECTS
   ========================================================================== */
.project-card {
    background-color: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-sm);
    overflow: hidden;
    transition: var(--transition-normal);
    display: flex;
    flex-direction: column;
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-hover);
    border-color: var(--color-text-primary);
}

.project-info {
    padding: var(--space-lg);
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.project-category {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--color-accent-indigo);
    margin-bottom: var(--space-xs);
}

.project-title {
    font-family: var(--font-serif);
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.project-desc {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    margin-bottom: var(--space-md);
    flex-grow: 1;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
    margin-bottom: var(--space-lg);
}

.project-tech span {
    font-size: 0.75rem;
    font-weight: 500;
    background-color: var(--color-bg-secondary);
    color: var(--color-text-primary);
    padding: 0.25rem 0.5rem;
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--color-border);
}

.project-footer {
    margin-top: auto;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-top: var(--space-md);
}

.project-more-btn {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
    font-weight: 500;
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--color-border);
    background-color: transparent;
    color: var(--color-text-muted);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: var(--transition-fast);
}

.project-more-btn:hover {
    background-color: var(--color-accent-soft);
    color: var(--color-text-primary);
    border-color: var(--color-text-primary);
}

.project-more-btn svg {
    transition: var(--transition-fast);
}

.project-more-btn:hover svg {
    transform: translate(2px, -2px);
}

/* Projects Carousel & Controls */
.projects-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.carousel-controls {
    display: flex;
    gap: var(--space-xs);
}

.carousel-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--color-border);
    background-color: var(--color-white);
    color: var(--color-text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-fast);
}

.carousel-btn:hover {
    background-color: var(--color-accent-indigo);
    color: var(--color-white);
    border-color: var(--color-accent-indigo);
}

.carousel-btn:focus {
    outline: none;
    box-shadow: 0 0 0 2px rgba(71, 85, 105, 0.4);
}

.projects-carousel {
    position: relative;
    overflow: visible;
    margin: 0 calc(-1 * var(--space-md));
    padding: var(--space-xs) var(--space-md) var(--space-lg);
}

.projects-track {
    display: flex;
    gap: var(--space-lg);
    overflow-x: auto;
    scroll-behavior: smooth;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    -ms-overflow-style: none;
    padding-bottom: var(--space-xs);
}

.projects-track::-webkit-scrollbar {
    display: none;
}

.projects-track .project-card {
    flex: 0 0 100%;
    scroll-snap-align: start;
}

@media (min-width: 768px) {
    .projects-track .project-card {
        flex: 0 0 calc((100% - var(--space-lg)) / 2);
    }
}

@media (min-width: 1024px) {
    .projects-track .project-card {
        flex: 0 0 calc((100% - 2 * var(--space-lg)) / 3);
    }
}

/* ==========================================================================
   SKILLS
   ========================================================================== */
.skill-category {
    background-color: var(--color-white);
    padding: var(--space-lg);
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--color-border);
    transition: var(--transition-normal);
}

.skill-category:hover {
    border-color: var(--color-text-primary);
    box-shadow: var(--shadow-md);
}

.skill-category-header {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    margin-bottom: var(--space-md);
    border-bottom: 1px solid var(--color-border);
    padding-bottom: var(--space-sm);
}

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

.skill-category-header h3 {
    font-size: 1.15rem;
    font-weight: 600;
}

.skill-list li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 0.6rem;
    padding-bottom: 0.6rem;
    border-bottom: 1px dashed var(--color-border);
    font-size: 0.95rem;
}

.skill-list li:last-child {
    border-bottom: none;
}

.skill-badge {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-accent-indigo);
    background-color: var(--color-accent-soft);
    padding: 0.15rem 0.5rem;
    border-radius: 12px;
}

/* ==========================================================================
   CONTACT SECTION
   ========================================================================== */
.contact-desc {
    margin-bottom: var(--space-md);
    color: var(--color-text-muted);
}

.social-links {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    margin-top: var(--space-lg);
}

.social-link-item {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 500;
    color: var(--color-text-primary);
}

.social-link-item svg {
    color: var(--color-text-muted);
    transition: var(--transition-fast);
}

.social-link-item:hover svg {
    color: var(--color-accent-indigo);
    transform: translateX(4px);
}

.contact-form {
    background-color: var(--color-white);
    padding: var(--space-lg);
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
}

.form-group {
    margin-bottom: var(--space-md);
}

.form-group label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 0.4rem;
    color: var(--color-text-primary);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    background-color: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-sm);
    font-size: 0.95rem;
    color: var(--color-text-primary);
    transition: var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--color-accent-indigo);
    background-color: var(--color-white);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

/* Button Loading State */
.btn-loader {
    display: none;
    width: 16px;
    height: 16px;
    border: 2px solid transparent;
    border-top-color: currentColor;
    border-radius: 50%;
    margin-left: var(--space-xs);
    animation: spin 0.6s linear infinite;
}

.btn.loading .btn-loader {
    display: inline-block;
}

.btn.loading span {
    opacity: 0.7;
}

.form-message {
    margin-top: var(--space-md);
    padding: 0.75rem;
    border-radius: var(--border-radius-sm);
    font-size: 0.9rem;
    display: none;
}

.form-message.success {
    display: block;
    background-color: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.form-message.error {
    display: block;
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.footer {
    padding-top: var(--space-lg);
    padding-bottom: var(--space-lg);
    border-top: 1px solid var(--color-border);
    background-color: var(--color-bg-secondary);
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
}

@media (min-width: 768px) {
    .footer-content {
        flex-direction: row;
        justify-content: space-between;
    }
}

.footer-meta {
    font-size: 0.8rem;
}

/* ==========================================================================
   ANIMATIONS & REVEALS
   ========================================================================== */
.scroll-reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity var(--transition-slow), transform var(--transition-slow);
}

.scroll-reveal.active {
    opacity: 1;
    transform: translateY(0);
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}