:root {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent: #6366f1;
    --accent-hover: #4f46e5;
    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    --shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    --backdrop-blur: blur(10px);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow: hidden;
    background-image: 
        radial-gradient(at 0% 0%, hsla(253,16%,7%,1) 0, transparent 50%), 
        radial-gradient(at 50% 0%, hsla(225,39%,30%,1) 0, transparent 50%), 
        radial-gradient(at 100% 0%, hsla(339,49%,30%,1) 0, transparent 50%);
    background-size: cover;
    background-position: center;
}

#app-container {
    width: 100vw;
    height: 100vh;
    position: relative;
}

.screen {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    transition: opacity 0.5s ease, transform 0.5s ease;
    display: flex;
    flex-direction: column;
}

.screen.hidden {
    opacity: 0;
    pointer-events: none;
    transform: scale(0.98);
}

.screen.active {
    opacity: 1;
    pointer-events: all;
    transform: scale(1);
    z-index: 10;
}

/* Setup Screen */
#setup-screen {
    padding: 3rem;
    max-width: 1200px;
    margin: 0 auto;
    align-items: center;
    overflow-y: auto;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

header h1 {
    font-size: 3.5rem;
    font-weight: 700;
    background: linear-gradient(to right, #a855f7, #6366f1, #ec4899);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

.upload-container {
    width: 100%;
    max-width: 800px;
    border: 2px dashed var(--glass-border);
    border-radius: 24px;
    padding: 4rem 2rem;
    text-align: center;
    background: var(--glass-bg);
    backdrop-filter: var(--backdrop-blur);
    -webkit-backdrop-filter: var(--backdrop-blur);
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow);
}

.upload-container:hover, .upload-container.dragover {
    border-color: var(--accent);
    background: rgba(99, 102, 241, 0.1);
    transform: translateY(-2px);
}

.upload-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.upload-icon {
    color: var(--accent);
    margin-bottom: 1rem;
}

.upload-content h2 {
    font-weight: 500;
    font-size: 1.5rem;
}

.supported-formats {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 1rem;
}

.hidden {
    display: none !important;
}

.text-btn {
    background: none;
    border: none;
    color: var(--accent);
    font-family: inherit;
    font-size: inherit;
    cursor: pointer;
    text-decoration: underline;
    font-weight: 500;
}

.text-btn:hover {
    color: var(--accent-hover);
}

#preview-section {
    width: 100%;
    max-width: 1000px;
    margin-top: 3rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.primary-btn {
    background: linear-gradient(135deg, #6366f1, #a855f7);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 9999px;
    font-family: inherit;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
}

.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.6);
}

.thumbnail-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 1rem;
    width: 100%;
}

.thumbnail {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    aspect-ratio: 16/9;
    background: var(--bg-secondary);
    box-shadow: var(--shadow);
    animation: fadeIn 0.4s ease forwards;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.remove-btn {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    background: rgba(0, 0, 0, 0.6);
    color: white;
    border: none;
    border-radius: 50%;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    backdrop-filter: blur(4px);
    transition: background 0.2s;
}

.remove-btn:hover {
    background: rgba(239, 68, 68, 0.8);
}

/* Presentation Screen */
#presentation-screen {
    background: #000;
    justify-content: center;
    align-items: center;
}

.slide-container {
    width: 100%;
    height: 100%;
    position: relative;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    justify-content: center;
}

.slide.active {
    opacity: 1;
    z-index: 2;
}

.slide img {
    max-width: 100%;
    max-height: 100%;
    object-fit: contain;
}

.controls-container {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: 1.5rem;
    background: var(--glass-bg);
    backdrop-filter: var(--backdrop-blur);
    padding: 0.75rem 1.5rem;
    border-radius: 9999px;
    border: 1px solid var(--glass-border);
    z-index: 20;
    opacity: 0;
    transition: opacity 0.3s;
}

#presentation-screen:hover .controls-container,
#presentation-screen:hover #exit-btn {
    opacity: 1;
}

.icon-btn {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s;
}

.icon-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: scale(1.1);
}

.icon-btn:active {
    transform: scale(0.95);
}

.icon-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.slide-indicator {
    font-weight: 500;
    letter-spacing: 1px;
}

#exit-btn {
    position: absolute;
    top: 2rem;
    right: 2rem;
    z-index: 20;
    opacity: 0;
    transition: opacity 0.3s;
}

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: rgba(0,0,0,0.1);
}
::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.2);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: rgba(255,255,255,0.3);
}