:root {
    --bg-main: #09090b;
    --bg-secondary: #111118;
    --bg-tertiary: #181825;
    --accent-primary: #6366f1;
    --accent-hover: #4f46e5;
    --text-primary: #f8fafc;
    --text-secondary: #a1a1aa;
    --border-color: rgba(255, 255, 255, 0.08);
    --success: #10b981;
    --error: #f43f5e;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.2);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
}

@keyframes mesh-gradient {
    0% { background-position: 0% 0%; }
    50% { background-position: 100% 100%; }
    100% { background-position: 0% 0%; }
}

body {
    background-color: var(--bg-main);
    background-image: 
        radial-gradient(circle at 15% 50%, rgba(99, 102, 241, 0.15), transparent 35%),
        radial-gradient(circle at 85% 30%, rgba(236, 72, 153, 0.15), transparent 35%);
    background-size: 150% 150%;
    animation: mesh-gradient 20s ease-in-out infinite;
    background-attachment: fixed;
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.app-container {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    width: 100%;
}

/* Header */
.top-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 3rem;
    background: rgba(15, 17, 26, 0.4);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}
.logo i {
    color: var(--accent-primary);
}
.logo-img {
    height: 28px;
    width: auto;
    display: inline-block;
    vertical-align: middle;
}

.top-nav nav a {
    color: var(--text-secondary);
    text-decoration: none;
    margin-left: 2rem;
    font-weight: 500;
    transition: color 0.3s;
}

.top-nav nav a:hover {
    color: var(--text-primary);
}

/* Hero Section */
.upload-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

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

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -1px;
    line-height: 1.2;
}

.hero h1 span {
    background: linear-gradient(to right, #3b82f6, #8b5cf6, #ec4899);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.6;
}

/* Drop Zone */
.drop-zone {
    width: 100%;
    max-width: 700px;
    height: 350px;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.04) 0%, rgba(255, 255, 255, 0.01) 100%);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: 24px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.5s cubic-bezier(0.19, 1, 0.22, 1);
    box-shadow: 0 16px 40px -10px rgba(0, 0, 0, 0.4), inset 0 1px 0 rgba(255,255,255,0.1);
    position: relative;
    overflow: hidden;
}

@keyframes pulse-border {
    0% { box-shadow: 0 0 0 0 rgba(99, 102, 241, 0.4); }
    70% { box-shadow: 0 0 0 15px rgba(99, 102, 241, 0); }
    100% { box-shadow: 0 0 0 0 rgba(99, 102, 241, 0); }
}

.drop-zone:hover, .drop-zone.drag-active {
    border-color: rgba(99, 102, 241, 0.5);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.08) 0%, rgba(236, 72, 153, 0.05) 100%);
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 30px 60px rgba(0, 0, 0, 0.5), 0 0 40px rgba(99, 102, 241, 0.2), inset 0 1px 0 rgba(255,255,255,0.2);
    animation: pulse-border 2s infinite;
}

.drop-zone-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.icon-container {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.2), rgba(236, 72, 153, 0.2));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    color: #fff;
    box-shadow: 0 0 30px rgba(99, 102, 241, 0.4);
    border: 1px solid rgba(255,255,255,0.1);
    transition: transform 0.3s cubic-bezier(0.19, 1, 0.22, 1);
}

.drop-zone:hover .icon-container {
    transform: scale(1.1);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.3), rgba(236, 72, 153, 0.3));
}

.icon-container svg {
    width: 40px;
    height: 40px;
}

.drop-zone h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    font-weight: 600;
    letter-spacing: -0.5px;
}

.drop-zone p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.file-limits {
    font-size: 0.85rem;
    color: rgba(255,255,255,0.6);
    background: rgba(0,0,0,0.3);
    padding: 0.4rem 1rem;
    border-radius: 999px;
    border: 1px solid rgba(255,255,255,0.05);
}

/* Progress Bar */
.progress-container {
    position: absolute;
    bottom: 2rem;
    width: 80%;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    font-weight: 500;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: rgba(255,255,255,0.1);
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--accent-primary);
    width: 0%;
    transition: width 0.2s;
}

.error-message {
    color: var(--error);
    margin-top: 1rem;
    font-weight: 500;
    display: none;
}

footer {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    border-top: 1px solid var(--border-color);
}