:root {
    --bg-app: #f5f5f7;
        --bg-card: #ffffff;
        --bg-input: #f0f0f2;
        --accent-primary: #007aff;
        --accent-secondary: #5856d6;
        --text-main: #1d1d1f;
        --text-muted: #6e6e73;
        --border-color: #d2d2d7;
        --success: #34c759;
    
    --font-main: 'Outfit', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
}

body.dark-mode {
    --bg-app: #0a0b10;
    --bg-card: #13151c;
    --bg-input: #1c1f29;
    --accent-primary: #00f0ff;
    --accent-secondary: #7000ff;
    --text-main: #e0e0e0;
    --text-muted: #8b9bb4;
    --border-color: #2a2f3d;
    --success: #00ff9d;
}
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-app);
    color: var(--text-main);
    font-family: var(--font-main);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    justify-content: center;
}

.app-container {
    width: 100%;
    max-width: 1200px;
    padding: 1rem;
}

header {
    margin-bottom: 1rem;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

header h1 {
    font-size: 1.8rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--text-main) 0%, var(--accent-primary) 100%);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.25rem;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.0rem;
}

/* Layout */
.calculator-grid {
    display: grid;
    grid-template-columns: 1fr 300px;
        gap: 1rem;
}

@media (max-width: 900px) {
    .calculator-grid {
        grid-template-columns: 1fr;
    }
}

/* Cards */
.card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
        padding: 1rem;
        margin-bottom: 1rem;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
    border-color: var(--accent-primary);
    box-shadow: 0 4px 25px rgba(0, 122, 255, 0.15);
    }
    
    body.dark-mode .card:hover {
    box-shadow: 0 4px 25px rgba(0, 240, 255, 0.1);
}

.card h2 {
    font-size: 1rem;
        margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-main);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.card-header h2 {
    margin-bottom: 0;
    border-bottom: none;
    padding-bottom: 0;
}

/* Forms */
.form-group {
    margin-bottom: 0.75rem;
    }
    
    .form-group-inline {
        display: flex;
        align-items: center;
        gap: 0.75rem;
        margin-bottom: 0.75rem;
    }
    
    .form-group-inline label {
        margin-bottom: 0;
        white-space: nowrap;
        min-width: fit-content;
    }
    
    .form-group-inline input,
    .form-group-inline select {
        flex: 1;
}

label {
    display: block;
    margin-bottom: 0.25rem;
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 500;
}

input[type="number"], select {
    width: 100%;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 0.5rem;
    color: var(--text-main);
    font-family: var(--font-mono);
    font-size: 1.0rem;
    transition: all 0.2s;
}

input[type="number"]:focus, select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 2px rgba(0, 240, 255, 0.2);
}

.hint {
    display: block;
    margin-top: 0.25rem;
    font-size: 0.9rem;
    color: var(--text-muted);
    opacity: 0.7;
}

/* Input with Unit */
.input-with-unit .input-wrapper {
    display: flex;
    gap: 0.5rem;
}

.input-with-unit input {
    flex: 2;
        min-width: 0;
}

.input-with-unit select {
    flex: 1;
        min-width: 150px;
}

/* Levels */
.level-row {
    background-color: rgba(255, 255, 255, 0.03);
    padding: 0.75rem;
    border-radius: var(--radius-md);
    margin-bottom: 0.75rem;
    position: relative;
    border: 1px solid transparent;
}

.level-row:hover {
    border-color: rgba(255, 255, 255, 0.1);
}

.level-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
        font-size: 0.95rem;
    font-weight: 600;
    color: var(--accent-primary);
}

.level-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1.5fr;
    gap: 0.5rem;
}

.level-inputs input {
    padding: 0.4rem;
        font-size: 0.95rem;
}

.remove-level-btn {
    background: none;
    border: none;
    color: #ff4d4d;
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0 0.5rem;
    opacity: 0.7;
    transition: opacity 0.2s;
}

.remove-level-btn:hover {
    opacity: 1;
}

.btn-icon {
    background-color: var(--accent-primary);
    color: #000;
    border: none;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    font-size: 1.2rem;
    font-weight: bold;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s, background-color 0.2s;
}

.btn-icon:hover {
    transform: scale(1.1);
    background-color: #fff;
}

.btn-export {
    background-color: transparent;
    border: 1px solid var(--accent-primary);
    color: var(--accent-primary);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.btn-export:hover {
    background-color: var(--accent-primary);
    color: #fff;
}
/* Toggle Switch */
.toggle-group {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.75rem;
}

.switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 24px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--bg-input);
    transition: .4s;
    border: 1px solid var(--border-color);
}

.slider:before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 4px;
    bottom: 3px;
    background-color: var(--text-muted);
    transition: .4s;
}

input:checked + .slider {
    background-color: var(--accent-secondary);
    border-color: var(--accent-secondary);
}

input:checked + .slider:before {
    transform: translateX(26px);
    background-color: #fff;
}

.slider.round {
    border-radius: 24px;
}

.slider.round:before {
    border-radius: 50%;
}

.hidden {
    display: none;
}

/* Output Section */
.sticky-wrapper {
    position: sticky;
    top: 1rem;
}

.result-card {
    border-color: var(--accent-primary);
    background: linear-gradient(180deg, var(--bg-card) 0%, rgba(0, 122, 255, 0.05) 100%);
    }
    
    body.dark-mode .result-card {
    background: linear-gradient(180deg, var(--bg-card) 0%, rgba(0, 240, 255, 0.05) 100%);
}

.result-group {
    margin-bottom: 0.75rem;
}

.result-group .label {
    display: block;
    color: var(--text-muted);
    font-size: 0.85rem;
        margin-bottom: 0.2rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.result-group .value {
    font-family: var(--font-mono);
    font-size: 1rem;
    color: var(--text-main);
}

.divider {
    height: 1px;
    background-color: var(--border-color);
    margin: 1rem 0;
}

.highlight .label {
    color: var(--accent-primary);
}

.highlight-secondary .label {
    color: var(--accent-secondary);
}

.value-large {
    font-family: var(--font-mono);
    font-size: 1.1rem; /* Adjusted to fit */
    color: #fff;
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: 0.5rem;
}

.time-part {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-primary);
}

.eq {
    color: var(--text-muted);
    font-weight: 300;
}

.value-large-vertical {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.time-row {
    font-family: var(--font-mono);
    color: var(--text-muted);
}

.time-row-large {
    font-size: 1.4rem;
        font-weight: 700;
}
.time-row-small {
    font-size: 1rem;
        font-weight: 700;
}
.time-row .time-part {
  color: var(--accent-primary);
  font-weight: 700;
  font-size: 1.3rem;
  margin-right: 0.5rem;
}
.time-part-large {
    font-size: 2rem !important;
}

.time-part-small {
    font-size: 1.1rem !important;
}

.value-medium {
    font-family: var(--font-mono);
    color: var(--text-muted);
    }
    
    .value-medium-large {
        font-family: var(--font-mono);
        font-size: 1.4rem;
    font-weight: 700;
    margin-top: 0.4rem;
        color: var(--text-muted);
    }
    
    .value-medium-large span {
    color: var(--accent-secondary);
    font-size: 2rem;
        margin-right: 0.5rem;
}

.value-medium-small {
    font-family: var(--font-mono);
    font-size: 1rem;
        font-weight: 700;
        color: var(--text-muted);
        opacity: 0.8;
        margin-top: 0.5rem;
    }
    
    .value-medium-small span {
    color: var(--accent-secondary);
    font-size: 1.1rem;
        margin-right: 0.5rem;
}

/* Theme Toggle */
.theme-toggle {
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1.2rem;
}

.theme-toggle:hover {
    background-color: var(--accent-primary);
    border-color: var(--accent-primary);
    transform: scale(1.1);
}

.theme-icon {
    transition: transform 0.3s ease;
}

.theme-toggle:hover .theme-icon {
    transform: rotate(20deg);
}
/* Help Icons and Tooltips */
.help-icon {
    display: inline-block;
    cursor: help;
    font-size: 0.9em;
    opacity: 0.7;
    margin-left: 0.25rem;
    position: relative;
    transition: opacity 0.2s;
}

.help-icon:hover {
    opacity: 1;
}

.help-icon::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%) translateY(-8px);
    background-color: var(--bg-card);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    white-space: normal;
    width: 250px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s, transform 0.2s;
    z-index: 1000;
    font-family: var(--font-main);
    font-weight: 400;
    line-height: 1.4;
}

.help-icon:hover::after {
    opacity: 1;
    transform: translateX(-50%) translateY(-4px);
}

.help-text {
    background-color: rgba(0, 122, 255, 0.1);
    border-left: 3px solid var(--accent-primary);
    padding: 0.5rem 0.75rem;
    margin-bottom: 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    color: var(--text-muted);
}

body.dark-mode .help-text {
    background-color: rgba(0, 240, 255, 0.1);
}

.help-text strong {
    color: var(--accent-primary);
}
code {
    font-family: var(--font-mono);
    background: rgba(0, 0, 0, 0.05);
    padding: 0.1em 0.3em;
    border-radius: 3px;
    font-size: 0.9em;
}