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

:root {
    --bg-color: #030305;
    --bg-secondary: #0a0a0f;
    --bg-tertiary: #12121a;
    --text-main: #ffffff;
    --text-muted: #9494a8;
    --primary: #00eaff;
    --secondary: #ff00c8;
    --accent: #7000ff;
    --success: #00ff88;
    --glass-bg: rgba(20, 20, 25, 0.6);
    --glass-border: rgba(255, 255, 255, 0.08);
    --card-radius: 16px;
    --transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

body {
    font-family: 'Outfit', sans-serif;
    background: var(--bg-color);
    color: var(--text-main);
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 25px;
    padding: 25px 20px;
    background: var(--glass-bg);
    border-radius: var(--card-radius);
    border: 1px solid var(--glass-border);
    position: relative;
}

.back-link {
    position: absolute;
    top: 20px;
    left: 20px;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: var(--transition);
}

.back-link:hover { color: var(--primary); }

header h1 {
    font-size: 2.2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

header h1 i { margin-right: 12px; }

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

.result-display {
    background: linear-gradient(135deg, rgba(0, 234, 255, 0.1), rgba(255, 0, 200, 0.1));
    border: 1px solid rgba(0, 234, 255, 0.3);
    border-radius: var(--card-radius);
    padding: 40px 30px;
    text-align: center;
    margin-bottom: 20px;
}

.result-value {
    font-family: 'JetBrains Mono', monospace;
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--primary);
    word-break: break-all;
    line-height: 1.3;
}

.result-value.animating {
    animation: pulse 0.1s ease infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.settings-panel {
    background: var(--glass-bg);
    border-radius: var(--card-radius);
    border: 1px solid var(--glass-border);
    padding: 20px;
    margin-bottom: 20px;
}

.setting-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-bottom: 15px;
}

.setting-row:last-child { margin-bottom: 0; }

.setting-group label {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.setting-group input {
    width: 100%;
    padding: 12px 15px;
    background: var(--bg-tertiary);
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    color: var(--text-main);
    font-family: 'JetBrains Mono', monospace;
    font-size: 1rem;
    outline: none;
    transition: var(--transition);
}

.setting-group input:focus { border-color: var(--primary); }

.checkbox-row {
    display: flex;
    gap: 20px;
    padding-top: 10px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.checkbox-label input { display: none; }

.checkmark {
    width: 20px;
    height: 20px;
    border: 2px solid var(--glass-border);
    border-radius: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.checkbox-label input:checked + .checkmark {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-color: transparent;
}

.checkbox-label input:checked + .checkmark::after {
    content: '\f00c';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    font-size: 0.7rem;
    color: #000;
}

.actions {
    display: flex;
    gap: 12px;
    margin-bottom: 20px;
}

.btn {
    flex: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 16px 24px;
    border-radius: 12px;
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: #000;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 234, 255, 0.3);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-main);
    border: 1px solid var(--glass-border);
}

.btn-secondary:hover { border-color: var(--secondary); color: var(--secondary); }

.history-panel {
    background: var(--glass-bg);
    border-radius: var(--card-radius);
    border: 1px solid var(--glass-border);
    overflow: hidden;
}

.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 15px;
    background: var(--bg-tertiary);
    border-bottom: 1px solid var(--glass-border);
}

.history-header h3 {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.history-header h3 i { margin-right: 8px; color: var(--primary); }

.btn-small {
    background: transparent;
    border: 1px solid var(--glass-border);
    border-radius: 6px;
    padding: 5px 12px;
    color: var(--text-muted);
    font-size: 0.8rem;
    cursor: pointer;
    transition: var(--transition);
}

.btn-small:hover { color: var(--error); border-color: var(--error); }

.history-list {
    max-height: 200px;
    overflow-y: auto;
    padding: 10px;
}

.placeholder {
    color: var(--text-muted);
    opacity: 0.5;
    text-align: center;
    padding: 20px;
}

.history-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 12px;
    background: var(--bg-tertiary);
    border-radius: 8px;
    margin-bottom: 6px;
    animation: slideIn 0.3s ease;
}

.history-item:last-child { margin-bottom: 0; }

@keyframes slideIn {
    from { opacity: 0; transform: translateX(-10px); }
    to { opacity: 1; transform: translateX(0); }
}

.history-range {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.history-result {
    font-family: 'JetBrains Mono', monospace;
    color: var(--primary);
    font-size: 0.9rem;
}

::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-secondary); }
::-webkit-scrollbar-thumb { background: var(--glass-border); border-radius: 3px; }

.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--bg-tertiary);
    border: 1px solid var(--success);
    border-radius: 10px;
    padding: 12px 24px;
    color: var(--success);
    font-size: 0.9rem;
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 1000;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

footer {
    text-align: center;
    padding: 20px;
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-top: 15px;
}

@media (max-width: 500px) {
    .container { padding: 15px; }
    header h1 { font-size: 1.8rem; }
    .result-value { font-size: 2.5rem; }
    .setting-row { grid-template-columns: 1fr; }
    .checkbox-row { flex-direction: column; gap: 10px; }
}