/**
 * CSS Essentials v1.0.0
 * A zero-dependency CSS utility toolkit.
 * Author: Ahmed Habib
 * License: MIT
 *
 * Modules: Layout, Typography, Animation, Components, Effects, Responsive, Tokens
 */

/* ═══════════════════════════════════════════════════════
   TOKENS — Design-token custom properties
   ═══════════════════════════════════════════════════════ */
:root {
    /* Color palette */
    --ce-color-primary: #4361ee;
    --ce-color-primary-light: #6b83f2;
    --ce-color-primary-dark: #2a46d1;
    --ce-color-secondary: #7209b7;
    --ce-color-accent: #f72585;
    --ce-color-success: #22c55e;
    --ce-color-warning: #eab308;
    --ce-color-danger: #ef4444;
    --ce-color-info: #06b6d4;
    --ce-color-neutral-100: #f1f5f9;
    --ce-color-neutral-300: #cbd5e1;
    --ce-color-neutral-500: #64748b;
    --ce-color-neutral-700: #334155;
    --ce-color-neutral-900: #0f172a;

    /* Spacing scale */
    --ce-space-xs: clamp(0.25rem, 0.5vw, 0.375rem);
    --ce-space-sm: clamp(0.5rem, 1vw, 0.75rem);
    --ce-space-md: clamp(0.75rem, 1.5vw, 1rem);
    --ce-space-lg: clamp(1rem, 2vw, 1.5rem);
    --ce-space-xl: clamp(1.5rem, 3vw, 2rem);
    --ce-space-2xl: clamp(2rem, 4vw, 3rem);
    --ce-space-3xl: clamp(3rem, 6vw, 4.5rem);

    /* Border radius */
    --ce-radius-sm: 4px;
    --ce-radius-md: 8px;
    --ce-radius-lg: 12px;
    --ce-radius-full: 9999px;

    /* Font size scale */
    --ce-font-xs: clamp(0.7rem, 0.65rem + 0.25vw, 0.75rem);
    --ce-font-sm: clamp(0.8rem, 0.75rem + 0.25vw, 0.875rem);
    --ce-font-md: clamp(0.9rem, 0.85rem + 0.25vw, 1rem);
    --ce-font-lg: clamp(1.1rem, 1rem + 0.5vw, 1.25rem);
    --ce-font-xl: clamp(1.4rem, 1.2rem + 1vw, 1.75rem);

    /* Z-index scale */
    --ce-z-base: 1;
    --ce-z-dropdown: 100;
    --ce-z-sticky: 200;
    --ce-z-overlay: 300;
    --ce-z-modal: 400;

    /* Transition presets */
    --ce-ease-out: cubic-bezier(0.22, 1, 0.36, 1);
    --ce-ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);
    --ce-ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1);
}


/* ═══════════════════════════════════════════════════════
   LAYOUT — Flexbox & grid shortcuts
   ═══════════════════════════════════════════════════════ */
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-col { display: flex; flex-direction: column; }
.flex-wrap { display: flex; flex-wrap: wrap; }
.grid-2 { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 280px), 1fr)); gap: var(--ce-space-md); }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 220px), 1fr)); gap: var(--ce-space-md); }
.grid-4 { display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 180px), 1fr)); gap: var(--ce-space-md); }
.container { width: 100%; max-width: 1200px; margin-inline: auto; padding-inline: var(--ce-space-lg); }
.aspect-square { aspect-ratio: 1 / 1; }
.aspect-video { aspect-ratio: 16 / 9; }
.aspect-portrait { aspect-ratio: 3 / 4; }
.sticky-top { position: sticky; top: 0; z-index: var(--ce-z-sticky); }
.full-bleed { width: 100vw; margin-inline: calc(50% - 50vw); }
.overlay { position: absolute; inset: 0; }


/* ═══════════════════════════════════════════════════════
   TYPOGRAPHY — Text utilities
   ═══════════════════════════════════════════════════════ */
.text-gradient {
    background: linear-gradient(135deg, var(--ce-color-primary), var(--ce-color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.text-balance { text-wrap: balance; }
.text-truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.text-clamp-2 {
    display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
    overflow: hidden; text-overflow: ellipsis;
}
.text-clamp-3 {
    display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical;
    overflow: hidden; text-overflow: ellipsis;
}
.font-smooth { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
.drop-cap::first-letter {
    float: left; font-size: 3.5em; line-height: 0.8; font-weight: 700;
    margin-right: 0.1em; color: var(--ce-color-primary);
}
.underline-fancy {
    text-decoration: none; background-image: linear-gradient(var(--ce-color-accent), var(--ce-color-accent));
    background-size: 0% 2px; background-repeat: no-repeat; background-position: 0 100%;
    transition: background-size 0.3s var(--ce-ease-out);
}
.underline-fancy:hover { background-size: 100% 2px; }
.text-shadow-soft { text-shadow: 0 1px 3px rgba(0, 0, 0, 0.12); }
.text-shadow-hard { text-shadow: 2px 2px 0 var(--ce-color-neutral-300); }
.sr-only {
    position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
    overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}
.prose-flow { max-width: 65ch; line-height: 1.75; }


/* ═══════════════════════════════════════════════════════
   ANIMATION — Keyframes & utility classes
   ═══════════════════════════════════════════════════════ */
@keyframes ce-fade-in { from { opacity: 0; } to { opacity: 1; } }
@keyframes ce-slide-up { from { opacity: 0; transform: translateY(1rem); } to { opacity: 1; transform: translateY(0); } }
@keyframes ce-slide-down { from { opacity: 0; transform: translateY(-1rem); } to { opacity: 1; transform: translateY(0); } }
@keyframes ce-slide-left { from { opacity: 0; transform: translateX(1rem); } to { opacity: 1; transform: translateX(0); } }
@keyframes ce-slide-right { from { opacity: 0; transform: translateX(-1rem); } to { opacity: 1; transform: translateX(0); } }
@keyframes ce-scale { from { opacity: 0; transform: scale(0.9); } to { opacity: 1; transform: scale(1); } }
@keyframes ce-bounce { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-8px); } }
@keyframes ce-pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.5; } }
@keyframes ce-spin { to { transform: rotate(360deg); } }
@keyframes ce-shake { 0%, 100% { transform: translateX(0); } 20%, 60% { transform: translateX(-4px); } 40%, 80% { transform: translateX(4px); } }

.animate-fade-in { animation: ce-fade-in 0.5s var(--ce-ease-out) both; }
.animate-slide-up { animation: ce-slide-up 0.5s var(--ce-ease-out) both; }
.animate-slide-down { animation: ce-slide-down 0.5s var(--ce-ease-out) both; }
.animate-slide-left { animation: ce-slide-left 0.5s var(--ce-ease-out) both; }
.animate-slide-right { animation: ce-slide-right 0.5s var(--ce-ease-out) both; }
.animate-scale { animation: ce-scale 0.4s var(--ce-ease-spring) both; }
.animate-bounce { animation: ce-bounce 1s ease infinite; }
.animate-pulse { animation: ce-pulse 2s ease-in-out infinite; }
.animate-spin { animation: ce-spin 1s linear infinite; }
.animate-shake { animation: ce-shake 0.4s ease; }
.hover-lift { transition: transform 0.25s var(--ce-ease-out), box-shadow 0.25s var(--ce-ease-out); }
.hover-lift:hover { transform: translateY(-3px); box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12); }
.hover-glow { transition: box-shadow 0.3s var(--ce-ease-out); }
.hover-glow:hover { box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.35); }


/* ═══════════════════════════════════════════════════════
   COMPONENTS — Pure CSS, zero JS
   ═══════════════════════════════════════════════════════ */
.btn-base {
    display: inline-flex; align-items: center; gap: 0.5em; padding: 0.6em 1.2em;
    font-weight: 600; font-size: var(--ce-font-sm); border: none; border-radius: var(--ce-radius-md);
    cursor: pointer; transition: all 0.2s var(--ce-ease-out);
    background: var(--ce-color-primary); color: #fff;
}
.btn-base:hover { background: var(--ce-color-primary-dark); }
.btn-base:focus-visible { outline: 2px solid var(--ce-color-primary); outline-offset: 2px; }

.badge {
    display: inline-flex; align-items: center; padding: 0.2em 0.65em;
    font-size: var(--ce-font-xs); font-weight: 600; border-radius: var(--ce-radius-full);
    background: var(--ce-color-primary-light); color: #fff;
}

.card-hover {
    border-radius: var(--ce-radius-lg); overflow: hidden;
    transition: transform 0.25s var(--ce-ease-out), box-shadow 0.25s var(--ce-ease-out);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}
.card-hover:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(0, 0, 0, 0.1); }

.tooltip { position: relative; }
.tooltip::after {
    content: attr(data-tooltip); position: absolute; bottom: calc(100% + 6px); left: 50%;
    transform: translateX(-50%) scale(0.9); opacity: 0;
    padding: 0.35em 0.7em; font-size: var(--ce-font-xs); white-space: nowrap;
    background: var(--ce-color-neutral-900); color: #fff; border-radius: var(--ce-radius-sm);
    pointer-events: none; transition: all 0.2s var(--ce-ease-out);
}
.tooltip:hover::after { opacity: 1; transform: translateX(-50%) scale(1); }

.divider {
    display: flex; align-items: center; gap: 1em;
    color: var(--ce-color-neutral-500); font-size: var(--ce-font-sm);
}
.divider::before, .divider::after {
    content: ''; flex: 1; height: 1px; background: var(--ce-color-neutral-300);
}

.skeleton {
    background: linear-gradient(90deg, var(--ce-color-neutral-100) 25%, #e2e8f0 50%, var(--ce-color-neutral-100) 75%);
    background-size: 200% 100%; border-radius: var(--ce-radius-md);
    animation: ce-skeleton-shimmer 1.5s ease-in-out infinite;
}
@keyframes ce-skeleton-shimmer { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }

.avatar {
    width: 40px; height: 40px; border-radius: 50%; object-fit: cover;
    display: inline-flex; align-items: center; justify-content: center;
    background: var(--ce-color-primary-light); color: #fff; font-weight: 700;
    font-size: var(--ce-font-sm);
}

.pill {
    display: inline-flex; align-items: center; padding: 0.25em 0.75em;
    font-size: var(--ce-font-xs); font-weight: 500; border-radius: var(--ce-radius-full);
    border: 1px solid var(--ce-color-neutral-300); color: var(--ce-color-neutral-700);
}

.ribbon {
    position: absolute; top: 12px; right: -30px; transform: rotate(45deg);
    padding: 0.25em 2em; font-size: var(--ce-font-xs); font-weight: 700;
    background: var(--ce-color-accent); color: #fff; text-transform: uppercase;
}

.progress-bar {
    height: 8px; border-radius: var(--ce-radius-full); overflow: hidden;
    background: var(--ce-color-neutral-100);
}
.progress-bar > * {
    height: 100%; border-radius: var(--ce-radius-full);
    background: linear-gradient(90deg, var(--ce-color-primary), var(--ce-color-accent));
    background-size: 30px 8px;
    transition: width 0.6s var(--ce-ease-out);
}


/* ═══════════════════════════════════════════════════════
   EFFECTS — Visual enhancements
   ═══════════════════════════════════════════════════════ */
.glass {
    background: rgba(255, 255, 255, 0.15); backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.gradient-primary { background: linear-gradient(135deg, var(--ce-color-primary), var(--ce-color-secondary)); }
.gradient-sunset { background: linear-gradient(135deg, #f97316, #ec4899, #8b5cf6); }
.gradient-ocean { background: linear-gradient(135deg, #06b6d4, #3b82f6, #6366f1); }

.shadow-soft { box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08); }
.shadow-hard { box-shadow: 4px 4px 0 var(--ce-color-neutral-900); }
.shadow-inner { box-shadow: inset 0 2px 6px rgba(0, 0, 0, 0.1); }
.shadow-glow { box-shadow: 0 0 20px rgba(67, 97, 238, 0.4); }

.blur-bg { backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); }

.noise-bg {
    position: relative;
}
.noise-bg::after {
    content: ''; position: absolute; inset: 0; opacity: 0.04; pointer-events: none;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
}

.border-gradient {
    border: 2px solid transparent;
    background-image: linear-gradient(var(--ce-color-neutral-100), var(--ce-color-neutral-100)),
                       linear-gradient(135deg, var(--ce-color-primary), var(--ce-color-accent));
    background-origin: border-box; background-clip: padding-box, border-box;
}

.clip-circle { clip-path: circle(50%); }
.clip-polygon { clip-path: polygon(50% 0%, 100% 38%, 82% 100%, 18% 100%, 0% 38%); }

.filter-grayscale { filter: grayscale(100%); transition: filter 0.3s ease; }
.filter-grayscale:hover { filter: grayscale(0%); }
.filter-sepia { filter: sepia(80%); transition: filter 0.3s ease; }
.filter-sepia:hover { filter: sepia(0%); }


/* ═══════════════════════════════════════════════════════
   RESPONSIVE — Visibility & layout helpers
   ═══════════════════════════════════════════════════════ */
@media (max-width: 768px) {
    .hide-mobile { display: none !important; }
    .stack-mobile { flex-direction: column !important; }
    .text-center-mobile { text-align: center !important; }
}
@media (min-width: 769px) {
    .hide-desktop { display: none !important; }
}

/* Container queries */
@container (max-width: 400px) {
    .cq-stack { flex-direction: column; }
    .cq-hide { display: none; }
}
@container (min-width: 600px) {
    .cq-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--ce-space-md); }
}