/* ==========================================================================
   Design System — rafaelziliao.dev
   Dracula color palette + shared components
   ========================================================================== */

/* --- Tokens ---------------------------------------------------------------- */

:root {
    /* Colors */
    --background:    #282a36;
    --current-line:  #44475a;
    --foreground:    #f8f8f2;
    --comment:       #6272a4;
    --cyan:          #8be9fd;
    --green:         #50fa7b;
    --orange:        #ffb86c;
    --pink:          #ff79c6;
    --purple:        #bd93f9;
    --red:           #ff5555;
    --yellow:        #f1fa8c;

    /* Typography */
    --font-sans:    'Inter', sans-serif;
    --font-display: 'Poppins', sans-serif;
    --font-mono:    'JetBrains Mono', monospace;

    /* Spacing scale */
    --sp-1: 0.25rem;
    --sp-2: 0.5rem;
    --sp-3: 0.75rem;
    --sp-4: 1rem;
    --sp-5: 1.25rem;
    --sp-6: 1.5rem;
    --sp-8: 2rem;
    --sp-10: 2.5rem;
    --sp-12: 3rem;

    /* Radius */
    --radius-sm:   4px;
    --radius-md:   0.75rem;
    --radius-lg:   1rem;
    --radius-xl:   1.25rem;
    --radius-pill: 999px;

    /* Borders */
    --border-subtle:  1px solid var(--current-line);
    --border-comment: 1px solid var(--comment);
}

/* --- Base ------------------------------------------------------------------ */

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

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    background-color: var(--background);
    color: var(--foreground);
    line-height: 1.75;
    min-height: 100vh;
}

h1, h2, h3, h4 {
    font-family: var(--font-display);
    font-weight: 700;
}

p {
    font-size: 1.0625rem;
    color: var(--foreground);
    opacity: 0.9;
    margin-bottom: 1.125rem;
}

p strong { font-weight: 600; opacity: 1; }

a { color: inherit; }

code {
    font-family: var(--font-mono);
    font-size: 0.875em;
    color: var(--pink);
    background: rgba(255, 121, 198, 0.1);
    border-radius: var(--radius-sm);
    padding: 0.125em 0.4em;
}

/* --- Reading progress bar -------------------------------------------------- */

#progress-bar {
    position: fixed;
    top: 0; left: 0;
    height: 2px;
    background: linear-gradient(to right, var(--cyan), var(--purple));
    z-index: 100;
    width: 0%;
    transition: width 0.1s linear;
}

/* --- Navigation ------------------------------------------------------------ */

.top-nav {
    position: sticky;
    top: 0;
    z-index: 50;
    background-color: rgba(40, 42, 54, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: var(--border-subtle);
}

/* --- Hero ------------------------------------------------------------------ */

.hero {
    border-bottom: var(--border-subtle);
    background: linear-gradient(180deg, rgba(68, 71, 90, 0.3) 0%, transparent 100%);
}

/* --- Article typography ---------------------------------------------------- */

.section-label {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--purple);
    display: block;
    margin-bottom: 0.5rem;
}

.section-heading {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--foreground);
    margin-top: 3.5rem;
    margin-bottom: 1.125rem;
}

.meta-item {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--comment);
}

.divider {
    border: none;
    border-top: 1px solid var(--current-line);
    margin: 3rem 0;
}

/* --- Badges & tags --------------------------------------------------------- */

.chapter-tag {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    border-radius: var(--radius-pill);
    padding: 0.25rem 0.875rem;
}

.chapter-tag--green {
    color: var(--green);
    background: rgba(80, 250, 123, 0.08);
    border: 1px solid rgba(80, 250, 123, 0.25);
}

.chapter-tag--orange {
    color: var(--orange);
    background: rgba(255, 184, 108, 0.08);
    border: 1px solid rgba(255, 184, 108, 0.25);
}

.topic-tag {
    font-family: var(--font-mono);
    font-size: 0.62rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--comment);
    background: rgba(98, 114, 164, 0.1);
    border: 1px solid rgba(98, 114, 164, 0.2);
    border-radius: var(--radius-sm);
    padding: 0.15rem 0.5rem;
}

/* --- Callouts -------------------------------------------------------------- */

.callout {
    border-radius: 0.625rem;
    padding: var(--sp-4) var(--sp-5);
    margin: 1.75rem 0;
    display: flex;
    gap: 0.875rem;
}

.callout-icon {
    font-size: 1rem;
    flex-shrink: 0;
    padding-top: 0.15rem;
}

.callout-body {
    font-size: 0.9375rem;
    line-height: 1.65;
    opacity: 0.9;
}

.callout-body strong {
    display: block;
    margin-bottom: 0.2rem;
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    font-family: var(--font-mono);
}

.callout.insight {
    background: rgba(139, 233, 253, 0.06);
    border: 1px solid rgba(139, 233, 253, 0.18);
}
.callout.insight .callout-body strong { color: var(--cyan); }

.callout.tip {
    background: rgba(80, 250, 123, 0.06);
    border: 1px solid rgba(80, 250, 123, 0.18);
}
.callout.tip .callout-body strong { color: var(--green); }

.callout.challenge-note {
    background: rgba(189, 147, 249, 0.06);
    border: 1px solid rgba(189, 147, 249, 0.18);
}
.callout.challenge-note .callout-body strong { color: var(--purple); }

.callout.warning {
    background: rgba(255, 184, 108, 0.06);
    border: 1px solid rgba(255, 184, 108, 0.18);
}
.callout.warning .callout-body strong { color: var(--orange); }

/* --- Reflection quote ------------------------------------------------------ */

.reflection-quote {
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--cyan);
    line-height: 1.5;
    margin: 2rem 0;
    padding: 1.5rem 2rem;
    background: rgba(139, 233, 253, 0.05);
    border-left: 3px solid var(--cyan);
    border-radius: 0 0.5rem 0.5rem 0;
}

/* --- Code blocks ----------------------------------------------------------- */

.code-block {
    background: #1e1f29;
    border: 1px solid var(--current-line);
    border-radius: var(--radius-md);
    overflow: hidden;
    margin: 1.75rem 0;
    font-family: var(--font-mono);
    font-size: 0.875rem;
}

.code-block-header {
    background: var(--current-line);
    padding: 0.45rem 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
}

.code-block-lang {
    font-size: 0.65rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--comment);
}

.code-dots { display: flex; gap: 0.3rem; }
.code-dot  { width: 9px; height: 9px; border-radius: 50%; }

.code-block-body {
    padding: 1.25rem 1.5rem;
    overflow-x: auto;
    line-height: 1.75;
}

.code-block-body .prompt  { color: var(--green);   user-select: none; }
.code-block-body .cmd     { color: var(--foreground); }
.code-block-body .output  { color: var(--comment); }
.code-block-body .str     { color: var(--green); }
.code-block-body .addr    { color: var(--orange); }
.code-block-body .comment-line { color: var(--comment); font-style: italic; }

/* Copy button */
.copy-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--comment);
    background: transparent;
    border: none;
    padding: 0.2rem;
    cursor: pointer;
    transition: color 0.15s;
    margin-left: auto;
    flex-shrink: 0;
    line-height: 0;
}
.copy-btn:hover  { color: var(--foreground); }
.copy-btn.copied { color: var(--green); }

/* --- Scrollbar ------------------------------------------------------------- */

::-webkit-scrollbar       { width: 8px; }
::-webkit-scrollbar-track { background: var(--background); }
::-webkit-scrollbar-thumb { background: var(--current-line); border-radius: 4px; }

/* --- Responsive ------------------------------------------------------------ */

@media (max-width: 640px) {
    .hero h1   { font-size: 2.25rem; }
    .section-heading { font-size: 1.25rem; }
    .code-block-body { padding: 1rem; font-size: 0.8rem; }
}