/* ==========================================================================
   Calculator — Standalone Modern Theme & Layout
   Zero-dependency, bulletproof grid & flex layout for all browsers.
   ========================================================================== */

/* ── 1. Popover Container ───────────────────────────────────────────────── */
.popover.calc-popover,
.popover:has(#calculator),
.popover:has(.calc-container) {
    position: fixed !important;
    top: 50% !important;
    left: 50% !important;
    transform: translate(-50%, -50%) !important;
    width: 320px !important;
    max-width: 95vw !important;
    height: auto !important;
    max-height: 90vh !important;
    z-index: 999999 !important;
    background: #0f172a !important;
    border-radius: 16px !important;
    box-shadow: 0 20px 50px -10px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.12) !important;
    border: none !important;
    overflow: hidden !important;
    padding: 0 !important;
    margin: 0 !important;
}

.popover.calc-popover > .arrow,
.popover:has(#calculator) > .arrow,
.popover:has(.calc-container) > .arrow {
    display: none !important;
}

.popover.calc-popover .popover-content,
.popover:has(#calculator) .popover-content,
.popover:has(.calc-container) .popover-content {
    width: 100% !important;
    height: 100% !important;
    padding: 0 !important;
    margin: 0 !important;
    box-sizing: border-box !important;
    background: #0f172a !important;
    display: flex !important;
    flex-direction: column !important;
}

/* ── 2. Calculator Main Shell ──────────────────────────────────────────── */
#calculator,
.calc-container {
    width: 320px !important;
    max-width: 100% !important;
    box-sizing: border-box !important;
    padding: 0 !important;
    margin: 0 !important;
    background: #0f172a !important;
    color: #f8fafc !important;
    display: flex !important;
    flex-direction: column !important;
    border-radius: 16px !important;
    overflow: hidden !important;
    user-select: none !important;
    -webkit-user-select: none !important;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif !important;
}

/* ── 3. Header Bar ─────────────────────────────────────────────────────── */
.calc-header {
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    padding: 8px 12px !important;
    background: #0f172a !important;
    border-bottom: 1px solid #1e293b !important;
    box-sizing: border-box !important;
}

.calc-header-title {
    display: flex !important;
    align-items: center !important;
    gap: 8px !important;
}

.calc-header-icon {
    width: 26px !important;
    height: 26px !important;
    border-radius: 6px !important;
    background: rgba(16, 185, 129, 0.15) !important;
    border: 1px solid rgba(16, 185, 129, 0.3) !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    color: #34d399 !important;
}

.calc-header-text {
    font-size: 13px !important;
    font-weight: 700 !important;
    color: #f8fafc !important;
    line-height: 1.2 !important;
}

.calc-header-sub {
    font-size: 10px !important;
    color: #64748b !important;
    font-family: "SF Mono", monospace !important;
    display: flex !important;
    align-items: center !important;
    gap: 4px !important;
}

.calc-header-actions {
    display: flex !important;
    align-items: center !important;
    gap: 4px !important;
}

.calc-icon-btn {
    width: 28px !important;
    height: 28px !important;
    padding: 0 !important;
    border: none !important;
    background: transparent !important;
    color: #94a3b8 !important;
    border-radius: 6px !important;
    cursor: pointer !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    transition: all 0.15s ease !important;
}
.calc-icon-btn:hover {
    background: #1e293b !important;
    color: #ffffff !important;
}
.calc-icon-btn:active {
    transform: scale(0.92) !important;
}

/* ── 4. Display Area ───────────────────────────────────────────────────── */
.calc-display-section {
    background: #020617 !important;
    padding: 10px 12px !important;
    border-bottom: 1px solid #1e293b !important;
    box-sizing: border-box !important;
    position: relative !important;
}

.calc-expression-row {
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    min-height: 18px !important;
    margin-bottom: 4px !important;
    padding: 0 2px !important;
}

#calc-expression {
    color: #64748b !important;
    font-family: "SF Mono", "Consolas", monospace !important;
    font-size: 12px !important;
    text-align: right !important;
    flex: 1 !important;
    overflow: hidden !important;
    text-overflow: ellipsis !important;
    white-space: nowrap !important;
}

#calc-live-preview {
    font-family: "SF Mono", "Consolas", monospace !important;
    font-size: 12px !important;
    font-weight: 600 !important;
    color: #34d399 !important;
    margin-right: 8px !important;
}

.calc-display-wrap {
    position: relative !important;
    display: flex !important;
    align-items: center !important;
    width: 100% !important;
    box-sizing: border-box !important;
}

.calc-screen-input {
    width: 100% !important;
    box-sizing: border-box !important;
    height: 48px !important;
    background: #090d16 !important;
    border: 1px solid #1e293b !important;
    border-radius: 10px !important;
    color: #ffffff !important;
    font-family: "SF Mono", "Consolas", "JetBrains Mono", monospace !important;
    font-size: 26px !important;
    font-weight: 700 !important;
    padding: 8px 12px 8px 36px !important;
    text-align: right !important;
    outline: none !important;
    box-shadow: inset 0 2px 6px rgba(0, 0, 0, 0.6) !important;
    letter-spacing: -0.5px !important;
}

.calc-screen-input:focus {
    border-color: #10b981 !important;
    box-shadow: inset 0 2px 6px rgba(0, 0, 0, 0.6), 0 0 0 2px rgba(16, 185, 129, 0.25) !important;
}

#calc-copy-btn {
    position: absolute !important;
    left: 6px !important;
    width: 24px !important;
    height: 24px !important;
    padding: 0 !important;
    border: none !important;
    background: transparent !important;
    color: #475569 !important;
    border-radius: 6px !important;
    cursor: pointer !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    transition: color 0.15s ease !important;
}
#calc-copy-btn:hover {
    color: #34d399 !important;
}

#calc-copy-toast {
    position: absolute !important;
    top: 6px !important;
    left: 10px !important;
    background: #10b981 !important;
    color: #ffffff !important;
    font-size: 10px !important;
    font-weight: 700 !important;
    padding: 2px 8px !important;
    border-radius: 12px !important;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease !important;
    z-index: 10 !important;
    display: flex !important;
    align-items: center !important;
    gap: 4px !important;
}

/* ── 5. Utility / Memory Bar ───────────────────────────────────────────── */
.calc-utility-bar {
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    padding: 5px 8px !important;
    background: #0b1120 !important;
    border-bottom: 1px solid #1e293b !important;
    gap: 3px !important;
    box-sizing: border-box !important;
}

.calc-mem-btn {
    flex: 1 1 0 !important;
    height: 24px !important;
    padding: 0 !important;
    border: none !important;
    background: transparent !important;
    color: #94a3b8 !important;
    font-family: "SF Mono", "Consolas", monospace !important;
    font-size: 11px !important;
    font-weight: 600 !important;
    border-radius: 4px !important;
    cursor: pointer !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    transition: all 0.12s ease !important;
}
.calc-mem-btn:hover {
    background: #1e293b !important;
    color: #ffffff !important;
}
.calc-mem-btn:active {
    transform: scale(0.92) !important;
}

.calc-bar-divider {
    width: 1px !important;
    height: 14px !important;
    background: #334155 !important;
    margin: 0 2px !important;
}

/* ── 6. Keypad Grid (Strict 4x5 CSS Grid) ──────────────────────────────── */
.calc-keypad {
    display: grid !important;
    grid-template-columns: repeat(4, 1fr) !important;
    grid-gap: 6px !important;
    gap: 6px !important;
    padding: 10px !important;
    background: #0f172a !important;
    box-sizing: border-box !important;
    width: 100% !important;
}

.calc-btn {
    width: 100% !important;
    height: 44px !important;
    min-height: 44px !important;
    max-height: 44px !important;
    margin: 0 !important;
    padding: 0 !important;
    box-sizing: border-box !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
    font-family: "SF Mono", "Consolas", "JetBrains Mono", monospace !important;
    font-size: 17px !important;
    font-weight: 600 !important;
    border-radius: 10px !important;
    cursor: pointer !important;
    user-select: none !important;
    border: 1px solid transparent !important;
    outline: none !important;
    transition: all 0.08s ease !important;
    box-shadow: 0 2px 0 rgba(0, 0, 0, 0.4) !important;
}

.calc-btn:active,
.calc-btn.btn-pressed {
    transform: translateY(2px) !important;
    box-shadow: none !important;
}

/* Digit Buttons (0-9, ., 00) */
.calc-btn-num {
    background: #1e293b !important;
    color: #f8fafc !important;
    border-color: #334155 !important;
}
.calc-btn-num:hover {
    background: #334155 !important;
    color: #ffffff !important;
    border-color: #475569 !important;
}
.calc-btn-num:active,
.calc-btn-num.btn-pressed {
    background: #475569 !important;
}

/* Operator Buttons (+, -, *, /) */
.calc-btn-op {
    background: #064e3b !important;
    color: #34d399 !important;
    border-color: #059669 !important;
    font-size: 19px !important;
}
.calc-btn-op:hover {
    background: #047857 !important;
    color: #ffffff !important;
    border-color: #10b981 !important;
}
.calc-btn-op:active,
.calc-btn-op.btn-pressed {
    background: #059669 !important;
    color: #ffffff !important;
}

/* Clear Buttons (AC, CE) */
.calc-btn-ac,
.calc-btn-ce {
    background: #450a0a !important;
    color: #f87171 !important;
    border-color: #7f1d1d !important;
}
.calc-btn-ac:hover,
.calc-btn-ce:hover {
    background: #991b1b !important;
    color: #ffffff !important;
    border-color: #ef4444 !important;
}
.calc-btn-ac:active,
.calc-btn-ac.btn-pressed,
.calc-btn-ce:active,
.calc-btn-ce.btn-pressed {
    background: #b91c1c !important;
    color: #ffffff !important;
}

/* Equals Button (=) */
.calc-btn-eq {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%) !important;
    color: #ffffff !important;
    font-weight: 700 !important;
    font-size: 20px !important;
    border-color: #34d399 !important;
    box-shadow: 0 2px 0 #047857, 0 4px 12px rgba(16, 185, 129, 0.4) !important;
}
.calc-btn-eq:hover {
    background: linear-gradient(135deg, #059669 0%, #047857 100%) !important;
    box-shadow: 0 2px 0 #065f46, 0 6px 16px rgba(16, 185, 129, 0.5) !important;
}
.calc-btn-eq:active,
.calc-btn-eq.btn-pressed {
    background: #047857 !important;
    transform: translateY(2px) !important;
    box-shadow: none !important;
}

/* ── 7. History Drawer ─────────────────────────────────────────────────── */
.calc-history-drawer {
    display: none;
    background: #0b1120 !important;
    border-bottom: 1px solid #1e293b !important;
    padding: 8px 10px !important;
    box-sizing: border-box !important;
}

.calc-history-drawer.is-open {
    display: flex !important;
    flex-direction: column !important;
}

.calc-history-head {
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    padding-bottom: 6px !important;
    border-bottom: 1px solid #1e293b !important;
    margin-bottom: 6px !important;
}

.calc-history-item {
    display: flex !important;
    align-items: center !important;
    justify-content: space-between !important;
    padding: 6px 8px !important;
    background: #1e293b !important;
    border: 1px solid #334155 !important;
    border-radius: 6px !important;
    margin-bottom: 4px !important;
    cursor: pointer !important;
    transition: all 0.1s ease !important;
}
.calc-history-item:hover {
    background: #334155 !important;
    border-color: #10b981 !important;
}

.calc-history-expr {
    font-size: 11px !important;
    color: #94a3b8 !important;
    font-family: "SF Mono", monospace !important;
}

.calc-history-res {
    font-size: 12px !important;
    font-weight: 700 !important;
    color: #34d399 !important;
    font-family: "SF Mono", monospace !important;
}

/* ── 8. Mobile Screen Adaptation ───────────────────────────────────────── */
@media (max-width: 480px) {
    .popover.calc-popover,
    .popover:has(#calculator),
    .popover:has(.calc-container) {
        width: 100vw !important;
        max-width: 100vw !important;
        height: 100vh !important;
        max-height: 100vh !important;
        top: 0 !important;
        left: 0 !important;
        transform: none !important;
        border-radius: 0 !important;
    }
    #calculator,
    .calc-container {
        width: 100vw !important;
        height: 100vh !important;
        border-radius: 0 !important;
    }
    .calc-btn {
        height: 52px !important;
        min-height: 52px !important;
        max-height: 52px !important;
        font-size: 19px !important;
    }
    .calc-screen-input {
        height: 54px !important;
        font-size: 28px !important;
    }
}