/* ============================================================
   Nazmun Nahar — Academic Site
   Shared stylesheet
   Type: Lora (display/serif) + Inter (body/sans)
   ============================================================ */

:root {
    --bg:           #FAF9F6;
    --surface:      #FFFFFF;
    --ink:          #1A1A1A;
    --ink-dim:      #5C5F66;
    --ink-faint:    #8A8D93;
    --rule:         #E5E2DA;
    --rule-strong:  #D8D4C9;
    --accent:       #1F4B43;
    --accent-soft:  #EAF1EF;
    --accent-line:  #BFD6D0;

    --serif: 'Lora', Georgia, 'Times New Roman', serif;
    --sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    --sidebar-w: 280px;
    --header-h: 64px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
    background: var(--bg);
    color: var(--ink);
    font-family: var(--sans);
    font-size: 16px;
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }
}

h1, h2, h3, h4 { font-family: var(--serif); font-weight: 600; color: var(--ink); letter-spacing: -0.01em; }

.eyebrow {
    font-family: var(--sans);
    text-transform: uppercase;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    color: var(--accent);
}

/* ---------------- TOP HEADER ---------------- */
.site-header {
    position: sticky;
    top: 0;
    z-index: 200;
    height: var(--header-h);
    background: rgba(250, 249, 246, 0.92);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--rule);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
}

.brand {
    font-family: var(--serif);
    font-size: 1.15rem;
    font-weight: 600;
    text-decoration: none;
    color: var(--ink);
    letter-spacing: -0.01em;
}

.site-nav { display: flex; gap: 2.1rem; }
.site-nav a {
    font-size: 0.92rem;
    font-weight: 500;
    text-decoration: none;
    color: var(--ink-dim);
    padding: 0.3rem 0;
    border-bottom: 2px solid transparent;
    transition: color 0.2s, border-color 0.2s;
}
.site-nav a:hover { color: var(--ink); }
.site-nav a.active { color: var(--accent); border-bottom-color: var(--accent); }

.hamburger {
    display: none;
    width: 40px; height: 40px;
    border: 1px solid var(--rule-strong);
    border-radius: 8px;
    background: var(--surface);
    cursor: pointer;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
}
.hamburger span { display: block; width: 18px; height: 2px; background: var(--ink); transition: 0.3s; }
.hamburger.open span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.mobile-drawer {
    position: fixed; top: var(--header-h); right: 0;
    width: 240px; height: calc(100vh - var(--header-h));
    background: var(--surface);
    border-left: 1px solid var(--rule);
    z-index: 199;
    display: flex; flex-direction: column;
    padding: 1.5rem;
    gap: 0.3rem;
    transform: translateX(100%);
    transition: transform 0.3s ease;
}
.mobile-drawer.open { transform: translateX(0); }
.mobile-drawer a { text-decoration: none; color: var(--ink-dim); font-size: 1rem; padding: 0.7rem 0.5rem; border-radius: 6px; }
.mobile-drawer a:hover, .mobile-drawer a.active { color: var(--accent); background: var(--accent-soft); }

.drawer-backdrop {
    display: none; position: fixed; inset: 0; top: var(--header-h);
    background: rgba(0,0,0,0.25); z-index: 198; opacity: 0; transition: opacity 0.3s;
}
.drawer-backdrop.open { display: block; opacity: 1; }

/* ---------------- PAGE SHELL (sidebar + content) ---------------- */
.page-shell { display: flex; max-width: 1200px; margin: 0 auto; }

.bio-sidebar {
    width: var(--sidebar-w);
    flex-shrink: 0;
    padding: 3rem 1.75rem 3rem 0;
}

.bio-photo {
    width: 180px; height: 180px;
    border-radius: 10px;
    object-fit: cover;
    border: 2px solid var(--rule-strong);
    margin-bottom: 1.3rem;
}

.bio-sidebar h1 { font-size: 1.55rem; line-height: 1.25; margin-bottom: 0.4rem; }
.bio-sidebar .role { font-size: 0.95rem; color: var(--accent); font-weight: 500; margin-bottom: 1.4rem; line-height: 1.45; }

.bio-links { display: flex; flex-direction: column; gap: 0.55rem; margin-bottom: 1.6rem; }
.bio-links a {
    display: flex; align-items: center; gap: 10px;
    font-size: 0.9rem; color: var(--ink-dim); text-decoration: none;
    transition: color 0.2s;
}
.bio-links a:hover { color: var(--accent); }
.bio-links i { width: 16px; text-align: center; color: var(--accent); }

.bio-affiliation {
    font-size: 0.85rem; color: var(--ink-faint); line-height: 1.6;
    padding-top: 1.4rem; border-top: 1px solid var(--rule);
}

.content-area { flex: 1; min-width: 0; padding: 3rem 0 5rem 2.75rem; border-left: 1px solid var(--rule); }
.content-area.wide { border-left: none; padding-left: 0; }

.content-area h2.page-title {
    font-size: 2.1rem; margin-bottom: 0.6rem;
}
.page-intro { color: var(--ink-dim); font-size: 1.05rem; margin-bottom: 2.6rem; max-width: 640px; }

/* ---------------- GENERIC CONTENT BLOCKS ---------------- */
.block { margin-bottom: 3rem; }
.block h3.block-title {
    font-size: 1.3rem; margin-bottom: 1.3rem;
    padding-bottom: 0.6rem; border-bottom: 1px solid var(--rule);
}

.tag-row { display: flex; flex-wrap: wrap; gap: 0.6rem; }
.tag {
    font-size: 0.82rem; color: var(--accent);
    border: 1px solid var(--accent-line);
    background: var(--accent-soft);
    padding: 4px 12px; border-radius: 100px;
}

/* ---------------- TIMELINE (experience / education) ---------------- */
.timeline { border-left: 2px solid var(--rule-strong); padding-left: 1.8rem; margin-left: 0.4rem; }
.timeline-item { position: relative; margin-bottom: 2.6rem; }
.timeline-item:last-child { margin-bottom: 0; }
.timeline-dot {
    position: absolute; left: -2.3rem; top: 6px;
    width: 9px; height: 9px; background: var(--accent); border-radius: 50%;
}
.timeline-item h4 { font-size: 1.15rem; margin-bottom: 0.15rem; }
.timeline-meta { font-size: 0.88rem; color: var(--accent); font-weight: 500; margin-bottom: 0.7rem; }
.timeline-item ul { margin-left: 1.2rem; color: var(--ink-dim); font-size: 0.97rem; }
.timeline-item li { margin-bottom: 0.35rem; }
.timeline-item p { color: var(--ink-dim); font-size: 0.97rem; }

/* ---------------- PUBLICATIONS ---------------- */
.pub-list { list-style: none; }
.pub-item { padding: 1.6rem 0; border-bottom: 1px solid var(--rule); }
.pub-item:first-child { padding-top: 0; }
.pub-item .pub-status {
    display: inline-block; font-size: 0.7rem; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.07em; color: var(--accent); background: var(--accent-soft);
    border: 1px solid var(--accent-line); padding: 2px 9px; border-radius: 4px; margin-bottom: 0.6rem;
}
.pub-item h4 { font-size: 1.18rem; margin-bottom: 0.4rem; line-height: 1.4; }
.pub-item .pub-authors { font-size: 0.95rem; color: var(--ink-dim); margin-bottom: 0.3rem; }
.pub-item .pub-venue { font-size: 0.9rem; color: var(--ink-faint); font-style: italic; margin-bottom: 0.6rem; }
.pub-item .pub-links a {
    font-size: 0.88rem; text-decoration: none; color: var(--accent); margin-right: 1.2rem;
    display: inline-flex; align-items: center; gap: 6px;
}
.pub-item .pub-links a:hover { text-decoration: underline; }

/* ---------------- BUTTONS ---------------- */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    font-size: 0.9rem; font-weight: 500; text-decoration: none;
    color: var(--accent); border: 1px solid var(--accent-line);
    padding: 0.55rem 1.1rem; border-radius: 7px;
    background: var(--accent-soft);
    transition: 0.2s;
}
.btn:hover { background: var(--accent); color: #fff; border-color: var(--accent); }

/* ---------------- FOOTER ---------------- */
.site-footer {
    text-align: center; padding: 3.5rem 2rem 2.5rem;
    border-top: 1px solid var(--rule); color: var(--ink-faint); font-size: 0.85rem;
}
.footer-socials { display: flex; justify-content: center; gap: 1.8rem; font-size: 1.25rem; margin-bottom: 1.2rem; }
.footer-socials a { color: var(--ink-dim); transition: color 0.2s; }
.footer-socials a:hover { color: var(--accent); }

/* ---------------- RESPONSIVE ---------------- */
@media (max-width: 980px) {
    .page-shell { flex-direction: column; }
    .bio-sidebar { width: 100%; padding: 2.2rem 0 2rem; border-bottom: 1px solid var(--rule); margin-bottom: 0; }
    .bio-photo { width: 110px; height: 110px; }
    .bio-links { flex-direction: row; flex-wrap: wrap; gap: 1rem 1.4rem; }
    .bio-affiliation { border-top: none; padding-top: 0.8rem; }
    .content-area { border-left: none; padding: 2.5rem 0 4rem; }
    .site-nav { display: none; }
    .hamburger { display: flex; }
    .drawer-backdrop { display: none; }
    .drawer-backdrop.open { display: block; }
    .site-header { padding: 0 1.25rem; }
}

@media (max-width: 600px) {
    .page-shell { padding: 0 1.25rem; }
    .content-area h2.page-title { font-size: 1.7rem; }
}

.page-shell { padding: 0 2rem; }