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

body {
    font-family: 'Inter', sans-serif;
    background-color: #0f172a;
    color: #f8fafc;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background-image: radial-gradient(circle at top right, #1e293b, #0f172a);
}

.container {
    width: 90%;
    max-width: 800px;
    background: rgba(30, 41, 59, 0.7);
    padding: 3rem;
    border-radius: 24px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(16px);
    border: 1px solid rgba(255, 255, 255, 0.05);
    text-align: center;
    animation: fadeIn 0.5s ease-out;
}

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

h1 {
    font-weight: 300;
    margin-bottom: 1rem;
    color: #e2e8f0;
    letter-spacing: 0.025em;
    font-size: 2.25rem;
}

p.subtitle {
    color: #94a3b8;
    margin-bottom: 2.5rem;
    font-size: 1.1rem;
}

.nav-buttons {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    font-size: 1.125rem;
    font-weight: 500;
    text-decoration: none;
    border-radius: 16px;
    transition: all 0.3s ease;
    border: 1px solid transparent;
    cursor: pointer;
}

.btn-primary {
    background: linear-gradient(135deg, #38bdf8 0%, #0284c7 100%);
    color: #fff;
    box-shadow: 0 10px 20px -10px rgba(56, 189, 248, 0.6);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 25px -10px rgba(56, 189, 248, 0.8);
    border-color: rgba(255, 255, 255, 0.2);
}

.btn-secondary {
    background: linear-gradient(135deg, #f43f5e 0%, #be123c 100%);
    color: #fff;
    box-shadow: 0 10px 20px -10px rgba(244, 63, 94, 0.6);
}

.btn-secondary:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 25px -10px rgba(244, 63, 94, 0.8);
    border-color: rgba(255, 255, 255, 0.2);
}

.btn-outline {
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: #e2e8f0; 
    margin-top: 2rem;
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-3px);
}

.content-area {
    background: rgba(15, 23, 42, 0.6);
    padding: 2rem;
    border-radius: 16px;
    margin-bottom: 2rem;
    color: #cbd5e1;
}

.file-upload-wrapper {
    position: relative;
    overflow: hidden;
    display: inline-block;
}

.file-upload-input {
    font-size: 100px;
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
}

.drop-zone {
    border: 2px dashed rgba(255, 255, 255, 0.2);
    transition: all 0.3s ease;
    position: relative;
    cursor: pointer;
}

.drop-zone:hover {
    border-color: rgba(255, 255, 255, 0.4);
}

.drop-zone.drag-over {
    border-color: #38bdf8;
    background: rgba(56, 189, 248, 0.1);
    transform: scale(1.02);
}

.history-section {
    margin-bottom: 2rem;
    text-align: left;
    background: rgba(15, 23, 42, 0.6);
    padding: 1.5rem;
    border-radius: 16px;
}

.history-list {
    list-style: none;
    padding: 0;
    margin: 0;
    max-height: 200px;
    overflow-y: auto;
}

.history-item {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    font-size: 0.95rem;
    color: #cbd5e1;
    transition: background 0.2s ease;
}

.history-item:last-child {
    border-bottom: none;
}

.history-item-name {
    font-weight: 500;
    color: #f8fafc;
}

.history-item-date {
    font-size: 0.85rem;
    color: #94a3b8;
}

/* Sidebar Layout */
body.dashboard-layout {
    display: flex;
    justify-content: flex-start;
    align-items: stretch;
    overflow: hidden;
}

.sidebar {
    width: 280px;
    background: rgba(15, 23, 42, 0.9);
    backdrop-filter: blur(20px);
    border-right: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    flex-direction: column;
    padding: 2rem 1.5rem;
    transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 100;
}

.sidebar.hidden {
    transform: translateX(-100%);
    position: absolute;
    height: 100%;
}

.sidebar-brand {
    font-size: 1.5rem;
    font-weight: 600;
    color: #e2e8f0;
    margin-bottom: 2.5rem;
    padding-left: 4rem;
}

.sidebar-nav {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.sidebar-item {
    padding: 1rem;
    border-radius: 12px;
    color: #94a3b8;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
}

.sidebar-item:hover {
    background: rgba(255, 255, 255, 0.05);
    color: #f8fafc;
}

.sidebar-item.active {
    background: linear-gradient(135deg, rgba(56, 189, 248, 0.2) 0%, rgba(2, 132, 199, 0.2) 100%);
    color: #38bdf8;
    border: 1px solid rgba(56, 189, 248, 0.2);
}

.main-content {
    flex: 1;
    height: 100vh;
    overflow-y: auto;
    padding: 3rem;
    transition: margin-left 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    width: 100%;
}

.sidebar-toggle-btn {
    position: absolute;
    top: 1.5rem;
    left: 1.5rem;
    background: rgba(30, 41, 59, 0.8);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: #e2e8f0;
    width: 44px;
    height: 44px;
    border-radius: 12px;
    cursor: pointer;
    z-index: 200;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.25rem;
    transition: all 0.3s ease;
    backdrop-filter: blur(8px);
}

.sidebar-toggle-btn:hover {
    background: rgba(255, 255, 255, 0.1);
}

.dashboard-view {
    display: none;
    animation: fadeIn 0.4s ease-out;
    width: 100%;
    margin: 0;
    padding-top: 2rem;
}

.dashboard-view.active {
    display: block;
}

.empty-space {
    border: 2px dashed rgba(255, 255, 255, 0.1);
    background: transparent;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 300px;
    color: #64748b;
    font-size: 1.1rem;
}