:root {
    --primary-color: var(--tg-theme-button-color, #007aff);
    --background-color: var(--tg-theme-bg-color, #f9f9f9);
    --card-background: var(--tg-theme-bg-color, #ffffff);
    --text-color: var(--tg-theme-text-color, #333333);
    --border-color: var(--tg-theme-hint-color, #dddddd);
    --gray-text: var(--tg-theme-hint-color, #8e8e93);
    --secondary-bg: var(--tg-theme-secondary-bg-color, #f0f0f0);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: var(--tg-safe-area-inset-top, 20px) var(--tg-safe-area-inset-right, 20px) var(--tg-safe-area-inset-bottom, 20px) var(--tg-safe-area-inset-left, 20px);
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
}

.container {
    background-color: var(--card-background);
    border-radius: 12px;
    padding: 20px;
    max-width: 800px;
    width: 100%;
    box-sizing: border-box;
}

header {
    text-align: center;
    margin-bottom: 20px;
}

h1 {
    margin: 0 0 10px 0;
    font-size: 24px;
    color: var(--text-color);
}

p {
    margin: 0;
    color: var(--gray-text);
}

.controls {
    margin-bottom: 20px;
}

input[type="file"] {
    display: none;
}

.drop-zone {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    min-height: 200px;
    border: 2px dashed var(--primary-color);
    border-radius: 12px;
    background-color: var(--secondary-bg);
    cursor: pointer;
    transition: background-color 0.2s, border-color 0.2s;
    box-sizing: border-box;
}

.drop-zone:hover {
    background-color: rgba(0, 122, 255, 0.05);
}

.drop-zone-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    color: var(--primary-color);
}

.drop-zone-content svg {
    opacity: 0.8;
}

.drop-zone-content span {
    font-weight: 500;
    font-size: 16px;
}

.preview-area {
    border-radius: 8px;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
    position: relative;
    background-color: transparent;
    width: 100%;
}

canvas {
    max-width: 100%;
    height: auto;
    display: none;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    border-radius: 4px;
}