diff --git a/iso/preseed.cfg b/iso/preseed.cfg
new file mode 100644
index 0000000..8bfc3d1
--- /dev/null
+++ b/iso/preseed.cfg
@@ -0,0 +1,69 @@
+# Yino preseed configuration for Debian 13 (Trixie)
+# Performs an unattended install, prompting only for:
+#   1. LUKS encryption passphrase
+#   2. Full name, username, and password
+
+# Locale and keyboard
+d-i debian-installer/locale string en_US.UTF-8
+d-i keyboard-configuration/xkb-keymap select us
+
+# Network — skip (offline DVD install)
+d-i netcfg/enable boolean false
+
+# Mirror — no network mirror
+d-i apt-setup/use_mirror boolean false
+
+# Clock
+d-i clock-setup/utc boolean true
+d-i time/zone string UTC
+
+# Partitioning — encrypted LVM with btrfs root
+d-i partman-auto/method string crypto
+d-i partman-lvm/device_remove_lvm boolean true
+d-i partman-md/device_remove_md boolean true
+d-i partman-lvm/confirm boolean true
+d-i partman-lvm/confirm_nooverwrite boolean true
+d-i partman-auto-lvm/guided_size string max
+d-i partman-auto-crypto/erase_disks boolean false
+d-i partman/default_filesystem string btrfs
+d-i partman-auto/choose_recipe select atomic
+d-i partman-partitioning/confirm_write_new_label boolean true
+d-i partman/choose_partition select finish
+d-i partman/confirm boolean true
+d-i partman/confirm_nooverwrite boolean true
+
+# Packages — minimal base + essentials
+tasksel tasksel/first multiselect standard
+d-i pkgsel/include string sudo btrfs-progs
+
+# Don't eject CD (fails in QEMU, causes prompt loop)
+d-i cdrom-detect/eject boolean false
+
+# Skip upgrade check (offline install, nothing to upgrade)
+d-i pkgsel/upgrade select none
+
+# No security/updates services (offline)
+d-i apt-setup/services-select multiselect
+
+# No popularity contest
+popularity-contest popularity-contest/participate boolean false
+
+# GRUB
+d-i grub-installer/only_debian boolean true
+d-i grub-installer/bootdev string default
+
+# Skip additional media scan
+d-i apt-setup/cdrom/set-first boolean false
+d-i apt-setup/cdrom/set-next boolean false
+d-i apt-setup/cdrom/set-failed boolean false
+
+# Finish
+d-i finish-install/reboot_in_progress note
+
+# Post-install: enable auto-login on tty1 for the created user
+d-i preseed/late_command string \
+    USER=$(grep ':x:1000:' /target/etc/passwd | cut -d: -f1); \
+    mkdir -p /target/etc/systemd/system/getty@tty1.service.d; \
+    echo '[Service]' > /target/etc/systemd/system/getty@tty1.service.d/autologin.conf; \
+    echo 'ExecStart=' >> /target/etc/systemd/system/getty@tty1.service.d/autologin.conf; \
+    echo "ExecStart=-/sbin/agetty --autologin $USER --noclear %I \$TERM" >> /target/etc/systemd/system/getty@tty1.service.d/autologin.conf