:root {
    --color-bg-page: #F0F2F6; /* minimal blue-grey */
    --color-bg-main: #FFFFFF; /* stark white */
    --color-bg-surface: #F2F2F7;
    --color-primary-base: #101010;
    --color-primary-hover: #333333;
    --color-accent-base: #101010;
    --color-accent-hover: #6E6E73;
    --color-text-main: #101010;
    --color-text-muted: #6E6E73;
    --color-border-light: #F5F5F5;
    --color-status-success: #34C759;
    --color-status-error: #FF3B30;

    --font-family-sans: 'Inter Tight', sans-serif;
    --text-size-sm: 0.875rem;
    --text-size-base: 1rem;
    --text-size-lg: 1.25rem;
    --text-size-xl: 1.5rem;
    --text-size-2xl: 2.5rem;
    --text-size-3xl: 4rem;
    
    --font-weight-regular: 400;
    --font-weight-medium: 500;
    --font-weight-bold: 600;

    --space-xs: 8px;
    --space-sm: 12px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 40px;
    --space-2xl: 80px;

    --radius-sm: 12px;
    --radius-md: 20px;
    --radius-lg: 32px;
    --radius-pill: 9999px;

    --border-width-default: 1px;
}

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

body {
    font-family: var(--font-family-sans);
    background-color: var(--color-bg-page);
    color: var(--color-text-main);
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    overflow-y: scroll;
}

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

.fade-in {
    animation: fadeIn 0.4s ease-out forwards;
}

/* App Container */
.app-container {
    width: 100%;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
}

/* Header */
.app-header {
    width: 100%;
    padding: var(--space-lg) var(--space-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: var(--border-width-default) solid var(--color-border-light);
}

.app-brand {
    font-size: var(--text-size-xl);
    font-weight: var(--font-weight-bold);
    letter-spacing: -0.02em;
}

/* Content Area */
.content-area {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    padding: var(--space-2xl) var(--space-lg);
}

/* Dropzone styling */
.dropzone {
    text-align: center;
    cursor: pointer;
    transition: opacity 0.2s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 50vh;
    background-color: var(--color-bg-main);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(0,0,0,0.03);
    padding: var(--space-2xl);
}

.dropzone:hover, .dropzone.dragover {
    opacity: 0.6;
}

.dropzone-icon {
    font-size: 3rem;
    margin-bottom: var(--space-md);
    color: var(--color-primary-base);
}

.dropzone-text {
    font-size: var(--text-size-3xl);
    font-weight: var(--font-weight-bold);
    letter-spacing: -0.03em;
    margin-bottom: var(--space-md);
    line-height: 1.1;
}

.dropzone-muted {
    font-size: var(--text-size-lg);
    color: var(--color-text-muted);
}

#file-input {
    display: none;
}

/* Buttons */
.btn {
    font-family: var(--font-family-sans);
    font-weight: var(--font-weight-medium);
    border-radius: var(--radius-pill);
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-block;
    border: none;
    outline: none;
}

/* Default/Medium size */
.btn {
    padding: var(--space-sm) var(--space-lg);
    font-size: var(--text-size-base);
}

/* Small size */
.btn-sm {
    padding: var(--space-xs) var(--space-md);
    font-size: var(--text-size-sm);
}

.btn-primary {
    background-color: var(--color-primary-base);
    color: #FFFFFF;
}

.btn-primary:hover {
    background-color: var(--color-primary-hover);
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-text-main);
    border: var(--border-width-default) solid var(--color-border-light);
}

.btn-secondary:hover {
    background-color: var(--color-bg-surface);
}

.btn-ghost {
    background-color: transparent;
    color: var(--color-text-main);
}

.btn-ghost:hover {
    background-color: var(--color-bg-surface);
}

/* Loader */
.loader-container {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 50vh;
}

.loader {
    width: 48px;
    height: 48px;
    border: 3px solid var(--color-border-light);
    border-bottom-color: var(--color-primary-base);
    border-radius: 50%;
    display: inline-block;
    box-sizing: border-box;
    animation: rotation 1s linear infinite;
    margin-bottom: var(--space-md);
}

@keyframes rotation {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Result Section */
.result-section {
    display: none;
    flex-direction: column;
}

.transcript-toolbar {
    display: flex;
    align-items: center;
    border-bottom: var(--border-width-default) solid var(--color-border-light);
    padding-bottom: var(--space-lg);
    margin-bottom: var(--space-xl);
}

.transcript-title {
    font-size: var(--text-size-xl);
    font-weight: var(--font-weight-regular);
    flex-grow: 1;
    color: var(--color-text-muted);
}

.transcript-box {
    background-color: var(--color-bg-main);
    border-radius: var(--radius-md);
    padding: var(--space-xl) var(--space-2xl);
    font-size: var(--text-size-lg);
    line-height: 1.8;
    color: var(--color-text-main);
    border: 1px solid rgba(0,0,0,0.03);
}

.action-buttons {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
    margin-top: var(--space-2xl);
    padding-top: var(--space-xl);
    border-top: var(--border-width-default) solid var(--color-border-light);
}

#error-message {
    font-size: var(--text-size-base);
    color: var(--color-status-error);
    margin-top: var(--space-md);
    text-align: center;
    display: none;
}

/* Markdown Summary Styles */
.markdown-body {
    background-color: var(--color-bg-main);
    border-radius: var(--radius-md);
    padding: var(--space-xl) var(--space-2xl);
    font-size: var(--text-size-lg);
    line-height: 1.8;
    color: var(--color-text-main);
    margin-top: var(--space-2xl);
    border: 1px solid rgba(0,0,0,0.03);
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4 {
    font-weight: var(--font-weight-bold);
    margin-top: var(--space-xl);
    margin-bottom: var(--space-md);
    line-height: 1.25;
    letter-spacing: -0.01em;
}

.markdown-body h1 { font-size: var(--text-size-2xl); }
.markdown-body h2 { font-size: var(--text-size-xl); }

.markdown-body p,
.markdown-body blockquote,
.markdown-body ul,
.markdown-body ol,
.markdown-body dl,
.markdown-body table,
.markdown-body pre {
    margin-top: 0;
    margin-bottom: var(--space-lg);
}

.markdown-body ul,
.markdown-body ol {
    padding-left: var(--space-lg);
}

.markdown-body li {
    margin-bottom: var(--space-sm);
}

.markdown-body blockquote {
    padding: 0 var(--space-lg);
    color: var(--color-text-muted);
    border-left: 2px solid var(--color-primary-base);
}

.markdown-body strong {
    font-weight: var(--font-weight-bold);
}