/* ==========================================================================
   Animations — Envelope, Ken Burns, Particles, Transitions
   ========================================================================== */

/* Envelope Overlay */
.envelope-overlay {
    position: fixed;
    inset: 0;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(160deg, var(--color-primary-dark) 0%, var(--color-primary) 40%, #3D1018 100%);
    transition: opacity 0.8s ease, visibility 0.8s ease;
}

.envelope-overlay.opening .envelope-flap {
    transform: rotateX(180deg);
    z-index: 1;
}

.envelope-overlay.opening .envelope-seal {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0);
}

.envelope-overlay.opening .envelope-letter {
    transform: translateY(-120px);
    opacity: 1;
}

.envelope-overlay.revealed {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.envelope-scene {
    perspective: 1200px;
    text-align: center;
}

.envelope {
    position: relative;
    width: clamp(280px, 70vw, 360px);
    height: clamp(200px, 50vw, 240px);
    margin: 0 auto;
    cursor: pointer;
    transform-style: preserve-3d;
    animation: envelopeFloat 4s ease-in-out infinite;
}

.envelope-back {
    position: absolute;
    inset: 0;
    background: var(--color-cream);
    border-radius: 4px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

.envelope-front {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 65%;
    background: linear-gradient(180deg, var(--color-cream-dark) 0%, var(--color-cream) 100%);
    clip-path: polygon(0 100%, 50% 30%, 100% 100%);
    z-index: 3;
}

.envelope-flap {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 55%;
    background: linear-gradient(180deg, #E8DFD3 0%, var(--color-cream-dark) 100%);
    clip-path: polygon(0 0, 50% 100%, 100% 0);
    transform-origin: top center;
    transition: transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 4;
}

.envelope-letter {
    position: absolute;
    top: 12%;
    left: 8%;
    right: 8%;
    bottom: 20%;
    background: var(--color-white);
    border-radius: 4px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
    transform: translateY(0);
    opacity: 0.9;
    transition: transform 1s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.6s ease;
    z-index: 2;
}

.letter-script {
    font-family: var(--font-script);
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    color: var(--color-primary);
    line-height: 1.2;
}

.letter-date {
    font-family: var(--font-serif);
    font-size: 0.9rem;
    letter-spacing: 0.25em;
    color: var(--color-gold-dark);
    margin-top: 8px;
}

.envelope-seal {
    position: absolute;
    top: 42%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 52px;
    height: 52px;
    color: var(--color-primary);
    z-index: 5;
    transition: opacity 0.4s ease, transform 0.4s ease;
    filter: drop-shadow(0 2px 8px rgba(0, 0, 0, 0.3));
    animation: sealPulse 2s ease-in-out infinite;
}

.envelope-seal svg {
    width: 100%;
    height: 100%;
}

.envelope-hint {
    margin-top: 32px;
    font-family: var(--font-serif);
    font-size: 0.95rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: rgba(247, 240, 232, 0.7);
    animation: hintPulse 2s ease-in-out infinite;
}

.envelope-overlay.opening .envelope-hint,
.envelope-overlay.revealed .envelope-hint {
    opacity: 0;
}

/* Ken Burns Effect */
@keyframes kenBurns1 {
    0% {
        transform: scale(1) translate(0, 0);
    }
    100% {
        transform: scale(1.15) translate(-2%, -1%);
    }
}

@keyframes kenBurns2 {
    0%, 45% {
        opacity: 0;
        transform: scale(1.1) translate(1%, 1%);
    }
    50% {
        opacity: 1;
    }
    100% {
        opacity: 1;
        transform: scale(1.2) translate(-1%, -2%);
    }
}

/* Button Glow */
@keyframes btnGlow {
    0%, 100% {
        box-shadow: 0 8px 40px rgba(126, 30, 43, 0.3), 0 0 0 0 rgba(215, 180, 106, 0);
    }
    50% {
        box-shadow: 0 8px 40px rgba(126, 30, 43, 0.3), 0 0 30px 4px rgba(215, 180, 106, 0.25);
    }
}

/* Scroll Indicator */
@keyframes scrollBounce {
    0%, 100% {
        transform: translateX(-50%) translateY(0);
        opacity: 1;
    }
    50% {
        transform: translateX(-50%) translateY(10px);
        opacity: 0.4;
    }
}

/* Heart Beat */
@keyframes heartBeat {
    0%, 100% {
        transform: scale(1);
    }
    15% {
        transform: scale(1.12);
    }
    30% {
        transform: scale(1);
    }
    45% {
        transform: scale(1.08);
    }
}

/* Countdown Tick */
@keyframes countTick {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.15);
        color: var(--color-gold);
    }
    100% {
        transform: scale(1);
    }
}

/* Separator Blink */
@keyframes sepBlink {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.3;
    }
}

/* Music Pulse */
@keyframes musicPulse {
    0% {
        transform: scale(1);
        opacity: 0.6;
    }
    100% {
        transform: scale(1.5);
        opacity: 0;
    }
}

/* Envelope Float */
@keyframes envelopeFloat {
    0%, 100% {
        transform: translateY(0) rotateX(5deg);
    }
    50% {
        transform: translateY(-12px) rotateX(5deg);
    }
}

/* Seal Pulse */
@keyframes sealPulse {
    0%, 100% {
        transform: translate(-50%, -50%) scale(1);
    }
    50% {
        transform: translate(-50%, -50%) scale(1.08);
    }
}

/* Hint Pulse */
@keyframes hintPulse {
    0%, 100% {
        opacity: 0.7;
    }
    50% {
        opacity: 0.4;
    }
}

/* Spin Loader */
@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Floating Flower */
@keyframes floatFlower {
    0% {
        transform: translateY(100vh) rotate(0deg) scale(0);
        opacity: 0;
    }
    10% {
        opacity: var(--flower-opacity, 0.6);
        transform: translateY(90vh) rotate(45deg) scale(1);
    }
    90% {
        opacity: var(--flower-opacity, 0.6);
    }
    100% {
        transform: translateY(-10vh) rotate(360deg) scale(0.8);
        opacity: 0;
    }
}

/* Invitation Reveal */
.invitation.revealed {
    animation: invitationReveal 1s ease forwards;
}

@keyframes invitationReveal {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Parallax layers */
.parallax-slow {
    will-change: transform;
    transition: transform 0.1s linear;
}

/* AOS custom overrides */
[data-aos] {
    pointer-events: auto;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    .hero-bg-slide {
        animation: none !important;
    }

    html {
        scroll-behavior: auto;
    }
}