/* ==========================================================================
   Animations & Transitions
   Shared by portfolio, education, experience and certificates pages.
   Everything here is progressive enhancement and is disabled under
   prefers-reduced-motion.
   ========================================================================== */

:root {
    --gold: var(--accent);
    --gold-light: var(--accent-light);
    --blue: var(--accent2);
    --ease-out: cubic-bezier(0.22, 1, 0.36, 1);
    --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* --------------------------------------------------------------------------
   Scroll progress bar
   -------------------------------------------------------------------------- */
.scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    width: 100%;
    background: linear-gradient(90deg, var(--gold), var(--blue), var(--gold));
    background-size: 200% 100%;
    transform-origin: left;
    transform: scaleX(0);
    z-index: 1000;
    pointer-events: none;
    animation: gradient-slide 4s linear infinite;
}

@keyframes gradient-slide {
    from { background-position: 0% 0; }
    to   { background-position: 200% 0; }
}

/* --------------------------------------------------------------------------
   Cursor glow (pointer devices only)
   -------------------------------------------------------------------------- */
.cursor-glow {
    position: fixed;
    top: 0;
    left: 0;
    width: 420px;
    height: 420px;
    margin: -210px 0 0 -210px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(var(--accent-rgb), 0.10) 0%, rgba(var(--accent2-rgb), 0.05) 35%, transparent 65%);
    pointer-events: none;
    z-index: 0;
    opacity: 0;
    transition: opacity 0.6s ease;
    will-change: transform;
}

.cursor-glow.on {
    opacity: 1;
}

@media (hover: none), (pointer: coarse) {
    .cursor-glow { display: none; }
}

/* --------------------------------------------------------------------------
   Page load
   -------------------------------------------------------------------------- */
.navbar {
    animation: nav-drop 0.7s var(--ease-out) both;
}

@keyframes nav-drop {
    from { transform: translateY(-100%); opacity: 0; }
    to   { transform: translateY(0); opacity: 1; }
}

.nav-title {
    background: linear-gradient(90deg, var(--gold) 0%, var(--accent-glow) 50%, var(--gold) 100%);
    background-size: 200% auto;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: text-shimmer 5s linear infinite;
}

@keyframes text-shimmer {
    to { background-position: 200% center; }
}

.nav-links li {
    animation: nav-item-in 0.5s var(--ease-out) both;
}

.nav-links li:nth-child(1) { animation-delay: 0.25s; }
.nav-links li:nth-child(2) { animation-delay: 0.32s; }
.nav-links li:nth-child(3) { animation-delay: 0.39s; }
.nav-links li:nth-child(4) { animation-delay: 0.46s; }
.nav-links li:nth-child(5) { animation-delay: 0.53s; }
.nav-links li:nth-child(6) { animation-delay: 0.60s; }

@keyframes nav-item-in {
    from { opacity: 0; transform: translateY(-8px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* Dropdown: fade + slide instead of a hard display toggle */
@media (min-width: 737px) {
    .dropdown-menu {
        display: block;
        opacity: 0;
        visibility: hidden;
        transform: translate(-50%, 8px);
        transition: opacity 0.25s var(--ease-out), transform 0.25s var(--ease-out), visibility 0s linear 0.25s;
    }

    .nav-dropdown:hover .dropdown-menu,
    .nav-dropdown:focus-within .dropdown-menu {
        opacity: 1;
        visibility: visible;
        transform: translate(-50%, 0);
        transition-delay: 0s;
    }

    .dropdown-menu li a {
        transition: background 0.2s, padding-left 0.2s var(--ease-out), color 0.2s;
    }

    .dropdown-menu li a:hover {
        padding-left: 1.4rem;
        color: var(--gold);
    }
}

/* --------------------------------------------------------------------------
   Section reveals
   -------------------------------------------------------------------------- */
.section .container {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
}

.section.in-view .container {
    opacity: 1;
    transform: none;
}

/* Heading: slide in with a gold sweep underline */
.section h1,
.section h2 {
    position: relative;
    display: inline-block;
}

.section h1::after,
.section h2::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -4px;
    height: 2px;
    width: 100%;
    background: linear-gradient(90deg, var(--gold), transparent);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.9s var(--ease-out) 0.25s;
}

.section.in-view h1::after,
.section.in-view h2::after {
    transform: scaleX(1);
}

/* Divider grows out from the left */
.divider {
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.9s var(--ease-out) 0.3s;
    background-size: 200% 100%;
    animation: gradient-slide 3s linear infinite;
}

.section.in-view .divider {
    transform: scaleX(1);
}

/* Header buttons pop in after the title */
.section-header .btn-primary {
    opacity: 0;
    transform: translateX(16px);
    transition: opacity 0.6s var(--ease-out) 0.35s, transform 0.6s var(--ease-out) 0.35s, background 0.2s, box-shadow 0.3s;
}

.section.in-view .section-header .btn-primary {
    opacity: 1;
    transform: translateX(0);
}

/* --------------------------------------------------------------------------
   Staggered reveal for cards / list items
   JS applies a per-item inline transition-delay for the reveal and clears it afterwards.
   -------------------------------------------------------------------------- */
.fade-up {
    opacity: 0;
    transform: translateY(28px) scale(0.98);
    transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}

.fade-up.visible {
    opacity: 1;
    transform: translateY(0) scale(1);
}

.fade-left {
    opacity: 0;
    transform: translateX(-32px);
    transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}

.fade-left.visible {
    opacity: 1;
    transform: translateX(0);
}

/* --------------------------------------------------------------------------
   Project cards
   -------------------------------------------------------------------------- */
.project-card {
    position: relative;
    isolation: isolate;
    transition:
        transform 0.5s var(--ease-out),
        opacity 0.7s var(--ease-out),
        box-shadow 0.45s var(--ease-out),
        border-color 0.45s var(--ease-out);
}

.project-card:hover {
    transform: translateY(-8px) scale(1.015);
    border-color: rgba(var(--accent-rgb), 0.45);
    box-shadow:
        0 18px 40px rgba(var(--shadow-rgb), 0.45),
        0 0 0 1px rgba(var(--accent-rgb), 0.15),
        0 12px 32px rgba(var(--accent-rgb), 0.12);
}

/* Thumb zoom + subtle brightness on hover */
.project-card .project-thumb {
    transition: transform 0.7s var(--ease-out), filter 0.5s ease, opacity 0.6s ease;
    transform-origin: center;
}

.project-card:hover .project-thumb {
    transform: scale(1.07);
    filter: brightness(1.08) saturate(1.1);
}

/* Blur-up image loading */
img.lazy-img {
    opacity: 0;
    filter: blur(6px);
    transition: opacity 0.6s ease, filter 0.6s ease, transform 0.7s var(--ease-out);
}

img.lazy-img.loaded {
    opacity: 1;
    filter: blur(0);
}

/* Diagonal shine sweep across the card */
.project-card::before {
    content: '';
    position: absolute;
    inset: 0;
    z-index: 2;
    background: linear-gradient(115deg, transparent 30%, rgba(var(--fg-rgb), 0.10) 48%, rgba(var(--fg-rgb), 0.18) 50%, rgba(var(--fg-rgb), 0.10) 52%, transparent 70%);
    transform: translateX(-120%);
    pointer-events: none;
    transition: transform 0s;
}

.project-card:hover::before {
    transform: translateX(120%);
    transition: transform 0.9s var(--ease-out);
}

/* Title and stack slide slightly on hover */
.project-info h3,
.project-info p {
    transition: transform 0.4s var(--ease-out), color 0.3s ease;
}

.project-card:hover .project-info h3 {
    transform: translateX(4px);
    color: var(--gold-light);
}

.project-card:hover .project-info p {
    transform: translateX(4px);
}

/* Small "open" arrow in the corner */
.project-card .project-info {
    position: relative;
}

.project-card .project-info::after {
    content: '↗';
    position: absolute;
    right: 1.1rem;
    top: 50%;
    transform: translate(8px, -50%);
    opacity: 0;
    color: var(--gold);
    font-size: 1.1em;
    transition: opacity 0.3s ease, transform 0.4s var(--ease-spring);
}

.project-card:hover .project-info::after {
    opacity: 1;
    transform: translate(0, -50%);
}

.project-card.no-link .project-info::after {
    display: none;
}

/* --------------------------------------------------------------------------
   Article cards
   -------------------------------------------------------------------------- */
.article-card {
    position: relative;
    overflow: hidden;
    transition: transform 0.4s var(--ease-out), box-shadow 0.4s ease, border-color 0.4s ease, background 0.4s ease;
}

.article-card::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, var(--gold), var(--blue));
    transform: scaleY(0);
    transform-origin: top;
    transition: transform 0.4s var(--ease-out);
}

.article-card:hover::before {
    transform: scaleY(1);
}

.article-card:hover {
    transform: translateX(10px);
    border-color: rgba(var(--accent-rgb), 0.35);
    background: rgba(var(--fg-rgb), 0.07);
}

.article-thumb {
    transition: transform 0.5s var(--ease-spring), box-shadow 0.4s ease;
}

.article-card:hover .article-thumb {
    transform: rotate(-3deg) scale(1.08);
    box-shadow: 0 8px 20px rgba(var(--shadow-rgb), 0.4);
}

.article-card h3 {
    transition: color 0.3s ease;
}

.article-card:hover h3 {
    color: var(--gold-light);
}

/* --------------------------------------------------------------------------
   Timeline (education / experience)
   -------------------------------------------------------------------------- */
.timeline-item {
    opacity: 0;
    transform: translateX(-30px);
    transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}

.timeline-item.visible {
    opacity: 1;
    transform: translateX(0);
}

.timeline-marker {
    transition: transform 0.4s var(--ease-spring), box-shadow 0.4s ease;
}

.timeline-item:hover .timeline-marker {
    transform: scale(1.4);
    box-shadow: 0 0 0 6px rgba(var(--accent-rgb), 0.15);
}

.timeline-marker.current {
    animation: marker-pulse 2.2s ease-in-out infinite;
}

@keyframes marker-pulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(var(--accent-rgb), 0.55); }
    60%      { box-shadow: 0 0 0 12px rgba(var(--accent-rgb), 0); }
}

.timeline-content {
    transition: transform 0.4s var(--ease-out), box-shadow 0.4s ease, border-color 0.4s ease;
}

.timeline-item:hover .timeline-content {
    transform: translateX(6px);
    box-shadow: 0 12px 30px rgba(var(--shadow-rgb), 0.35);
}

.timeline-logo {
    transition: transform 0.5s var(--ease-spring), filter 0.4s ease;
}

.timeline-item:hover .timeline-logo {
    transform: scale(1.08) rotate(-2deg);
}

.tag {
    transition: transform 0.25s var(--ease-spring), background 0.25s ease, color 0.25s ease, border-color 0.25s ease;
}

.tag:hover {
    transform: translateY(-2px);
    background: rgba(var(--accent-rgb), 0.18);
}

/* --------------------------------------------------------------------------
   Buttons & links
   -------------------------------------------------------------------------- */
.btn-primary,
.btn-outline,
.tag-link {
    position: relative;
    overflow: hidden;
    isolation: isolate;
}

.btn-primary::before,
.btn-outline::before {
    content: '';
    position: absolute;
    inset: 0;
    z-index: -1;
    background: linear-gradient(115deg, transparent 35%, rgba(var(--fg-rgb), 0.35) 50%, transparent 65%);
    transform: translateX(-120%);
    transition: transform 0s;
}

.btn-primary:hover::before,
.btn-outline:hover::before {
    transform: translateX(120%);
    transition: transform 0.7s var(--ease-out);
}

.btn-primary:hover {
    transform: translateY(-2px) scale(1.03);
    box-shadow: 0 10px 24px rgba(var(--accent-rgb), 0.3);
}

.btn-primary:active {
    transform: translateY(0) scale(0.98);
}

/* Tag links fill from the left */
.tag-link::before {
    content: '';
    position: absolute;
    inset: 0;
    z-index: -1;
    background: var(--gold);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.35s var(--ease-out);
}

.tag-link:hover {
    background: transparent;
    transform: translateY(-2px);
    box-shadow: 0 8px 18px rgba(var(--accent-rgb), 0.25);
}

.tag-link:hover::before {
    transform: scaleX(1);
}

/* Click ripple (span injected by JS) */
.ripple {
    position: absolute;
    border-radius: 50%;
    background: rgba(var(--fg-rgb), 0.45);
    transform: scale(0);
    animation: ripple 0.6s var(--ease-out) forwards;
    pointer-events: none;
    z-index: 1;
}

@keyframes ripple {
    to { transform: scale(4); opacity: 0; }
}

.footer-links a {
    position: relative;
    text-decoration: none;
    transition: color 0.3s ease, transform 0.3s var(--ease-spring);
    display: inline-block;
}

.footer-links a::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -3px;
    width: 100%;
    height: 1px;
    background: var(--gold);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform 0.35s var(--ease-out);
}

.footer-links a:hover {
    transform: translateY(-2px);
}

.footer-links a:hover::after {
    transform: scaleX(1);
    transform-origin: left;
}

.timeline-org {
    transition: color 0.3s ease, letter-spacing 0.3s ease;
}

.timeline-org:hover {
    letter-spacing: 0.02em;
}

/* --------------------------------------------------------------------------
   About section
   -------------------------------------------------------------------------- */
.about-photo {
    animation: photo-float 6s ease-in-out infinite;
    transition: transform 0.5s var(--ease-out), box-shadow 0.5s ease, border-color 0.5s ease;
    box-shadow: 0 20px 40px rgba(var(--shadow-rgb), 0.35);
}

.about-photo:hover {
    animation-play-state: paused;
    transform: scale(1.04) rotate(-1deg);
    border-color: rgba(var(--accent-rgb), 0.7);
    box-shadow: 0 25px 50px rgba(var(--shadow-rgb), 0.5), 0 0 40px rgba(var(--accent-rgb), 0.2);
}

@keyframes photo-float {
    0%, 100% { transform: translateY(0); }
    50%      { transform: translateY(-10px); }
}

.about-text {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 0.9s var(--ease-out) 0.2s, transform 0.9s var(--ease-out) 0.2s;
}

.about-text.visible {
    opacity: 1;
    transform: none;
}

/* --------------------------------------------------------------------------
   Ambient background motion
   -------------------------------------------------------------------------- */
.bg-decoration::before {
    animation: drift-a 26s ease-in-out infinite alternate;
}

.bg-decoration::after {
    animation: drift-b 32s ease-in-out infinite alternate;
}

@keyframes drift-a {
    from { transform: translate(0, 0) scale(1); }
    to   { transform: translate(-40px, 30px) scale(1.08); }
}

@keyframes drift-b {
    from { transform: rotate(45deg) translate(0, 0); }
    to   { transform: rotate(60deg) translate(30px, -30px); }
}

.bg-shape {
    animation: shape-spin 40s linear infinite;
}

.bg-shape--circle-sm { animation-duration: 28s; }
.bg-shape--diamond   { animation-duration: 36s; animation-direction: reverse; }
.bg-shape--circle-md { animation-duration: 44s; }
.bg-shape--square    { animation-duration: 50s; animation-direction: reverse; }
.bg-shape--hex       { animation-duration: 32s; }

@keyframes shape-spin {
    from { rotate: 0deg; }
    to   { rotate: 360deg; }
}

.bg-shape--circle-lg {
    animation: breathe 12s ease-in-out infinite;
}

@keyframes breathe {
    0%, 100% { transform: translate(-50%, -50%) scale(1); opacity: 0.5; }
    50%      { transform: translate(-50%, -50%) scale(1.12); opacity: 0.8; }
}

/* --------------------------------------------------------------------------
   Back to top
   -------------------------------------------------------------------------- */
.back-to-top {
    position: fixed;
    right: 1.5rem;
    bottom: 1.5rem;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 1px solid rgba(var(--accent-rgb), 0.4);
    background: var(--panel-bg);
    color: var(--gold);
    font-size: 1.1rem;
    display: grid;
    place-items: center;
    cursor: pointer;
    opacity: 0;
    transform: translateY(16px) scale(0.8);
    pointer-events: none;
    transition: opacity 0.35s ease, transform 0.35s var(--ease-spring), background 0.3s ease, box-shadow 0.3s ease;
    z-index: 900;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.back-to-top.show {
    opacity: 1;
    transform: translateY(0) scale(1);
    pointer-events: auto;
}

.back-to-top:hover {
    background: var(--gold);
    color: var(--on-accent);
    box-shadow: 0 10px 24px rgba(var(--accent-rgb), 0.35);
    transform: translateY(-3px) scale(1.06);
}

/* --------------------------------------------------------------------------
   Hamburger + mobile nav
   -------------------------------------------------------------------------- */
@media (max-width: 736px) {
    .nav-links {
        display: flex;
        opacity: 0;
        visibility: hidden;
        transform: translateY(-10px);
        transition: opacity 0.3s var(--ease-out), transform 0.3s var(--ease-out), visibility 0s linear 0.3s;
    }

    .nav-links.active {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
        transition-delay: 0s;
    }

    .nav-links li {
        animation: none;
    }

    .project-card:hover {
        transform: translateY(-4px);
    }
}

/* --------------------------------------------------------------------------
   Reduced motion
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.001ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.001ms !important;
        transition-delay: 0s !important;
        scroll-behavior: auto !important;
    }

    .section .container,
    .fade-up,
    .fade-left,
    .timeline-item,
    .about-text,
    .section-header .btn-primary,
    img.lazy-img {
        opacity: 1 !important;
        transform: none !important;
        filter: none !important;
    }

    .divider,
    .section h1::after,
    .section h2::after {
        transform: scaleX(1) !important;
    }

    .cursor-glow,
    .scroll-progress {
        display: none;
    }
}