/* ═══════════════════════════════════════════════════
   Design Tokens
   ═══════════════════════════════════════════════════ */
:root {
    /* Background layers */
    --bg-deep:       #0a0f1a;
    --bg-surface:    #0d1117;
    --bg-elevated:   #161b22;
    --bg-card:       rgba(22, 27, 34, 0.85);
    --bg-card-hover: rgba(30, 37, 48, 0.95);

    /* Borders & glass */
    --border-subtle:  rgba(48, 54, 61, 0.6);
    --border-default: rgba(48, 54, 61, 0.9);

    /* Accent palette */
    --accent-cyan:   #00d4ff;
    --accent-blue:   #58a6ff;
    --accent-green:  #39d353;
    --accent-amber:  #f0b429;
    --accent-purple: #a78bfa;
    --accent-red:    #f97583;

    /* Text */
    --text-primary:   #e6edf3;
    --text-secondary: #8b949e;
    --text-muted:     #6e7681;

    /* Effects */
    --glow-cyan:  0 0 20px rgba(0, 212, 255, 0.15);
    --glow-green: 0 0 20px rgba(57, 211, 83, 0.12);
    --shadow-card:     0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-elevated: 0 16px 48px rgba(0, 0, 0, 0.4);

    /* Typography */
    --font-heading: "Space Grotesk", system-ui, sans-serif;
    --font-body:    "Plus Jakarta Sans", system-ui, sans-serif;
    --font-mono:    "JetBrains Mono", "Fira Code", monospace;

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

    /* Radii */
    --radius-sm:   8px;
    --radius-md:   12px;
    --radius-lg:   16px;
    --radius-xl:   20px;
    --radius-pill: 999px;

    /* Motion */
    --ease-out:        cubic-bezier(0.22, 1, 0.36, 1);
    --duration-fast:   150ms;
    --duration-normal: 250ms;
    --duration-slow:   400ms;

    /* Focus */
    --focus-outline: var(--accent-cyan);
}

[data-theme="light"] {
    --bg-deep: #f4f7fb;
    --bg-surface: #ffffff;
    --bg-elevated: #eef2f7;
    --bg-card: rgba(255, 255, 255, 0.88);
    --bg-card-hover: rgba(248, 250, 252, 0.97);

    --border-subtle: rgba(148, 163, 184, 0.38);
    --border-default: rgba(100, 116, 139, 0.52);

    --text-primary: #0f172a;
    --text-secondary: #334155;
    --text-muted: #64748b;

    --glow-cyan: 0 0 16px rgba(0, 153, 204, 0.14);
    --glow-green: 0 0 16px rgba(46, 125, 50, 0.1);
    --shadow-card: 0 8px 24px rgba(2, 6, 23, 0.09);
    --shadow-elevated: 0 12px 32px rgba(2, 6, 23, 0.13);
}

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

html,
body {
    margin: 0;
    min-height: 100%;
}

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

img {
    max-width: 100%;
    height: auto;
}

/* ═══════════════════════════════════════════════════
   Background Aura
   ═══════════════════════════════════════════════════ */
.background-aura {
    position: fixed;
    inset: 0;
    z-index: -1;
    pointer-events: none;
    opacity: 0.55;
    background:
        radial-gradient(ellipse at 10% 15%, rgba(0, 212, 255, 0.08), transparent 50%),
        radial-gradient(ellipse at 85% 20%, rgba(167, 139, 250, 0.06), transparent 45%),
        radial-gradient(ellipse at 50% 80%, rgba(57, 211, 83, 0.05), transparent 50%);
}

[data-theme="light"] .background-aura {
    opacity: 0.4;
    background:
        radial-gradient(ellipse at 10% 15%, rgba(0, 153, 204, 0.12), transparent 56%),
        radial-gradient(ellipse at 85% 20%, rgba(167, 139, 250, 0.08), transparent 50%),
        radial-gradient(ellipse at 50% 80%, rgba(57, 211, 83, 0.08), transparent 55%);
}

/* ═══════════════════════════════════════════════════
   Site Shell
   ═══════════════════════════════════════════════════ */
.site-shell {
    min-height: 100vh;
    width: min(1200px, 100% - 2.6rem);
    margin: 0 auto;
    padding: 1.2rem 0 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.3rem;
}

/* ═══════════════════════════════════════════════════
   Header
   ═══════════════════════════════════════════════════ */
.site-header {
    display: grid;
    grid-template-columns: minmax(240px, 1fr) minmax(300px, 2fr) auto;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.2rem;
    border-radius: var(--radius-lg);
    background: rgba(13, 17, 23, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border-subtle);
    box-shadow: var(--shadow-card);
    animation: rise-in 480ms var(--ease-out);
}

[data-theme="light"] .site-header {
    background: rgba(255, 255, 255, 0.88);
}

.brand-block {
    display: flex;
    align-items: center;
    gap: 0.85rem;
}

.brand-mark {
    display: inline-flex;
    width: 2.4rem;
    height: 2.4rem;
    border-radius: 0.6rem;
    align-items: center;
    justify-content: center;
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 0.95rem;
    letter-spacing: 0.02em;
    color: var(--bg-deep);
    background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
    box-shadow: var(--glow-cyan);
}

.brand-name {
    margin: 0;
    font-family: var(--font-heading);
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
}

.brand-role {
    margin: 0.12rem 0 0;
    color: var(--text-secondary);
    font-size: 0.84rem;
}

.brand-sep {
    color: var(--text-muted);
    margin: 0 0.1rem;
}

/* ── Navigation ── */
.site-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.55rem;
}

.nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.92rem;
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-pill);
    padding: 0.42rem 0.8rem;
    background: rgba(22, 27, 34, 0.6);
    transition: all var(--duration-normal) var(--ease-out);
}

.nav-link:hover {
    color: var(--text-primary);
    border-color: var(--accent-cyan);
    background: rgba(0, 212, 255, 0.06);
    transform: translateY(-1px);
}

.nav-link.is-active {
    color: var(--accent-cyan);
    border-color: var(--accent-cyan);
    background: rgba(0, 212, 255, 0.1);
    box-shadow: var(--glow-cyan);
}

.endpoint-id {
    font-family: var(--font-mono);
    font-size: 0.84rem;
    color: var(--accent-cyan);
    margin-right: 0.25rem;
}

/* ── Resume Button ── */
.header-actions {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.45rem;
    height: 2.45rem;
    border: 1px solid rgba(0, 212, 255, 0.4);
    border-radius: var(--radius-pill);
    background: rgba(0, 212, 255, 0.08);
    color: var(--accent-cyan);
    cursor: pointer;
    transition: transform var(--duration-fast) var(--ease-out),
                box-shadow var(--duration-fast) var(--ease-out),
                background var(--duration-fast) var(--ease-out);
}

.theme-toggle:hover {
    background: rgba(0, 212, 255, 0.15);
    box-shadow: var(--glow-cyan);
    transform: translateY(-1px);
}

.theme-toggle-icon {
    font-size: 1rem;
    line-height: 1;
}

.resume-button {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    text-decoration: none;
    color: var(--accent-cyan);
    font-weight: 700;
    font-family: var(--font-body);
    font-size: 0.92rem;
    border: 1px solid rgba(0, 212, 255, 0.4);
    border-radius: var(--radius-pill);
    padding: 0.55rem 1rem;
    background: rgba(0, 212, 255, 0.08);
    transition: all var(--duration-normal) var(--ease-out);
    white-space: nowrap;
}

[data-theme="light"] .theme-toggle,
[data-theme="light"] .resume-button {
    background: rgba(0, 153, 204, 0.1);
    border-color: rgba(0, 153, 204, 0.35);
}

[data-theme="light"] .theme-toggle:hover,
[data-theme="light"] .resume-button:hover {
    background: rgba(0, 153, 204, 0.18);
}

.resume-button:hover {
    background: rgba(0, 212, 255, 0.15);
    box-shadow: var(--glow-cyan);
    transform: translateY(-1px);
}

.resume-arrow {
    font-size: 1.05rem;
}

/* ═══════════════════════════════════════════════════
   Main Content
   ═══════════════════════════════════════════════════ */
.site-main {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    animation: rise-in 560ms var(--ease-out);
}

/* ═══════════════════════════════════════════════════
   Card Surface (shared glass card)
   ═══════════════════════════════════════════════════ */
.card-surface {
    background: var(--bg-card);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-card);
    transition: border-color var(--duration-normal) var(--ease-out),
                box-shadow var(--duration-normal) var(--ease-out);
}

/* ═══════════════════════════════════════════════════
   Footer
   ═══════════════════════════════════════════════════ */
.site-footer {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 0.75rem;
    padding: 1rem 1.2rem;
    background: rgba(13, 17, 23, 0.6);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-md);
    margin-top: auto;
}

[data-theme="light"] .site-footer {
    background: rgba(255, 255, 255, 0.78);
}

[data-theme="light"] .nav-link {
    background: rgba(255, 255, 255, 0.78);
}

[data-theme="light"] .nav-link:hover {
    background: rgba(0, 153, 204, 0.08);
}

[data-theme="light"] .nav-link.is-active {
    background: rgba(0, 153, 204, 0.14);
}

[data-theme="light"] .meta-chip,
[data-theme="light"] .skill-chip,
[data-theme="light"] .experience-card,
[data-theme="light"] .metric-card,
[data-theme="light"] .plot-card,
[data-theme="light"] .plot-media,
[data-theme="light"] .build-note-card,
[data-theme="light"] .p5-module,
[data-theme="light"] .p5-response {
    background: rgba(255, 255, 255, 0.86);
}

[data-theme="light"] .table-shell {
    background: rgba(255, 255, 255, 0.94);
}

[data-theme="light"] .table-shell th {
    background: rgba(0, 153, 204, 0.08);
}

[data-theme="light"] .stack-chip,
[data-theme="light"] .project-tag {
    background: rgba(0, 153, 204, 0.08);
    border-color: rgba(0, 153, 204, 0.25);
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 0.15rem;
}

.footer-sig {
    margin: 0;
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 0.92rem;
    color: var(--text-primary);
}

.footer-tech {
    margin: 0;
    font-size: 0.8rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

.footer-links {
    list-style: none;
    display: flex;
    gap: 0.9rem;
    margin: 0;
    padding: 0;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.88rem;
    transition: color var(--duration-fast);
}

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

/* ═══════════════════════════════════════════════════
   Focus & Accessibility
   ═══════════════════════════════════════════════════ */
a:focus-visible,
button:focus-visible,
input:focus-visible,
summary:focus-visible {
    outline: 2px solid var(--focus-outline);
    outline-offset: 2px;
}

/* ═══════════════════════════════════════════════════
   Keyframes
   ═══════════════════════════════════════════════════ */
@keyframes rise-in {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ═══════════════════════════════════════════════════
   Responsive: Tablet
   ═══════════════════════════════════════════════════ */
@media (max-width: 1024px) {
    .site-shell {
        width: min(980px, 100% - 1.8rem);
    }

    .site-header {
        grid-template-columns: 1fr;
        justify-items: center;
        text-align: center;
    }

    .brand-block {
        justify-content: center;
    }

    .resume-button {
        width: 100%;
        justify-content: center;
        text-align: center;
    }

    .header-actions {
        width: 100%;
        justify-content: center;
    }

    .theme-toggle {
        width: 2.5rem;
        height: 2.5rem;
    }
}

/* ═══════════════════════════════════════════════════
   Responsive: Mobile
   ═══════════════════════════════════════════════════ */
@media (max-width: 700px) {
    .site-shell {
        width: calc(100% - 1rem);
        padding-top: 0.6rem;
    }

    .site-header,
    .site-footer {
        padding: 0.8rem;
    }

    .site-nav {
        justify-content: flex-start;
        width: 100%;
    }

    .nav-link {
        flex: 1 1 calc(50% - 0.55rem);
        text-align: center;
    }

    .footer-links {
        flex-direction: column;
        gap: 0.35rem;
        width: 100%;
    }

    .header-actions {
        flex-direction: row;
        width: 100%;
    }

    .theme-toggle {
        flex: 0 0 auto;
    }

    .resume-button {
        flex: 1 1 auto;
    }
}

/* ═══════════════════════════════════════════════════
   Reduced Motion
   ═══════════════════════════════════════════════════ */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 1ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 1ms !important;
        scroll-behavior: auto !important;
    }
}