/* ======================================
   BLUEPRINT / TECHNICAL THEME v2.0
   Engineering document aesthetic
   ====================================== */

:root {
    --bg-primary: #0c0c0e;
    --bg-secondary: #111114;
    --bg-tertiary: #18181c;
    --border: #252529;
    --border-strong: #3a3a40;

    --text-primary: #e8e8ec;
    --text-secondary: #9898a0;
    --text-muted: #5c5c64;

    --accent: #4a9eff;
    --accent-dim: rgba(74, 158, 255, 0.15);

    --font-sans: 'IBM Plex Sans', -apple-system, sans-serif;
    --font-mono: 'IBM Plex Mono', monospace;

    --text-xs: 0.7rem;
    --text-sm: 0.8rem;
    --text-base: 0.95rem;
    --text-lg: 1.1rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 2rem;

    --max-width: 1100px;
    --nav-height: 56px;
    --space: 1rem;
}

*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--nav-height) + 2rem);
}

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
}

a {
    color: inherit;
    text-decoration: none;
}

ul {
    list-style: none;
}

strong {
    color: var(--text-primary);
    font-weight: 600;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 calc(var(--space) * 2);
}

.blueprint-grid {
    position: fixed;
    inset: 0;
    background-image:
        linear-gradient(var(--border) 1px, transparent 1px),
        linear-gradient(90deg, var(--border) 1px, transparent 1px);
    background-size: 80px 80px;
    opacity: 0.3;
    pointer-events: none;
    z-index: -1;
}

/* ======================================
   NAVIGATION WITH SUBTEXT
   ====================================== */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(12, 12, 14, 0.95);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
}

.nav__container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 calc(var(--space) * 2);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav__logo {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 600;
    letter-spacing: 0.1em;
    color: var(--text-primary);
}

.nav__menu {
    display: flex;
    gap: calc(var(--space) * 2.5);
}

.nav__link {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    transition: color 150ms;
}

.nav__link span {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 500;
    color: var(--text-secondary);
    letter-spacing: 0.15em;
    transition: color 150ms;
}

.nav__link small {
    font-size: 0.6rem;
    color: var(--text-muted);
    letter-spacing: 0.05em;
    opacity: 0;
    transform: translateY(-4px);
    transition: all 150ms;
}

.nav__link:hover span {
    color: var(--accent);
}

.nav__link:hover small {
    opacity: 1;
    transform: translateY(0);
}

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

.nav__toggle span {
    width: 20px;
    height: 1px;
    background: var(--text-primary);
}

/* ======================================
   BUTTONS
   ====================================== */

.btn {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 500;
    letter-spacing: 0.1em;
    padding: 12px 24px;
    border: 1px solid var(--border);
    transition: all 150ms;
}

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

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

.btn--secondary {
    background: transparent;
    color: var(--text-secondary);
}

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

/* ======================================
   HEADER
   ====================================== */

.header {
    padding: calc(var(--nav-height) + 4rem) 0 4rem;
    border-bottom: 1px solid var(--border);
}

.header__meta {
    display: flex;
    gap: calc(var(--space) * 3);
    margin-bottom: calc(var(--space) * 2);
}

.header__ref,
.header__status {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--text-muted);
    letter-spacing: 0.1em;
}

.header__status {
    color: var(--accent);
}

.header__title {
    font-family: var(--font-mono);
    font-size: var(--text-3xl);
    font-weight: 600;
    letter-spacing: 0.05em;
    margin-bottom: 8px;
}

.header__subtitle {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    color: var(--text-muted);
    letter-spacing: 0.2em;
    margin-bottom: calc(var(--space) * 2);
}

.header__summary {
    max-width: 640px;
    margin-bottom: calc(var(--space) * 2);
}

.header__summary p {
    color: var(--text-secondary);
    line-height: 1.8;
}

.header__actions {
    display: flex;
    gap: var(--space);
}

/* ======================================
   PROFILE FRAME - TECHNICAL STYLE
   ====================================== */

.header__layout {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: calc(var(--space) * 3);
    align-items: start;
}

.profile-frame {
    order: 2;
}

.header__content {
    display: flex;
    flex-direction: column;
}

.profile-frame {
    width: 230px;
}

.profile-frame__label {
    font-family: var(--font-mono);
    font-size: 0.6rem;
    color: var(--text-muted);
    letter-spacing: 0.15em;
    margin-bottom: 8px;
    padding-left: 2px;
}

.profile-frame__container {
    position: relative;
    width: 230px;
    height: 270px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    padding: 8px;
}

/* Corner markers */
.profile-frame__corner {
    position: absolute;
    width: 12px;
    height: 12px;
    border-color: var(--accent);
    border-style: solid;
    border-width: 0;
}

.profile-frame__corner--tl {
    top: -1px;
    left: -1px;
    border-top-width: 2px;
    border-left-width: 2px;
}

.profile-frame__corner--tr {
    top: -1px;
    right: -1px;
    border-top-width: 2px;
    border-right-width: 2px;
}

.profile-frame__corner--bl {
    bottom: -1px;
    left: -1px;
    border-bottom-width: 2px;
    border-left-width: 2px;
}

.profile-frame__corner--br {
    bottom: -1px;
    right: -1px;
    border-bottom-width: 2px;
    border-right-width: 2px;
}

/* Grid overlay */
.profile-frame__grid {
    position: absolute;
    top: 8px;
    left: 8px;
    right: 8px;
    bottom: 8px;
    background-image:
        linear-gradient(var(--border) 1px, transparent 1px),
        linear-gradient(90deg, var(--border) 1px, transparent 1px);
    background-size: 20px 20px;
    opacity: 0.4;
    pointer-events: none;
    z-index: 1;
}

.profile-frame__image {
    position: relative;
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center top;
    filter: grayscale(30%);
    z-index: 0;
}

.profile-frame__meta {
    display: flex;
    justify-content: space-between;
    margin-top: 8px;
    font-family: var(--font-mono);
    font-size: 0.55rem;
    color: var(--text-muted);
    letter-spacing: 0.1em;
}

.profile-frame__meta span:last-child {
    color: var(--accent);
}

/* ======================================
   SECTIONS
   ====================================== */

.section {
    padding: 4rem 0;
    border-bottom: 1px solid var(--border);
}

.section--closing {
    background: var(--bg-secondary);
}

.section__header {
    display: flex;
    align-items: baseline;
    gap: var(--space);
    margin-bottom: calc(var(--space) * 3);
    padding-bottom: var(--space);
    border-bottom: 1px solid var(--border);
}

.section__number {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--accent);
    letter-spacing: 0.1em;
}

.section__title {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    font-weight: 600;
    letter-spacing: 0.15em;
    color: var(--text-primary);
}

/* ======================================
   SPECIFICATION WITH LINKS
   ====================================== */

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

.spec-block {
    padding: calc(var(--space) * 1.5);
    border: 1px solid var(--border);
    background: var(--bg-secondary);
}

.spec-block__title {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--text-muted);
    letter-spacing: 0.15em;
    margin-bottom: var(--space);
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border);
}

.spec-block__list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.spec-block__list li {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    line-height: 1.6;
}

.spec-link {
    color: var(--accent);
    border-bottom: 1px solid transparent;
    transition: border-color 150ms;
}

.spec-link:hover {
    border-bottom-color: var(--accent);
}

/* ======================================
   STACK GRID
   ====================================== */

.stack-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: calc(var(--space) * 2);
}

.stack-category {
    border: 1px solid var(--border);
    background: var(--bg-secondary);
}

.stack-category__header {
    display: flex;
    align-items: center;
    gap: var(--space);
    padding: var(--space);
    border-bottom: 1px solid var(--border);
    background: var(--bg-tertiary);
}

.stack-category__icon {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--accent);
}

.stack-category__header h3 {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.15em;
    color: var(--text-secondary);
}

.stack-table {
    width: 100%;
    border-collapse: collapse;
}

.stack-table tr {
    border-bottom: 1px solid var(--border);
}

.stack-table tr:last-child {
    border-bottom: none;
}

.stack-table td {
    padding: 10px var(--space);
    font-size: var(--text-sm);
}

.stack-table td:first-child {
    font-family: var(--font-mono);
    font-weight: 500;
    color: var(--text-primary);
    width: 35%;
}

.stack-table td:last-child {
    color: var(--text-muted);
}

/* ======================================
   SYSTEMS (PROJECTS) - ENHANCED
   ====================================== */

.systems-list {
    display: flex;
    flex-direction: column;
    gap: calc(var(--space) * 3);
}

.system-card {
    border: 1px solid var(--border);
    background: var(--bg-secondary);
}

.system-card__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space) calc(var(--space) * 1.5);
    border-bottom: 1px solid var(--border);
    background: var(--bg-tertiary);
}

.system-card__id {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--accent);
    letter-spacing: 0.1em;
}

.system-card__link {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--text-muted);
    letter-spacing: 0.1em;
    transition: color 150ms;
}

.system-card__link:hover {
    color: var(--accent);
}

.system-card__body {
    padding: calc(var(--space) * 1.5);
}

.system-card__title {
    font-family: var(--font-mono);
    font-size: var(--text-lg);
    font-weight: 600;
    margin-bottom: calc(var(--space) * 1.5);
    letter-spacing: 0.02em;
}

/* Architecture Diagram */
.system-card__diagram {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    padding: var(--space);
    margin-bottom: calc(var(--space) * 1.5);
    overflow-x: auto;
}

.system-card__diagram pre {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    color: var(--text-muted);
    line-height: 1.4;
    white-space: pre;
    margin: 0;
}

.system-card__grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: calc(var(--space) * 2);
    margin-bottom: calc(var(--space) * 1.5);
}

.system-card__section h4 {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--text-muted);
    letter-spacing: 0.15em;
    margin-bottom: 8px;
}

.system-card__section p {
    font-size: var(--text-sm);
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Failure + Security + Scale Meta */
.system-card__specs {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space);
    margin-bottom: calc(var(--space) * 1.5);
}

.system-card__spec {
    padding: var(--space);
    background: var(--bg-primary);
    border: 1px solid var(--border);
}

.system-card__spec-label {
    display: block;
    font-family: var(--font-mono);
    font-size: 0.6rem;
    color: var(--accent);
    letter-spacing: 0.15em;
    margin-bottom: 6px;
}

.system-card__spec-value {
    font-size: var(--text-xs);
    color: var(--text-muted);
    line-height: 1.5;
}

.system-card__stack {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tech-tag {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    padding: 4px 10px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    color: var(--text-muted);
}

/* ======================================
   CLOSING SECTION
   ====================================== */

.closing {
    max-width: 700px;
}

.closing__statement {
    font-size: var(--text-lg);
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: calc(var(--space) * 2);
}

.closing__links {
    display: flex;
    gap: calc(var(--space) * 2);
}

.closing__link {
    flex: 1;
    padding: calc(var(--space) * 1.5);
    border: 1px solid var(--border);
    background: var(--bg-tertiary);
    transition: all 150ms;
}

.closing__link:hover {
    border-color: var(--accent);
}

.closing__link-label {
    display: block;
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--text-muted);
    letter-spacing: 0.15em;
    margin-bottom: 6px;
}

.closing__link-value {
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    color: var(--text-secondary);
}

.closing__link:hover .closing__link-value {
    color: var(--accent);
}

/* ======================================
   FOOTER
   ====================================== */

.footer {
    padding: calc(var(--space) * 2) 0;
    border-top: 1px solid var(--border);
}

.footer .container {
    display: flex;
    justify-content: space-between;
}

.footer span {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    color: var(--text-muted);
    letter-spacing: 0.1em;
}

/* ======================================
   RESPONSIVE
   ====================================== */

@media (max-width: 900px) {
    .header__layout {
        grid-template-columns: 1fr;
        justify-items: center;
        text-align: center;
    }

    .header__content {
        align-items: center;
    }

    .profile-frame {
        margin-bottom: var(--space);
    }

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

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

    .system-card__grid {
        grid-template-columns: 1fr;
    }

    .system-card__specs {
        grid-template-columns: 1fr;
    }

    .closing__links {
        flex-direction: column;
    }
}

@media (max-width: 600px) {
    .nav__menu {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background: var(--bg-primary);
        border-bottom: 1px solid var(--border);
        flex-direction: column;
        padding: var(--space);
        gap: var(--space);
        display: none;
    }

    .nav__menu.active {
        display: flex;
    }

    .nav__link {
        align-items: flex-start;
    }

    .nav__link small {
        opacity: 1;
        transform: none;
    }

    .nav__toggle {
        display: flex;
    }

    .header {
        padding-top: calc(var(--nav-height) + 2rem);
    }

    .header__meta {
        flex-direction: column;
        gap: 8px;
    }

    .header__actions {
        flex-direction: column;
    }
}