/*======================================================================
  Interaction Layer : cursor, split text, palette, wordmark, media reveal
======================================================================*/

/*-- Header Search Trigger --*/
.search-trigger {
    display: flex;
    align-items: center;
    gap: 8px;
    height: 40px;
    padding: 0 8px 0 12px;
    border-radius: 999px;
    font-size: 13.5px;
    color: var(--muted);
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.09), rgba(255, 255, 255, 0.02)),
        rgba(14, 30, 64, 0.38);
    border: 1px solid rgba(255, 255, 255, 0.12);
    -webkit-backdrop-filter: blur(22px) saturate(180%);
    backdrop-filter: blur(22px) saturate(180%);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2), 0 8px 24px rgba(2, 6, 23, 0.4);
    transition: color 200ms ease-out, border-color 200ms ease-out, background-color 200ms ease-out;
}

.search-trigger i {
    font-size: 17px;
}

.search-trigger kbd {
    padding: 2px 7px;
    border-radius: 6px;
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--dim);
    background: rgba(5, 10, 24, 0.6);
    border: 1px solid var(--border);
}

.search-trigger:hover {
    color: #fff;
    border-color: var(--border-strong);
    background: var(--surface-hover);
}

/*-- Header : tucks away while reading, returns on scroll up --*/
.site-header {
    transition: transform 400ms var(--ease-out), background-color 300ms ease-out, border-color 300ms ease-out;
}

.site-header.is-hidden {
    transform: translateY(-100%);
}

/*-- Split Text : words rise into place --*/
.split-word {
    display: inline-block;
    overflow: hidden;
    vertical-align: top;
    padding-bottom: 0.1em;
    margin-bottom: -0.1em;
}

.split-word > span {
    display: inline-block;
}

/*-- Animated Gradient Border --*/
@property --angle {
    syntax: "<angle>";
    initial-value: 0deg;
    inherits: false;
}

.glow-border::after {
    content: "";
    position: absolute;
    inset: -1px;
    border-radius: inherit;
    padding: 1px;
    background: conic-gradient(from var(--angle), transparent 0 60%, rgba(96, 165, 250, 0.9) 75%, rgba(34, 211, 238, 0.9) 85%, transparent 100%);
    -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    animation: border-spin 6s linear infinite;
    pointer-events: none;
}

@keyframes border-spin {
    to { --angle: 360deg; }
}

/*-- Back To Top --*/
.to-top {
    position: fixed;
    right: 22px;
    bottom: 22px;
    z-index: 950;
    display: grid;
    place-items: center;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    font-size: 22px;
    color: #fff;
    background: rgba(11, 24, 51, 0.85);
    border: 1px solid var(--border);
    -webkit-backdrop-filter: blur(10px);
    backdrop-filter: blur(10px);
    opacity: 0;
    visibility: hidden;
    transform: translateY(12px) scale(0.9);
    transition: opacity 300ms var(--ease-out), transform 400ms var(--spring), visibility 0s linear 300ms;
}

.to-top.is-visible {
    opacity: 1;
    visibility: visible;
    transform: none;
    transition: opacity 300ms var(--ease-out), transform 400ms var(--spring), visibility 0s;
}

.to-top i {
    position: relative;
    transition: transform 250ms var(--ease-out);
}

.to-top:hover i {
    transform: translateY(-3px);
}

.to-top svg {
    position: absolute;
    inset: -1px;
    width: calc(100% + 2px);
    height: calc(100% + 2px);
    transform: rotate(-90deg);
}

.to-top circle {
    fill: none;
    stroke: var(--primary-2);
    stroke-width: 2.5;
    stroke-linecap: round;
}

/*-- Toast --*/
.ui-toast {
    position: fixed;
    left: 50%;
    bottom: 28px;
    z-index: 2950;
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 20px;
    border-radius: 999px;
    font-size: 14px;
    font-weight: 500;
    white-space: nowrap;
    color: #fff;
    background: rgba(11, 24, 51, 0.95);
    border: 1px solid var(--border-strong);
    box-shadow: var(--shadow);
    opacity: 0;
    visibility: hidden;
    transform: translate(-50%, 16px);
    transition: opacity 250ms ease-in, transform 250ms ease-in, visibility 0s linear 250ms;
}

.ui-toast.show {
    opacity: 1;
    visibility: visible;
    transform: translate(-50%, 0);
    transition: opacity 300ms var(--ease-out), transform 450ms var(--spring), visibility 0s;
}

.ui-toast i {
    font-size: 18px;
    color: var(--accent);
}

/*-- Command Palette --*/
.palette {
    position: fixed;
    inset: 0;
    z-index: 2800;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 14vh 16px 16px;
    background: rgba(2, 6, 18, 0.6);
    -webkit-backdrop-filter: blur(8px);
    backdrop-filter: blur(8px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 200ms ease-in, visibility 0s linear 200ms;
}

.palette.is-open {
    opacity: 1;
    visibility: visible;
    transition: opacity 250ms var(--ease-out), visibility 0s;
}

.palette-panel {
    width: min(620px, 100%);
    overflow: hidden;
    border-radius: 20px;
    background: rgba(9, 20, 44, 0.97);
    border: 1px solid var(--border-strong);
    box-shadow: 0 40px 100px rgba(0, 0, 0, 0.6);
    transform: translateY(-12px) scale(0.97);
    transition: transform 200ms ease-in;
}

.palette.is-open .palette-panel {
    transform: none;
    transition: transform 400ms var(--spring);
}

.palette-search {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 0 18px;
    border-bottom: 1px solid var(--border);
}

.palette-search i {
    font-size: 20px;
    color: var(--muted);
}

.palette-search input {
    flex: 1;
    height: 58px;
    font: inherit;
    font-size: 16px;
    color: #fff;
    background: transparent;
    border: none;
    outline: none;
}

.palette-search input:focus-visible {
    outline: none;
}

.palette-search input::placeholder {
    color: var(--dim);
}

.palette-search kbd,
.palette-foot kbd {
    padding: 2px 7px;
    border-radius: 6px;
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--muted);
    background: rgba(5, 10, 24, 0.6);
    border: 1px solid var(--border);
}

.palette-list {
    max-height: min(420px, 50vh);
    overflow-y: auto;
    padding: 8px;
    list-style: none;
}

.palette-group {
    padding: 10px 12px 6px;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--dim);
}

.palette-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 12px;
    border-radius: 12px;
    font-size: 14.5px;
    color: var(--text);
    cursor: pointer;
    transition: background-color 150ms ease-out;
}

.palette-item > i {
    display: grid;
    place-items: center;
    width: 32px;
    height: 32px;
    flex-shrink: 0;
    border-radius: 9px;
    font-size: 17px;
    color: var(--primary-2);
    background: rgba(59, 130, 246, 0.12);
    border: 1px solid var(--border);
}

.palette-item small {
    margin-left: auto;
    font-size: 12px;
    color: var(--dim);
}

.palette-item mark {
    color: #fff;
    background: none;
    text-decoration: underline;
    text-decoration-color: var(--primary-2);
    text-underline-offset: 3px;
}

.palette-item.is-active {
    background: rgba(59, 130, 246, 0.16);
}

.palette-item.is-active small {
    color: var(--muted);
}

.palette-empty {
    padding: 28px;
    text-align: center;
    color: var(--muted);
}

.palette-foot {
    display: flex;
    gap: 16px;
    padding: 10px 18px;
    font-size: 12px;
    color: var(--dim);
    border-top: 1px solid var(--border);
}

.palette-foot span {
    display: flex;
    align-items: center;
    gap: 6px;
}

/*-- Text Scramble Characters --*/
.scramble-char {
    color: var(--accent);
    opacity: 0.8;
}

@media (max-width: 1100px) {
    .search-trigger span,
    .search-trigger kbd {
        display: none;
    }

    .search-trigger {
        width: 40px;
        padding: 0;
        justify-content: center;
    }
}

@media (max-width: 560px) {
    .to-top {
        right: 16px;
        bottom: 16px;
    }

    .palette {
        padding-top: 10vh;
    }

    .palette-foot {
        display: none;
    }
}

@media (prefers-reduced-motion: reduce) {
    .glow-border::after {
        animation: none;
    }
}