* {
    box-sizing: border-box;
    user-select: none;
    -webkit-user-select: none;
}

body {
    background-color: #0d0e10;
    color: #fff;
    font-family: 'Courier New', Courier, monospace;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 10px;
}

.cdu-container {
    background: #999d9e;
    width: 100%;
    max-width: 430px;
    padding: 16px;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.8), inset 0 2px 3px rgba(255,255,255,0.6);
    border: 4px solid #6c7072;
}

.cdu-top-layout {
    display: flex;
    gap: 6px;
    align-items: flex-start;
}

.screen-frame {
    background-color: #111;
    border: 3px solid #444;
    border-radius: 6px;
    padding: 6px;
    flex: 1;
}

.screen {
    background-color: #000;
    height: 270px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    font-weight: bold;
    font-size: 11px;
    padding: 4px;
    overflow: hidden;
    transition: background-color 0.3s;
}

/* Siyah / Beyaz Tema */
.screen.light-mode {
    background-color: #e8ecef !important;
    color: #111 !important;
}

.screen.light-mode .magenta { color: #aa00aa; }
.screen.light-mode .green { color: #007700; }
.screen.light-mode .cyan { color: #007799; }
.screen.light-mode .white { color: #000; }
.screen.light-mode .editable-input {
    background: rgba(0,0,0,0.05);
    border-bottom: 1px dashed #555;
}

.screen.power-off {
    background-color: #050505 !important;
}
.screen.power-off * {
    display: none !important;
}

/* Renk Sınıfları */
.magenta { color: #ff00ff; }
.green { color: #00ff66; }
.cyan { color: #00ffff; }
.white { color: #ffffff; }

.screen-header {
    display: flex;
    justify-content: space-between;
    border-bottom: 1px dashed #333;
    padding-bottom: 4px;
}

.screen-body {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-top: 4px;
}

.screen-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 4px;
}

/* Tıklanabilir & Düzenlenebilir Input Alanı */
.editable-input {
    background: transparent;
    border: none;
    border-bottom: 1px dashed #00ff66;
    outline: none;
    font-family: inherit;
    font-size: 11px;
    font-weight: bold;
    padding: 1px 2px;
    width: 110px;
    user-select: text;
    -webkit-user-select: text;
}

.editable-input:focus {
    background: #113311;
    border-bottom: 1px solid #00ffff;
}

.scratchpad-area {
    border-top: 1px solid #333;
    padding-top: 2px;
    color: #fff;
    font-size: 13px;
    min-height: 18px;
    word-break: break-all;
}

.lsk-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 20px;
}

.lsk-right-col {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.btn-lsk {
    background: linear-gradient(145deg, #555, #333);
    border: 1px solid #111;
    width: 28px;
    height: 24px;
    border-radius: 4px;
    cursor: pointer;
    box-shadow: 0 2px 0 #111;
}

.btn-lsk:active {
    transform: translateY(1px);
}

.power-btn {
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: radial-gradient(circle, #ff4444, #990000);
    border: 2px solid #333;
    cursor: pointer;
    box-shadow: 0 2px 4px rgba(0,0,0,0.5);
    margin-top: 10px;
}

.keyboard {
    margin-top: 12px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.func-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 4px;
}

.main-pad {
    display: flex;
    gap: 8px;
}

.num-pad {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 4px;
    flex: 1;
}

.alpha-pad {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 4px;
    flex: 1.6;
}

button.key {
    background: linear-gradient(145deg, #3a3d42, #212327);
    color: #fff;
    border: 1px solid #1a1b1d;
    padding: 8px 0;
    font-size: 10px;
    font-weight: bold;
    border-radius: 4px;
    cursor: pointer;
    box-shadow: 0 2px 0 #111;
}

button.key:active {
    transform: translateY(1px);
    background: #111;
}

button.func-key {
    background: linear-gradient(145deg, #4a4d52, #2a2c30);
}

button.exec-key {
    background: linear-gradient(145deg, #008844, #004422);
    color: #00ff66;
}

button.action-key {
    background: linear-gradient(145deg, #664422, #332211);
    color: #ffaa55;
}