:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --primary-light: #eef2ff;
    --bg-color: #f9fafb;
    --card-bg: #ffffff;
    --text-main: #111827;
    --text-muted: #6b7280;
    --border-color: #e5e7eb;
    --input-bg: #ffffff;
    --danger-color: #ef4444;
    --success-color: #10b981;
    --radius: 12px;
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

[data-theme="dark"] {
    --primary-color: #6366f1;
    --primary-hover: #818cf8;
    --primary-light: #312e81;
    --bg-color: #111827;
    --card-bg: #1f2937;
    --text-main: #f9fafb;
    --text-muted: #9ca3af;
    --border-color: #374151;
    --input-bg: #111827;
}

/* Material Symbols Icon Font Class */
.material-symbols-rounded {
    font-family: 'Material Symbols Rounded';
    font-weight: normal;
    font-style: normal;
    font-size: 24px;
    display: inline-block;
    line-height: 1;
    text-transform: none;
    letter-spacing: normal;
    word-wrap: normal;
    white-space: nowrap;
    direction: ltr;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
    -moz-osx-font-smoothing: grayscale;
    font-feature-settings: 'liga';
}

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

body {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    min-height: 100vh;
    padding: 40px 24px;
    transition: background-color 0.3s ease;
}

[data-theme="dark"] body {
    background: linear-gradient(135deg, #1e3a8a 0%, #312e81 100%);
}

.app-container {
    width: 100%;
    max-width: 650px;
}

.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
    color: white;
}

.brand .icon {
    font-size: 36px;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.brand h1 {
    font-size: 28px;
    font-weight: 700;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.theme-toggle button {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    cursor: pointer;
    color: white;
    padding: 10px;
    border-radius: 50%;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle button:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.05);
}

.main-content {
    background-color: var(--card-bg);
    padding: 40px;
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    transition: background-color 0.3s ease;
}

.form-group {
    margin-bottom: 24px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    font-size: 14px;
    color: var(--text-main);
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-icon {
    position: absolute;
    left: 14px;
    color: var(--text-muted);
    font-size: 20px;
    pointer-events: none;
}

input,
textarea {
    width: 100%;
    padding: 12px 16px 12px 44px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 15px;
    color: var(--text-main);
    background-color: var(--input-bg);
    transition: all 0.2s;
}

textarea {
    padding: 12px 16px;
    resize: vertical;
    font-family: 'Inter', sans-serif;
}

input:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px var(--primary-light);
}

.helper-text {
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 6px;
}

/* Rich Text Editor - Modern Design */
.rich-editor-container {
    border: 2px solid var(--border-color);
    border-radius: 10px;
    background-color: var(--input-bg);
    overflow: hidden;
    transition: all 0.2s;
}

.rich-editor-container:focus-within {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px var(--primary-light);
}

.toolbar {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 10px;
    background: linear-gradient(to bottom, var(--bg-color), var(--card-bg));
    border-bottom: 2px solid var(--border-color);
    flex-wrap: wrap;
}

.toolbar button {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    cursor: pointer;
    color: var(--text-main);
    padding: 8px;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.15s;
    min-width: 36px;
    min-height: 36px;
}

.toolbar button:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-1px);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.toolbar button:active {
    transform: translateY(0);
}

.toolbar button span {
    font-size: 20px;
}

.toolbar .separator {
    width: 1px;
    height: 28px;
    background-color: var(--border-color);
    margin: 0 6px;
}

.editor-content {
    min-height: 280px;
    padding: 20px;
    outline: none;
    overflow-y: auto;
    font-size: 15px;
    line-height: 1.7;
    color: var(--text-main);
    background-color: var(--input-bg);
    cursor: text;
}

/* Placeholder for ContentEditable */
.editor-content:empty:before {
    content: attr(placeholder);
    color: var(--text-muted);
    opacity: 0.6;
    pointer-events: none;
    display: block;
    font-style: italic;
}

/* File Upload */
.file-upload-area {
    border: 2px dashed var(--border-color);
    border-radius: 10px;
    padding: 32px 24px;
    text-align: center;
    position: relative;
    cursor: pointer;
    transition: all 0.2s;
    background: var(--bg-color);
}

.file-upload-area:hover,
.file-upload-area.dragover {
    border-color: var(--primary-color);
    background-color: var(--primary-light);
    transform: scale(1.01);
}

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

.upload-placeholder {
    color: var(--text-muted);
}

.upload-icon {
    font-size: 40px;
    margin-bottom: 12px;
    color: var(--primary-color);
}

.file-list {
    margin-top: 12px;
    list-style: none;
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: var(--bg-color);
    padding: 10px 14px;
    margin-bottom: 8px;
    border-radius: 8px;
    font-size: 13px;
    border: 1px solid var(--border-color);
}

.remove-file {
    background: none;
    border: none;
    color: var(--danger-color);
    cursor: pointer;
    font-size: 20px;
    display: flex;
    align-items: center;
    transition: transform 0.2s;
}

.remove-file:hover {
    transform: scale(1.2);
}

/* Settings Box */
.settings-box {
    border: 2px solid var(--border-color);
    border-radius: 10px;
    padding: 20px;
    background: linear-gradient(to bottom, var(--bg-color), var(--card-bg));
}

.settings-box .form-group:last-child {
    margin-bottom: 0;
}

/* Button */
.btn-primary {
    width: 100%;
    padding: 16px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-weight: 600;
    font-size: 16px;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    transition: all 0.2s;
    box-shadow: 0 4px 6px -1px rgba(79, 70, 229, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(79, 70, 229, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

/* Toast */
.toast {
    position: fixed;
    bottom: 24px;
    right: 24px;
    background-color: var(--text-main);
    color: var(--card-bg);
    padding: 14px 24px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    gap: 12px;
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.2);
    transform: translateY(0);
    opacity: 1;
    transition: all 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

.toast.hidden {
    transform: translateY(100%);
    opacity: 0;
}

.toast.success {
    background-color: var(--success-color);
    color: white;
}

.toast.error {
    background-color: var(--danger-color);
    color: white;
}

/* Loader */
.loader {
    display: none;
    width: 20px;
    height: 20px;
    border: 2px solid white;
    border-bottom-color: transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

.btn-primary.loading .loader {
    display: block;
}

.btn-primary.loading .btn-text,
.btn-primary.loading .btn-icon {
    display: none;
}

@keyframes spin {
    0% {
        transform: rotate(0deg);
    }

    100% {
        transform: rotate(360deg);
    }
}

/* Footer */
.app-footer {
    margin-top: 32px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

.app-footer p {
    font-size: 13px;
    color: var(--text-muted);
}

.app-footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s;
}

.app-footer a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

@media (max-width: 480px) {
    body {
        padding: 20px 16px;
    }

    .app-container {
        padding: 0;
    }

    .main-content {
        border-radius: 12px;
        padding: 28px 20px;
    }

    .brand h1 {
        font-size: 24px;
    }
}