/* =========================================================
   CESRG MODERN WEBSITE SYSTEM
   Control & Energy Systems Research Group
   COMSATS University Islamabad
   ========================================================= */

/* =========================================================
   1. ROOT VARIABLES
   ========================================================= */

:root {
    --cesrg-primary: #0b1f3a;
    --cesrg-primary-2: #123b69;
    --cesrg-blue: #1769aa;
    --cesrg-accent: #00a8e8;
    --cesrg-cyan: #00c2ff;
    --cesrg-green: #18a77a;

    --cesrg-dark: #071525;
    --cesrg-text: #172033;
    --cesrg-muted: #667085;
    --cesrg-light: #f5f8fc;
    --cesrg-white: #ffffff;
    --cesrg-border: #e6ebf2;

    --cesrg-radius-sm: 10px;
    --cesrg-radius-md: 16px;
    --cesrg-radius-lg: 24px;

    --cesrg-shadow-sm: 0 5px 20px rgba(7, 21, 37, 0.07);
    --cesrg-shadow-md: 0 12px 35px rgba(7, 21, 37, 0.10);
    --cesrg-shadow-lg: 0 25px 60px rgba(7, 21, 37, 0.15);

    --cesrg-transition: 0.3s ease;
}


/* =========================================================
   2. GLOBAL RESET
   ========================================================= */

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    padding: 0;
    background: #f7f9fc;
    color: var(--cesrg-text);
    font-family:
        Inter,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        Helvetica,
        Arial,
        sans-serif;

    font-size: 16px;
    line-height: 1.7;

    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

body::selection {
    background: var(--cesrg-accent);
    color: white;
}

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

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

a {
    color: var(--cesrg-blue);
    text-decoration: none;
    transition: color var(--cesrg-transition);
}

a:hover {
    color: var(--cesrg-accent);
    text-decoration: none;
}


/* =========================================================
   3. OLD BOOTSTRAP CONTAINER — MODERNIZE IT
   ========================================================= */

.container {
    width: min(1180px, calc(100% - 40px));
    max-width: 1180px;
    margin-left: auto;
    margin-right: auto;
}

.row-fluid {
    width: 100%;
    margin-left: 0;
}

.span12,
.span4,
.span3,
.span6,
.span8 {
    box-sizing: border-box;
}


/* =========================================================
   4. MODERN PAGE BACKGROUND
   ========================================================= */

body {
    background:
        radial-gradient(
            circle at 10% 10%,
            rgba(0, 168, 232, 0.05),
            transparent 28%
        ),
        radial-gradient(
            circle at 90% 20%,
            rgba(23, 105, 170, 0.05),
            transparent 30%
        ),
        #f7f9fc;
}


/* =========================================================
   5. HEADER / HERO
   ========================================================= */

.jumbotron {
    position: relative;

    margin: 0 auto;
    padding: 85px 35px 80px;

    border: 0;
    border-radius: 0 0 var(--cesrg-radius-lg) var(--cesrg-radius-lg);

    overflow: hidden;

    color: white;

    background:
        linear-gradient(
            135deg,
            rgba(7, 21, 37, 0.97),
            rgba(18, 59, 105, 0.94)
        );

    box-shadow: var(--cesrg-shadow-lg);
}

.jumbotron::before {
    content: "";

    position: absolute;

    width: 420px;
    height: 420px;

    right: -140px;
    top: -160px;

    border-radius: 50%;

    background: rgba(0, 194, 255, 0.15);

    filter: blur(2px);
}

.jumbotron::after {
    content: "";

    position: absolute;

    width: 260px;
    height: 260px;

    left: -120px;
    bottom: -140px;

    border-radius: 50%;

    background: rgba(24, 167, 122, 0.12);
}

.jumbotron h1 {
    position: relative;
    z-index: 2;

    margin: 0 auto 15px;

    max-width: 950px;

    color: white;

    font-size: clamp(34px, 5vw, 64px);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -1.5px;
}

.jumbotron p {
    position: relative;
    z-index: 2;

    margin: 0;

    color: rgba(255,255,255,0.82);

    font-size: clamp(17px, 2vw, 22px);
    font-weight: 400;
}


/* =========================================================
   6. NAVIGATION
   ========================================================= */

.masthead {
    position: sticky;
    top: 0;
    z-index: 999;

    margin: 0 auto;

    background: rgba(255,255,255,0.88);

    border-bottom: 1px solid rgba(230,235,242,0.8);

    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);

    box-shadow: 0 4px 20px rgba(7,21,37,0.06);
}

.masthead .navbar {
    margin: 0;
    border: 0;
    background: transparent;
}

.masthead .navbar-inner {
    min-height: 68px;

    padding: 0;

    border: 0;
    border-radius: 0;

    background: transparent;
    box-shadow: none;
}

.masthead .navbar .container {
    display: flex;
    align-items: center;
    justify-content: center;

    min-height: 68px;
}

.masthead .nav {
    display: flex;

    align-items: center;
    justify-content: center;

    gap: 5px;

    margin: 0;
    padding: 0;

    list-style: none;
}

.masthead .nav > li {
    float: none;
    display: block;
}

.masthead .nav > li > a {
    position: relative;

    display: flex;
    align-items: center;

    min-height: 48px;

    padding: 10px 16px;

    border-radius: 12px;

    color: var(--cesrg-text);

    font-size: 14px;
    font-weight: 650;

    background: transparent;

    transition:
        color var(--cesrg-transition),
        background var(--cesrg-transition),
        transform var(--cesrg-transition);
}

.masthead .nav > li > a:hover {
    color: var(--cesrg-blue);

    background: rgba(23,105,170,0.07);

    transform: translateY(-1px);
}

.masthead .nav > li.active > a {
    color: white;

    background:
        linear-gradient(
            135deg,
            var(--cesrg-primary),
            var(--cesrg-blue)
        );

    box-shadow: 0 7px 18px rgba(23,105,170,0.22);
}

.masthead .nav > li.active > a:hover {
    color: white;
}


/* =========================================================
   7. GENERAL HEADINGS
   ========================================================= */

h1,
h2,
h3,
h4,
h5,
h6 {
    color: var(--cesrg-primary);

    font-family:
        Inter,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        Roboto,
        Helvetica,
        Arial,
        sans-serif;

    font-weight: 750;

    line-height: 1.25;
}

h2 {
    font-size: clamp(28px, 4vw, 42px);
    letter-spacing: -0.5px;
}

h3 {
    font-size: 25px;
}

h4 {
    font-size: 19px;
}


/* =========================================================
   8. SECTION SYSTEM
   ========================================================= */

.my-5 {
    margin-top: 65px !important;
    margin-bottom: 65px !important;
}

hr {
    height: 1px;

    margin: 55px auto;

    border: 0;

    background: linear-gradient(
        90deg,
        transparent,
        #dfe6ef,
        transparent
    );
}


/* =========================================================
   9. CAROUSEL
   ========================================================= */

#main-carousel {
    position: relative;

    overflow: hidden;

    border-radius: var(--cesrg-radius-lg);

    background: var(--cesrg-dark);

    box-shadow: var(--cesrg-shadow-lg);
}

.carousel-image {
    display: block;

    width: 100%;
    height: min(650px, 65vh);

    min-height: 350px;

    object-fit: cover;

    border-radius: 0;
}

.carousel-caption {
    position: absolute;

    left: 5%;
    right: 5%;
    bottom: 30px;

    width: auto;

    padding: 25px 30px;

    text-align: left;

    background:
        linear-gradient(
            135deg,
            rgba(7,21,37,0.92),
            rgba(7,21,37,0.68)
        );

    border: 1px solid rgba(255,255,255,0.12);

    border-radius: 18px;

    backdrop-filter: blur(10px);

    box-shadow: 0 15px 40px rgba(0,0,0,0.25);
}

.carousel-caption h4 {
    margin: 0 0 5px;

    color: white;

    font-size: clamp(18px, 2.2vw, 28px);
    line-height: 1.3;
}

.carousel-caption p {
    margin: 5px 0 0;

    color: rgba(255,255,255,0.8);

    font-size: 15px;
}

.carousel-control {
    width: 48px;
    height: 48px;

    top: 50%;

    margin-top: -24px;

    border-radius: 50%;

    opacity: 0.9;

    background: rgba(7,21,37,0.65);

    border: 1px solid rgba(255,255,255,0.15);

    transition:
        background var(--cesrg-transition),
        transform var(--cesrg-transition);
}

.carousel-control:hover {
    background: var(--cesrg-blue);

    transform: scale(1.08);
}


/* =========================================================
   10. MODERN CARD SYSTEM
   ========================================================= */

.cesrg-card,
.card,
.panel,
.feature-card,
.research-card,
.person-card,
.publication-card,
.news-card {
    background: white;

    border: 1px solid var(--cesrg-border);

    border-radius: var(--cesrg-radius-md);

    box-shadow: var(--cesrg-shadow-sm);

    transition:
        transform var(--cesrg-transition),
        box-shadow var(--cesrg-transition),
        border-color var(--cesrg-transition);
}

.cesrg-card:hover,
.card:hover,
.panel:hover,
.feature-card:hover,
.research-card:hover,
.person-card:hover,
.publication-card:hover,
.news-card:hover {
    transform: translateY(-6px);

    border-color: rgba(23,105,170,0.20);

    box-shadow: var(--cesrg-shadow-md);
}


/* =========================================================
   11. BUTTONS
   ========================================================= */

.btn,
button {
    border-radius: 12px !important;

    font-weight: 650 !important;

    transition:
        transform var(--cesrg-transition),
        box-shadow var(--cesrg-transition),
        background var(--cesrg-transition) !important;
}

.btn:hover,
button:hover {
    transform: translateY(-2px);
}

.btn-primary {
    color: white !important;

    background:
        linear-gradient(
            135deg,
            var(--cesrg-primary),
            var(--cesrg-blue)
        ) !important;

    border: 0 !important;

    box-shadow:
        0 8px 22px rgba(23,105,170,0.20);
}

.btn-primary:hover {
    color: white !important;

    box-shadow:
        0 12px 30px rgba(23,105,170,0.30);
}


/* =========================================================
   12. ABOUT / CONTENT SECTIONS
   ========================================================= */

.about-section,
.section-card {
    padding: 55px 35px;

    background: white;

    border: 1px solid var(--cesrg-border);

    border-radius: var(--cesrg-radius-lg);

    box-shadow: var(--cesrg-shadow-sm);
}

.section-title {
    position: relative;

    margin-bottom: 35px;

    text-align: center;
}

.section-title::after {
    content: "";

    display: block;

    width: 55px;
    height: 4px;

    margin: 14px auto 0;

    border-radius: 50px;

    background:
        linear-gradient(
            90deg,
            var(--cesrg-blue),
            var(--cesrg-accent)
        );
}


/* =========================================================
   13. RESEARCH TAGS / PILLS
   ========================================================= */

.research-pill,
.research-tag,
.tag {
    display: inline-flex;

    align-items: center;

    margin: 5px;

    padding: 10px 17px;

    color: var(--cesrg-primary);

    background: #eef7fc;

    border: 1px solid #d8edf8;

    border-radius: 50px;

    font-size: 14px;
    font-weight: 650;

    transition:
        background var(--cesrg-transition),
        transform var(--cesrg-transition);
}

.research-pill:hover,
.research-tag:hover,
.tag:hover {
    background: #dff3fc;

    transform: translateY(-2px);
}


/* =========================================================
   14. STATISTICS
   ========================================================= */

.stats-container {
    display: grid;

    grid-template-columns:
        repeat(auto-fit, minmax(180px, 1fr));

    gap: 20px;
}

.stat-card {
    padding: 32px 20px;

    text-align: center;

    background: white;

    border: 1px solid var(--cesrg-border);

    border-radius: var(--cesrg-radius-md);

    box-shadow: var(--cesrg-shadow-sm);
}

.stat-card h1,
.stat-card h2 {
    margin: 0 0 8px;

    color: var(--cesrg-blue);

    font-size: 42px;
    font-weight: 800;
}

.stat-card p {
    margin: 0;

    color: var(--cesrg-muted);

    font-weight: 600;
}


/* =========================================================
   15. NEWS / NOTICE BOARD
   ========================================================= */

.cesrg-notice-board {
    position: relative;

    overflow: hidden;

    background: white;

    border: 1px solid var(--cesrg-border);

    border-radius: var(--cesrg-radius-md);

    box-shadow: var(--cesrg-shadow-md);
}

.cesrg-notice-header {
    display: flex;

    align-items: center;
    justify-content: space-between;

    padding: 18px 22px;

    color: white;

    background:
        linear-gradient(
            135deg,
            var(--cesrg-primary),
            var(--cesrg-blue)
        );
}

.cesrg-notice-header h3 {
    margin: 0;

    color: white;

    font-size: 18px;
}

.cesrg-notice-header span {
    font-size: 12px;

    padding: 5px 10px;

    border-radius: 50px;

    background: rgba(255,255,255,0.15);
}

.cesrg-notice-track {
    display: flex;

    gap: 20px;

    width: max-content;

    padding: 18px;

    animation: cesrgMarquee 35s linear infinite;
}

.cesrg-notice-board:hover .cesrg-notice-track {
    animation-play-state: paused;
}

.cesrg-notice-item {
    display: flex;

    align-items: center;

    gap: 12px;

    min-width: 280px;

    padding: 14px 18px;

    background: #f8fafc;

    border: 1px solid var(--cesrg-border);

    border-radius: 12px;
}

.cesrg-notice-dot {
    flex: 0 0 auto;

    width: 10px;
    height: 10px;

    border-radius: 50%;

    background: var(--cesrg-accent);

    box-shadow:
        0 0 0 5px rgba(0,194,255,0.10);
}

@keyframes cesrgMarquee {
    from {
        transform: translateX(0);
    }

    to {
        transform: translateX(-50%);
    }
}


/* =========================================================
   16. PEOPLE / FACULTY
   ========================================================= */

.people-grid,
.faculty-grid {
    display: grid;

    grid-template-columns:
        repeat(auto-fit, minmax(250px, 1fr));

    gap: 25px;
}

.person-card {
    overflow: hidden;

    text-align: center;
}

.person-card img {
    width: 100%;
    height: 280px;

    object-fit: cover;
}

.person-card-content {
    padding: 22px;
}

.person-card h3 {
    margin: 0 0 5px;
}

.person-card p {
    margin: 5px 0;

    color: var(--cesrg-muted);
}


/* =========================================================
   17. PUBLICATIONS
   ========================================================= */

.publication-card {
    position: relative;

    margin-bottom: 18px;

    padding: 25px 28px;

    background: white;
}

.publication-card::before {
    content: "";

    position: absolute;

    left: 0;
    top: 18px;
    bottom: 18px;

    width: 4px;

    border-radius: 0 5px 5px 0;

    background:
        linear-gradient(
            180deg,
            var(--cesrg-blue),
            var(--cesrg-accent)
        );
}

.publication-card h3 {
    margin-top: 0;
}

.publication-card .year {
    display: inline-block;

    margin-bottom: 8px;

    padding: 5px 11px;

    color: var(--cesrg-blue);

    background: #edf7fc;

    border-radius: 50px;

    font-size: 12px;
    font-weight: 700;
}


/* =========================================================
   18. GALLERY
   ========================================================= */

.gallery-grid {
    display: grid;

    grid-template-columns:
        repeat(auto-fit, minmax(230px, 1fr));

    gap: 18px;
}

.gallery-item {
    position: relative;

    overflow: hidden;

    min-height: 220px;

    border-radius: var(--cesrg-radius-md);

    background: #e9eef5;

    box-shadow: var(--cesrg-shadow-sm);
}

.gallery-item img {
    display: block;

    width: 100%;
    height: 100%;

    min-height: 220px;

    object-fit: cover;

    transition:
        transform 0.5s ease,
        filter 0.5s ease;
}

.gallery-item:hover img {
    transform: scale(1.06);

    filter: brightness(0.78);
}

.gallery-item::after {
    content: "View";

    position: absolute;

    left: 50%;
    top: 50%;

    transform:
        translate(-50%, -50%)
        scale(0.8);

    padding: 9px 16px;

    color: white;

    background: rgba(7,21,37,0.78);

    border-radius: 50px;

    opacity: 0;

    transition:
        opacity var(--cesrg-transition),
        transform var(--cesrg-transition);
}

.gallery-item:hover::after {
    opacity: 1;

    transform:
        translate(-50%, -50%)
        scale(1);
}


/* =========================================================
   19. RESEARCH EVENT ARROWS
   ========================================================= */

.research-event {
    position: relative;

    padding: 20px 55px 20px 22px;

    margin-bottom: 15px;

    background: white;

    border: 1px solid var(--cesrg-border);

    border-radius: 14px;

    box-shadow: var(--cesrg-shadow-sm);

    transition:
        transform var(--cesrg-transition),
        box-shadow var(--cesrg-transition);
}

.research-event:hover {
    transform: translateX(4px);

    box-shadow: var(--cesrg-shadow-md);
}

.research-event-arrow {
    position: absolute;

    right: 18px;
    top: 50%;

    width: 34px;
    height: 34px;

    display: flex;

    align-items: center;
    justify-content: center;

    transform: translateY(-50%);

    color: white;

    background: var(--cesrg-blue);

    border-radius: 50%;

    font-size: 18px;

    transition:
        background var(--cesrg-transition),
        transform var(--cesrg-transition);
}

.research-event:hover .research-event-arrow {
    background: var(--cesrg-accent);

    transform:
        translateY(-50%)
        translateX(3px);
}


/* =========================================================
   20. FOOTER
   ========================================================= */

#footer,
footer {
    position: relative;

    margin-top: 80px;

    padding: 55px 25px 25px;

    color: rgba(255,255,255,0.75);

    background:
        linear-gradient(
            135deg,
            #061322,
            #0c2949
        );

    border-radius: 28px 28px 0 0;

    box-shadow:
        0 -15px 50px rgba(7,21,37,0.10);
}

#footer h3,
footer h3 {
    color: white;
}

#footer a,
footer a {
    color: #69d8ff;
}

#footer a:hover,
footer a:hover {
    color: white;
}

#footer hr,
footer hr {
    background: rgba(255,255,255,0.15);
}


/* =========================================================
   21. SCROLL REVEAL
   ========================================================= */

.cesrg-reveal {
    opacity: 0;

    transform: translateY(25px);

    transition:
        opacity 0.7s ease,
        transform 0.7s ease;
}

.cesrg-reveal.cesrg-visible {
    opacity: 1;

    transform: translateY(0);
}


/* =========================================================
   22. BACK TO TOP
   ========================================================= */

#cesrg-back-top {
    position: fixed;

    right: 22px;
    bottom: 22px;

    z-index: 9999;

    width: 45px;
    height: 45px;

    display: flex;

    align-items: center;
    justify-content: center;

    color: white;

    background:
        linear-gradient(
            135deg,
            var(--cesrg-primary),
            var(--cesrg-blue)
        );

    border: 0;

    border-radius: 50%;

    box-shadow: 0 10px 25px rgba(7,21,37,0.20);

    opacity: 0;

    visibility: hidden;

    transform: translateY(15px);

    cursor: pointer;

    transition:
        opacity var(--cesrg-transition),
        visibility var(--cesrg-transition),
        transform var(--cesrg-transition);
}

#cesrg-back-top.visible {
    opacity: 1;

    visibility: visible;

    transform: translateY(0);
}

#cesrg-back-top:hover {
    transform:
        translateY(-3px)
        scale(1.05);
}


/* =========================================================
   23. MOBILE NAVIGATION
   ========================================================= */

.cesrg-mobile-toggle {
    display: none;

    width: 44px;
    height: 44px;

    align-items: center;
    justify-content: center;

    margin: 10px auto;

    color: white;

    background: var(--cesrg-primary);

    border: 0;

    border-radius: 10px;

    cursor: pointer;

    font-size: 22px;
}


/* =========================================================
   24. MOBILE RESPONSIVE
   ========================================================= */

@media (max-width: 900px) {

    .container {
        width: min(100% - 28px, 720px);
    }

    .jumbotron {
        padding: 65px 22px 60px;
    }

    .masthead .navbar-inner {
        min-height: auto;
    }

    .masthead .navbar .container {
        display: block;
    }

    .cesrg-mobile-toggle {
        display: flex;
    }

    .masthead .nav {
        display: none;

        flex-direction: column;

        width: 100%;

        padding: 10px 0 15px;

        gap: 3px;
    }

    .masthead .nav.cesrg-mobile-open {
        display: flex;
    }

    .masthead .nav > li {
        width: 100%;
    }

    .masthead .nav > li > a {
        justify-content: center;

        width: 100%;
    }

    .carousel-image {
        height: 55vh;

        min-height: 320px;
    }

    .carousel-caption {
        left: 15px;
        right: 15px;
        bottom: 15px;

        padding: 18px;
    }

    .carousel-control {
        display: none;
    }

    .about-section,
    .section-card {
        padding: 35px 20px;
    }
}


@media (max-width: 600px) {

    body {
        font-size: 15px;
    }

    .container {
        width: calc(100% - 22px);
    }

    .jumbotron {
        padding: 50px 18px;
    }

    .jumbotron h1 {
        letter-spacing: -0.7px;
    }

    .my-5 {
        margin-top: 40px !important;
        margin-bottom: 40px !important;
    }

    hr {
        margin: 35px auto;
    }

    .carousel-image {
        height: 430px;

        min-height: 0;
    }

    .carousel-caption {
        padding: 15px;
    }

    .carousel-caption p {
        font-size: 13px;
    }

    .cesrg-notice-track {
        animation-duration: 28s;
    }

    .cesrg-notice-item {
        min-width: 245px;
    }

    .gallery-grid {
        grid-template-columns: 1fr 1fr;

        gap: 10px;
    }

    .gallery-item,
    .gallery-item img {
        min-height: 150px;
    }

    #footer,
    footer {
        margin-top: 50px;

        padding: 40px 18px 20px;
    }
}


/* =========================================================
   25. ACCESSIBILITY
   ========================================================= */

a:focus-visible,
button:focus-visible {
    outline: 3px solid rgba(0,194,255,0.45);

    outline-offset: 3px;
}


/* =========================================================
   26. REDUCE MOTION
   ========================================================= */

@media (prefers-reduced-motion: reduce) {

    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}
/* =====================================================
   CESRG LAB VIDEO
   ===================================================== */

.lab-video-wrapper {
    position: relative;
    overflow: hidden;
    margin-bottom: 25px;
    background: #071525;
    border: 1px solid #e3e8ee;
    border-radius: 20px;
    box-shadow: 0 10px 35px rgba(7,21,37,.10);
}

.lab-video {
    display: block;
    width: 100%;
    max-height: 600px;
    object-fit: cover;
    background: #071525;
}

.lab-video-label {
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    padding: 55px 22px 20px;
    background: linear-gradient(
        transparent,
        rgba(4,14,27,.88)
    );
    color: white;
    font-size: 14px;
    font-weight: 700;
    pointer-events: none;
}

@media (max-width: 650px) {

    .lab-video {
        min-height: 240px;
        max-height: 400px;
    }

    .lab-video-label {
        padding: 45px 15px 15px;
        font-size: 12px;
    }

}