/* Custom Properties*/
:root {
    --bg: #000000;
    --surface: #0d0d0d;
    --light-black: #111111;
    --border: #222222;
    --text: #ffffff;
    --text-muted: #999999;
}

/* Smooth scrolling for anchor links & back-to-top */
html {
    scroll-behavior: smooth;
}

/* Upload area*/
.upload-zone {
    border: 2px dashed #333333;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
.upload-zone.drag-over {
    border-color: #ffffff;
    background-color: #0f0f0f;
    transform: scale(1.01);
    box-shadow: 0 0 60px rgba(255, 255, 255, 0.05);
}

.upload-zone:hover {
    border-color: #ffffff;
    background-color: #0a0a0a;
}

/*File Checklist Item */
.file-item {
    transition: background-color 0.15s ease;
    cursor: pointer;
}
.file-item:hover {
    background-color: #161616;
}

/*Custom Checkbox*/
.custom-checkbox {
    appearance: none;
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border: 1.5px solid #444444;
    border-radius: 4px;
    background: transparent;
    cursor: pointer;
    transition: all 0.2s ease;
    flex-shrink: 0;
    position: relative;
}
.custom-checkbox:checked {
    background: #ffffff;
    border-color: #ffffff;
}
.custom-checkbox:checked::after {
    content: '';
    position: absolute;
    left: 5px;
    top: 2px;
    width: 5px;
    height: 9px;
    border: solid #000000;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}
.custom-checkbox:hover {
    border-color: #ffffff;
}

/*Back to Top Visibility*/
#backToTop.visible {
    opacity: 1;
    pointer-events: auto;
}
#backToTop:hover {
    background-color: #1a1a1a;
    border-color: #555555;
}
#backToTop:active {
    transform: scale(0.94);
}

/*Hamburger Overlay States*/
#hamburgerOverlay.open {
    opacity: 1;
    pointer-events: auto;
}
#hamburgerOverlay.open #hamburgerPanel {
    transform: translateX(0);
}

/* Feature/Stage Cards Hover */
.feature-card {
    transition: border-color 0.3s ease, background-color 0.3s ease;
}
.feature-card:hover {
    border-color: #444444;
    background-color: #111111;
}

/* Fade‑in Animation */
.fade-section {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}
.fade-section.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* ===== Toast Notification ===== */
#toast.show {
    opacity: 1;
    transform: translate(-50%, 0);
}