body {
    font-family: 'Segoe UI', 'Malgun Gothic', Arial, sans-serif;
    background: linear-gradient(120deg, #e0e7ef 0%, #f6f8fa 100%);
    margin: 0;
    padding: 0;
    min-height: 100vh;
}
body.dark-mode {
    background: #181a1b;
}
body.dark-mode .container {
    background: #23272a;
    color: #e5e7eb;
    box-shadow: 0 2px 12px rgba(0,0,0,0.25);
}
body.dark-mode h2, body.dark-mode h3 {
    color: #e5e7eb;
}
body.dark-mode .folder-label { color: #60a5fa; }
body.dark-mode .folder-label:hover { color: #93c5fd; }
body.dark-mode .file-label { color: #d1d5db; }
body.dark-mode .tree-li, body.dark-mode .folder-row, body.dark-mode .file-row {
    background: none !important;
}
body.dark-mode .download-btn {
    background: none;
    color: #34d399 !important;
}
body.dark-mode .download-btn:hover {
    background: #134e4a;
    color: #6ee7b7 !important;
}
body.dark-mode .download-btn i.fa-download {
    color: #34d399 !important;
}
body.dark-mode .download-btn:hover i.fa-download {
    color: #6ee7b7 !important;
}
body.dark-mode input, body.dark-mode button {
    background: #23272a;
    color: #e5e7eb;
    border-color: #374151;
}
body.dark-mode #uploadForm button {
    background: #059669;
    color: #e5e7eb;
}
body.dark-mode #uploadForm button:hover {
    background: #10b981;
}
.container {
    max-width: 750px;
    margin: 48px auto 48px auto;
    background: #fff;
    border-radius: 18px;
    box-shadow: 0 4px 32px rgba(0,0,0,0.10);
    padding: 40px 48px 32px 48px;
    min-height: 500px;
}
@media (max-width: 900px) {
    .container { padding: 24px 8vw; }
}
@media (max-width: 600px) {
    .container { padding: 16px 2vw; }
}
h2, h3 {
    color: #2d3a4b;
    margin-top: 0;
    margin-bottom: 18px;
}
ul { list-style-type: none; padding-left: 18px; }
.folder, .file {
    display: flex;
    align-items: center;
    padding: 4px 0;
}
.folder-label {
    font-weight: 600;
    color: #2563eb;
    cursor: pointer;
    margin-left: 8px;
    transition: color 0.2s;
}
.folder-label:hover { color: #1e40af; }
.file-row {
    display: flex;
    align-items: center;
    gap: 3px;
}
.file-label {
    color: #374151;
    margin-left: 2px;
}
.download-btn {
    display: inline-flex;
    align-items: center;
    background: none;
    border: none;
    color: #10b981 !important;
    font-size: 18px;
    margin-left: 0;
    cursor: pointer;
    padding: 3px 6px;
    border-radius: 50%;
    transition: background 0.15s, color 0.15s;
}
.download-btn:hover {
    background: #d1fae5;
    color: #059669 !important;
}
.download-btn i.fa-download {
    color: #10b981 !important;
    transition: color 0.15s;
}
.download-btn:hover i.fa-download {
    color: #059669 !important;
}
.hidden { display: none; }
#uploadForm {
    margin-top: 24px;
    margin-bottom: 32px;
    display: flex;
    flex-direction: column;
    gap: 14px;
    align-items: flex-start;
}
#uploadForm input[type="file"] {
    border: 1px solid #d1d5db;
    border-radius: 4px;
    padding: 4px 8px;
    background: #f9fafb;
}
#uploadForm button {
    background: #10b981;
    color: #fff;
    border: none;
    border-radius: 4px;
    padding: 6px 18px;
    font-size: 15px;
    cursor: pointer;
    transition: background 0.2s;
}
#uploadForm button:hover { background: #059669; }
#tree {
    margin-top: 32px;
}
.file-icon-btn,
.upload-icon-btn {
    background: #10b981;
    color: #fff;
    border: none;
    border-radius: 20px;
    width: 56px;
    height: 56px;
    font-size: 26px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    vertical-align: middle;
    transition: background 0.15s;
}
.file-icon-btn:hover,
.upload-icon-btn:hover {
    background: #059669;
}
.file-icon-btn i.fa-paperclip,
.upload-icon-btn i.fa-arrow-up-from-bracket {
    font-size: 26px;
    vertical-align: middle;
    line-height: 1;
}
.folder-row i.fa-folder {
    margin-right: 8px;
}
.file-btn, .upload-btn, .folder-btn {
    background: #10b981;
    color: #fff;
    border: none;
    border-radius: 8px;
    min-width: 90px;
    min-height: 40px;
    font-size: 17px;
    font-weight: 500;
    padding: 0 22px;
    cursor: pointer;
    transition: background 0.15s;
}
.file-btn:hover, .upload-btn:hover, .folder-btn:hover {
    background: #059669;
} 