/* ====================================================
   Nikhil A P — Academic Website  |  Clean Academic CSS
   ==================================================== */

:root {
    --navy:       #2d5986;
    --navy-dark:  #1e3d5f;
    --navy-light: rgba(45, 89, 134, 0.08);
    --green:      #198754;
    --amber:      #d97706;
    --text:       #1a1a2e;
    --muted:      #6c757d;
    --border:     #dee2e6;
    --bg-light:   #f8f9fa;
}

/* ── Base ─────────────────────────────────────────── */
body {
    font-family: 'Lato', 'Segoe UI', sans-serif;
    color: var(--text);
    background: #fff;
    line-height: 1.75;
    font-size: 1rem;
}
a { color: var(--navy); }
a:hover { color: var(--navy-dark); }

/* ── Navbar ───────────────────────────────────────── */
.site-nav {
    position: sticky;
    top: 0;
    z-index: 999;
    background: var(--navy);
    border-bottom: none;
    padding: 0.6rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.18);
}
.site-nav .navbar-brand {
    font-size: 1.2rem;
    font-weight: 700;
    color: #fff;
    letter-spacing: 0.02em;
}
.site-nav .navbar-brand:hover { color: rgba(255,255,255,0.85); }
.site-nav .nav-link {
    color: rgba(255,255,255,0.82);
    font-size: 0.92rem;
    padding: 0.35rem 0.85rem;
    border-radius: 4px;
    font-weight: 500;
    transition: all 0.18s;
}
.site-nav .nav-link:hover { color: #fff; background: rgba(255,255,255,0.14); }
.site-nav .nav-link.active  { color: #fff; background: rgba(255,255,255,0.18); font-weight: 700; }

/* ── Page Banner (Publications / Presentations / CV) ─ */
.page-banner {
    background: linear-gradient(135deg, var(--navy) 0%, var(--navy-dark) 100%);
    color: #fff;
    padding: 2.5rem 0 2rem;
}
.page-banner h1 { font-size: 2rem; font-weight: 700; margin: 0; }
.page-banner p  { margin: 0.3rem 0 0; opacity: 0.85; font-size: 0.95rem; }

/* ── Section Title ────────────────────────────────── */
.section-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--navy);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    border-bottom: 2px solid var(--navy);
    padding-bottom: 0.4rem;
    margin-bottom: 1.5rem;
    display: inline-block;
}

/* ── Hero / Profile ───────────────────────────────── */
.hero-section {
    position: relative;
    padding: 5rem 0 4rem;
    background: url('../assets/img/hero-bg.png') center center / cover no-repeat;
    background-attachment: fixed;
}
.hero-section::before {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(4, 14, 32, 0.62);
}
.hero-section .container { position: relative; z-index: 1; }

.profile-photo {
    width: 235px;
    height: 235px;
    object-fit: cover;
    border-radius: 50%;
    border: 4px solid rgba(255,255,255,0.55);
    box-shadow: 0 8px 36px rgba(0,0,0,0.45);
}
.hero-name {
    font-size: 2.5rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 0.15rem;
    line-height: 1.2;
}
.hero-title {
    color: rgba(255,255,255,0.78);
    font-size: 1rem;
    margin-bottom: 1.1rem;
    font-weight: 400;
}
.hero-bio { font-size: 0.97rem; line-height: 1.75; color: rgba(255,255,255,0.88); }
.hero-bio a { color: #90c5ff; }
.hero-bio strong { color: #fff; }
.hero-contact { font-size: 0.9rem; color: rgba(255,255,255,0.72); }
.hero-contact a { color: #90c5ff; text-decoration: none; }
.hero-contact a:hover { text-decoration: underline; color: #fff; }

/* ── Social Buttons ───────────────────────────────── */
.social-links { display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 1rem 0 1.25rem; }
.social-btn {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 0.35rem 0.8rem;
    border: 1px solid rgba(255,255,255,0.38);
    border-radius: 20px;
    color: rgba(255,255,255,0.88);
    background: rgba(255,255,255,0.08);
    text-decoration: none;
    font-size: 0.84rem;
    transition: all 0.18s;
}
.social-btn:hover {
    border-color: rgba(255,255,255,0.75);
    color: #fff;
    background: rgba(255,255,255,0.18);
    text-decoration: none;
}

/* ── Research Interests Strip ─────────────────────── */
.interests-strip { background: var(--bg-light); padding: 1.5rem 0; }
.interests-strip .label {
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--muted);
    margin-bottom: 0.6rem;
}

/* ── Buttons ──────────────────────────────────────── */
.btn-navy         { background: var(--navy); color: #fff; border: none; }
.btn-navy:hover   { background: var(--navy-dark); color: #fff; }
.btn-outline-navy { color: var(--navy); border: 1px solid var(--navy); background: transparent; }
.btn-outline-navy:hover { background: var(--navy); color: #fff; }

/* ── Publication Entry ────────────────────────────── */
.pub-entry {
    display: flex;
    gap: 1rem;
    padding: 1rem 1.1rem;
    border-radius: 6px;
    border-left: 3px solid var(--navy);
    background: var(--navy-light);
    margin-bottom: 1rem;
    transition: transform 0.18s, background 0.18s;
    align-items: flex-start;
}
.pub-entry:hover { transform: translateX(4px); background: rgba(45,89,134,0.13); }
.pub-entry.under-review  { border-color: var(--amber); background: rgba(217,119,6,0.07); }
.pub-entry.under-review:hover { background: rgba(217,119,6,0.13); }
.pub-entry.preparation   { border-color: var(--muted); background: rgba(108,117,125,0.07); }
.pub-badge {
    flex-shrink: 0;
    font-size: 0.72rem;
    font-weight: 700;
    padding: 0.25em 0.6em;
    border-radius: 3px;
    color: #fff;
    margin-top: 3px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}
.pub-badge.accepted    { background: var(--green); }
.pub-badge.review      { background: var(--amber); }
.pub-badge.preparation { background: var(--muted); }
.pub-title { font-weight: 600; margin-bottom: 0.2rem; color: #212529; font-size: 0.96rem; }
.pub-title a { color: inherit; text-decoration: none; }
.pub-title a:hover { color: var(--navy); text-decoration: underline; }
.pub-meta  { font-size: 0.87rem; color: var(--muted); line-height: 1.4; }
.pub-meta em { font-style: italic; }
.pub-doi   { font-size: 0.82rem; color: var(--navy); }

/* ── Timeline (Education / Experience) ───────────── */
.timeline { border-left: 2px solid var(--border); padding-left: 1.5rem; }
.timeline-item { position: relative; margin-bottom: 1.75rem; }
.timeline-item::before {
    content: '';
    position: absolute;
    left: -1.83rem;
    top: 6px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--navy);
    border: 2px solid #fff;
    box-shadow: 0 0 0 2px var(--navy);
}
.timeline-date     { font-size: 0.82rem; color: var(--navy); font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; }
.timeline-degree   { font-size: 1.05rem; font-weight: 700; color: #212529; margin-bottom: 0.1rem; }
.timeline-inst     { font-weight: 600; color: var(--navy); font-size: 0.93rem; margin-bottom: 0.15rem; }
.timeline-detail   { font-size: 0.9rem; color: #555; }

/* ── Award Entry ──────────────────────────────────── */
.award-entry {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    padding: 0.8rem 1rem;
    border-left: 3px solid var(--navy);
    background: var(--navy-light);
    border-radius: 0 5px 5px 0;
    margin-bottom: 0.65rem;
    font-size: 0.93rem;
}
.award-entry i { color: var(--navy); margin-top: 2px; flex-shrink: 0; }

/* ── Presentation Entry ───────────────────────────── */
.pres-entry {
    padding: 1rem 1.25rem;
    border-radius: 6px;
    background: var(--bg-light);
    border-left: 3px solid #0d6efd;
    margin-bottom: 1rem;
    transition: transform 0.18s, box-shadow 0.18s;
}
.pres-entry:hover { transform: translateX(4px); box-shadow: 0 2px 10px rgba(0,0,0,0.08); }
.pres-title  { font-weight: 600; color: #212529; font-size: 0.96rem; margin-bottom: 0.2rem; }
.pres-detail { font-size: 0.88rem; color: var(--muted); }

/* ── Skill pills ──────────────────────────────────── */
.skill-pill {
    display: inline-block;
    padding: 0.3em 0.8em;
    background: var(--navy-light);
    color: var(--navy);
    border: 1px solid rgba(45,89,134,0.2);
    border-radius: 20px;
    font-size: 0.87rem;
    font-weight: 500;
    margin: 0.2rem 0.15rem;
}

/* ── Footer ───────────────────────────────────────── */
.site-footer {
    background: #1e2a3a;
    color: rgba(255,255,255,0.7);
    padding: 2rem 0;
    font-size: 0.88rem;
}
.site-footer a { color: rgba(255,255,255,0.85); }

/* ── Navbar toggler on dark nav ───────────────────── */
.site-nav .navbar-toggler {
    border-color: rgba(255,255,255,0.35);
}
.site-nav .navbar-toggler-icon {
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%28255%2c255%2c255%2c0.8%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

/* ── Responsive tweaks ────────────────────────────── */
@media (max-width: 767px) {
    .hero-name { font-size: 1.85rem; }
    .profile-photo { width: 170px; height: 170px; }
    .hero-section { padding: 2.5rem 0 2rem; background-attachment: scroll; }
}