/**
 * Core Engineering Palette and Layout
 * Pure CSS variables, zero runtime frameworks.
 */
:root {
    --bg-main: #0f1115;
    --bg-surface: #161920;
    --bg-card: #1c212b;
    --bg-header: rgba(15, 17, 21, 0.9);
    --border-color: #2b3240;
    --border-accent: #3d4659;
    --bg-vector-opacity: 0.06;
    
    --text-primary: #e6edf3;
    --text-secondary: #9aa5b8;    --text-muted: #657185;
    
    --accent-blue: #3b82f6;
    --accent-hover: #60a5fa;
    --code-bg: #12151b;
    
    --font-stack: 'Vazirmatn NL', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-mono: SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
    --font-latin-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    
    --container-width: 1040px;
    --radius-sm: 4px;
    --radius-md: 8px;
}

[data-theme="light"] {
    --bg-main: #f8fafc;
    --bg-surface: #ffffff;
    --bg-card: #f1f5f9;
    --bg-header: rgba(255, 255, 255, 0.9);
    --border-color: #e2e8f0;
    --border-accent: #cbd5e1;
    --bg-vector-opacity: 0.035;
        --text-primary: #0f172a;    --text-secondary: #334155;
    --text-muted: #64748b;
        --accent-blue: #2563eb;    --accent-hover: #1d4ed8;
    --code-bg: #e2e8f0;
}

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

:focus-visible {
    outline: 2px solid var(--accent-blue);
    outline-offset: 2px;
}

/* Accessibility Skip Link */
.skip-link {
    position: absolute;
    top: -999px;
    left: 1.5rem;
    background: var(--accent-blue);
    color: #ffffff;
    padding: 0.5rem 1rem;
    z-index: 1000;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 600;
    text-decoration: none;
}
.skip-link:focus {
    top: 1rem;
}

html {
    background-color: var(--bg-main);    min-height: 100vh;
    color: var(--text-primary);
    font-family: var(--font-stack);
    /* Force tabular figures for numbers globally */    font-feature-settings: "tnum" 1;
    font-variant-numeric: tabular-nums;
    line-height: 1.7;
    font-size: 16px;
}

html[lang="en"] {
    font-family: var(--font-latin-sans);
    font-feature-settings: normal;
    font-variant-numeric: normal;
}

@media (prefers-reduced-motion: no-preference) {
    html {
        scroll-behavior: smooth;
    }
}

html::before {
    content: "";
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    background-image: url("../icons/globe.svg");
    background-repeat: no-repeat;
    background-size: 950px 950px;
    opacity: var(--bg-vector-opacity);
    pointer-events: none;
    z-index: -1;
}

html[dir="rtl"]::before {
    background-position: top -100px left -200px;
}

html[dir="ltr"]::before {
    background-position: top -100px right -200px;
}

body {    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {    color: var(--accent-blue);    text-decoration: none;
    transition: color 0.15s ease;
}

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

/* Layout Containers */
.site-wrapper {
    width: 100%;
    display: flex;
    flex-direction: column;
}

.content-container {    width: 100%;    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Navigation */
.header {
    background-color: var(--bg-header);
    -webkit-backdrop-filter: blur(8px);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;    top: 0;
    z-index: 100;
}

.nav-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.brand-logo {
    display: flex;
    flex-direction: column;
    color: var(--text-primary);
}

.brand-name {
    font-weight: 700;
    font-size: 1.15rem;
    letter-spacing: -0.02em;
}

.brand-sub {
    font-size: 0.78rem;
    color: var(--text-muted);
}

.nav-controls {
    display: none;
    align-items: center;
    gap: 0.75rem;
}

.menu-toggle {
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    width: 2rem;
    height: 2rem;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0.25rem;
    z-index: 101;
}

.menu-toggle span {
    width: 100%;
    height: 2px;
    background-color: var(--text-primary);
    border-radius: 2px;
    transition: all 0.2s ease-in-out;
}

.menu-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 1.5rem;
    align-items: center;
}

.nav-links a {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

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

.nav-links a.active {
    color: var(--accent-blue);
    font-weight: 600;
}

.nav-actions {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}

.lang-switch {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    height: 1.85rem;
    box-sizing: border-box;
    border: 1px solid var(--border-accent);
    padding: 0 0.55rem;
    border-radius: var(--radius-sm);
    font-size: 0.78rem !important;
    line-height: normal;
    color: var(--text-secondary);
}

.lang-switch:hover {
    color: var(--text-primary);
    border-color: var(--accent-blue);
}

.theme-toggle {
    background: transparent;    border: 1px solid var(--border-accent);
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    width: 1.85rem;
    height: 1.85rem;
    padding: 0;
    box-sizing: border-box;
    cursor: pointer;
    display: inline-flex;
    align-items: center;    justify-content: center;
    transition: all 0.15s ease;
}

.theme-toggle:hover {
    color: var(--text-primary);
    border-color: var(--accent-blue);
}

[data-theme="dark"] .icon-moon,
:root:not([data-theme="light"]) .icon-moon {
    display: none;
}

[data-theme="dark"] .icon-sun,
:root:not([data-theme="light"]) .icon-sun {
    display: block;
}

[data-theme="light"] .icon-sun {
    display: none;
}

[data-theme="light"] .icon-moon {
    display: block;
}

.lang-switch-mobile {
    display: none;
}

/* Generic Sections */
.section {
    padding: 4rem 0;
    border-bottom: 1px solid var(--border-color);
    scroll-margin-top: 5rem;
}

.section-header {    margin-bottom: 2.5rem;
}

.section-title {
    font-size: 1.65rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.section-desc {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Hero Section */
.hero-section {
    padding: 5rem 0 4rem 0;
}

.hero-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border: 1px solid var(--border-accent);
    background-color: var(--bg-surface);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    color: var(--accent-blue);
    margin-bottom: 1.5rem;
}

.hero-title {
    font-size: 2.3rem;
    line-height: 1.35;
    font-weight: 800;
    margin-bottom: 1.25rem;
    max-width: 860px;
}

.hero-summary {
    font-size: 1.15rem;
    color: var(--text-secondary);
    line-height: 1.8;
    max-width: 820px;
    margin-bottom: 2.5rem;
    text-align: justify;
    text-justify: inter-word;
    text-align-last: start;
}

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

.spec-block {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    padding: 1rem;
    border-radius: var(--radius-md);
    box-shadow: inset 0 1px 0 0 rgba(255, 255, 255, 0.04);
}

.spec-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 0.25rem;
}

.spec-val {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.65rem 1.25rem;
    border-radius: var(--radius-md);
    font-size: 0.9rem;    font-weight: 600;
    cursor: pointer;
    border: 1px solid transparent;
}

.btn-icon {
    display: block;
    flex-shrink: 0;
}

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

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

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

/* Grids & Cards */
.grid {
    display: grid;
    gap: 1.5rem;
}

.grid-2 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 360px), 1fr)); }
.grid-3 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 280px), 1fr)); }

.card {
    background-color: var(--bg-surface);    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.2rem;
    box-shadow: inset 0 1px 0 0 rgba(255, 255, 255, 0.04);
    position: relative;
}

.card-num {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--accent-blue);
    margin-bottom: 0.75rem;
    font-family: var(--font-mono);
}

.card-title {
    font-size: 1.15rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.card-body {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
    text-align: justify;
    text-justify: inter-word;
    text-align-last: start;
}

code {
    font-family: var(--font-mono);
    background-color: var(--code-bg);
    padding: 0.15rem 0.4rem;
    border-radius: var(--radius-sm);
    font-size: 0.85em;
    border: 1px solid var(--border-color);
}

/* Projects View */
.projects-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.project-entry {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: inset 0 1px 0 0 rgba(255, 255, 255, 0.04);
    padding: 1.75rem;
    display: grid;
    grid-template-columns: 200px 1fr auto;
    gap: 1.5rem;
    align-items: start;
}

.projects-group {
    margin-bottom: 2.5rem;
}

.projects-group-title {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--accent-blue);
    margin-bottom: 1.25rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.project-metrics-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
    gap: 0.75rem;
    margin-bottom: 1rem;
    padding: 0.75rem;
    background-color: var(--code-bg);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
}

.metric-item {
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.project-icon {
    color: var(--accent-blue);
    margin-bottom: 0.5rem;
}

.project-icon svg,
.project-icon img {
    display: block;
}

.project-tag {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--accent-blue);
    margin-bottom: 0.25rem;
}

.project-year {
    font-size: 0.8rem;
    font-family: var(--font-mono);
    font-weight: 500;
    color: var(--text-muted);
}

.project-name {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.project-title-link {
    display: inline-flex;
    align-items: center;
    color: var(--text-muted);
    font-size: 1rem;
    line-height: 1;
    transition: color 0.15s ease;
    vertical-align: middle;
}

.project-title-link:hover {
    color: var(--accent-blue);
}

.project-ext-links {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
}

.project-ext-icon {
    display: block;
    opacity: 0.75;
    transition: opacity 0.15s ease;
}

.project-ext-links a:hover .project-ext-icon {
    opacity: 1;
}

.project-summary {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
    text-align: justify;
    text-justify: inter-word;
    text-align-last: start;
}

.project-breakdown {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    margin-bottom: 1rem;
    font-size: 0.88rem;
    color: var(--text-secondary);
}

.breakdown-item {
    position: relative;
    padding-inline-start: 0.85rem;
    border-inline-start: 2px solid var(--border-accent);
    line-height: 1.6;
}

.breakdown-item strong {
    color: var(--text-primary);
    font-weight: 600;
    margin-inline-end: 0.35rem;
}

.breakdown-item.solution {
    border-inline-start-color: var(--accent-blue);
}

.project-action {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.tech-stack {    display: flex;
    gap: 0.5rem;    flex-wrap: wrap;
}

.tech-stack span {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 0.2rem 0.6rem;
    border-radius: var(--radius-sm);
    font-size: 0.78rem;
    color: var(--text-secondary);
}

/* Credentials Section */
.credentials-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.cred-heading {
    font-size: 1.15rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.cred-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.cred-list strong {
    display: block;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.cred-list span {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

.footnote-box {
    background-color: var(--bg-surface);
    border-inline-start: 3px solid var(--accent-blue);
    padding: 1rem 1.25rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Footer */
.footer {
    margin-top: auto;
    background-color: var(--bg-surface);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0 2rem 0;
    scroll-margin-top: 5rem;
}

.footer-container {    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 1.5rem;
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-heading {
    font-size: 1rem;
    margin-bottom: 0.75rem;
}

.footer-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.footer-mail {
    font-family: var(--font-mono);
    font-size: 1rem;
    font-weight: 600;
}

.copy-btn {
    background: transparent;
    border: 1px solid var(--border-accent);
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    padding: 0.2rem 0.5rem;
    font-size: 0.75rem;
    cursor: pointer;
    margin-inline-start: 0.5rem;
    vertical-align: middle;
    transition: all 0.15s ease;
}

.copy-btn:hover {
    color: var(--text-primary);
    border-color: var(--accent-blue);
}

.copy-btn.copied {
    color: #10b981;
    border-color: #10b981;
}

.contact-wrapper {
    display: inline-flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.social-links-row {
    display: flex;    gap: 0.75rem;
    align-items: center;
}

.social-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.25rem;
    height: 2.25rem;
    border: 1px solid var(--border-accent);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    transition: color 0.15s ease, border-color 0.15s ease;
}

.social-btn:hover {
    color: var(--accent-blue);
    border-color: var(--accent-blue);
}

.footer-bottom {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 1.5rem 1.5rem 0 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    color: var(--text-muted);
    flex-wrap: wrap;
    gap: 0.75rem;
}

/* Responsive Tweaks */
@media (max-width: 820px) {
    .content-container {
        padding: 0 1rem;
    }
    .hero-title {
        font-size: 1.85rem;
    }
    .nav-controls {
        display: flex;
    }
    .lang-switch-mobile {
        display: inline-flex;
    }
    .desktop-only {
        display: none;
    }
    .main-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--bg-surface);
        border-bottom: 1px solid var(--border-color);
        padding: 1.25rem 1.5rem;
        max-height: calc(100vh - 4.5rem);
        overflow-y: auto;
        box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
    }
    .main-nav.nav-open {        display: block;
    }
    .nav-links {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
    .nav-links a {
        display: block;
        width: 100%;
        font-size: 1rem;
        padding: 0.25rem 0;
    }
    .grid-2,
    .grid-3 {
        grid-template-columns: 1fr;
    }
    .project-entry {
        grid-template-columns: 1fr;
        padding: 1.25rem 1rem;
    }
    .credentials-grid {
        grid-template-columns: 1fr;    }
    .footer-container {
        grid-template-columns: 1fr;
    }
}

/* Print Optimization */
@media print {
    .header,
    .theme-toggle,
    .lang-switch,
    .menu-toggle,
    .hero-actions,
    .project-action,
    .copy-btn,
    .social-links-row,
    html::before {
        display: none !important;
    }
    body, html {
        background: #ffffff !important;
        color: #000000 !important;
    }
    .card, .project-entry, .spec-block, .footnote-box {
        border: 1px solid #cbd5e1 !important;
        box-shadow: none !important;
        background: #ffffff !important;
        break-inside: avoid;
    }
}