:root {
    --bg-gradient-start: #e0f7ff;
    --bg-gradient-end: #fce4ec;
    --card-bg: #ffffff;
    --text-primary: #2c3e50;
    --text-secondary: #6c757d;
    --text-muted: #95a5a6;
    --border-color: #e1e8ed;
    --input-bg: #ffffff;
    --input-border: #cbd5e0;
    --button-primary: #1e88e5;
    --button-primary-hover: #1565c0;
    --button-warning: #e67e22;
    --button-warning-hover: #d35400;
    --progress-bg: #ecf0f1;
    --progress-fill: #00bcd4;
    --log-bg: #f8f9fa;
    --info-bg: #e3f2fd;
    --info-border: #64b5f6;
    --error-color: #e74c3c;
    --shadow: rgba(0, 0, 0, 0.08);
    --shadow-hover: rgba(0, 0, 0, 0.12);
    --focus-shadow: rgba(30, 136, 229, 0.15);
    --active-ring: rgba(30, 136, 229, 0.2);
    --font-monospace: 'Consolas', 'Monaco', 'Courier New', monospace;
}

[data-theme="dark"] {
    --bg-gradient-start: #1a1a2e;
    --bg-gradient-end: #16213e;
    --card-bg: #0f3460;
    --text-primary: #eaeaea;
    --text-secondary: #b8c5d6;
    --text-muted: #8b9bb3;
    --border-color: #2d4263;
    --input-bg: #1a2942;
    --input-border: #2d4263;
    --button-primary: #3498db;
    --button-primary-hover: #5dade2;
    --button-warning: #e67e22;
    --button-warning-hover: #f39c12;
    --progress-bg: #1a2942;
    --progress-fill: #27ae60;
    --log-bg: #1a2942;
    --info-bg: #1a2942;
    --info-border: #3498db;
    --error-color: #e74c3c;
    --shadow: rgba(0, 0, 0, 0.3);
    --shadow-hover: rgba(0, 0, 0, 0.4);
    --focus-shadow: rgba(52, 152, 219, 0.2);
    --active-ring: rgba(52, 152, 219, 0.3);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    max-width: 900px;
    margin: 0 auto;
    padding: 24px;
    background: linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 100%);
    min-height: 100vh;
    color: var(--text-primary);
    transition: background 0.3s ease, color 0.3s ease;
}

body > div:first-child {
    background: var(--card-bg);
    border-radius: 8px;
    padding: 32px;
    box-shadow: 0 2px 8px var(--shadow);
    transition: background 0.3s ease, box-shadow 0.3s ease;
}

h2 {
    margin: 0 0 8px;
    text-align: center;
    font-size: 28px;
    font-weight: 600;
    color: var(--text-primary);
}

p {
    margin: 0 0 24px;
    font-size: 14px;
    text-align: center;
    color: var(--text-secondary);
}

label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
}

button, input {
    display: block;
    width: 100%;
    padding: 12px 16px;
    margin: 12px 0;
    border: 1px solid var(--input-border);
    border-radius: 6px;
    font-family: inherit;
    font-size: 16px;
    background: var(--input-bg);
    color: var(--text-primary);
    transition: all 0.2s ease;
}

button {
    background: var(--button-primary);
    color: #ffffff;
    cursor: pointer;
    border: none;
    font-weight: 500;
    box-shadow: 0 1px 3px var(--shadow);
}

button:hover:not(:disabled) {
    background: var(--button-primary-hover);
    box-shadow: 0 2px 6px var(--shadow-hover);
    transform: translateY(-1px);
}

button:active:not(:disabled) {
    transform: translateY(0);
    box-shadow: 0 1px 3px var(--shadow);
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.detach-btn {
    display: none;
    background: var(--button-warning);
}

.detach-btn:hover:not(:disabled) {
    background: var(--button-warning-hover);
}

input[type=file] {
    padding: 10px;
    cursor: pointer;
}

input[type=file]::file-selector-button {
    padding: 8px 16px;
    margin-right: 16px;
    background: var(--button-primary);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 500;
    transition: background 0.2s ease;
}

input[type=file]::file-selector-button:hover {
    background: var(--button-primary-hover);
}

input[type=text] {
    font-family: var(--font-monospace);
}

input:focus {
    outline: none;
    border-color: var(--button-primary);
    box-shadow: 0 0 0 3px var(--focus-shadow);
}

#p-erase, #p-write, #l {
    display: none;
}

.progress-wrap {
    margin: 12px 0;
}

.progress-title {
    font-size: 13px;
    font-weight: 600;
    color: var(--text-secondary);
    margin: 0 0 6px;
}

#pe,
#p {
    height: 36px;
    background: var(--progress-bg);
    margin: 0;
    border-radius: 18px;
    overflow: hidden;
    box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.1);
}

#pe div,
#p div {
    height: 100%;
    background: var(--progress-fill);
    width: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    transition: width 0.3s ease;
    font-size: 14px;
    font-weight: 600;
    border-radius: 18px;
}

#l {
    font-family: var(--font-monospace);
    font-size: 13px;
    max-height: 220px;
    overflow-y: auto;
    background: var(--log-bg);
    padding: 16px;
    margin: 12px 0;
    border-radius: 6px;
    line-height: 1.6;
    border: 1px solid var(--border-color);
}

#l::-webkit-scrollbar {
    width: 8px;
}

#l::-webkit-scrollbar-track {
    background: var(--progress-bg);
    border-radius: 4px;
}

#l::-webkit-scrollbar-thumb {
    background: var(--input-border);
    border-radius: 4px;
}

#l::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

.e {
    color: var(--error-color);
    font-weight: 500;
}

#info {
    display: none;
    margin: 12px 0;
    padding: 12px 16px;
    border: 1px solid var(--info-border);
    border-radius: 6px;
    background: var(--info-bg);
    font-family: var(--font-monospace);
    font-size: 13px;
    line-height: 1.5;
    white-space: pre-wrap;
    word-break: break-word;
    color: var(--text-primary);
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

#theme-switcher {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--card-bg);
    border-radius: 24px;
    padding: 8px;
    box-shadow: 0 2px 8px var(--shadow);
    display: flex;
    gap: 8px;
    z-index: 1000;
    transition: background 0.3s ease, box-shadow 0.3s ease, opacity 0.2s ease;
}

#theme-switcher.scrolling {
    opacity: 0.6;
}

.theme-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all 0.2s ease;
    padding: 0;
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
}

.theme-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 2px 8px var(--shadow-hover);
}

.theme-btn.active {
    border-color: var(--button-primary);
    box-shadow: 0 0 0 2px var(--active-ring);
}

.theme-btn[data-theme="light"] {
    background: linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 100%);
}

.theme-btn[data-theme="dark"] {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
}

@media (max-width: 600px) {
    body {
        padding: 16px;
        padding-top: calc(72px + env(safe-area-inset-top));
    }

    body > div:first-child {
        padding: 24px;
    }

    #theme-switcher {
        top: calc(10px + env(safe-area-inset-top));
        right: 10px;
        padding: 4px 6px;
        gap: 4px;
        border-radius: 16px;
        background: color-mix(in srgb, var(--card-bg) 68%, transparent);
        border: 1px solid color-mix(in srgb, var(--border-color) 70%, transparent);
        backdrop-filter: blur(8px);
        -webkit-backdrop-filter: blur(8px);
        box-shadow: 0 1px 6px var(--shadow);
    }

    .theme-btn {
        width: 30px;
        height: 30px;
        font-size: 13px;
        line-height: 1;
    }

    .theme-btn:hover {
        transform: none;
    }
}