/* ============================================================
 * King Scroll Navigator —  Theme-Matched Aesthetic
 * Inspired by King (v10) design tokens:
 *   - 14px rounded surfaces
 *   - glassmorphism with backdrop-filter
 *   - deep ink #13151d, faint surface rgba(255,255,255,.72)
 *   - subtle purple haze glow used by .king-bbutton
 * ============================================================ */

:root {
	--ksn-accent: #13151d;
	--ksn-accent-soft: rgba(19, 21, 29, 0.08);
	--ksn-surface: rgba(255, 255, 255, 0.72);
	--ksn-surface-solid: #ffffff;
	--ksn-ink: #13151d;
	--ksn-muted: #6b7077;
	--ksn-ring: rgba(136, 126, 242, 0.22);
	--ksn-shadow-1: 0 4px 14px rgba(19, 21, 29, 0.08);
	--ksn-shadow-2: 0 18px 48px -16px rgba(19, 21, 29, 0.28);
	--ksn-radius: 18px;
	--ksn-btn-size: 48px;
	--ksn-gap: 10px;
	--ksn-offset-bottom: 96px;
	--ksn-show-labels: 1;
	--ksn-hide-mobile: 0;
}

.ksn-root {
	--bg: var(--ksn-surface);
	position: fixed;
	right: 22px;
	bottom: var(--ksn-offset-bottom);
	z-index: 9999;
	display: flex;
	flex-direction: column;
	gap: var(--ksn-gap);
	padding: 12px 10px;
	border-radius: 28px;
	background: var(--bg);
	-webkit-backdrop-filter: blur(18px) saturate(1.4);
	backdrop-filter: blur(18px) saturate(1.4);
	box-shadow: var(--ksn-shadow-2), inset 0 0 0 1px rgba(255, 255, 255, 0.6);
	opacity: 0;
	transform: translateY(20px) scale(0.96);
	pointer-events: none;
	transition: opacity 0.5s ease, transform 0.5s cubic-bezier(0.2, 0.8, 0.2, 1);
	font-family: inherit;
}

.ksn-root.ksn-pos-left {
	right: auto;
	left: 22px;
}

.ksn-root.is-visible {
	opacity: 1;
	transform: translateY(0) scale(1);
	pointer-events: auto;
}

/* Buttons */
.ksn-btn {
	position: relative;
	width: var(--ksn-btn-size);
	height: var(--ksn-btn-size);
	border: 0;
	border-radius: var(--ksn-radius);
	background: transparent;
	color: var(--ksn-ink);
	display: inline-flex;
	align-items: center;
	justify-content: center;
	cursor: pointer;
	overflow: hidden;
	transition: transform 280ms cubic-bezier(0.2, 0.8, 0.2, 1),
		background 280ms ease,
		color 280ms ease,
		box-shadow 280ms ease;
	-webkit-tap-highlight-color: transparent;
}

.ksn-btn::before {
	content: "";
	position: absolute;
	inset: 0;
	border-radius: inherit;
	background: var(--ksn-accent-soft);
	opacity: 0;
	transition: opacity 280ms ease;
}

.ksn-btn::after {
	content: "";
	position: absolute;
	inset: -2px;
	border-radius: inherit;
	box-shadow: 0 0 0 0 var(--ksn-ring);
	transition: box-shadow 320ms ease;
	pointer-events: none;
}

.ksn-btn svg {
	width: 22px;
	height: 22px;
	fill: currentColor;
	transition: transform 320ms cubic-bezier(0.2, 0.8, 0.2, 1);
	will-change: transform;
}

.ksn-btn:hover {
	background: var(--ksn-accent);
	color: #fff;
	transform: translateY(-2px);
	box-shadow: 0 14px 30px -12px rgba(19, 21, 29, 0.35);
}

.ksn-btn:hover::after {
	box-shadow: 0 0 0 6px var(--ksn-ring);
}

.ksn-btn:hover svg {
	transform: translateY(-1px);
}

.ksn-btn:active {
	transform: translateY(0) scale(0.96);
}

/* Direction-tied micro motion */
.ksn-btn--up:hover svg { animation: ksn-bounce-up 0.9s ease infinite; }
.ksn-btn--down:hover svg { animation: ksn-bounce-down 0.9s ease infinite; }
.ksn-btn--top:hover svg { animation: ksn-bounce-up 0.9s ease infinite; }
.ksn-btn--bottom:hover svg { animation: ksn-bounce-down 0.9s ease infinite; }

@keyframes ksn-bounce-up {
	0%, 100% { transform: translateY(0); }
	50% { transform: translateY(-3px); }
}
@keyframes ksn-bounce-down {
	0%, 100% { transform: translateY(0); }
	50% { transform: translateY(3px); }
}

/* Labels (slide-out caption) */
.ksn-label {
	position: absolute;
	top: 50%;
	/* 默认靠左滑出；当容器在右侧时标签从按钮的左侧滑出，反之亦然 */
	right: calc(100% + 12px);
	transform: translate(6px, -50%);
	background: var(--ksn-accent);
	color: #fff;
	font-size: 12px;
	letter-spacing: 0.04em;
	padding: 6px 10px;
	border-radius: 10px;
	white-space: nowrap;
	opacity: 0;
	pointer-events: none;
	transition: opacity 200ms ease, transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
	box-shadow: 0 8px 20px -10px rgba(19, 21, 29, 0.6);
}

.ksn-root.ksn-pos-left .ksn-label {
	right: auto;
	left: calc(100% + 12px);
	transform: translate(-6px, -50%);
}

.ksn-label::before {
	content: "";
	position: absolute;
	top: 50%;
	right: -4px;
	width: 8px;
	height: 8px;
	background: var(--ksn-accent);
	transform: translateY(-50%) rotate(45deg);
	border-radius: 1px;
}

.ksn-root.ksn-pos-left .ksn-label::before {
	right: auto;
	left: -4px;
}

.ksn-btn:hover .ksn-label,
.ksn-btn:focus-visible .ksn-label {
	opacity: 1;
	transform: translate(0, -50%);
}

.ksn-root.ksn-pos-left .ksn-btn:hover .ksn-label,
.ksn-root.ksn-pos-left .ksn-btn:focus-visible .ksn-label {
	transform: translate(0, -50%);
}

.ksn-btn:focus-visible {
	outline: none;
}
.ksn-btn:focus-visible::after {
	box-shadow: 0 0 0 4px var(--ksn-ring);
}

/* Hide labels when disabled */
.ksn-root[data-show-labels="0"] .ksn-label { display: none; }

/* Progress ribbon (vertical) — decorative progress at the side of the dock */
.ksn-progress {
	position: absolute;
	left: 50%;
	top: 78px;
	bottom: 78px;
	width: 2px;
	background: rgba(19, 21, 29, 0.08);
	border-radius: 2px;
	transform: translateX(-50%);
	overflow: hidden;
}

.ksn-root.ksn-pos-left .ksn-progress { display: none; }

.ksn-progress-bar {
	position: absolute;
	left: 0;
	top: 0;
	width: 100%;
	height: 0%;
	background: linear-gradient(180deg, #13151d 0%, #887ef2 100%);
	transition: height 120ms linear;
}

/* Special "top" + "bottom" buttons get accent outline */
.ksn-btn--top,
.ksn-btn--bottom {
	box-shadow: inset 0 0 0 1.5px var(--ksn-accent);
}

.ksn-btn--top:hover,
.ksn-btn--bottom:hover {
	box-shadow: 0 14px 30px -12px rgba(19, 21, 29, 0.45), inset 0 0 0 0 transparent;
}

/* Compact collapsed mode when at the very top */
.ksn-root.is-at-top .ksn-btn--top {
	opacity: 0.35;
	pointer-events: none;
	transform: scale(0.9);
}
.ksn-root.is-at-bottom .ksn-btn--bottom {
	opacity: 0.35;
	pointer-events: none;
	transform: scale(0.9);
}

/* Mobile */
@media (max-width: 768px) {
	.ksn-root[data-hide-mobile="1"] { display: none; }
	.ksn-root {
		--ksn-btn-size: 42px;
		right: 14px;
		bottom: 80px;
		padding: 10px 8px;
		gap: 8px;
	}
	.ksn-root.ksn-pos-left { left: 14px; }
	.ksn-label { display: none; }
	.ksn-progress { display: none; }
}

/* Reduced motion respect */
@media (prefers-reduced-motion: reduce) {
	.ksn-root, .ksn-btn, .ksn-btn::before, .ksn-btn::after, .ksn-btn svg, .ksn-label {
		transition: none !important;
		animation: none !important;
	}
}